Use of sodium nitroprusside in post-coronary bypass surgery. A plea for conservatism.

In 292 patients who underwent coronary artery bypass graft (CABG) surgery, seven patients developed sodium nitroprusside (SNP) toxicity in the postoperative period. Duration of infusion varied between 26 to 160 hrs and total SNP dose ranged from 1.8 to 12 mg/kg body weight. All patients were critically ill and required ventilatory support in the postoperative period. Tachyphylaxis to SNP requiring increase of SNP dose for control of hypertension, and loss of consciousness were the major signs of toxicity. Other commonly described signs of SNP toxicity were absent in those patients. Discontinuation of SNP therapy and treatment with sodium thiosulfate was followed by improvement in four patients. Three patients who failed to regain consciousness later died because of hemodynamic, pulmonary and/or renal complications. Our observation suggests that recommended doses of SNP may be toxic in unstable post-CABG patients. We recommend that the dose and duration of SNP infusion be minimized in critically ill patients.

Acute complications of pulmonary artery catheter insertion in critically ill patients.

Of 142 critically ill patients undergoing pulmonary artery catheter (PAC) insertion, 1.4% suffered pneumothorax and 7.7% experienced arterial puncture during central venous access. Catheterization was successful in all cases; however, 8.4% of patients required special maneuvers for pulmonary artery cannulation. The 52.3% incidence of cardiac arrhythmias during PAC insertion was primarily due to ventricular arrhythmia (VA), which was more common among patients with complicated myocardial infarction (p less than .01) and less common in patients with sepsis (p less than .05). The development of VA was significantly related to the duration of PAC insertion. Our study suggests that PAC placement carries certain risks and complications which should be weighed against the advantages of a PAC in each patient.

Value of fluoroscopic assistance during transpyloric intubation.

Blind insertion of a weighted nasoenteric tube (NET) has a low chance of immediate duodenal intubation and may cause serious complications. This study used fluoroscopic assistance to facilitate the passage of an NET to the duodenum. The success rate and complications were compared to those for NET insertion without fluoroscopy. Blind passage of a weighted feeding tube was associated with a 15% success rate in 13 patients; by contrast, fluoroscopic assistance allowed 95% of 20 patients to be intubated successfully in an average of 14 +/- 12 min. Although blind insertion caused intrabronchial intubation in two patients, there were no complications associated with fluoroscopy.