Searching for the Holy Grail: a review of markers of tissue perfusion in pediatric critical care.

Goal-directed therapy has become the key to resuscitating critically ill patients since 2001. However, the ideal marker to guide pediatric resuscitation has remained elusive.The ideal marker is specific, sensitive, easy to use, safe, validated, and cost-effective. Lactate and base deficit are validated prognosticators, but both are affected by confounding conditions and resuscitative efforts. Mixed venous oximetry has been successfully used for guiding therapy but requires a pulmonary artery catheter for measurement. Central venous oximetry, on the other hand, can be more easily measured and is now the standard of care in goal-directed therapy for adult septic shock. Pediatric literature related to central venous oximetry is still in relative infancy, but seems promising. Sublingual capnometry may also prove to be useful, but no pediatric research has been published related to this device. Finally, near-infrared spectroscopy monitoring may be useful in highlighting changes in patient conditions, but its use in goal-directed therapy is limited by the wide interpatient variability. In summary, the search for the ideal marker of tissue perfusion continues, but there is promise on the horizon.