ABSTRACT
Treatment of hemorrhagic shock with fluid resuscitation alone results in diastolic dysfunction as measured by peak systolic pressure/end systolic volume ratio (PSP/ESV). The purpose of this study was to test the ability of a simple Doppler device to track diastolic dysfunction in hemorrhagic shock. In this prospective, controlled crossover study, five adult swine were resuscitated from hemorrhagic shock using fluids. Diastolic dysfunction was confirmed using PSP/ESV ratio. The effect of nitroprusside and dobutamine on this diastolic dysfunction was evaluated. Data (PSP/ESV, Doppler-derived acceleration, and oxygen transport parameters) were collected at each stage of the model. Arterial pressure and oxygen transport parameters corrected to baseline values; however, the PSP/ESV and Doppler-derived acceleration failed to correct with fluid resuscitation alone. Treatment with nitroprusside and dobutamine increased oxygen transport parameters, PSP/ESV ratio, and Doppler-derived acceleration significantly. Doppler-derived acceleration tracks left ventricular dysfunction seen in hemorrhagic shock.
Subject(s)
Monitoring, Ambulatory , Shock, Hemorrhagic/complications , Ultrasonography, Doppler , Ventricular Dysfunction, Left/diagnostic imaging , Animals , Cardiac Output/drug effects , Cardiac Volume/drug effects , Cardiotonic Agents/therapeutic use , Cross-Over Studies , Diastole , Disease Models, Animal , Dobutamine/therapeutic use , Fluid Therapy , Monitoring, Ambulatory/instrumentation , Nitroprusside/therapeutic use , Oxygen/blood , Oxygen Consumption/drug effects , Prospective Studies , Resuscitation , Shock, Hemorrhagic/drug therapy , Shock, Hemorrhagic/therapy , Swine , Systole , Ultrasonography, Doppler/instrumentation , Vascular Resistance/drug effects , Vasodilator Agents/therapeutic use , Ventricular Dysfunction, Left/etiology , Ventricular Pressure/drug effectsABSTRACT
OBJECTIVE AND DESIGN: We evaluated the utility of rectal mucosal pH measurement for tracking cardiac performance in hemorrhagic shock as compared with gastric tonometry. MATERIALS AND METHODS: Hemorrhagic shock was induced in five adult swine to a mean arterial pressure of 45-65 mm Hg. Hypotension was maintained for 30 minutes, resuscitation was accomplished with the shed blood and lactated Ringer's solution (3x blood volume). Gastric tonometry, rectal pH, and oxygen transport data were obtained at baseline, 0, and 30 minutes after onset of hypotension and after resuscitation. RESULTS: Intramucosal pH readings from gastric tonometry and rectal mucosal pH both showed a significant change from baseline to 0 and 30 minutes after onset of hypotension. Data after resuscitation were found to be statistically the same as baseline values. CONCLUSIONS: Rectal mucosal pH tracks cardiac performance as well as does gastric tonometry in hemorrhagic shock without as many limitations.
Subject(s)
Rectum/chemistry , Shock, Hemorrhagic/physiopathology , Animals , Cardiac Output , Disease Models, Animal , Gastric Acidity Determination , Gastric Mucosa/chemistry , Hydrogen-Ion Concentration , Intestinal Mucosa/chemistry , Monitoring, Physiologic/methods , Oxygen Consumption , Resuscitation , Shock, Hemorrhagic/diagnosis , Splanchnic Circulation , SwineABSTRACT
Load-independent left ventricular (LV) function has been recently shown to be reversibly depressed in septic shock. The peak systolic pressure to end systolic volume ratio (PSP/ESV) is a load independent measure of LV function. We evaluated PSP/ESV in a porcine model of hemorrhagic shock. Hemorrhagic shock was induced in five adult swine by arterial bleeding to a mean arterial pressure of 45-65 mmHg. This hypotension was maintained for 30 min, and then each animal was resuscitated to baseline mean arterial pressure using shed blood and crystalloid solution. Data (echocardiographically derived ejection fraction and oxygen transport parameters) were collected at baseline, after 30 min of hypotension and postresuscitation. Although the cardiac index, a marker for systolic function, and the mean arterial pressure, as well as oxygen delivery and consumption returned to baseline levels, the PSP/ESV ratio remained low despite adequate fluid resuscitation. This model provides a reproducible hemodynamically stable cardiac dysfunction associated with hemorrhagic shock.
