Causes of metabolic acidosis in canine hemorrhagic shock: role of unmeasured ions

Introduction: Metabolic acidosis during hemorrhagic shock is common and conventionally considered to be due to hyperlactatemia. There is increasing awareness, however, that other nonlactate, unmeasured anions contribute to this type of acidosis. Methods: Eleven anesthetized dogs were hemorrhaged to a mean arterial pressure of 45 mm Hg and were kept at this level until a metabolic oxygen debt of 120 mLO2/kg body weight had evolved. Blood pH, partial pressure of carbon dioxide, and concentrations of sodium, potassium, magnesium, calcium, chloride, lactate, albumin, and phosphate were measured at baseline, in shock, and during 3 hours post-therapy. Strong ion difference and the amount of weak plasma acid were calculated. To detect the presence of unmeasured anions, anion gap and strong ion gap were determined. Capillary electrophoresis was used to identify potential contributors to unmeasured anions. Results: During induction of shock, pH decreased significantly from 7.41 to 7.19. The transient increase in lactate concentration from 1.5 to 5.5 mEq/L during shock was not sufficient to explain the transient increases in anion gap (+11.0 mEq/L) and strong ion gap (+7.1 mEq/L), suggesting that substantial amounts of unmeasured anions must have been generated. Capillary electrophoresis revealed increases in serum concentration of acetate (2.2 mEq/L), citrate (2.2 mEq/L), alpha-ketoglutarate (35.3 microEq/L), fumarate (6.2 microEq/L), sulfate (0.1 mEq/L), and urate (55.9 microEq/L) after shock induction. Conclusion: Large amounts of unmeasured anions were generated after hemorrhage in this highly standardized model of hemorrhagic shock. Capillary electrophoresis suggested that the hitherto unmeasured anions citrate and acetate, but not sulfate, contributed significantly to the changes in strong ion gap associated with induction of shock

Shock 2017 military supplement an overview of two human trials of perfluorocarbon emulsions in non-cardiac surgery

Perfluorochemicals (PFCs) constitute one class of artificial oxygen carriers that are being produced completely synthetically. One formulation that has been evaluated extensively in clinical trials is a 60% w/v perflubron-based emulsion. Efficacy and safety of this perflubron emulsion was evaluated in a Phase 2 and a large prospective randomized Phase 3 multicenter European study, which collectively included a total of 639 patients. Perflubron emulsion was highly successful in improving organ function, reversing physiologic transfusion triggers and in reducing the need for allogeneic blood transfusions. There were no major safety issues

Evaluation of MP4OX for prevention of perioperative hypotension in patients undergoing primary hip arthroplasty with spinal anesthesia: a randomized, double-blind, multicenter study.

MP4OX (oxygenated polyethylene glycol-modified hemoglobin) is an oxygen therapeutic agent with potential applications in clinical settings where targeted delivery of oxygen to ischemic tissues is required. The primary goal of this study was to investigate MP4OX for preventing hypotensive episodes. An additional goal was to establish the safety profile of MP4OX in a large surgical population

Analysis of anions in canine serum using a polyvinyl alcohol (PVA) capillary

<p><b>Copyright information:</b></p><p>Taken from "Causes of metabolic acidosis in canine hemorrhagic shock: role of unmeasured ions"</p><p>http://ccforum.com/content/11/6/R130</p><p>Critical Care 2007;11(6):R130-R130.</p><p>Published online 14 Dec 2007</p><p>PMCID:PMC2246228.</p><p></p> The retention times for some other organic anions not detected in canine blood serum are indicated. The peak at 6.283 minutes remains unidentified. The detection limits were as follows: acetate 1.0 mmol/L, α-ketoglutarate 10.0 μmol/L, citrate 0.1 mmol/L, fumarate 1.0 μmol/L, β-hydroxybutyrate 0.7 mmol/L, and urate 0.1 μmol/L. The conditions were as follows: PVA capillary (60 cm × 50 μm internal diameter); phosphate buffer, pH 7.0; running voltage, 20 kV; 25°C; detection: UV light absorption at 214 nm; sample: canine serum diluted with distilled water (1:100)