The effect of pH of resuscitative fluids in treatment of severe hemorrhagic shock.

Commercially available Ringer's lactate solution has a pH of approximately 6.5. In a situation such as shock, which is normally accompanied by a metabolic acidosis, this additional acid load could have an adverse effect on resuscitation when massive amounts of fluid are required. We prepared a similar solution with a pH of 7.4 and compared the two solutions. Fourteen dogs were shocked according to a Wiggers' hemorrhagic shock model. Six dogs (43%) died during shock, 8 dogs survived the model, 4 were resuscitated over a 150-minute observation period to a pulmonary capillary wedge pressure (PCWP) of 8-12 mmHg with Ringer's lactate with a pH of 7.4. The cardiac output, lactate levels, amount of fluid required to maintain the PCWP, and arterial and mixed venous pH were measured at 30, 60, 90, 120, and 150 minutes. No significant differences were found except for occasionally higher arterial pH values in the group treated with Ringer's lactate with a pH of 7.4. There was no difference between the groups in any measurement at the end of the observation period or in survival. All dogs died within 12 hours of the end of the shock period. Our data indicate that the somewhat acidic pH of standard Ringer's lactate does not adversely affect the adequacy of resuscitation. There is no advantage to using Ringer's lactate with a pH of 7.4.