2009 Southern Regional Meeting Abstracts

Case Report: Severe lactic acidosis which has been reported to occur in patients struggling against restraints, especially in association with the use of stimulant drugs such as cocaine, can lead to cardiac arrhythmias and cardiac arrest. Removing the stimulus for lactic acid production (excessive muscle activity) by aggressive sedation and ventilatory assistance coupled with fluid administration to improve tissue perfusion can be life-saving.

A 24 year old male presented with agitated delirium and hypertensive urgency after cocaine abuse and required restraint in the prone position for self protection. Due to continued combativeness, the patient required sedation, muscular paralysis and mechanical ventilation. Vital signs before intubation were Bp 224/120 mmHg, HR 180 b/min. Physical examination was unremarkable.
Laboratory studies revealed Serum creatinine 1.9 mg/dl and BUN 9 mg/dl. HCO₃^- 7 mEq/l. Serum Na⁺, K⁺, Cl^-, Ca⁺² and PO4^-3 were normal. Plasma anion gap 29 mEq/l, plasma lactate 20 mmol/l, blood glucose 327 mg/dl, albumin 4.1 gm/dl, CPK 231 U/l, blood alcohol level 104 mg/dl, and serum osmolality 315 mosm/kg H₂0, and the corrected plasma osmolal gap 5 mosm/kg H₂0. Serum and urinary ketones were negative. ABG showed a pH 7.10, PaCO₂ 44 mmHg, HCO₃^- 12 mEq/l, PaO₂ 327 mmHg (FIO₂:100%). Salicylate and acetaminophen levels were undetectable. Urine drug screen was positive for cocaine. EKG showed sinus tachycardia (175bpm). Abdominal CT examination was normal. Cardiac injury was ruled out with normal EKGs and negative troponins.
After 3-hours of sedation, mechanical ventilation and 4 L normal saline administration, repeat laboratory studies showed plasma lactate level of 2.0 mmol/l, Cr 1.1 mg/dl, HCO₃^- 23 mEq/l, anion gap 4 mEq/l and glucose 86 mg/dl. The patient was weaned from sedation and extubated with no complications.
Conclusion: Severe lactic acidosis is a recognized life threatening emergency occurring in patients with agitated delirium who are struggling against restraints, especially in association with stimulant drugs, such as cocaine. Early intervention including sedation, muscle paralysis, fluid administration, and mechanical ventilation can be life saving.