Skip to main content

Co-oximeter



A co-oximeter is a blood gas analyzer that, in addition to the status of gas tensions provided by traditional blood gas measurements, measures concentrations of

oxygenated hemoglobin (oxyHb),
deoxygenated hemoglobin (deoxyHb or reduced Hb)
carboxyhemoglobin (COHb)
methemoglobin (MetHb) 

It measures these types of Hb as a percentage of the total hemoglobin concentration in the blood sample.

Use of co-oximetry is indicated

when a history is consistent with toxin exposure

hypoxia fails to improve with the administration of oxygen

there is a discrepancy between the Pao2 on a blood gas determination and the oxygen saturation on pulse oximetry (Spo2),
suspicion of dyshemoglobinemias such as methemoglobinemia or carboxyhemoglobinemia.

Pulse oximetry measures the oxygen saturation (Sao2) of hemoglobin in arterial blood or the average amount of oxygen bound to each hemoglobin molecule.

 Blood gas analyzers calculate oxygen saturation from the measured parameters Po2 and pH on the basis of standard oxygen-dissociation curves.

Unfortunately, pulse oximetry, a noninvasive procedure, does not distinguish among the different types of hemoglobins. For example, in the case of methemoglobinemia, pulse oximetry may read 88%, but desaturation can be demonstrated with co-oximetry, recording 70% oxyHb and 30% MetHb.
Labels:

Comments

Post a Comment

Popular posts from this blog

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

The 12 decision making steps for post dural puncture headache treatment

Treatment decision-making algorithm for postdural puncture headache. 1. When diagnosis is made, all patients should receive supportive measures (reassurance, bed rest, analgesics, hydration, quiet environment). 2. Severity of symptoms should be classified using VAS scale (mild 1–3, moderate 4–6, severe 7–10). 3. Virtually all patients will improve in time even without additional therapy. (dashed lines) 4. Symptoms worsen or fail to resolve within 5 days. 5. Patient preference dictates the choice between pharmacologic (less effective) and epidural blood patch (EBP). 6. In patients with severe symptoms, EBP is strongly suggested. 7. The most common pharmacologic measure is  caffeine  prescription. 8. The failure, worsening, or recurrence of symptoms after pharmacologic measures favors the use of EBP. 9. In addition to EBP, other epidural treatment options can be considered in select patients (eg,  dextran , saline). 10. A period of 24 h should lapse before repeating EBP. 11...
1 comment
Read more

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more