hi everybody! this is Dr A for our basics of urinalysis we're going to look at the types of urine specimens and then things that can contaminate urine specimens all right! first the random specimen, it can be collected at any time of the day, it is the most common type of specimen collected for tests to be performed on, um, if you think about patients showing up to the ER to, you know, be assessed and they want to run a urinalysis, it would obviously have to be a random specimen because people go to the ER at random times of the day, the disadvantage of a random specimen is they're often dilute, have low concentrations of the solutes, it is easy to miss the pathological metabolites, and diet can affect the results, what they've been eating can affect those results, the first morning specimen is collected in the morning upon arising from bed, so when a person gets up that first amount of urine to leave that bladder, that's the specimen that's collected, so it's a more concentrated specimen, it is preferred for all urinalysis testing if it is possible to obtain, pregnancy testing should be performed with this type of specimen, a lower ph is typical, and specific gravity tends to be higher because it's more concentrated urine, and it's been sitting in the bladder all night too, so maybe the lower ph is tied to that, also, you know, at night when you're sleeping, your body's doing a lot of maintenance, and so that could also be tied to the lower ph of that first morning urine, the best specimen to detect UTIs is a first morning specimen because of that longer time of the urine in the bladder and the bacteria then can accumulate more, and it'll be easier to detect, it is usually a fasting specimen, and so that can also facilitate the detection of diabetes, but of course you can't do a first morning specimen on somebody that is in the ER, for example, you could do some of the first morning specimen on somebody that is an inpatient at the hospital, or you can send a specimen collection cup home with a patient with orders to collect the first morning specimen, and then bring it right away to the clinic, or the lab, then you have a postprandial specimen, it's a specimen that's collected two hours after eating a meal, and so this could be used to detect glycosuria, so urine glucose, and that could be suggestive of diabetes, so, if two hours after a person has eaten, their sugar in the urine is still elevated, then that could indicate the person isn't metabolizing those carbohydrates right and has diabetes, um, one of the key for this to be accurate is the patient must void, or empty their bladder, before eating their meal, for that test to be valid, so it would be that, therefore, the urine that's produced is the urine that um is produced during the meal, and post meal in that two hour window from the time of the meal to the time of the collection of the specimen, a 24-hour specimen, uh, it's a urine specimen that's collected under a strict time regimen in order to detect certain solutes because of diurnal variation, so it's a big 24 hour window, so we can start this at any time we just have to go for 24 hours, um, so if it started at four o'clock in the afternoon, then it would run until four o'clock the next afternoon, uh, there are very explicit instructions that a patient has to stick to, things such as you want them to completely empty their bladder before you start the time clock, so that, you know, that everything is collected from then on is in that 24-hour window, every urine that is produced needs to be collected, so nothing needs to be discarded, the containers are usually really big, and sometimes a patient, if they're producing a lot of urine, might need several containers, and the amount of the volume of specimen is also something that's measured with a 24-hour urine specimen, uh, sometimes there's certain instructions, like the specimen should be kept on ice, or kept refrigerated, anyway so that is a 24 hour specimen, next is a catheterized specimen, it is employed to collect a urine specimen for microbiology testing and also to measure the excretory function of an individual's kidneys, or when a patient is unable to void, or use the bathroom, um, an example of when a patient would be unable to void, it would be a male with a swollen prostate and they, they can't, you know, they cannot empty their bladder, and so a catheter can be basically pushed through and pushed kind of past that swollen prostate, and that allows the urine, uh, to be drained from the bladder, if they're bed bound, sometimes ICU patients will have an indwelling catheter and then it will measure the amount of urine that's being produced during the day, during the night, and all that is logged, and that can help assess individual's kidney function, and if the one from the microbiology testing is usually what we call an in-and-out cath, and it's when you want to make sure that you get urine that's straight from the bladder and hasn't been contaminated by bacteria from the labia, et cetera, so the disadvantage of a catheter specimen is it's not really comfortable for the patient, and you do have a risk of infecting the bladder, because whenever you push the catheter in, um, if you don't clean the site properly the catheter could pick up bacteria and it can be introduced straight into the bladder, and so that, that could be a problem, the suprapubic specimen, it is collected externally by introducing needle into a bladder, so that is definitely not comfortable either, the patients are usually infants, elderly, or women, the advantages is that it would be collected under sterile conditions, so it's a specimen that's suitable for microbiology testing, and also for locating the source of UTIs in women if there's a big risk of vaginal contamination, the disadvantages, of course, is discomfort to the patient, and risk of infecting the bladder also, same as the catheter, whenever you invade a space, there's always the risk of introducing bacteria in, in that procedure, next is the midstream clean catch specimen so this is the best alternative to the catheter specimen, the procedure says that the patient must clean the meatus, which is the opening of the urethra, with towelettes, which are little wipes, um, and for the male you have to retract the foreskin, they have to retract the foreskin to clean, females, you have to make sure that um they wipe through the, uh, across both and down the labia really good, clean the labia really good, so, um, trying to basically decontaminate the exit, if you will, and then, um, the patient starts to void, starts to pee, and the first portion of the urine goes into the toilet, and then, um, so then like mid-stream, so first a little bit goes into the toilet, put the cup in and start collecting the urine, um, so that, the cleaning plus, like, discarding that first little part, uh, should limit the contamination of the specimen from skin bacteria, um, so obviously, for that you also want to use a clean sterile container, and this type of urine specimen is ideal for sediment evaluation, and microscopic studies, and for, it's really good for detecting your UTIs, urinalysis, uh, i'm sorry, urines that are contaminated with bacteria, so whether that is coming from the bladder or the kidneys, either way, UTI detection especially in, at the clinics, or in the ERs, where you really don't want to, again, do the catheterization, if possible, avoid that, so what are the sources of contamination in urine specimens? so menstrual blood, blood, uh , it can produce a false positive for the blood and the protein test, of course and the presence of blood could mislead the tech into thinking there's something more going on, other than simply normal, a normal period, vaginal secretions, that could cause an increased number of epithelial cells, and that could have obscured the other sediment components, such as bacteria, the mucus could be present from the vaginal secretions, it could be mistaken, for hyaline or hyaline cast so, um, you know, for the menstrual blood, if if the blood flow is pretty heavy, this could be an instance where a catheter might be the better option to get accurate testing, if the flow is not too heavy, then a midstream clean catch should be able to do the trick, and then, lastly, fecal material this can be identified by the presence of undigested plant and animal tissues, so they, they're quite odd looking, but they don't belong in urine, so when those are seen in urine, um, they're indicative that there's fecal contamination, uh, it is indicative of one of three things, either careless bathroom technique or uncleanness, so, you know, improper wiping, or no cleaning, no wiping, falsifying urine specimens by substituting commode water, that's possible, especially if they think you're testing for drugs, and vestigosigmoid fistula, which is an unnatural opening between a colon and urinary bladder, and the urine is likely to have a brown color, many bacteria, and colored urinary components and fecal odor, so that is a possibility, so that's a true pathology for sure, and needs to be detected, and that wraps up our specimens for urinalysis thank you