Cultures

All right in this lesson we're going to take a look at cultures.

We're going to have to do a little bit of time travel we're going to go back to our microbiology that we all took prior to nursing school. But remember what the purpose of cultures are. What we want to do is we want to find out what's going on with our patient, meaning is there a specific pathogen that's coming maybe a bacteria or a virus or a fungus that is causing our patient to become sick in terms of having an infection. The purpose of the cultures to isolate that pathogen, so we'll get a sample send it to the lab, grow it over a couple of days, and then we can do is call the sensitivity where we actually go and look at the specifics of what particular medication is going to destroy that pathogen. So if we have a bacteria that grows, which antibiotic is going to fight it and take care of it. So let's get into some of the specifics with cultures.

Now when we talk about patho of using cultures, the goal here is to refresh our memory about microbiology when were talking about different types of pathogens. Remember your patients can get infections from direct contact with types of bacteria, they can ingest them, they can be delivered by Airborne or droplet, even some contamination, so think in terms of your Foley catheter care. If you're not using good clean technique, then you're potentially going to contaminate your patience urinary tract, and they can get a urinary tract infection because we've exposed them to a potential pathogen because it's become contaminated. Often with surgeries, some surgical sites can become contaminated, which is why sterile technique is so important. Sometimes environmental exposures you can also put patients at risk for different types of pathogens.

Pathogens become problematic when they cause harm to our patient. So if your patient has a weakened immune system, they are not going to be able to fight off that bacterial infection that we normally would be able to and it's going to require some medical intervention. This is why we do cultures.

So your role is the nurse is to obtain the sample for the culture. Only in certain situations are providers going to need to do that, but for the most part it's going to be your responsibility and getting them. There's a couple of different ways to get them and we'll go over those here.

For our direct type of sampling, these are going to be things like oral swabs, oropharyngeal swabs, those are your tonsil swabs. You may also swallow balloons or skin or other areas of Suspicion when it comes to maybe a bacterial infection. You're also going to get direct samples for blood cultures, as well as urine cultures are even fecal cultures.

The other interesting type of sample that you're going to get is a sputum sample. The best way to do this is to have your patient take a couple of deep breaths and then give a good deep cough and then spit up to sample into a cup. One thing you do want to be mindful of is that there may be a contaminant via their saliva, so just make sure that you notate that wherever you need to. The other type of sputum sample that you make it is something called a bronchoalveolar lavage or a bal. What that is is that either you or the respiratory therapist will get a sample of the sputum directly from the patient's lungs. That's been sent to the lab to grow whatever pathogen the providers may be suspicious of.

There are a couple of other unique situations where you're going to have to get a different type of sample, and this is going to be either a tissue culture, and that's mostly going to be your providers that are going to get those for you. Or it's going to be a device.

In some facilities it may be your responsibility to get the tip or the end of a central line or maybe some sort of other catheter device that you sent to the lab and they're going to grow a culture off that. I just don't want you to be surprised in those certain types of situations because they are kind of rare.

So what do you need to be aware of as the nurse?

Will the first thing you need to do is to follow policy. Find out what your unit facility policy is regarding different types of samples, and make sure you follow those. If you have a question about a specific type of culture that you're supposed to get, then call the lab and find out what the specifics are. They'll let you know.

In most cases you're going to be responsible for getting that direct sample. So make sure that you follow sterile technique when you have to or even when there's question. The last thing that you want to do is have some sort of contaminant on your hands or on you that falls into the sample and it grows and actually gives us a false positive of some other type of pathogen. That just results and delay of care for your patient

Okay so your patient had culture sent off and you waited 3 days and you get your results back. No growth. What does that mean? Well it means that there's a likely no pathogen there, and then there's some other reason that needs to be investigated if there's a suspicion of infection. It doesn't necessarily always mean that there's nothing growing there, but it just didn't grow enough of the sample to warrant a concern.

What about abnormal results?

Your abnormal results they're going to indicate a specific type of pathogen. Then they're going to test for susceptibility or sensitivity to different types of medication. That's going to help him providers hone in on what treatment is going to work for this patient to get rid of the infection.

Remember that when we're dealing with cultures, we're focusing on infection control and lab values for a patient.

So let's Recap.

The purpose of the cultures to isolate the pathogen and figure out what specifically is causing an infection.

Sensitivities look for the appropriate treatment to figure out what medication or class of medication is going to help to get rid of the pathogen.

When you are unsure of what to do, follow lab policy and follow facility policy. They’ll help you find what you need for your sample.

And lastly make sure you're using proper technique. If you are unsure of what type of technique to use, whether that's clean gloves or sterile gloves, always opted for the sterile technique make sure that you're not contaminating your sample, and get that sent off to the lab.

That’s our lesson on cultures. Make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!