Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Identification of occult shock is a major clinical problem compounded by inadequate criteria for assessing the efficacy of fluid resuscitation. We suggest that these problems may be resolved in part by understanding both the physiological mechanisms underlying oxygen debt accumulation and, more importantly, the debt repayment schedule during resuscitation. We present a simplified tutorial that incorporates the concept of the oxygen supply-delivery relationship with that of oxygen debt and show how this is relevant to the understanding of shock and resuscitation. ⋯ Because of difficulties inherent in measuring oxygen debt in the prehospital and emergency settings, various metabolic end points such as lactate and base deficit have been proposed as surrogates. We demonstrate the heuristic value of this model in providing a predictive framework for both the optimum therapeutic time window and optimum fluid loadings before critical transitions to an irreversible shock state can occur. The model also provides an unambiguous and objective standard for quantifying the behavior of various postulated shock "markers".