Transcript for:
ENT Lecture Key Topics Overview

ENT Made Ridiculously Easy Nasal Cavity is divided into two by nasal septum. Problems arise when it is not dividing it symmetrically, leading to a condition known as DNS or Deviated Nasal Septum. Causes of DNS There are 4 important causes: Number one is trauma. Any abnormal pressure applied to nasal septum, results in its deviation to one side or another. Example: being hit by a boxer on the nose. Number two is developmental or abnormalities acquired during the formation of nasal septum. Example: palate forms the base of nasal septum, if palate is high arched, then automatically, nasal septum deviation will occur. Number three is racial. Some races like Caucasians have more incidence of DNS. Number four is hereditary. Some families have more incidence of DNS. Types of DNS: 1. Anterior dislocation: The nasal septum is dislocated into one of the nasal chambers 2. C-Shaped dislocation: Septum is deviated in a simple curve to one side. Compensatory hypertrophy of Turbinates occur in other side. 3. S-shaped Deformity: Nasal septum shows S-shaped deformity. This results in bilateral nasal obstruction. 4. Spurs: Shelf like projection. It touches lateral wall and may give rise to headaches. Clinical Features of DNS Clinical Features of DNS can be simply remembered using the mnemonic: NASEEM has DNS N is for Nasal obstruction: Naturally, any deviation in nasal septum causes less nasal space and results in nasal obstruction on the side of DNS. A is for Anosmia: Patient is unable to smell. As there is failure of inspired air to reach the olfactory region. Loss of smell may be partial or total. S is for Sinusitis: since all sinuses have only one opening and that is in the lateral wall of nose, DNS causes obstruction of these openings due to nasal obstruction. E is for epistaxis. E is for External deformity, particularly in young females or males who are more conscious of this. M is for middle ear infection: DNS also predisposes to middle ear infection because Eustachian tube which is the only drainage source of middle ear opens in nasopharynx and DNS can cause its obstruction and resulting in middle ear infections. Treatment Minor cases of DNS require no treatment. If the symptoms are severe, then on reaching the age of 17, we can opt for septoplasty, in which the most deviated parts of nasal septum are removed and the rest of septum is corrected and repositioned using plastic means. A more radical form of this operation is submucous resection in which mucoperichondrial and mucoperiosteal flaps overlying one side of the septum are lifted. Most of the septum is removed and flaps repositioned. Allergic Rhinitis 'Rhin' comes from Greek word, meaning 'nose' and 'itis' means inflammation. So it means 'Inflammation of the Nose' and 'Allergic' means it is caused by allergens. Allergens are anything harmless (or neutral) that can be inhaled in air by nose and trigger excessive immune reaction. Common examples of allergens include pollen and dust. Once inside nose they will meet immune system, particularly Mast cells attached to IgE antibodies. Allergen will bind to IgE antibody which will then activate and alert Mast cells. In a normal person, the reaction is minimal. But in those suffering from Allergic rhinitis, this cell over-reacts big time. It signals to all cells in surrounding by releasing histamine. Histamine will now cause inflammation and swelling up of nasal mucosa which will then cause excessive mucus production. This results in Nasal Drip. This excessive mucus production will block two very important structures opening in nose. 1) Nasolacrimal duct: the purpose of this duct is to drain tears from eyes into nose. but once blocked by excessive mucus production by allergic rhinitis, now you will start having Watery Eyes. 2) Eustachian Tube: This drains drainage from middle ear, with it blocked too by excessive mucus production by allergic rhinitis, now you will have stuffed ears sensation too. Finally the nerves in nasal cavity will start getting irritated and lead to sneezing. All of it will lead to difficulty in breathing for person suffering from Allergic rhinitis. To summarize, Allergic rhinitis will lead to 1: The swelling and congestion of Nasal Mucosa 2: Watery Eyes 3: Stuffed Ears 4: Nasal drip due to excessive mucus production 5: Sneezing 6: Difficulty breathing For Diagnosis of Allergic Rhinitis: 1) Patient History Usually the person complains of all symptoms mentioned above and if the timing of these symptoms is specific and seasonal, then we can easily reach a diagnosis of Seasonal allergic rhinitis. 2) Skin Prick Testing In this test, allergen is introduced using a skin prick and reaction of body is seen to confirm allergy to a particular allergen. 3) Blood Tests A) Total blood eosinophil count As with the total serum IgE, an elevated eosinophil count supports the diagnosis of allergic rhinitis. B) Total serum IgE This is a measurement of the total level of IgE in the blood. An elevated serum IgE level supports allergic rhinitis diagnosis. This test can be performed using Radio Allergo Sorbent Method, hence is also called as RAST test. 4) Nasal Smear Test: A nasal smear can sometimes be helpful for establishing the diagnosis of allergic rhinitis. A sample of secretions and cells is scraped from the surface of the nasal mucosa using a special sampling probe. Treatment of Allergic Rhinitis is achieved by targeting different steps in pathway to allergy: 1) Avoid Allergens This can be done by taking precautionary measures to avoid exposure, for example, wearing face masks in Pollen Season. 2) Decrease inflammation This can be achieved by Steroids applied directly to nasal mucosa. 3) Anti-Histamines: These target the action of histamines by blocking the Histamine receptors, thus stopping the action of histamine. 4) Mast Cell stabilizers: Mast cell stabilizers are common medications used to prevent or control certain allergic disorders. They block a calcium channel essential for mast cell degranulation, stabilizing the cell and thereby preventing the release of histamine. 5) Immunotherapy: When you get immunotherapy in the form of allergy shots, your allergist or doctor injects small doses 3of substances that you are allergic to (allergens) under your skin. This helps your body "get used to" the allergen, which can result in fewer or less severe symptoms of allergic rhinitis. What is Sinusitis? Before we can answer that question, we should talk a little bit about anatomy. Sinuses are hollow spaces in the bones around the nose that connect to the nose through small, narrow channels. Humans possess four paired paranasal sinuses. Your cheekbones hold your maxillary sinuses, the largest. The low-center of your forehead is where your frontal sinuses are located. Between your eyes are your ethmoid sinuses. In bones behind your nose are your sphenoid sinuses. They’re lined with soft, pink tissue called mucosa. Sinusitis means your sinuses are inflamed. What causes sinusitis? 98 percent of sinusitis occur due to viral infection. It can also be caused by bacterial infection. While small population can have it due to fungal disease. There are some predisposing factors that make it more likely that you get sinusitis including: Allergic rhinitis, which makes it easier for infection to occur. Exposure to smoke or cigarette smoking. Anatomical abnormailities which make it difficult for sinuses to drain. The central event in sinusitis is blockage of the sinus openings or ostia, as a result of inflammation. Unable to circulate air and eliminate the secretions that are produced, obstructed sinuses become an ideal environment for bacterial infection. Types of Sinusitis Types of sinusitis include: Acute Sinusitis, which lasts up to 4 weeks. Subacute Sinsusitis, which lasts 4 to 12 weeks. Chronic Sinusitis, which lasts more than 12 weeks and can continue for months or even years. Recurrent Sinusitis, with several attacks within a year. What are the signs and symptoms of sinusitis? First thing that most people notice is going to be pain. The pain may be localized to the sinus involved or it can also cause generalized pain which may present as headache. If you tap on the sinus involved with finger, it can produce tenderness. Also, since the mucosa is inflammed, it will produce lots of mucus, which is going to drain into the nasal cavity through sinus openings or ostia. Once in the nasal cavity, there is only two things it can do. First thing is to come out of your nose so people will notice nasal discharge. The second thing it can do is go to back of your throat as the back of your nose is related to back of your throat and there it causes irritation and cause you to cough. Inflammation of mucosa can also alter the smell and taste of things. Patients can also have fever because of the infection and inflammation. How can we diagnose sinusitis? By and Large the diagnosis of sinusitis is made by symptoms alone. Common symptoms include: Nasal or post nasal drip, sinus pain or pressure, nasal congestion, decreased ability to smell, cough, headache and fever. But sometimes the symptoms aren't clear cut. In that case, there are some other tests that can be done to diagnose. sometimes a medical practitioner will take a look inside your nose to get a better look at nasal or post nasal drip. This is called Rhinoscopy. X-rays can be done to visualize sinuses. The gold standard to diagnose is CT scan. Other tests are only done if needed in special circumstances. How can we treat sinusitis? For acute viral sinusitis, the most common type of sinusitis, there is not a lot we can do to actually treat the disease itself, but we can treat symptoms. One of the first drugs to treat symptoms is going to be nasal decongestants. These medications shrink swollen nasal passages, facilitating the flow of drainage from the sinuses. We also give mucolytics medications which help clear mucus. We also ask the patient to remain well hydrated, as being well hydrated helps in drainage of mucus as mucus formed is not so sticky that it gets stuck in if your body is well hydrated. Finally, we also give pain killers to help relieve the pain. For acute bacterial sinusitis, we give all of the above plus antibiotics for 10-14 days. For chronic sinusitis, again all of the above but the antibiotics have to be given for a lot longer period. Most people recommend 4-6 weeks of antibiotics. If the sinusitis is too severe and the person is at risk of complications, we go for surgery. Surgery may be done to remove small amounts of bone or other material blocking the sinus openings or to remove growths blocking sinuses, also called as polyps. Normally, a thin, lighted tool called an endoscope is inserted through the nose so the doctor can see and remove whatever is blocking the sinuses. Tonsillitis and Tonsillectomy When a person opens his mouth, there are a lot of things you can see. One of the most important organs that helps fight off infections are among them, also known as tonsils. Tonsils are often overlooked when you open your mouth. This is because they're often small and hidden between the two arches. These tonsils are known as palatine tonsils due to their location near the palate or the roof of the mouth. How Tonsils Fight off Infection The tonsils act like entry point from the throat, picking up virus and bacteria particles which are breathed in or swallowed and relaying this to the immune system. To help with this role, the surfaces of the tonsils are pitted with a number of little recesses, also called tonsil crypts. This increases surface area of the tonsils, relaying more viruses or bacteria to the immune system. How tonsils get infected Tonsils can also become clogged with bacteria and food particles which can lead to problems. When this happens, the tonsil itself becomes infected and starts to get swollen due to inflammation because of infection, leading to condition known as tonsillitis or inflammation of the tonsils. Because the tonsils are always trapping bacteria, they can become infected quite commonly, especially in children, leading to condition known as recurrent acute tonsillitis. Signs and Symptoms of Tonsillitis. The main symptom of tonsillitis is sore throat, but since throat and ears share the same nerves, the pain is often felt in the ears too. This process is known as referred pain. The pain is usually worse when swallowing, also known as Odynophagia. Very young children may not complain of a sore throat, but may simply refuse to eat. In addition, you may also have a cough, fever due to infection, head ache, feel sick, feel tired, and swollen and tender glands (lymph nodes), on the side of the neck, as well as bad breath. How Tonsillitis is Diagnosed Diagnosis is based on the physical examination of your throat. Your doctor may also take a throat culture by gently swabbing the back of your throat. The culture will be sent to a laboratory to identify the bacteria causing the throat infection. Treatment for Tonsillitis. A mild case of tonsillitis does not necessarily require treatment, especially if a virus, such as cold, causes it. Good rest and remaining well hydrated are treatment of choice in such cases. Painkiller medicines can be added to relief the throat pain. Treatment for more severe cases of tonsillitis may include antibiotic or tonsillectomy. Antibiotics will be prescribed to fight the bacterial infection. It's important you complete the full course of antibiotics. Tonsillectomy is the surgical removal of tonsils to permanently end the problem of tonsillitis. Criteria for tonsillectomy: At least 7 episodes in the previous year, at least 5 episodes in each of the previous two years or at least 3 episodes in each of the previous three years. How tonsillectomy is done. Dissection and snare method. There are multiple methods to do tonsillectomy. One of the most commonly used is dissection and snare method. Steps of Dissection and snare method. 1. Patient is placed in rose position. 2. Boyle-Davis mouth gag is introduced and opened. It is held in place by Draffin’s, bipods or string over pulley. 3. Tonsil is grasped with forceps and pulled medially, incision made in the mucous membrane. 4. A blunt-curved scissor may be used to dissect the tonsil from the peritonsilar tissue and separate its upper pole. 5. Tonsil is held at its upper pole and traction applied downwards and medially or scissor until lower pole is reached. 6. Wire loop of tonsilar snare is threaded over the tonsil onto its pedicle, tightened. 7. Pedicle is cut and the tonsil removed. 8. A gauze sponge is placed in the fossa and pressure applied for a few minutes. 9. Bleeding points are tied with silk. Procedure is repeated on the other side. EPISTAXIS What is Epistaxis? Bleeding from inside the nose is also known as Epistaxis. Why does it occur? There are many different reasons. Most important ones are: Among Children due to Trauma due to nasal picking. Another important cause in children is foreign body in nose. Infections of nose, Deviated Nasal Septum, raised blood pressure, kidney disease and liver disease. What are the sites of Epistaxis? 1. Most important site of epistaxis in nose is Little's area. In 90% of cases, Epistaxis occurs from here. It is situated in antero-inferior part of Nasal Septum. Four Arteries- Anterior Ethmoidal, septal branch of superior Labial, Septal branch of sphenopalatine and the greater Palatine artery anastamose here. 2. Posterior part of nasal cavity After bleeding from here blood flows directly into pharynx. 3. Diffuse: it is bleeding from septum and lateral wall. This is often seen in general systemic disorders and blood dyscrasias. How will you manage a case of Epistaxis? In any case of epistaxis, it is important to ask the patient: 1) Mode of Onset Was it spontaneous or was there finger nail trauma? 2) Duration and frequency of bleeding 3) Amount of blood loss 4) Side of nose from where bleeding is occurring or is it occuring from both sides of nose. 5) Any known bleeding tendency in patient or family 6) Any history of drug intake? Analgesics? Anticoagulants? etc. How will you treat epistaxis? 1. First Aid Most of time, bleeding occurs from little's area and can be controlled by pinching nose with thumb and index for 5 minutes. This compresses blood vessels of Little's area. 2. Cauterisation Useful in patients where bleeding point has been located. 3. Anterior Nasal Packing 4. Posterior Nasal Packing General Measures 1. Make the patient sit up 2. Reassure the patient 3. Keep check on pulse and BP Nasal Polyp What is a Nasal Polyp? Nasal Polyp are fleshy swellings that develop in the lining mucosa of the nose and paranasal sinuses, (air-filled spaces, linked to the nasal cavity). They are non-cancerous growths. What causes Nasal Polyp? The mucosa is a very wet layer that helps protect the inside of your nose and sinuses and humidifies the air you breathe. During an infection or allergy-induced irritation, the nasal mucosa becomes swollen and red. With prolonged irritation, the mucosa may form a polyp. A polyp is a round growth, like a small cyst, that can block nasal passages. Although some people can develop polyps with no previous nasal problems, there’s often a trigger for developing polyps. These triggers include: A: chronic or recurring sinus infections B: asthma C: allergic rhinitis What are the symptoms of Nasal Polyp? Polyps can grow large enough to block your nasal passages, resulting in chronic congestion. Symptoms can include: 1: nasal congestion: a sensation that your nose is blocked. 2: runny nose 3: postnasal drip, which is when excess mucus runs down the back of your throat. 4: reduced sense of smell 5: breathing through your mouth 6: a feeling of pressure in your forehead or face What are the Major Types of Nasal Polyp? There are two major types of nasal polyp. 1) Antrochoanal: Single, unilateral, originate from maxillary sinus. Usually found in children. Infections is the common cause. 2) Ethmoidal: Bilateral, originate from ethmoid sinuses. Usually found in adults. Allergy is the common cause. How are Nasal Polyps diagnosed? A doctor will generally be able to make a diagnosis after asking about symptoms and examining the patient's nose. The doctor may also order the following tests: Nasal endoscopy A narrow tube with a small camera is inserted into the patient's nose. CT scan This enables the doctor to locate nasal polyps and other abnormalities linked to chronic inflammation. The doctor will also be able to identify any other obstructions. What is the treatment for nasal polyps? The following treatments are commonly used for nasal polyps: 1) Steroids The doctor may prescribe a steroid spray or nose drops, which will shrink the polyps by reducing inflammation. 2) Steroid tablets In cases of larger polyps or more severe inflammation, the patient may be prescribed steroid tablets. 3) Other medications Other medications may be given to treat conditions that are making the inflammation worse. Examples include antihistamines for allergies, antibiotics for bacterial infections, and antifungal drugs for fungal allergies. 4) Surgery Polypectomy This is the most common procedure for the removal of polyps. The patient is given general anesthetia. A long, thin tube with a video camera is inserted into the patient's nose and sinuses. Polyps are then cut out using micro-telescope to visualize it and surgical instruments to cut it. After surgery, the patient will most likely be prescribed a corticosteroid nasal spray to help prevent recurrence. Management of Deaf Child Who are deaf children and why they should be identified early? Children with profound (greater than 90 decibel hearing loss) or total deafness fail to develop speech and have often been termed as deaf and mute or deaf and dumb. However, these children have no defect in their speech producing apparatus. The main defect is deafness. They have never heard speech and therefore do not develop it. In lesser degrees of hearing loss, speech does develop but is defective. The period from birth to 5 years of life is critical for the development of speech and language. Therefore, there is need for early identification and of hearing loss and early rehabilitation in infants and children. It was observed that children whose hearing loss was observed and managed before 6 months of age had higher scores of vocabulary, better expressive and comprehensive language skills than those diagnosed and managed after 6 months of age, emphasizing the importance of early identification and treatment. Assessment of auditory function in neonates, infants and children demands special techniques. (a) Screening procedures. They are employed to test hearing in "high risk" infants and are based on infant's behavioural response to the sound signal. Arousal test. A high frequency narrow band noise is presented for 2 seconds to the infant when he is in light sleep. A normal hearing infant can be aroused twice when three such stimuli are presented to him. Auditory response cradle is a screening device for newborns, where baby is placed in a cradle and his behaviour including trunk and limb movement, head jerk and respiration in response to auditory stimulation are monitored by transducers. It can screen babies with moderate, severe or profound hearing loss. (b) Behaviour Observation Audiometry Auditory signal presented to an infant produces a change in behaviour, e.g. alerting, cessation of an activity, widening of eyes or facial grimacing. Moro's reflex is one of them and consists of sudden movement of limbs and extension of head in response to sound of 80-90 decibel. In cochleopalpebral reflex, the child responds by a blink to a loud sound. In cessation reflex, an infant stops activity or starts crying in response to a sound of 90 decibel. (c) Distraction techniques are used in children 6-7 months old. The child at this age turns his head to locate the source of sound. In this test, the child is seated in his mother's lap. An assistant distracts the child's attention while the examiner produces a sound from behind or from the side to see if the child tries to locate it. d) Conditioning Techniques Examples of this technique include: Play Audiometry The child is conditioned to perform act such as putting a plastic block in a bucket each time the child hears a sound signal. Each correct performance of the act is reinforced with praise, encouragement or reward. Speech Audiometry The child is asked to repeat the names of certain objects or to point them out on the pictures. The voice can be gradually lowered. In this way, hearing level and speech discrimination can be tested. The test can also be used to examine the child's expressive ability when he is asked to name the toys like horse, duck or objects like cup, plate, etc. (e) Objective Tests These tests are ideal for hearing assessment in children as they give results without the need of cooperation of child. Names of Objective Tests include: 1) Evoked response audiometry 2) Otoacoustic emissions 3) Impedance audiometry Management of Deaf Child It is essential to know the degree and type of hearing loss. Aims of rehabilitation of any hearing-impaired child are development of speech and language, adjustment in society and useful employment in a vocation. 1. Parental guidance It is a great emotional shock for parents to learn that their child is deaf. They should be dealt with sympathetically, so as to accept the child. They should be told of child's disability and how to care for it. Rehabilitation of the deaf demands a lot from parents: care and periodic replacement of hearing aid, change of ear moulds as child grows, follow up visits for reevaluation, education at home and the selection of vocation. 2. Hearing aids Most deaf children have a small but useful portion of residual hearing which can be exploited by amplification of sound. Hearing aids should be prescribed as early as possible. If necessary, binaural aids, one for each ear, can be used. Hearing aids help to develop lip-reading also. 3. Development of speech and language Communication is a two way process, depending on the receptive and expressive skills. Reception of information is through visual, auditory or tactile faculties while expression is through oral or written speech or the manual sign language. In the hearing-impaired, auditory faculty is poor or to totally absent. Thus, for proper communication, there is need either to improve hearing through amplification of the residual hearing or cochlear implants and, in the absence of feasibility of developing the auditory faculty, to develop visual or tactile means of communication. (a) Auditory Oral Communication This is the method used by a normal person and is the best way of communication. In the deaf, it can be used in those with moderate to severe hearing loss or those who are post-lingually deaf. Hearing aids are provided to augment auditory reception. At the same time, training is also imparted in speech reading, i.e. to read movements of lips, face and natural gestures of hand and body. Expressive skill is encouraged through oral speech. (b) Manual Communication It makes use of the sign language. (c) Total Communication It uses all modalities of sensory input, i.e. auditory, visual etc. Such children are taught to develop oral speech, lip-reading and sign language. All children with pre-lingual severe to profound deafness, should undergo training in this form of communication. 4. Education of the Deaf There are residential and day schools for the deaf. Some deaf children with moderate hearing loss can be integrated into schools for the normal children with preferential seating in the class; giving them benches closer to teachers, so that they can hear the teacher louder. 5. Vocational Guidance The deaf are sincere and good workers. Given the opportunity, commensurate with their ability, they can be usefully employed in several vocations. Acute Otitis Media What is Acute Otitis Media? Acute stand for abrupt onset. Ot stands for ear. Itis stands for infection and inflammation. While media stands for middle ear. So, acute otitis media means inflammation of the middle ear. What are the stages of acute otitis media? 1) Stage of Tubal Occlusion Since the middle ear drainage is entirely dependent on Eustachian tube, the first step in acute otitis media is the blockage of Eustachian tube. Children are particularly predisposed to acute otitis media because their Eustachian tube is shorter, wider and more horizontal as compared to adults, which increases the chances of Eustachian tube getting blocked. 2) Stage of Pre Suppuration. After the Eustachian tube is blocked, the microorganisms start infecting. 3) Stage of Suppuration. This is marked by formation of pus in the middle ear. Tympanic membrane starts bulging to the point of rupture. 4) Stage of Resolution. The tympanic membrane rupture with a release of pus and subsidence of symptoms. Inflammatory process begins to resolve. If proper treatment started early or the infection was mild, resolution may start even without rupture of tympanic membrane. 5) Stage of Complication. If virulence of organism is high, or resistance of patient is poor, resolution may not take place and disease spread beyond the confines of middle ear. Treatment 1) Antibacterial therapy It is indicated in all cases with fever and severe earache. 2) Decongestant Nasal Drops Nose drops should be used to relieve Eustachian tube edema and promote ventilation of middle ear. 4) Analgesics and Antipyretics Help to relieve pain and bring down temperature. 5) Ear Toilet If there is discharge in the ear, it is dry mopped with sterile cotton buds and a wick moisten with antibiotic may be inserted. 6) Dry Local Heat It helps to relieve pain. 7) Myringotomy It is incising the drum to evacuate pus and is indicated when a) drum is bulging and there is acute pain, b) there is an incomplete resolution despite antibiotics when drum remains full with persistent conductive deafness c) there is persistent effusion beyond 12 weeks. All cases of acute suppurative otitits media should be carefully followed till drum membrane return to its normal appearance. ADENOIDS What are Adenoids? The nasopharyngeal tonsils, commonly called adenoids, is situated at the junction of the roof and posterior wall of the nasopharynx. Adenoid tissue is present at birth, shows physiological enlargement up to the age of six years and then tends to atrophy at puberty and almost completely disappears by the age of 20. Why and When do they cause trouble? Adenoids are subject to physiological enlargement in childhood. Certain children have a tendency to generalised lymphoid hyperplasia in which adenoids also take part. Recurrent attacks of rhinitis, sinusitis or chronic tonsillitis may cause chronic adenoid infection and hyperplasia. Allergy of the upper respiratory tract may also contribute to the enlargement of adenoids. Clinical Features Symptoms and signs depend not merely on the absolute size of the adenoid mass, but are relative to the available space in the nasopharynx. Enlarged and infected adenoids may cause nasal, aural (ear) or general symptoms. A. Nasal Symptoms 1. Nasal obstruction is the commonest symptom. This leads to mouth breathing. Nasal obstruction also interferes with feeding or suckling a child. As respiration and feeding cannot take place simultaneously, a child with adenoid enlargement fails to thrive. 2. Nasal discharge. It is partly due to choanal obstruction, as the normal nasal secretions cannot drain into nasopharynx and partly due to associated chronic rhinitis. The child often has a wet bubbly nose. 3. Sinusitis. Chronic maxillary sinusitis is commonly associated with adenoids. It is due to persistence of nasal discharge and infection. Reverse is also true that a primary maxillary sinusitis may lead to infected and enlarged adenoids. 4. Epistaxis. When adenoids are acutely inflamed, epistaxis can occur with nose blowing. 5. Voice change, which is toneless and loses nasal quality due to nasal obstruction. B. Aural Symptoms 1. Tubal obstruction Adenoid mass blocks the Eustachian tube, leading to retracted tympanic membrane and conductive hearing loss. 2. Recurrent attacks of acute otitis media or infection of middle ear may occur due to spread of infection via the Eustachian tube because the Eustachian tube is blocked due to adenoids hypertrophy. 3. Chronic suppurative otitis media or long standing infection of middle ear occurs if the otitis media fails to resolve in the presence of infected adenoids. C. General Symptoms 1. Adenoid facies: Chronic nasal obstruction and mouth breathing lead to characteristic facial appearance called adenoid facies. The child has an elongated face with dull expression, prominent open mouth for breathing and crowded upper teeth, and hitched up upper lip. Nose gives a pinched-in appearance due to disuse atrophy of alae nasi. Hard palate in these cases is highly arched as the moulding action of the tongue on palate is lost because the child has to always keep the mouth open for breathing. 2. Pulmonary hypertension In long-standing nasal obstruction due to adenoid hypertrophy, the oxygen reaching lungs is decreased so the blood pressure in pulmonary artery increases to carry the oxygen needed for tissues of body which can cause pulmonary hypertension and cor-pulmonale. Diagnosis Examination of postnasal space is possible in some young children and an adenoid mass can be seen with a mirror. Soft tissue lateral radiograph of nasopharynx will reveal the size of adenoid and also the extent to which nasopharyngeal air space has been compromised. Detailed nasal examination should always be conducted to exclude other causes of nasal obstruction. Treatment When symptoms are not marked, breathing exercises, decongestant nasal drops and antihistamines for any coexistent nasal allergy can cure the condition without need of the surgery. When symptoms are marked, adenoidectomy is done for complete removal of adenoids. Acute Epiglotitis Causes, Symptoms, Treatment It is an acute inflammatory condition confined to supraglottic structures which include epiglottis, aryepiglottic folds and arytenoids. There is marked oedema of these structures which may obstruct the airway. What Causes Epiglottitis? It is a serious condition and affects children of 2-7 years of age but can also affect adults. H. influenzae B is the most common organism responsible for this condition in children. Clinical Features One: Onset of symptoms is abrupt with rapid progression. Two: Sore throat and dysphagia are the common presenting symptoms in adults. Three: Dyspnoea and stridor are the common presenting symptoms in children. They are rapidly progressive and may prove fatal unless relieved. Four: Fever may go up to 40°C. It is due to septicaemia. Patient's condition may rapidly deteriorate. Examination One: Depressing the tongue with a tongue depressor may show red and swollen epiglottis. Indirect laryngoscopy may show oedema and congestion of supraglottic structure. This examination is avoided for fear of precipitating complete obstruction. It is better done in operation theatre where facilities for intubation are available. Two: Lateral soft tissue X-ray of neck may show swollen epiglottis (thumb sign). Treatment One: Hospitalisation Essential because of the danger of respiratory obstruction. Two: Antibiotics Ampicillin or third generation cephalosporin are effective against H. influenzae and are given by parenteral route (i.m. or i.v.) without waiting for results of throat swab and blood culture. Three: Steroids given in appropriate doses relieve oedema and may obviate need for tracheostomy. Four: Adequate hydration Patient may require parenteral fluids. Five: Humidification and oxygen Six: Intubation or tracheostomy may be required for respiratory obstruction. Acute Laryngo-Tracheo Bronchitis Causes, Features, Treatment What is Acute Laryngo-Tracheo-Bronchitis? It is an inflammatory condition of the larynx, trachea and bronchi; more common than acute epiglottitis. What Causes Acute Laryngo-Tracheo-Bronchitis? Mostly, it is viral infection parainfluenza type I and II, affecting children between 6 months to 3 years of age. Male children are more often affected. Secondary bacterial infection by Gram positive cocci soon supervenes. What happens in Acute Laryngo-Tracheo-Bronchitis? The loose areolar tissue in the subglottic region swells up and causes respiratory obstruction and stridor. This, coupled with thick tenacious secretions and crusts, may completely occlude the airway. What are the Symptoms? Disease starts as upper respiratory infection with hoarseness and croupy cough. There is fever of 39-40°C. This may be followed by difficulty in breathing and inspiratory type of stridor. Respiratory difficulty may gradually increase with signs of upper airway obstruction, in other words, suprasternal and intercostal recession. What is the Treatment? One: Hospitalisation is often essential because of the increasing difficulty in breathing. Two: Antibiotics like ampicillin 50 mg/kg/day in divided doses is effective against secondary infections due to gram-positive cocci and H. influenzae. Three: Humidification helps to soften crusts and tenacious secretions which block tracheobronchial tree. Four: Parenteral fluids are essential to combat dehydration. Five: Steroids, in other words, hydrocortisone 100mg i.v. may be useful to relieve oedema. Six: Adrenaline Seven: Intubation or tracheostomy is done, should respiratory obstruction increase in spite of the above measures. Tracheostomy is done if intubation is required beyond 72 hours. Assisted ventilation may be required. Ludwig's Angina Where did the name come from? Ludwig was a scientist and "angina" means "strangling" or "feeling of strangling". Definition It is life threatening cellulitis meaning inflammation of cells. Its location is the infection of submandibular space, which is divided into two compartments by mylohyloid muscle, sublingual compartment (above muscle), submaxillary and submental compartment (below muscle). Causes It is cause by dental infection or tooth abscess, involving molars and premolars, as well as submandibular sialadenitis, injuries to oral mucosa and mandibular fracture. Commonly involved organisms Organisms mostly involved are Alpha-hemolytic Streptococci, Staphylococci and bacteroides. Signs External Signs External signs include bilateral lower facial oedema or swelling around mandible (jaw bone in upper neck). All compartments become swollen tender and in part woody hard feel when touching them. Intra oral sign include raised floor of mouth due to sublingual space involvement and posterior displacement of tongue. Symptoms Patient complain of dysphagia (difficulty swallowing), odynophagia (painful swallowing), drooling and trismus, reduced opening of jaw, Treatment Give IV fluids, systemic antibiotics, covering Gram + IVE and Metronidazole. Incision and drainage of abcess and localize. Intra oral incision is given if localize to sublingual space. External Incision if involving submaxillary space. Tracheostomy if airways is in danger. Complications The abscess or post-collection in Ludwig's angina can spread to nearby structures causing parapharyngeal and retropharyngeal abscess: airway obstruction as it causes laryngeal oedema, causing larynx to swell up and obstructing the air flow; septycemia: the infecting can spread through blood to all parts of body. Otosclerosis Otosclerosis, also called otospongiosis is disease of bony labyrinth and ossicles in ear who become knit together into an immovable mass. It mostly involves otic ganglion and stapes in which normal bone is replaced by spongy bone. Causes It is mostly inherited as ‘’autosomal dominant" pattern so patients have positive family history. It is more common in white races. It affects females twice as males and mostly discovered during or just after pregnancy. Mostly starts between 20-30 years of age. Chronic measles infection predisposes patient to otosclerosis. Otosclerosis is often associated with ‘osteogenesis imperfecta’ called ‘Van der Howe Syndrome’. Syndrome consists of otosclerosis, osteogenesis imperfecta and blue sclera of eyes. Symptoms Patient presents with bilateral conductive hearing loss or mixed type; both conductive and sensorineural hearing loss, tinnitus, vertigo, monotonous speech and Paracusis Willisii (patient hearing better in noisy environment). On Examination Tuning Fork Tests Negative Rinne and Weber lateralized to diseased ear (conductive types). Eustachian tube function is normal. On Audiometric testing: 1) Otoscopy: Reddish hue on tympanic membrane called ‘’schwartz sign’’. 2) Pure Tone Audiometry (PTA): Shows dip at 2000Hz called "carhart’s notch". 3) Tympanometry: Curve of ossicular stiffness present (as pattern on graph). Treatment 1) Non Surgical: a) sodium fluoride as dietary supplement b) hearing aids for sound amplification. 2) Surgical Stapedectomy with prosthesis, in which diseased stapes is replaced. Contra-Indication for surgery: a) Only hearing ear b) Associated Meniere’s disease c) Young children d) Athletes e) Frequent air travellers f) Divers. The course of the facial nerve can be divided into two parts: Intracranial – the course of the nerve through the cranial cavity and the cranium itself. Extracranial – the course of the nerve outside the cranium, through the face and neck. Intracranial The nerve arises in the pons, an area of the brainstem. It begins as two roots; a large motor root and a small sensory root (the part of the facial nerve that arises from the sensory root is sometimes known as the intermediate nerve). The two roots travel through the internal acoustic meatus, a 1 cm long opening in the petrous part of the temporal bone. Here, they are in very close proximity to the inner ear. Still within the temporal bone, the roots leave the internal acoustic meatus, and enter into the facial canal. The canal is a Z-shaped structure. Within the facial canal, three important events occur. Firstly, the two roots fuse to form the facial nerve. Next, the nerve forms the geniculate ganglion. A ganglion is a collection of nerve cell bodies. Lastly, the nerve gives rise to: - Greater petrosal nerve, which then supplies parasympathetic fibres to mucous glands and lacrimal gland. - Nerve to stapedius, which then supplies motor fibres to stapedius muscle of the middle ear. - Chorda tympani, which then supplies special sensory fibres to the anterior 2/3 tongue and parasympathetic fibres to the submandibular and sublingual glands. The facial nerve then exits the facial canal and the cranium via the stylomastoid foramen. This is an exit located just posterior to the styloid process of the temporal bone. Extracranial After exiting the skull, the first extracranial branch to arise is the posterior auricular nerve. It provides motor innervation to some of the muscles around the ear. Immediately distal to this, motor branches are sent to the posterior belly of the digastric muscle and to the stylohyoid muscle. The main trunk of the nerve, now termed the motor root of the facial nerve, continues anteriorly and inferiorly into the parotid gland. Within the parotid gland, the nerve terminates by splitting into five branches: 1) Temporal branch, which supplies Temporalis muscle on face. 2) Zygomatic branch, which supplies the zygomatic Arch. 3) Buccal branch, which supplies the buccal region. 4) Marginal mandibular branch, supplies the mandibular region. 5) Cervical branch, supplies cervical region. These branches are responsible for innervating the muscles of facial expression. What is Vertigo? Vertigo is a sense of rotation, rocking, or the world spinning, experienced even when someone is perfectly still. What is the Physiology of Balance? The human balance system works with our visual and skeletal systems to maintain orientation or balance. Visual signals are sent to the human brain about the body's position in relation to its surroundings. These signals are processed by the brain and compared to information from the vestibular, visual and the skeletal systems. Our brain receives inputs from our eyes, muscles, joints and vestibular system in our ears, then it processes these nerve impulses so that it can give the person a correct perception of the environment. Our ears contain special parts, like the saccule, utricle and three semicircular canals which are all part of the vestibular apparatus. The purpose of vestibular apparatus is to provide the brain the correct perception of equilibrium (balance), spatial orientation and motion. The parts that are responsible for vertical orientation are the saccule and utricle. The rotational movement is detected by the semicircular canals that contain fluid known as endolymph. The endolymph moves and triggers the sensory receptors within the canal which sends nerve impulses to the brain regarding the movement. Impulses from both canals of the side of the head would normally send symmetrical impulses in order for the brain to interpret the impulses properly. Types of Vertigo There are two possible causes of vertigo: Peripheral vertigo and Central vertigo. Peripheral Vertigo Peripheral vertigo refers to the disorders that involve disturbances in the inner ear. The common disorders that may affect the inner ear thereby causing the person to experience dizziness or vertigo include Vestibular Neuritis: Inflammation of the vestibular nerve which is responsible for taking the nerve impulses from the semicircular canals in the inner to the brain. Labyrinthitis: Inflammation of the labyrinth which is also in the inner ear and most of the time may also involve the vestibular nerve. Both of these disorders are usually caused by a viral infection that may have reached the inner ear. Other causes include Meniere’s Disease. This occurs due to increased fluid in inner ear. Benign Paroxysmal Positional Vertigo or BPPV This result from the movement of the otolith, which is a very small particle made of calcium inside the ear. The otolith organs detect the movement of your head and its relation to gravity. For some reason the otolith can be dislodged and move into the semicircular canals and affect the movement of the fluid inside, thereby causing it to send irregular nerve impulses to the brain making the person get dizzy. How to treat BPPV? The most common and effective treatment for BPPV is known as the Canalith Repositioning Procedure. The procedure consists of several simple and slow maneuvers for positioning your head. The aim is to move the particles from the semicircular canal to the utricle where they don't pose a problem. Each position is held for around 30 seconds after which any symptoms or abnormal eye movements stop. This procedure is more widely known as Epley’s Maneuver. Central Vertigo Central vertigo refers to the dizziness or vertigo that result from a problem in the brain. The area of the brain that is usually affected is the brainstem or cerebellum. How to Diagnose Vertigo? Vertigo can be diagnosed based on: 1) Clinical History and Symptoms being told by patient. 2) Blood tests to check for presence of infection. 3) Romberg test: The doctor will have you stand with your eyes open and feet together, then maintain your balance while your eyes are closed. 4) Vestibular testing: To check for any involuntary movements of the eye (nystagmus). 5) Fukuda-Unterberger test: In this test, the patient will have to close the eyes and march in place while trying not to lean to the side. In some instances, the doctor will require you to undergo diagnostic imaging tests like CT-Scan or MRI to rule out central causes of vertigo or any tumor presence. What is the medical treatment? Treatment of vertigo depends on the causative factor. Peripheral vertigo can be treated by bed rest, avoiding sudden position changes and use of Vestibular Blocking Agents or VBAs. These medications helps relieve the inflammation in the inner ear, relaxes the muscles and prevent other symptoms associated with vertigo like nausea and vomiting. What is the surgical treatment? Surgery can also be another treatment options especially for persons with Meniere’s disease who are suffering from intense and frequent vertigo attacks. Endolymphatic sac procedures: This involves the decompression of the endolymphatic sacs by removing a tiny part of the bone to allow better fluid absorption or decrease fluid production. A shunt may also be put in place to facilitate fluid drainage from the inner ear. Labyrinthectomy: The removal of both the hearing and balance organs of the ear. This is only done when the patient’s affected ear already has total hearing loss. Vestibular nerve section: This procedure is done by cutting the vestibular nerve which is the movement and balance sensors in the inner ear. This can help relieve vertigo attacks and at the same time prevent hearing loss. Prognosis Most of the symptoms associated with peripheral types of vertigo usually resolve on its own within a short period of time. Otherwise, you need to see a doctor to make a treatment plan. Difficulty Swallowing Intro When a patient says they are having difficulty swallowing, they may be referring to one, or a combination of the following symptoms. - Dysphagia, which means food is unable to pass through smoothly, or gets stuck. - Odynophagia, which means that swallowing is painful. - Reflux and regurgitation, which means food or gastric secretions come back into the throat or mouth. - Aspiration, in which the food or drink goes down the trachea, instead of the esophagus. This can further lead to aspiration pneumonia. - Gagging, in which patient may feel that the food is causing them to throw up and vomit. - Globus pharyngeus: a feeling of a lump in the throat. - Xerostomia; it means dry mouth, which may itself lead to dysphagia or odynophagia. Our main goal in this presentation is to discuss an approach to a patient with dysphagia, it's relevant history and workup, and what are the main differentials and some general management options for dysphagia. Many specialists have to deal with patients of dysphagia, such as otorhinolaryngologists, gastroenterologists, speech therapists, dentists, internists and geriatricians to name a few. Dysphagia is a fairly common cause of morbidity in the elderly population. The swallowing mechanism Let's begin by reviewing the physiology of the swallowing mechanism. It is generally divided into three phases: 1) Oral phase, in which the food is chewed and lubricated to form a bolus. 2) Pharyngeal phase, in which the movements of the soft palate, larynx and epiglottis separate the air passage from the food passage so that food and drink are not aspirated into the nose or trachea. 3) Esophageal phase, in which the food passes down the esophagus, via peristalsis, into the stomach. A disruption in any one of these phases could result in dysphagia and difficulty in the pharyngeal phase especially could lead to aspiration. Classification of Dysphagia Dysphagia is classified according to site: whether it is oropharyngeal or esophageal; and the type of disorder: whether it is a structural disorder or a motility/propulsive disorder. The differential diagnosis for dysphagia could also be divided according to the cause: Congenital, Infections, Trauma, Inflammatory, Autoimmune, Neoplastic, Neurological, Motility disorders, Iatrogenic, and Mechanical causes. History and Workup So as you have seen, a multitude of conditions can cause dysphagia. When a patient presents with difficulty swallowing, here are a few important points to consider in taking the patient's history: - Is it true dysphagia or other related problem like odynophagia, etc? - What is the onset and duration? - Any coughing or airway issues? (to check for aspiration). - Is it continuous, worsening or intermittent? - What is the location? - Is it oropharyngeal or esophageal dysphagia? - Is it more for solid food or liquids? - Is there associated regurgitation or reflux? - Does the patient have pain, weight loss and/or dehydration? This is to assess the general condition of the patient. Examination Oral and throat examination should be done, but the main way to assess dysphagia is to ask the patient to swallow solid food and liquids in front of you. Investigations We shall start with baseline investigations. Chest X-ray can give us a quick and rough idea about the esophagus, but more importantly, it gives an idea about any aspiration pneumonia. X-ray neck, antero-posterior and lateral view, can give a quick and rough idea about the pharynx, larynx and upper esophagus. If a neck pathology is suspected to cause dysphagia, CT scan or MRI may also be advised. Complete blood count, Urea and electrolytes can give an idea about the patient's condition. e.g does he/she have any electrolyte disturbance due to dehydration. The investigations specific for dysphagia are: 1) Fibre optic direct laryngoscopy, which can view the laryngeal inlet and is useful for investigating patients of oropharyngeal dysphagia. 2) Barium Swallow, in which patient is given a radio opaque contrast to drink, and the contrast is then X-rayed as it passes through the pharynx and esophagus. 3) Video fluoroscopy is similar to Barium swallow, but instead of still images, a video clip is made of the contrast's passage into the stomach. It is considered a better study than Barium swallow. 4) Esophageal endoscopy This is particularly useful in patients with esophageal dysphagia, in which a structural lesion is suspected. 5) Esophageal Manometry In this test a catheter is passed into the esophagus which measures the pressure along the length of the esophagus. This is useful in patients in which a motility/ propulsive cause of dysphagia is suspected. Management of Dysphagia Obviously the specific management of dysphagia depends on the underlying disease. In general here are the key points while managing a patient of dysphagia. Ensure adequate hydration and replenish any deficit electrolytes, such as sodium and potassium. Patients are usually malnourished and feeding can be started via nasogastric tube. If NG tube cannot be passed, then Total Parenteral Nutrition via IV route might be needed. Patient might require feeding jejunostomy or gastrostomy for long term feeding. Food consistency variation and diet modification might help some patient with dysphagia due to a motility disorder, especially geriatric and stroke patients. Swallow positioning and pharyngo-esophageal exercises are also useful. Reduce aspiration risk by regular swallowing assessment, patient's positioning and airway protection measures. Oral hygiene with use of mouthwashes. Proton pump inhibitors, like Omeprazole, might reduce the severity of discomfort of dysphagia. Antibiotics will reduce infection, especially in patients with increased risk of aspiration. Tracheostomy is a procedure in which an artificial opening is created in the throat to assist with patient’s breathing or to create an alternate airway. It is a fairly common procedure in patients with prolonged ICU stay or ventilator support. Indications for Tracheostomy Tracheostomy may be needed when there is (1) some sort of upper airway obstruction, e.g cancer of the larynx, laryngeal edema etc; (2) if patient is unable to remove respiratory secretions, e.g coma, respiratory muscles paralysis. In such cases, tracheostomy allows suctioning of the secretions and the cuff of the tracheostomy reduces further aspiration of secretions. (3) If patient has respiratory insufficiency, e.g chronic lung diseases, then tracheostomy might help oxygen ventilation by reducing respiratory dead space. (4) Prophylactic measures, in a patient on prolonged mechanical ventilation via endotracheal tube, there is a risk for tracheal stenosis, so in such patients tracheostomy is done. 5) As part of another procedure. Sometimes tracheostomy is done to gain access to airway for general anesthesia, or as a precautionary measure in some patients who undergo an extensive neck surgery. Type of Tracheostomy There are various types of tracheostomy procedures, depending on the circumstances of the patient and the treatment intent. Similarly, there are various types of tracheostomy tubes each with specific functions. The common types of tracheostomy procedures are (1) Emergency Tracheostomy (2) Elective Tracheostomy (3) Permanent Tracheostomy (4) Percutaneous Tracheostomy (5) Mini Tracheostomy, also known as cricothyroidotomy. Tracheostomy can also be classified as high, mid or low; depending on the level at which it is inserted into the trachea. Different varieties of tracheostomy tubes include cuffed, non cuffed, double lumen tubes, tubes with speaking valves, metallic tubes, and so on. Procedure The procedure is preferably done under general anesthesia, but emergency cases may necessitate local anesthesia only. There are variations on the technique of the procedure, but generally these are the steps: The patient is put in a supine position with neck extended, skin incision, which may be transverse or longitudinal, is given on the neck, subcutaneous fat and platysma are cut. Strap muscles of the neck are retracted or dissected away, if thyroid gland is encountered, then it is displaced upwards, or may be cut. Any blood vessels encountered along the way are ligated. Incision is given on the trachea. A hole is made and the tracheostomy tube is inserted, preferably through the second or third tracheal ring. The skin incision is closed and the tracheostomy tube is secured to the skin via stitches or simply tied around the neck. Care After tracheostomy is done, certain precautions and care is required to ensure proper functioning of the tracheostomy tube and to prevent complications. The tracheostomy forces the air to bypass the nasal and oral passages, hence the air entering the tracheostomy is not adequately humidified. This dry air leads to increased tracheal irritation and secretion production. Because these secretions may lead to crusting and blockage of the tracheostomy tube, the first point regarding care is adequate suctioning of the secretions through the tracheostomy tube. Secondly, humidification of air. This can be done with humidified air attached to the tube, placing a humidifier or steam near the patient’s bed or applying a wet porous gauze onto the tracheostomy tube, although the latter is considered a crude measure. Thirdly, keep the patient under regular supervision and ensure that the tube is functioning and not dislodged. Since the tracheostomy forces the air to bypass the vocal cords, patients would not be able to speak effectively. In such cases, a note pad and bell should be provided to the patient, to allow them to communicate effectively with their healthcare providers. Fourthly, if the patient has a cuffed tracheostomy in place, then the cuff should be deflated periodically to relieve pressure on the trachea. However, this may not be feasible in patients with increased risk of aspiration. In case the tracheostomy tube is damaged, infected, occluded or non functioning in any way, then a new tube should be inserted in place of the old one, under expert supervision. Complications Just like any invasive procedure, tracheostomy also has some potential complications. Surrounding structures may be damaged while performing the procedure. Therefore, there could be bleeding around the tracheostomy site, tracheostomy tube may get blocked by secretions or clots, or it may get dislodged. The dry air directly entering the trachea might cause tracheitis and crusting. The patient may have initial difficulty getting used to breathing via tracheostomy, along with apnea. There may be infections of the surgical wound, trachea or lungs. Decannulation If the patient improves and the healthcare team determines that tracheostomy is no longer necessary, then a trial of decannulation should be attempted. Decannulation is basically the removal of the tracheostomy tube and shifting the patient back to normal breathing. The tube is occluded for 24 hours and if the patient is able to tolerate it and breathe normally then the tube is removed and the wound closed. If patient is unable to tolerate the tube occlusion, then progressively smaller tracheostomy tube are inserted and occluded, until patient is able to resume normal breathing. External Ear Anatomy Today we are going to learn about Anatomy of External Ear. The ear is divided into 3 parts: 1. External ear 2. Middle ear 3. Internal ear The external ear is again divided into 3 parts which will make it easier to remember. Its 3 parts are (1) auricle or pinna (2) external acoustic canal and (3) the tympanic membrane 1. Auricle or Pinna The entire pinna, except its lobule which is made of fat, and the outer part of external acoustic canal, are made up of a framework of a single piece of yellow elastic cartilage which is then covered with skin. There is no cartilage between the tragus and crus of the helix, and this area which is without cartilage, is called the incisura terminalis. An incision made in this area will not cut through the cartilage since cartilage are unable to heal properly and therefore this area is used for endaural approach in surgery of the ear. Pinna is also the source of graft materials for the surgeon. Cartilage from the tragus, perichondrium from the tragus or concha, and fat from the lobule are frequently used for reconstructive surgery of the middle ear. The conchal cartilage has also been used to correct the depressed nasal bridge while the composite grafts of the skin and cartilage from the pinna are sometimes used for repair of defects of nasal ala in nasal surgery. 2. External Acoustic (Auditory) Canal It extends from the bottom of the concha to the tympanic membrane and measures about 24 mm along its posterior wall. It is not a straight tube; its outer part is directed upwards, backwards and medially, while its inner part is directed downwards, forwards and medially. Therefore, to see the tympanic membrane, the pinna has to be pulled upwards, backwards and laterally so as to bring the two parts in alignment. The canal is divided into two parts: (a) cartilaginous and (b) bony. (a) Cartilaginous Part It forms outer one-third (8 mm) of the canal. Cartilage is a continuation of the cartilage which forms the framework of the pinna. (b) Bony Part It forms inner two-thirds (16 mm). 3. Tympanic Membrane or the Drumhead It forms the partition between the external acoustic canal and the middle ear. It is obliquely set and as a result, its posterosuperior part is more lateral than its antero-inferior part. It is 9-10 mm tall, 8-9 mm wide and 0.1 mm thick. Tympanic membrane can be divided into two parts: Pars Tensa, Pars Flaccida.