crash course on codman drains

newohiorn, BSN, RN, EMT-P · Feb 25, 2009

Are the drains placed in the lumbar area or are you referring to drains placed in the ventricles of the brain? Sounds like they are placed in the brain based on your comment that you have them leveled at the ear. I've worked with both types of drains a fair amount and will try to answer any questions.

annmariern · Feb 25, 2009

Hi, The ones that are placed in the lumbar area are the ones im coming across. One of my questions is the settings mm/hg vs h20. Why would you use one vs the other, the ones I've seen the surgeon wants it raised to 10 mm/hg to slow drainage. Thanks

newohiorn, BSN, RN, EMT-P · Feb 26, 2009

I used to work in a spine unit where all we did was take care of post-op back surgery patients. For drains placed in the lumbar regions our surgeons usually wanted these placed at a level to drain off a certain amount of fluid per hour, i.e. they usually write to adjust the level of the drain to drain 10 ml of CSF per hour (or as close as we can get to that). The patients would come up from PACU with the drain having been clamped while being transported so we would get the patient comfortable and then open the drain, watching how it was dripping and choose a level that seemed like we would get 10 ml/hr and then watch it and adjust it from there, emptying the collection chamber every hour. Keep in mind one rarely gets a nice even prescribed amount per hour--when I gave report to the next nurse I usually reported that I got anywhere from 3 ml to 20 ml/hr--it's not an exact science. I don't think I have ever had a doc order a specific height (i.e. 10 mmHg) for a drain placed in the lumbar area--have only seen that when it is placed in the brain. If the doc is writing for the drain to be placed at a specific height it sounds like you are doing it correctly. Using the patient's ear as the starting point to raise the drain from is using the Foramen of Munro as the starting point, which I believe is located in the third ventricle of the brain near the choroid plexus which produces CSF. This type of order is very common when these drains are placed in the brain. It does not matter whether the doc writes it in mmHg of or cm of H20--it's just personal preference of the physician--probably depends on how they think of the pressure of CSF in the body in their own mind--whether they think of it in terms of mmHg or cm H2O. All of ours write in cm of H20 except one.

As you said, when I worked on the spine unit lumbar drains were mainly placed because there was a CSF leak or a possible CSF leak and very occasionally they were placed because of infections. I'm not a doctor but my understanding of why a lumbar drain is placed for a CSF leak is to lower the overall pressure of the CSF in the system so that the leak can heal on its own. Our patients with lumbar drains are always on flat bedrest, i.e. they can turn side to side but must stay flat. If they sit up they can dump too much CSF. If one dumps too much CSF they can lower the pressure in the system so much that the brain can herniate. I don't know how much of a CSF dump this takes but it is not as sensitive as I thought when I first started working with these drains, i.e. I have seen someone dump 40 ml of CSF in a minute after sitting partially up and coughing vigorously. I called the nurse practitioner in a panic and she was not worried. It is important to remember that any time the level of the bed is changed the level of the drain must be changed. I also noticed that most of these patients go stir crazy after being on flat bedrest for a few days. I would warn them as soon as they got to me that being on flat bedrest is not pleasant and that they were probably gonna get a little stir crazy and to bear with us and we'll get through it and I think that seemed to help when they knew what they were in for.

Hope this helps. I'll be happy to try to answer any specific questions.

annmariern · Feb 27, 2009

thanks,very informative post.

angelscrib · Apr 5, 2009

yes neurosurgeons asks for setting of 10 - 15 mm on the codman drain coz thats the normal pressure inside the brain. and normally CSF production in 24hours is about 450 - 500ml. u hav to maintain setting within normal, if u put setting less than 10 that means ur emptying more csf and leaving empty space that can cause brain to shrink and complications may occur and if u put settings more than 15 means there r more csf inside which is not helping the patient at all, and keeping the drain ineffective. take note we drain the excess csf only. if u noticed that ur drainage bag is empty check level if it is on 10 -15mm and also check patency. if drain is patent and still empty for about 2 or 3 days inform ur neurosurgeon right away coz thats the time the drain can be removed from the patient.