Optical spectroscopy to assess muscle oxygenation in infants undergoing extracorporeal life support

摘要

Extracorporeal life support (ECLS) is used in intensive care units (ICUs) as heart-lung bypass for critically ill patients tosupport either inadequate heart or lung function. Decisions to discontinue ECLS are typically based on clinical judgmentand patient trajectory during trial-off support. We investigated an optical measurement of muscle oxygenation (MOx) asan indicator for adequacy of circulatory function during trials-off ECLS. Clinicians were queried prior to trial-off as towhether the patient was deemed: ready, might be ready, or not likely ready to discontinue ECLS. MOx was determinedusing an optical analysis developed in our laboratory. Optical spectra were acquired from infants using a fiber-opticprobe affixed to the arm or leg. Five infants were studied during 6 trials-off ECLS. Mean initial MOx was 96.6+/-8.5%(n=6). In trials resulting in discontinuation of ECLS, MOx was > 94%. In those remaining on ECLS, MOx was lowerduring the trial off at all time points. Mean MOx trended lower (75.1+/-23.5%), in the first 6 minutes for those notremoved from ECLS, compared with those for whom ECLS was subsequently discontinued (97.2+/-3.8%). Lactatetrended higher in subjects remaining on ECLS (3.4+/-0.8) compared with those removed from support (1.7+/-0.7).Clinician predictions prior to trial-off did not correlate with ultimate decision for discontinuing ECLS. Althoughpreliminary, we believe that MOx may be useful to assist in objectively assessing adequacy of circulatory function andmay be helpful in the early determination of readiness for discontinuation of ECLS.