Hyperventilation and Respiratory Alkalosis After Olanzapine for Insomnia: A Case Report.

Olanzapine is increasingly used as a sleep aid in hospitalized patients. Although thought to have less extrapyramidal effects, known side effects include oversedation, arrythmias, and hypotension. We present the unusual case of hyperventilation with respiratory alkalosis after the administration of olanzapine for insomnia in an elderly postoperative patient. This led to a second admission to the intensive care unit with invasive interventions including mechanical ventilation and vasopressor support. Caution must be exercised in prescribing antipsychotics for off-label use, especially in a population whose baseline characteristics can affect the pharmacokinetics of second-generation antipsychotics.

Transesophageal echocardiographic evaluation of diastolic function.

Diastolic dysfunction is increasingly recognized as a cause of hemodynamic instability in the perioperative setting. Difficulty weaning from cardiopulmonary bypass and an increased need for inotropic support can occur in the absence of systolic impairment. Diastolic dysfunction can also impede hemodynamic stabilization and weaning progress in the mechanically ventilated critically ill patient. The use of transesophageal echocardiography in the ICU can assist in diagnosing the presence and progression of diastolic impairment, which may help to target therapeutic interventions that lead to positive outcomes. This review summarizes the conventional and new echocardiographic modalities for evaluating diastolic function in the perioperative setting.

Excessive argatroban anticoagulation for heparin-induced thrombocytopenia.

OBJECTIVE: To report 4 patients who became excessively anticoagulated with the recommended or lower starting doses of argatroban during treatment for heparin-induced thrombocytopenia type II (HIT-II) in a cardiothoracic intensive care unit. CASE SUMMARY: Four patients were treated with argatroban after confirmation of HIT-II after cardiac surgery. In 3 patients, argatroban was initiated at the recommended starting dose of 2 micro g/kg/min; in 1 patient, therapy was initiated at 1 micro g/kg/min. All patients had relatively normal hepatic function. In all cases, the resulting activated partial thromboplastin time was supertherapeutic and exceeded 100 seconds in 3 patients. Additionally, argatroban clearance appeared to be prolonged upon discontinuation. DISCUSSION: Argatroban pharmacokinetics in critically ill patients have not been investigated. Our case series demonstrates the potential over-anticoagulation that can occur in this patient population despite relatively normal hepatic function. An objective causality assessment revealed that the adverse drug event in these patients was probably caused by administration of argatroban. CONCLUSIONS: Formal pharmacokinetic studies of argatroban are needed in critically ill patients in order to optimize therapy.