Relationship between clinical evaluation of peripheral perfusion and global hemodynamics in adults after cardiac surgery.

The relationship between clinical indicators of peripheral perfusion and global hemodynamics after cardiac surgery was examined in 40 adults. We found no significant relationship between capillary refill, pedal pulses, or extremity (toe or finger) core temperature gradients and cardiac index (CI) or systemic vascular resistance index immediately after surgery on the day of operation. However, on the first postoperative day we did observe a crude (r = -.60) correlation between CI and toe-core temperature gradient.

Gentamicin solution for mediastinal irrigation: systemic absorption, bactericidal activity, and toxicity.

Local irrigation with gentamicin sulfate represents a possible substitute for neomycin sulfate, used for many years but now no longer available for use as an irrigation fluid. In this investigation, mediastinal irrigation with gentamicin was used in 12 patients who had experienced problems after a heart operation. The regimen employed for mediastinal irrigation with gentamicin was equipotent with that using neomycin. We sought to determine the degree of absorption and risk of either inadequate or toxic blood levels that might follow gentamicin absorption. Irrigation periods were short, ranging from one to four days and determined by measurements of plasma gentamicin concentration using radioimmunoassay evaluation. Systemic gentamicin absorption occurred in all patients. Toxic levels of higher than 8.0 micrograms/mL occurred and were size related, ie, correlated with smaller body weight and surface area, and sex related, ie, female sex. Larger-sized patients often had inadequate levels. Despite the potential risk from toxic blood levels, major increases in serum creatinine levels were not seen. These findings suggest that monitoring of plasma gentamicin levels during mediastinal irrigation with gentamicin is mandatory to avoid both inadequate treatment and toxicity.

Nalbuphine antagonism of fentanyl-induced ventilatory depression: a randomized trial.

The authors anesthetized 18 patients with good pulmonary and ventricular function for coronary artery bypass grafting with high doses of fentanyl. When the patients were arousable and their vital signs stable in the intensive care unit, the authors administered nalbuphine or placebo (randomly and double-blinded) until extubation criteria were met, and subsequently gave nalbuphine for analgesia. In one of ten placebo patients, tracheal extubation was accomplished without nalbuphine. This patient then retained CO2 and required nalbuphine; the other nine placebo patients could not be extubated after placebo trials and were given nalbuphine. In all other patients in both groups, tracheal extubation was successful following nalbuphine (median dose 60 micrograms/kg, range 30-180 micrograms/kg). One patient became renarcotized 4 h after tracheal extubation without an increase in plasma fentanyl concentration; he received an additional dose of nalbuphine and recovered without further incident. Nine patients required treatment with vasoactive agents or beta-blockers for hypertension or tachycardia associated with the administration of nalbuphine. Eight of 18 patients were not satisfied with nalbuphine analgesia, and required morphine for relief of their pain. Recurrent elevations of fentanyl concentrations in plasma were observed and appeared to be related to increasing motor activity. Nalbuphine is an effective opioid antagonist after fentanyl anesthesia, but its use is associated with side effects, and analgesia for the post-sternotomy patient may be unsatisfactory unless the dose is carefully titrated to the minimum required to antagonize respiratory depression.

Contamination reduction during central venous catheterization.

This study examined a simple technique for reducing contamination during catheterization of the internal jugular vein. Sixty patients were assigned randomly to receive either a traditional iodophor skin cleansing or an alcohol cleansing, followed by application of an iodophor-impregnated sterile film. In the cleansed with iodophor alone group, 83% of the anesthesiologists' glove tips were contaminated, and 13% of the catheter tips were contaminated. In contrast, in the group in which the sterile film was employed, contamination of gloves and catheters was virtually eliminated.

Effect of positive end-expiratory pressure on excessive mediastinal bleeding after cardiac operations. A controlled study.

The efficacy of mechanical ventilation with positive end-expiratory pressure (PEEP) in the therapy of excessive mediastinal hemorrhage following cardiac operations remains unproved. One hundred thirty-nine patients undergoing elective myocardial revascularization were divided into two groups on the basis of preoperative hematologic evaluation: Group I, 94 patients with no history of hematologic abnormalities and a normal coagulation profile; Group II, 45 patients with a recent use of antiplatelet medications and/or a prolonged template bleeding time. Both groups were randomized to receive mechanical ventilation with 10 cm H2O of PEEP or no PEEP beginning 1 hour after operation and continuing for an 8 hour study period. Mean blood loss at 8 hours (BVt) was not significantly different between PEEP and control patients in either group. Fifty-seven patients in Groups I and II had mediastinal bleeding in excess of 180 ml/hr at the initiation of the study period. There was no significant difference in mean BVt or mean hourly chest tube output with or without PEEP in either group of this subset. In view of the lack of demonstrable efficacy in decreasing mediastinal hemorrhage and the potential of adverse hemodynamic effects, PEEP should no longer be used for therapy of excessive bleeding after cardiac operation, especially in patients with reduced cardiac reserve.