Coma with absent brainstem reflexes resulting from zolpidem overdose.

Zolpidem is a nonbenzodiazepine hypnotic with a favorable adverse effect profile. There are single reports of respiratory decompensation associated with zolpidem overdose. We report a case ofa young woman with depression who developed deep coma with respiratory failure and a loss of brainstem reflexes as a result of zolpidem overdose. Supportive management led to a complete recovery of neurologic function. Acute zolpidem overdose should be considered in the differential diagnosis of coma with absent brainstem reflexes.

Head CT is of limited diagnostic value in critically ill patients who remain unresponsive after discontinuation of sedation.

BACKGROUND: Prolonged sedation is common in mechanically ventilated patients and is associated with increased morbidity and mortality. We sought to determine the diagnostic value of head computed tomography (CT) in mechanically ventilated patients who remain unresponsive after discontinuation of sedation. METHODS: A retrospective review of adult (age >18 years of age) patients consecutively admitted to the medical intensive care unit of a tertiary care medical center. Patients requiring mechanical ventilation for management of respiratory failure for longer than 72 hours were included in the study group. A group that did not have difficulty with awakening was included as a control. RESULTS: The median time after sedation was discontinued until a head CT was performed was 2 days (interquartile range 1.375-2 days). Majority (80%) of patients underwent head CT evaluation within the first 48 hours after discontinuation of sedation. Head CT was non-diagnostic in all but one patient who had a small subarachnoid hemorrhage. Twenty-five patients (60%) had a normal head CT. Head CT findings did not alter the management of any of the patients. The control group was similar to the experimental group with respect to demographics, etiology of respiratory failure and type of sedation used. However, while 37% of subjects in the control group had daily interruption of sedation, only 19% in the patient group had daily interruption of sedation (p < 0.05). CONCLUSION: In patients on mechanical ventilation for at least 72 hours and who remain unresponsive after sedative discontinuation and with a non-focal neurologic examination, head CT is performed early and is of very limited diagnostic utility. Routine use of daily interruption of sedation is used in a minority of patients outside of a clinical trial setting though it may decrease the frequency of unresponsiveness from prolonged sedation and the need for head CT in patients mechanically ventilated for a prolonged period.

Severe reversible left ventricular dysfunction associated with multiple cardiac myxomata.

A 22-year-old Caucasian woman presented with acrocyanosis of fingers and toes and dyspnea on exertion. Initial echocardiography showed multiple right and left atrial myxomata, mild enlargement of the left ventricle and severely depressed left ventricular systolic function. Resection of the tumors and replacement of the myxomatous mitral valve led to a complete resolution of echocardiographic evidence of left ventricular dysfunction, and was accompanied by disappearance of skin findings and symptoms of asthma.

Cardiologists use pulmonary artery catheter information to make homogenous treatment decisions.

Medical intensivists make heterogenous decisions using pulmonary artery catheter (PAC) data in medical intensive care unit patients. The object was to determine if cardiologists given PAC data from critically ill cardiology patients make uniform management choices. A survey questionnaire containing 3 coronary care unit (CCU) clinical vignettes was designed and mailed to board-certified cardiologists who are members of the American College of Cardiology. Twenty board-certified medical intensivists were also asked to complete the vignettes. Each vignette contained PAC data and one-half of the surveys contained echocardiographic (ECHO) information. Every respondent was asked to select 1 of 6 interventions for each vignette. In 2 of 3 vignettes 1 intervention was selected by more than 70% of cardiologists. In the third vignette, 1 intervention was selected by more than 50% of cardiologists. For each vignette, 1 intervention was selected by at least 75% of medical intensivists. There was no significant difference in the distribution of management choices between the ECHO and the non-ECHO subgroups. There is relative homogeneity in selecting an intervention based on PAC data among cardiologists and medical intensivists in CCU patients and is probably due to patient-related factors. The presence of ECHO information did not change the intervention selected. Cardiology patients may represent an ideal group in which to evaluate PAC efficacy.

Cholestyramine improves tropical-related diarrhea.

Patients exposed to the toxic dinoflagellate Pfiesteria develop an illness characterized by secretory diarrhea, conjunctival irritation, skin lesions, and varying degrees of neurologic manifestations. The anion-exchange resin, cholestyramine has been reported in one small case series to be an effective treatment of severe diarrhea associated with Pfiesteria intoxication. A 54-year-old man traveled to the Dominican Republic where he went swimming in what he describes as "dirty ocean water". Within an hour, he noted a generalized burning and itching of his skin. Later on, he noted pruritic vesicular skin lesions, intense frontal headache, and conjunctivitis. A few days later, he complained of abdominal cramping, nausea, and hourly episodes of watery, non-bloody diarrhea. Due to the constellation of symptoms, Pfiesteria intoxication was suspected. On arrival in the United States, he sought medical care for continued symptoms. Physical examination was remarkable for conjunctival injection, linear vesicular lesions (5 cm in length) over his right ankle and left orbit as well as erythema over foreskin of his penis. Mental status and memory were normal. Laboratory studies revealed an elevated serum creatinine, which eventually normalized, and stool studies were negative for leukocytes, blood, and enteric pathogens. Intense diarrhea persisted until he was started on cholestyramine (4 g PO tid). The diarrhea resolved within 2 hours of starting treatment. The headache was initially treated with narcotic agents but only resolved with IV diphenhydramine (25 mg q 4 h). Cholestyramine and diphenhydramine appear to be effective therapeutic agents for tropical-related diarrhea and headache, respectively.

Interdependency of beta-adrenergic receptors and CFTR in regulation of alveolar active Na+ transport.

Beta-adrenergic receptors (betaAR) regulate active Na+ transport in the alveolar epithelium and accelerate clearance of excess airspace fluid. Accumulating data indicates that the cystic fibrosis transmembrane conductance regulator (CFTR) is important for upregulation of the active ion transport that is needed to maintain alveolar fluid homeostasis during pulmonary edema. We hypothesized that betaAR regulation of alveolar active transport may be mediated via a CFTR dependent pathway. To test this hypothesis we used a recombinant adenovirus that expresses a human CFTR cDNA (adCFTR) to increase CFTR function in the alveolar epithelium of normal rats and mice. Alveolar fluid clearance (AFC), an index of alveolar active Na+ transport, was 92% greater in CFTR overexpressing lungs than controls. Addition of the Cl- channel blockers NPPB, glibenclamide, or bumetanide and experiments using Cl- free alveolar instillate solutions indicate that the accelerated AFC in this model is due to increased Cl- channel function. Conversely, CFTR overexpression in mice with no beta1- or beta2-adrenergic receptors had no effect on AFC. Overexpression of a human beta2AR in the alveolar epithelium significantly increased AFC in normal mice but had no effect in mice with a non-functional human CFTR gene (Deltaphi508 mutation). These studies indicate that upregulation of alveolar CFTR function speeds clearance of excess fluid from the airspace and that CFTRs effect on active Na+ transport requires the betaAR. These studies reveal a previously undetected interdependency between CFTR and betaAR that is essential for upregulation of active Na+ transport and fluid clearance in the alveolus.