The lowest O2 saturation I've ever seen

  1. I recently cared for a patient with severe ARDS. She was deteriorating rapidly and was placed on a rotoprone bed (prone rotation therapy). High PEEP and/ or APRV were not suitable for her as she already had a large amount of subcutaneous emphysema and was at extremely high risk for a tension pneumothorax. The patient had to be frequently bagged and once proned we could not flip her back supine or she would code.

    Over the course of about 36 hours the patients O2 sats dropped steadily even with the prone therapy. She favored laying on her right side (good lung down) for her best sat in the 60s. She quickly desatted to the 20s when flat prone and came up to the 40s when laying on her left side.

    Now slowly her levels dropped lower and although proning was futile the family was not ready to let go, she was young and it was very sad. Ultimately I ended up seeing her O2 sat drop as low as 3% while rotating prone. There were 3 stars of accuracy the whole time, a great waveform, pulse correlated exactly with the HR and her extremities were warm and pink. The MD told me an O2 sat is not linear at this low of a level but I'm not sure what he meant. Yes, the oxyhemoglobin dissociation curve is not linear but does that mean her sat was not accurate? It would happen time and time again to the single digits, teens and 20s for lengthy periods of time until she ultimately went into the inevitable PEA. (She was a DNR at that point.)

    I've never seen anything like it and would love some insight! Thanks.
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    About SaraBart

    Joined: Dec '13; Posts: 3; Likes: 2

    32 Comments

  3. by   SaraBart
    A peer captured a photo of the monitor (without a name of course); is that safe to post? It shows the accuracy stars, waveform and correlation with heart rate. This is a patient who would sat in the 30s to 40s for hours, never wavering, never coding, so please consider that before dismissing the shockingly low saturation.
  4. by   ausrnurse
    I believe you! I recently saw a ventilated pt get down to around 20% for about 5-10min - it was really scary. Actually, I don't think anything scares me more than a ventilated patient who desats/can ventilate. We ended up paralysing and bagging and using a heap of PEEP and O2. Probably the sickest pt I've seen - and they survived!
  5. by   Penelope_Pitstop
    I believe it! When I worked on the floor, I can think of four separate instances of a patient desatting to the 60s. One lady did just fine on six liters nasal cannula and stayed with us. Everyone else needed to be shipped out to stepdown or ICU.

    I agree with ausrnurse. I don't like it when ventilated patients desat or can't be ventilated. It freaks me out! We know the next step is proning or HFOV, and the final step for us is sending the patient to the CICU for ECMO.

    As an aside, I was once in a code in which we went through about five ambu bags. The patients was that difficult to ventilate, the ambu bags were ruined.
  6. by   Esme12
    Quote from SaraBart
    A peer captured a photo of the monitor (without a name of course); is that safe to post? It shows the accuracy stars, waveform and correlation with heart rate. This is a patient who would sat in the 30s to 40s for hours, never wavering, never coding, so please consider that before dismissing the shockingly low saturation.
    NO!..... I would not post the picture of the waveform. While it really may not show the patient name you NEVER post anything patient related and post it on social media. You don't take pictures of patients readings, monitors, wounds, labs, CXR...EVER!!! NEVER EVER!!!!! This is a patients datanot show and tell. I appreciate you wanting to learn and amazed at the complex ability of the body to sustain itself during a critical process....and the dying process....but it isn't a learning exception to show people how unbelievable the reading wasat that time.

    NO SOCIAL MEDIA FOR PATIENT DATA......NO PICTURES WHAT SO EVER!!!

    While it may not be HIPAA it is certainly against your facility policy and would be considered unprofessional. Would you want the dying process of your Mother, Father sister, brother or child on social media to prove how horrible it was? I'm willing to guess....probably not.

    Would you be happy about a staff member took a picture of your dying loved one to show all her friends an unbelievable reading that they had never seen while your loved one is dying? I'm wiling to bet the answer is no.
    __________________________________________________ ______________

    What the MD meant was that outside certain parameters the machines accuracy diminishes dramatically and disproportionately. While the O2 sat was very low and not conducive to survival...it probably wasn't actually 3% regardless of the waveform and pleth of the signal.

    While the monitor is useful in knowing the patient is not tolerating what you are doing and requires intervention.....it is probably not the "real" reading which is probably in the 30-40's by ABG.
    Last edit by Esme12 on Dec 2, '13
  7. by   Nalon1 RN/EMT-P
    The only true reading of actual O2 saturation is blood gas. Optical O2 sensors only measure hopoglobin saturation (usually oxygen) but could be something else (CO is the biggest false positive, but IV dyes and high billiruben can cause false lows also).

    Any ABG's done?

    Sounds like it was a trying patient for the staff though.
    Last edit by Nalon1 RN/EMT-P on Dec 2, '13
  8. by   ktliz
    Watching the monitor on a terminally extubated patient... sat slowly dropped to 4% with an excellent pleth, until it was unable to get a reading. We joked that the monitor hung in there all the way down to 4%, but 3% was just too much for it to handle. HR was in the 30s at that point. Patient went into PEA several minutes later.
  9. by   meanmaryjean
    In the PICU environment, we routinely deal with children who have complex, cyanotic heart defects. Their BASELINE sats at 60-70%. And they go home like this - and by 'go home' I mean back to school, playing and carrying on their normal ADLs.

    When they desat- it can be down to the 20s- all the while they are awake and alert and upset that you are messing with them!
  10. by   SaraBart
    Hi thank you for your reply. As I was caring for the patient I don't actually have the photo but I had already told my peer to delete it from their phone and they said they did. They also told me they were too scared to even show anybody (I do think they felt bad/ realized the violation AFTER the fact). Thank you so much for your concern! I appreciate it.
  11. by   Esme12
    Quote from SaraBart
    Hi thank you for your reply. As I was caring for the patient I don't actually have the photo but I had already told my peer to delete it from their phone and they said they did. They also told me they were too scared to even show anybody (I do think they felt bad/ realized the violation AFTER the fact). Thank you so much for your concern! I appreciate it.
    You're welcome...it seem so harmless I know but I have seen bad things happen to good people.
  12. by   PRNketamine
    I've seen 0% on 2 different pts both with a waveform and matching HR.
  13. by   Mully
    Was there ever an ABG done when they were saturating that low? I'd be curious to know their PaO2. It's pretty crazy what young hearts can take despite the lack of O2 and other vital nutrients.
  14. by   umcRN
    Quote from Mully
    Was there ever an ABG done when they were saturating that low? I'd be curious to know their PaO2. It's pretty crazy what young hearts can take despite the lack of O2 and other vital nutrients.
    I took care of a 50-something hypoplastic right heart pt once. When born her parents told her to take her home to die because the surgeries (which still don't have optimal outcomes) weren't yet available. Well her body developed collaterals and kept her alive. She satted in the 60's her entire life, married twice, adopted three children and worked full time. She's still out there somewhere, blue as blue can be.

    But like a previous poster said, working with congenital heart patients I don't get worried until my sats hit 30 or so in any of my single ventricle (and sometimes not single ventricle) patients. As our doctors sometimes say "just lower your standards". Maybe not the best way to look at things but sometimes there's nothing else you can do, and yes, they do survive.

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