Pulse oximeters can give a falsely high reading in the presence of carbon monoxide binding to haemoglobin about 250 times more strongly than oxygen and, once in place, prevents the binding of oxygen. It also turns haemoglobin bright red. The pulse oximeter is unable to distinguish between haemoglobin molecules saturated in oxygen and those carrying carbon monoxide. False high readings are also always obtained from smokers - readings are affected for up to four hours after smoking a cigarette. Other sources of carbon monoxide include fires, car-exhaust inhalation and prolonged exposure to heavy-traffic environments.
Shortness of breath question
- Thread starter Dillon Baker
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As others have said, I believe that's a good point why to treat the patient and not the machine and I've also heard nurses are notorious for trusting Spo2 readings without even realizing how inaccurate they can be.
I'm just a student and textbook says 4-6 cannula and 12-15 NRB but some patients can feel smothered by NRB which turns you to cannula and adjust to the patients comfort, I've heard that rest home patients are generally on 2lpm so that might be the comfort range as others have mentioned.
I'm just a student and textbook says 4-6 cannula and 12-15 NRB but some patients can feel smothered by NRB which turns you to cannula and adjust to the patients comfort, I've heard that rest home patients are generally on 2lpm so that might be the comfort range as others have mentioned.
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How about treating the patient using a complete assessment complete with important clinical information obtainable only by data from "machines"? It's not just nurses that trust sometimes inaccurate SpO2 readings. It happens to all levels of providers with a variety of experience levels, but frankly I've seen it more from EMS colleagues than anyone else.
SpO2 readings are accurate most of the time. There are confounding variables, but check for a good pleth waveform to correlate, be on the lookout for rare and strange presentations that can change SpO2 values, and use trending values.
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Ewok Jerky
PA-C
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A word of advice, as a student I would refrain from critisizing nurses or any other healthcare professional. EMS is not the be all end all of medicine, and nothing would happen if doctors didn't have a team of professionals getting things done for them.
It's an easy EMS trap to fall into, crapping on nurses, don't do it.
It's an easy EMS trap to fall into, crapping on nurses, don't do it.
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So just what is the incidence of clinically important carboxyhemoglobinemia as opposed to the incidence of clinically important hypoxemia that is accurately quantified by pulse oximetry?
Dyshemoglobinemias (met-, sulfe- and carboxy-) and their potential effect on pulse oximetry is an important concept to understand and keep in mind when you are pulling patients out of burning buildings and chemical plants, but is seriously overstated as a problem in patient assessment.
The folks who emphasize carboxyhemglobinemia as a reason why pulse oximetry "can't be trusted" both dramatically overestimate the extent of that problem and entirely miss the point of "look at the patient, not the monitor".
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Nightmare
The FNG
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By the sounds of it your patient was not having the symptoms of SOB but might have been thinking they had SOB, may be almost some form of an anxiety issue (i wouldn't call it an attack)...most people with this issue who don't have a medical background will think that they are getting better if they get extra O2...did you do anything wrong? no, absolutely not. did you help the patient? clinically, there doesn't appear to be much you could help. Mentally, you helped them out quite a bit i think.
As for the nurse giving you a strange look, may be the patient is a frequent flyer, or since the patient's SpO2 was fine she might have judged you a little. Bottom line, be a patient advocate, treat your patient, not your monitor, if they are presenting with SOB then give them oxygen. For the short amount of time you are with them it will not harm them.
Also keep in mind the patient that likes you, won't sue you. So if, in their mind, you did the best you could to help them they will be significantly happier than if you just told them to have a seat on the stretcher and did the chart on the way to the hospital.
As for the nurse giving you a strange look, may be the patient is a frequent flyer, or since the patient's SpO2 was fine she might have judged you a little. Bottom line, be a patient advocate, treat your patient, not your monitor, if they are presenting with SOB then give them oxygen. For the short amount of time you are with them it will not harm them.
Also keep in mind the patient that likes you, won't sue you. So if, in their mind, you did the best you could to help them they will be significantly happier than if you just told them to have a seat on the stretcher and did the chart on the way to the hospital.
ThadeusJ
Forum Lieutenant
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I always taught healthcare professionals (RT's, paramedics and nurses) that a great role of the oximeter is measuring pulse rate. I discovered this after watching a patient with an ECG reading of 80 but having a pleth of 40. People were wondering why the BP was low and the patient was SOB. I also have had to tell staff NOT to chart a pulse of 300 bpm just because that's what the oximeter said.
Undetected COHb does happen but not necessarily common. The RAD57 devices have been known to detect high levels of CO in patients exhibiting flu-like symptoms. Some of these have been cases where the CO detectors don't alarm at chronically low but present levels of carbon monoxide.
Undetected COHb does happen but not necessarily common. The RAD57 devices have been known to detect high levels of CO in patients exhibiting flu-like symptoms. Some of these have been cases where the CO detectors don't alarm at chronically low but present levels of carbon monoxide.