Critical Care Flashcards
CPR in a pregnant patient?
Although not specifically a part of current recommendations due to lack of data, the AHA has previously recommended shifting upward on the sternum during CPR in the pulseless pregnant patient in order to account for upward displacement of the heart by a gravid uterus
Hand placement location in CPR for obese patients?
Lee et al. performed a retrospective study that reviewed chest CTs to determine the location on the sternum that corresponded to the optimal point of maximal left ventricular diameter (OPLV), in both obese and non-obese patients.
Bottom Line: Radiographically, the location on the sternum that corresponds to optimal compression of the LV is more cranial in obese patients than in non-obese patients. It remains to be seen whether the recommendations for hand placement in CPR should be adjusted, but we may want to consider staying within 4cm of the bottom of the sternum in patients of normal weight.
They found that the OPLV was higher (more cranial) on the sternum for obese patients than for patients with normal weight, although 96% of obese patients’ OPLV fell within 2cm of where the guidelines recommend standard hand placement should be, compared to a notable 52% in non-obese patients.
Volume Responsiveness and the PLR (Passive leg raise)
Passive Leg Raise (PLR) is accomplished by starting with the patient at a 45’ semi recumbent position, lowering the body to horizontal, passively raising the patients legs to 45’ for 30-90 seconds, then returning the patient to the semi-recumbent position.
To assess volume responsiveness using PLR, you must assess cardiac output (CO) and not simply look at the changes in blood pressure or heart rate.
Previous papers have shown EtCO2 to be a reasonable surrogate of CO with PLR when ventilation is unchanged.
Another option for measuring CO is carotid ultrasound. One study demonstrated good correlation between carotid ultrasound and invasive measurements on ICU patients. It is calculated using the equation Diameter * VTi, where VTI is the velocity time integral.
Take Home Point - Be sure to measure CO with a PLR to help determine volume responsiveness- EtCO2 or carotid ultrasound can be considered as surrogates of CO.
