The first decade of continuous monitoring of jugular bulb oxyhemoglobin saturation: Management strategies and clinical outcome

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Abstract
Objective: To comparatively assess outcome of patients undergoing monitoring and management of cerebral extraction of oxygen along with cerebral perfusion pressure vs. outcome of patients undergoing monitoring and management of cerebral perfusion pressure alone in severe acute brain trauma. Design: Prospective, interventional study. Setting: Intensive care unit of a university hospital. Patients: Adults (n = 353) with severe acute brain trauma. A group of 178 patients underwent continuous monitoring and management of cerebral extraction of oxygen and cerebral perfusion pressure, while a control group of 175 patients underwent monltoring and management of cerebral perfusion pressure only. Interventions: Routine neuroemergency procedures. Measurements and Main Results: The two groups of patients were matched with regard to age, postresuscitation Glasgow Coma Scale scores, rates of acute surgical intracranial hematomas and brain swelling, pupillary abnormalities, early hypotensive events (before intensive care monitoring), as well as initial levels of intracranial pressure and cerebral perfusion pressure. Outcome at 6 months post injury was significantly better (p < .00005) in the 178 patients undergoing monitoring and management of cerebral extraction of oxygen along with cerebral perfusion pressure, than in the control group of 175 patients undergoing monitoring and management of cerebral perfusion pressure alone. Conclusion: In patients with severe acute brain trauma and intracranial hypertension associated with compromised cerebrospinal fluid spaces, monitoring and managing cerebral extraction of oxygen in conjunction with cerebral perfusion pressure result in better outcome than when cerebral perfusion pressure is managed alone. (Crit Care Med 1998; 26:344-351) Continuous fiberoptic monitoring of jugular bulb oxyhemoglobin saturation was first introduced by our team [1] in Critical Care Medicine approximately one decade ago. Over the years, a broad spectrum of newly derived physiologic variables and concepts have become available from the above-mentioned monitoring technique. The new variables include the cerebral extraction of oxygen [2-11], cerebral consumption of oxygen [7], systemic-cerebral oxygenation index and systemic-cerebral ventilatory index [8], and modified cerebral lactate-oxygen index [12]. Newly derived concepts include the cerebral hemodynamic reserve [4,6] and cerebral hemometabolic regulation [9]. The main findings reported from jugular monitoring during neuro intensive care concerned: a) oligemic cerebral hypoxia and related intracranial pressure problems[1,3,4,11,13,14]; b) relative cerebral hyperperfusion (reciprocal of oligemic hypoxia) and related intracranial pressure problems [4,5,8-11]; c) hypoxemic cerebral hypoxia [1,2,15]; and d) cerebral pressure autoregulatory abnormalities in relation to cerebral extraction of oxygen [16]. Regarding related therapeutic applications, the four main findings previously reported were those concerning: a) the combined effects of mannitol boluses in simultaneously normalizing increased intracranial pressure and cerebral extraction of oxygen [3]; b) the combined effects of optimized hyperventilation in simultaneously normalizing increased intracranial pressure and decreased cerebral extraction of oxygen [8]; c) the combined effects of optimized hyperventilation in simultaneously normalizing (matching) cerebral extraction of oxygen and glucose [10]; and d) the potential adverse effects of pentobarbital boluses, inducing transient oligemic cerebral hypoxia in some patients [14]. The present work is an expansion of our previous experience. This time an attempt was made to comparatively evaluate the outcome of severely brain-injured patients undergoing monitoring and management of cerebral extraction of oxygen in conjunction with cerebral perfusion pressure vs. patients subjected to monitoring and management of cerebral perfusion pressure alone.