Catheter-induced pulmonary artery perforation. Mechanisms, management, and modifications.

Six cases of pulmonary artery perforation associated with the use of Swan-Ganz catheters are reviewed. Risk factors included pulmonary hypertension, anticoagulation, and hypothermia. The mechanisms leading to perforation were clarified by the use of postmortem studies employing isolated whole lung preparations. These studies revealed that perforation results from (1) tip perforation of vasculature, (2) eccentric balloon configuration propelling the balloon through the vessel wall, and (3) balloon inflation disrupting the pulmonary artery (mean intraballoon pressure 250 mm Hg). Early clinical symptoms include hemoptysis of bright red blood and/or hypotension. Immediate evaluation may necessitate examination with a fiberoptic bronchoscope and "wedge" angiogram. If massive hemoptysis occurs, isolation of the unaffected lung by endobronchial intubation is mandatory. Pneumonectomy or lobectomy may be required. Revised guidelines for catheter insertion and pulmonary capillary wedge pressure (PCWP) measurements are presented. Finally, consideration is given to redesigning the pulmonary artery flow-guided catheter, particularly for use in patients undergoing cardiac operations with systemic anticoagulation. Modifications should be directed at (1) softer catheter tip with temperature-insensitive body, (2) low-pressure balloon, and (3) balloon pressure relief valve.

Is cocaine a sympathetic stimulant during general anesthesia?

Eighteen patients undergoing coronary artery surgery were observed to examine whether cocaine in a clinically used dose exerts sympathomimetic effects during general anesthesia. Eleven patients received cocaine hydrochloride as a 10% solution (1.5 mg/kg) applied topically to the nasal mucosa before nasotracheal intubation. Seven patients had a similar procedure without cocaine. Blood pressure, pulse rate, cardiac index, left ventricular stroke work index, total peripheral vascular resistance, and pulmonary vascular resistance were measured. There were no important differences in cardiovascular function between patient groups. The rapid rise in plasma cocaine concentration, reaching 331 ng/mL at 30 minutes and 320 ng/mL at 45 minutes, bore no apparent relationship to any changes in cardiovascular function. We conclude that under conditions of this study, administration of topical cocaine does not exert any clinically significant sympathomimetic effect and appears to be well tolerated in anesthetized patients with coronary artery disease.

The hemodynamic tracking system: a method of data management and guide for cardiovascular therapy.

In the operating room or intensive care unit, multiple measurements of circulatory function are almost mandatory in patients with significant cardiovascular disease. Use in these areas requires that the information must be easily organized, rapidly obtained, and inexpensive. A hemodynamic tracking system that meets these criteria is described. This system incorporates a hand-held programmable calculator (cost = $210 to $300) to derive variables computed from standard cardiovascular measurements. The time required to obtain a set of measurements (including thermodilution cardiac output determinations in duplicate), key the numbers into the calculator, and obtain the derived indices is 4 minutes. Two patients, who had acute mitral insufficiency and whose clinical management differed substantially are presented to illustrate the use of data obtained from the hemodynamic tracking system.

Improvement of myocardial and other vital organ functions and metabolism with a simple method of pulsatile flow (IABP) during clinical cardiopulmonary bypass.

A simple, safe, and effective method of producing pulsatile flow during cardiopulmonary bypass (CPB) with intra-aortic balloon pumping (IABP) was used in 56 patients. No complications were associated with IABP. Myocardial metabolic studies, including coronary sinus lactates, mycoardial venous-arterial lactate differences, myocardial lactate extraction, and "excess lactate" were determined serially during the first hour of CPB. Changes in myocardial metabolism were statistically less abnormal in pulsatile flow (PF) patients when contrasted with a comparable group of nonpulsatile flow (NPF) patients. The changes were probably myocardial in origin since alterations in arterial lactates and lactate/pyruvate ratios were similar in both groups. In a comparable group of coronary bypass NPF patients, the percentage of left ventricular ejection fractions fell during the immediate postoperative period, whereas it rose in the PF group. Over-all body tissue injury (lactic dehydrogenase) and probably hepatocellular injury (serum glutamic oxalacetic transaminase) were less apparent in the PF patients. Postoperative low-cardiac-output syndrome did not occur in the PF patients and supportive drugs and diuretics were not needed. PF does not produce excessive hemolysis. This procedure may improve mortality rates by improving myocardial and other vital organ perfusion and by sustaining their function during weaning from CPB. This technique may prove superior to other forms of PF and is indicated in patients with severe left ventricular or other vital organ dysfunction and/or prolonged CPB.