Coronary artery bypass grafting after a bilateral lung volume reduction operation.

A 67-year-old man underwent coronary artery bypass grafting 31/2 months after a bilateral lung volume reduction operation for end-stage pulmonary emphysema. The principles of anesthetic management we have developed for use during volume reduction operations were applied with success in this individual and are described in detail. With the increasing application of this intervention as an alternative to lung transplantation, we anticipate further experience in the operative management of associated conditions after lung volume reduction operations.

Inhaled nitric oxide at the time of harvest improves early lung allograft function.

BACKGROUND: Inhalation of nitric oxide (NO) has been shown to have beneficial effects on a variety of acute lung injuries, including lung allograft reperfusion injury. The purpose of the present study was to investigate the effects of inhaled NO at the time of harvest on function of canine left lung allografts after transplantation. METHODS: Ten dogs underwent left lung allotransplantation. Donor lungs were flushed with modified Euro-Collins solution and stored for 21 hours at 1 degree C. Immediately after transplantation, the contralateral main pulmonary artery and bronchus were ligated to assess isolated allograft function. Hemodynamics and arterial blood gases (inspired oxygen fraction, 1.0) were assessed intermittently for 6 hours prior to sacrifice. Allograft myeloperoxidase activity and wet to dry weight ratio were assessed. Donor animals were divided into two groups. Group I animals (n = 5) received no NO. In group II (n = 5), donors received inhaled NO (60 ppm) at the time of harvest. RESULTS: Pulmonary vascular resistance decreased to 79.6% of baseline because of inhalation of 60 ppm NO in group II donor animals. Thiobarbituric acid-reactive materials were reduced during the storage period in group II, a finding suggesting less oxidant injury during storage in donor lungs treated with NO. Throughout the 6-hour assessment, oxygenation in group II was superior to that in group I (p < 0.05). At 360 minutes of assessment, mean arterial oxygen tension in groups I and II was 88.9 +/- 11.4 mm Hg and 169.1 +/- 33.0 mm Hg, respectively. Myeloperoxidase activity was significantly decreased in group II (p < 0.05), data indicating reduced neutrophil sequestration. Wet to dry weight ratio was significantly lower in group II. CONCLUSIONS: These data suggest that inhaled NO at the time of harvest improves early function of preserved lung allografts by attenuating oxidant injury during storage and subsequent neutrophil sequestration.

Inhaled nitric oxide improves lung allograft function after prolonged storage.

Morbidity caused by early allograft dysfunction, manifested by a progressive increase in pulmonary vascular resistance and a decrease in oxygenation, remains a serious problem in lung transplantation. Inhalation of nitric oxide, an essential homeostatic molecule, has been shown to have beneficial effects on a variety of acute lung injuries. The purpose of the present study was to investigate the effect of inhaled nitric oxide on posttransplant function of canine left lung allografts. Fourteen dogs underwent left lung allotransplantation. Donors received systemic heparin and prostaglandin E1 followed by pulmonary artery flush with modified Euro-Collins solution. Donor left lungs were stored for 18 hours at 1 degree C and subsequently implanted. Immediately after reperfusion, the contralateral right main pulmonary artery and bronchus were ligated. The chest was closed and recipients turned to the supine position for the 6-hour assessment period. Hemodynamic and arterial and venous blood gas analyses were made at 15-minute intervals at an inspired oxygen fraction of 1.0 and 5 cm of water positive end-expiratory pressure. Animals were killed at the end of the assessment. Allograft myeloperoxidase activity assays and wet/dry weight ratios were done. In group I (n = 5), nitric oxide gas was administered continuously at concentrations of 60 to 70 ppm before reperfusion and throughout the 6-hour assessment period. In group II (n = 5), nitric oxide administration was initiated at the same concentration after reperfusion injury had developed. Group III animals (n = 4) received no nitric oxide. Significant improvement in gas exchange was apparent in group I. At the end of the 6-hour assessment period, mean arterial oxygen tension was 253.8 +/- 44.7 mm Hg and 114.9 +/- 25.5 mm Hg in groups I and III, respectively (p < 0.05). Group II animals had no improvement in oxygenation with nitric oxide. Systemic hemodynamics were unaffected by nitric oxide. However, an immediate decrease in pulmonary vascular resistance was noted. Group I myeloperoxidase activity was significantly lower than that in control group III (0.24 +/- 0.06 versus 0.36 +/- 0.04 units, respectively; p < 0.05).

Inhaled nitric oxide reduces human lung allograft dysfunction.

OBJECTIVE: Early severe graft dysfunction, as manifested by hypoxia and pulmonary hypertension, occurs in 10% to 20% of lung transplant recipients. We retrospectively investigated whether inhaled nitric oxide would reduce human lung allograft dysfunction by comparing postoperative hemodynamic data, gas exchange, and outcome in lung transplant recipients with early graft dysfunction treated with or without nitric oxide. METHOD: Among 243 adult lung transplant procedures, there were 32 patients (13.2%) in whom immediate severe allograft dysfunction developed (arterial oxygen tension/inspired oxygen concentration ratio <150). Group 1 (n = 17) included patients who underwent transplantation before nitric oxide became available in our center and were treated conventionally. Group 2 (n = 15) included those treated with nitric oxide as soon as severe allograft dysfunction was diagnosed. Duration of nitric oxide therapy (20 to 60 ppm) was 15 to 217 hours (average 84 hours). RESULTS: In group 2, nitric oxide lowered mean pulmonary artery pressure from 30 +/- 2 to 26 +/- 2 mm Hg (p < 0.05), improved the ratio of arterial oxygen tension to inspired oxygen fraction from 88 +/- 10 to 153 +/- 30 (p < 0.05) within 1 hour, and caused a sustained improvement in these parameters during extended therapy. Mean arterial pressure and cardiac index were unchanged during nitric oxide therapy. Transient methemoglobinemia (>6%) developed in two patients. However, no complications were associated with nitric oxide use. Duration of mechanical ventilation was 17 +/- 5 days in group 1 and 12 +/- 3 days in group 2. Four patients had airway complications in group 1, whereas no airway complication was encountered in group 2. Mortality was 24% (4/17) in group 1 and 7% (1/15) in group 2. CONCLUSION: Nitric oxide improves oxygenation and decreases pulmonary artery pressure without systemic circulatory effects in patients with severe allograft dysfunction. Furthermore, in these patients, nitric oxide may shorten postoperative mechanical ventilation time and reduce airway complications and mortality.

Anesthetic management for bilateral volume reduction surgery.

Bilateral volume reduction surgery has been designed to reduce total thoracic volume and improve chest wall mechanics in patients with severe emphysema who, up to now, had very limited viable surgical options. This procedure has been performed in more than 120 such patients at our institution. We present the anesthetic considerations and our experience from their management.

Single lung transplantation for pulmonary hypertension. Single institution experience in 34 patients.

BACKGROUND: The present study considered the uniformity and durability of the cardiopulmonary response to single lung transplantation in patients with severe pulmonary hypertension, as well as its effect on length and quality of survival. METHODS AND RESULTS: Thirty-four patients with pulmonary hypertension underwent evaluation, single lung transplantation, and follow-up assessment between November 1, 1989, and June 1, 1994. Operative survival for the entire group of patients was reasonable, with 91% (31 of 34 patients) surviving and being discharged from the hospital following transplantation. The actuarial survival for these 34 patients at 1-, 2-, and 3-year follow-up was 78%, 66%, and 61%, respectively. In the subgroup of 24 patients with primary pulmonary hypertension (PPH), 96% (23 of 24) were successfully discharged from the hospital after transplantation. The actuarial survival for this isolated PPH subgroup at 1-, 2-, and 3-year follow-up was 87%, 76%, and 68%, respectively. The uniform, early posttransplant normalization of pulmonary vascular resistance and right ventricular ejection fraction appears to persist throughout the 4-year follow-up period. Despite a high prevalence of bronchiolitis obliterans, the majority of survivors remain in New York Heart Association functional class I or II and are employed. CONCLUSIONS: Single lung transplantation can be performed in patients with end-stage pulmonary vascular disease with reasonable expectations for a relatively low operative mortality; immediate, complete, and durable amelioration of pulmonary hypertension and right ventricular failure; and optimal use of limited donor organ supply.

Pressure gradient across the pulmonary artery anastomosis during lung transplantation.

BACKGROUND: Perioperative monitoring of pulmonary artery (PA) pressures in lung transplant recipients is critical. This report characterizes an intraoperative gradient across the PA anastomosis in a series of patients undergoing bilateral sequential lung transplantation. METHODS: Hemodynamic measurements were obtained in a series of 10 patients before anesthetic induction, during one-lung ventilation/perfusion of the newly transplanted first lung with the PA catheter proximal and distal to the anastomosis and after arrival in the intensive care unit. The following measurements were recorded: central venous pressure, cardiac output, PA occlusion pressure, and systemic and pulmonary arterial pressures (systolic, diastolic, mean). RESULTS: Although a systolic pressure gradient of more than 10 mm Hg across the anastomosis was observed in all patients, there was a significant variation in systolic (13 to 59 mm Hg), diastolic (2 to 10 mm Hg), and mean (5 to 27 mm Hg) PA gradients. Mean proximal systolic PA pressure measurements (56.2 +/- 20.6 mm Hg) were greater when compared to measurements obtained distal to the anastomosis (28.6 +/- 10.1 mm Hg, p = 0.001) and to those obtained in the postoperative period (32.1 +/- 9.7 mm Hg, p = 0.004). CONCLUSIONS: The present study demonstrates that during single-lung ventilation and perfusion, the PA pressure measured proximally may not reflect accurately the pressure distal to the vascular anastomosis.

Bilateral pneumectomy (volume reduction) for chronic obstructive pulmonary disease.

We undertook surgical bilateral lung volume reduction in 20 patients with severe chronic obstructive pulmonary disease to relieve thoracic distention and improve respiratory mechanics. The operation, done through median sternotomy, involves excision of 20% to 30% of the volume of each lung. The most affected portions are excised with the use of a linear stapling device fitted with strips of bovine pericardium attached to both the anvil and the cartridge to buttress the staple lines and eliminate air leakage through the staple holes. Preoperative and postoperative assessment of results has included grading of dyspnea and quality of life, exercise performance, and objective measurements of lung function by spirometry and plethysmography. There has been no early or late mortality and no requirement for immediate postoperative ventilatory assistance. Follow-up ranges from 1 to 15 months (mean 6.4 months). The mean forced expiratory volume in 1 second has improved by 82% and the reduction in total lung capacity, residual volume, and trapped gas has been highly significant. These changes have been associated with marked relief of dyspnea and improvement in exercise tolerance and quality of life. Although the follow-up period is short, these preliminary results suggest that bilateral surgical volume reduction may be of significant value for selected patients with severe chronic obstructive pulmonary disease.

Effect of aprotinin on activated clotting time, whole blood and plasma heparin measurements.

Twenty cardiac surgical patients requiring cardiopulmonary bypass were enrolled in this study designed to evaluate the effect of aprotinin on activated clotting time (kaolin and celite), whole blood, and laboratory-based plasma (anti-Xa) heparin measurements. Whole blood heparin measurements were not different (p = 0.98) between aprotinin-treated (3.2 +/- 2.8 U/mL) and control (3.2 +/- 3.0 U/mL) specimens. Plasma anti-Xa heparin measurements were also not different (p = 0.95) between aprotinin-treated (2.7 +/- 2.5 U/mL) and control (2.8 +/- 2.5 U/mL) specimens. The relationship between whole blood (plasma equivalent) and plasma heparin measurements was similar (p = 0.1) in the presence (slope, 1.04; r2 = 0.89) or absence (slope, 1.11; r2 = 0.89) of aprotinin. In contrast to weak correlations between celite (r = 0.50) or kaolin (r = 0.53) activated clotting time values, whole blood heparin measurements correlated well (r = 0.93) with plasma heparin measurements during cardiopulmonary bypass in the presence of aprotinin. These findings indicate that whole blood heparin measurements are unaffected by aprotinin and correlate well with plasma anti-Xa heparin measurements even in the presence of aprotinin. Therefore, the automated protamine titration assay can be used to monitor accurately heparin concentrations in patients receiving aprotinin.

Predictors, frequency, and indications for cardiopulmonary bypass during lung transplantation in adults.

The records for 162 lung transplantations performed in 158 patients were reviewed with regard to the predictors for, frequency of, and indications for using cardiopulmonary bypass during the procedure. There were a total of 8 en bloc double-lung transplantations, 83 single-lung transplantations, and 71 bilateral single-lung transplantations. Bypass was used electively for all double en bloc and three of the bilateral sequential lung transplantation procedures and for 26 unilateral lung replacement procedures in patients with pulmonary hypertension. Of the remaining patients, 1 single-lung transplant recipient required bypass for correction of a surgical mishap and 18 bilateral single-lung recipients required bypass during replacement of the second lung. No preoperative predictors for the need of bypass could be identified. Among the bilateral sequential lung recipients, the use of bypass did not seem to adversely affect outcome, as expressed in terms of the time until extubation, the time spent in the intensive care unit, and the time required to reach a room air oxygen tension greater than 60 mm Hg.

Use of a Doppler pulmonary artery catheter for continuous measurement of right ventricular pump function and contractility during single lung transplantation.

Despite numerous technologic advances in intraoperative monitoring, the only methods routinely available for assessment of right ventricular function in lung transplant recipients are continuous measurement of right heart pressures and intermittent thermodilution determination of cardiac output and ejection fraction. Additional data may now be obtained with transesophageal echocardiography, although this technology is expensive and not widely available and requires diverting attention from a potentially unstable patient for data acquisition and analysis. Recently, a Doppler pulmonary artery catheter was introduced that measures beat-to-beat pulmonary artery blood flow-velocity, cross sectional area, and volume flow. Because of data indicating that acceleration of blood in the pulmonary artery (measured as the first derivative of either the velocity or flow waveform) is a sensitive indicator of right ventricular contractility, we have used waveforms obtained with the catheter for assessment of right ventricular pump function (stroke volume and peak pulmonary artery flow rate) and contractility in heart surgery patients. We report here our experience with this method in two patients undergoing left single lung transplantation.

Single lung transplantation for pulmonary hypertension. Technical aspects and immediate hemodynamic results.

Donor availability has limited the clinical applicability of heart-lung transplantation in patients with end-stage pulmonary hypertension. Satisfaction with single lung transplantation in other patient groups prompted its extension to patients with pulmonary hypertension. Nine patients with end-stage pulmonary hypertension underwent single lung transplantation. Important technical considerations included routine use of cardiopulmonary bypass, simultaneous closure of significant associated cardiac defects (n = 4), and use of remaining thoracic donor organs in multiple recipients (total thoracic transplants from eight donors = 21). Analysis of immediate postoperative hemodynamics suggests that early relief of pulmonary hypertension and improvement in right ventricular function can be expected. There was one postoperative death. Eight patients have been discharged and are alive and well at a mean follow-up period of 1 year. All eight survivors have returned to New York Heart Association functional class I from their preoperative levels of III or IV. These results support the use of single lung transplantation as a transplant option in patients with end-stage pulmonary hypertension. The question of long-term durability remains unanswered.

The evolution of single lung transplantation for emphysema. The Washington University Lung Transplant Group.

Classic transplantation dogma mandated bilateral lung replacement for lung transplant candidates with end-stage emphysema to avoid air trapping in the native lung and subsequent crowding of the newly transplanted lung. During a recent 12-month period 11 patients with emphysema received a single lung transplant. There was no hospital mortality and only one patient had any notable degree of air trapping in the native lung. Substantial improvement in pulmonary function was seen as early as 2 weeks after transplantation, with significant functional improvement seen by 6 weeks, despite some residual ventilation-perfusion mismatch. We have demonstrated the utility and safety of single lung transplantation for patients with end-stage emphysema, and it is our operation of choice in recipients more than 50 years of age.

Improved technique for bilateral lung transplantation: rationale and initial clinical experience.

We previously described a technique for en bloc double-lung transplantation that was initially applied to select patients with cystic fibrosis and emphysema. This procedure is quite complex and associated with several limitations, including a substantial incidence of airway ischemia, postoperative myocardial depression, and cardiac denervation. To address these problems we have developed a simpler procedure for replacing both lungs. The operation is done through a transverse thoracosternotomy and involves sequential replacement of the two lungs. Positive features include separate bronchial anastomoses to reduce ischemic airway complications, elimination of the need for total cardiopulmonary bypass and a period of ischemic cardiac arrest, improved exposure to reduce intraoperative and postoperative hemorrhage, and maintenance of cardiac innervation. Additionally, the technique can be more easily mastered and widely applied. Details of the procedure and its initial clinical application in 3 patients having emphysema, cystic fibrosis, and bronchiolitis obliterans following previous double-lung transplantation, respectively, are described. All 3 patients recovered without complication. Postoperative function was excellent in spite of lung ischemic times ranging up to 91/2 hours.

Comparison of neuromuscular blockade in upper facial and hypothenar muscles.

Facial and hand muscles are used frequently for monitoring neuromuscular blockade. Therefore, we compared changes in electrically evoked muscle potential magnitude in upper facial and hypothenar muscles after fixed doses of neuromuscular blockers (succinylcholine, 750 micrograms/kg; pancuronium, 70 micrograms/kg; vecuronium, 50 micrograms/kg; and atracurium, 300 micrograms/kg). Face-hand comparisons were made in both anesthetized (nitrous oxide/narcotic, n = 51) and comatose (closed-head injuries, n = 5) patients. In 24 anesthetized patients, complete blockade of the hypothenar muscles prevented quantitative comparison. In the remaining 27 patients, the relaxant effect (as determined by the percentage change from prerelaxant baseline muscle potentials) was significantly smaller (P less than 0.0001) in the upper facial muscles (65 +/- 24% versus 92 +/- 8%, mean +/- SD). All four evoked muscle responses to train-of-four stimulation were detectable in upper facial muscles of the 19 patients receiving non-depolarizing neuromuscular blocking drugs; this pattern was seen in hand muscles of only 7 patients (P less than 0.001). The neuromuscular blockade in both the hand (49 +/- 54%) and the upper facial area (68 +/- 28%, P greater than 0.05) of comatose patients was smaller and more variable than that seen during anesthesia. These results illustrate the value of quantitative monitoring of neuromuscular function, especially during highly variable and unpredictable drug-induced blockade in the comatose state. We conclude that during narcotic-based anesthesia the upper facial and hand muscles are differentially sensitive to commonly used neuromuscular blockers.

Temperature gradients in cardiac surgical patients--a comparison of halothane and fentanyl.

Narcotics and potent inhalation anesthetics have different effects on thermoregulation and the distribution of body heat. This study was designed to compare the effect of halothane vs fentanyl anesthesia on temperature gradients developed during and after hypothermic cardiopulmonary bypass. Twenty-two adult patients undergoing coronary artery surgery were given either fentanyl (100 micrograms/kg) or halothane (0.5-1.5%) and oxygen. Thermistor probes were inserted in rectum, esophagus, and deltoid muscle. Surface temperatures were measured on the ring finger and upper arm. All patients were cooled during cardiopulmonary bypass to 28 degrees C, and ambient temperature was maintained at 22-23 degrees C. The times to cool and rewarm were comparable in both groups. Rectal, esophageal, and skin temperatures had not reached equilibrium by 60 min after bypass, but changes in temperature were virtually identical at all sites in both groups. Regardless of differences in the effects of halothane and fentanyl on hormonal responses, blood flow, or central thermoregulation, their net effects on body temperature were the same.