Safety and efficacy of fast track in patients undergoing coronary artery bypass surgery.

BACKGROUND: The incidence of coronary artery bypass surgery has been increasing annually with increasing pressure on the health care system. Fast track has been proposed as a means to increase efficiency and volume, without an increase in hospital resources. To date this approach has not been critically assessed in Canada. METHODS: We examined 617 consecutive patients undergoing isolated CABG surgery. The patients were divided into (1) fast track (FT) recovery (n = 219), without admission to an ICU, and (2) non-fast track (NFT) recovery (n = 398) with direct admission to the ICU. There were no differences in age, gender, timing of surgery, left main stenosis, preoperative myocardial infarction, renal failure, diabetes, peripheral vascular disease, or in the incidence of chronic obstructive pulmonary disease between the two groups. The NFT group had a higher proportion of patients with NYHA Class III/IV symptoms preoperatively (65.7% vs. 57.3%, p = 0.048), in patients with an ejection fraction < 40% (42.5% vs. 30.6%, p = 0.004), or in the number of individuals with an IABP inserted before surgery (13 vs. 1, p < 0.001). RESULTS: In the FT group the average period of aortic occlusion (40.7 +/- 15.2 min vs. 71.8 +/- 26.5 min, p < 0.001) and perfusion time (67.8 +/- 24.5 min vs. 117.5 +/- 40.2 min, p < 0.001) were significantly less than in the NFT group. The number of grafts per patient was 3.3 +/- 1.0 vs. 3.2 +/- 1.0, respectively (p = 0.38). Operative mortality was 0.9% in the FT group and 1.3% in the NFT group (p = 1.0). Significant differences were seen in the proportion of patients that suffered from postoperative ventilatory failure (3.2% in FT vs. 12.1% in NFT, p < 0.001), and the proportion of patients that suffered any postoperative complication was significantly higher in the NFT group (21.4%) than in the FT group (9.1%, p < 0.001). The differences in postoperative complications resulted in a shorter length of stay (LOS) in FT patients (5.6 +/- 4.1 days vs. 9.7 +/- 9.4 days NFT, p < 0.001). Only 4.1% of patients that entered the FT group failed and required admission to the ICU. Multivariate stepwise logistic regression analysis identified non-fast track recovery as an independent predictor of morbidity in CABG surgery patients. CONCLUSIONS: The data indicate it is possible to perform isolated CABG surgery, in a large proportion of the population, without the need for admission to an ICU for postoperative care.

Left atrial epicardial pacing for chronotropic support in descending thoracic and thoracoabdominal aortic surgery.

Some patients undergoing surgery of the descending thoracic or thoracoabdominal aorta develop sustained bradycardia causing hemodynamic impairment. Seven patients had left atrial epicardial pacing at a physiological rate obviating their hemodynamic impairment during, and for up to several days after, their surgery. This simple technique can be readily used particularly when the aortic reconstruction is facilitated by left atrial to femoral artery bypass.

Neurological outcome in a porcine model of descending thoracic aortic surgery. Left atrial-femoral artery bypass versus clamp/repair.

BACKGROUND AND PURPOSE: In a porcine model of thoracic aortic cross-clamping (AoXC), we compared the incidence and severity of paraplegia with two surgical techniques: left atrial-femoral artery (LA-FA) bypass (BP group; n = 9) and clamp/repair (CR group; n = 8). The descending thoracic aorta was clamped near its origin and distal to the third intercostal artery for 30 minutes. The intervening three intercostal arteries were ligated and divided. METHODS: All animals received methohexital anesthesia and were hyperventilated to a Paco2 of 28 to 32 mm Hg. Animals in the CR group received mannitol, and after AoXC, proximal hypertension was controlled with phlebotomy. In the BP group, proximal hypertension was controlled with LA-FA bypass using a centrifugal pump (Biomedicus 520C). Proximal mean arterial pressure, distal mean arterial pressure, central venous pressure, and cerebrospinal fluid pressure were measured; radioactive microspheres were injected at baseline, at AoXC + 5 minutes, at AoXC + 20 minutes, at AoXC off + 5 minutes, and after resuscitation. Neurological function was assessed at 24 hours. The animals were killed, and the spinal cord was removed to determine spinal cord blood flow. Histological cross sections of the lumbar spinal cord were stained with cresyl violet/acid fuchsin and then examined with light microscopy to determine the ratio of altered to total spinal cord neurons. RESULTS: Fifteen animals survived (one death in each group) and were assessed neurologically at 24 hours after AoXC. Despite better distal perfusion and lumbar spinal cord blood flow in the BP group, during AoXC, and at AoXC off + 5 minutes, there was no significant difference in the severity of spinal cord ischemic injury between groups as assessed neurologically by Tarlov score (P = .90, Mann-Whitney U test). As well, the ratio of altered to total lumbar spinal cord neurons did not differ between groups (P = .24). CONCLUSIONS: In this chronic porcine model, distal circulatory support with LA-FA bypass afforded better distal perfusion and improved lumbar spinal cord blood flow but did not influence the severity of spinal cord ischemic injury when compared with a clamp/repair technique.

High-dose thiopentone for open-chamber cardiac surgery: a retrospective review.

PURPOSE: High-dose thiopentone has been reported to reduce the incidence of neurological dysfunction after open-chamber cardiac surgery. However, this technique delays tracheal extubation and increases requirements for inotropic support after cardiopulmonary bypass. As a quality assurance measure to determine the safety of high-dose thiopentone, we reviewed the records of all patients undergoing elective, open-chamber surgery at our institution between 1st March, 1987 and 31st Dec, 1989. METHODS: The charts of 236 patients were reviewed retrospectively, and 227 met our inclusion criteria. The perioperative characteristics of patients anaesthetized with thiopentone (Group T, n = 80) were compared with those of patients anaesthetized with opioids (Group O, n = 147). RESULTS: Anaesthetic technique was chosen by the attending anaesthetist. in Group T (n = 80) thiopentone 38.1 +/- 11.8 mg.kg-1 was infused to produce electroencephalographic burst-suppression during bypass. Moderate hypothermia and arterial line filtration were used during bypass. The groups did not differ with respect to demographics, type of surgery, or conduct of bypass. There were no strokes in Group T and 4 in Group O (P = NS). The time to extubation was prolonged in Group T compared with Group O (39 +/- 51 vs 27 +/- 24 h, P = 0.014), as was the duration of stay in intensive care (66 +/- 56 vs 51 +/- 29 h, P = 0.010). Thiopentone did not increase the need for inotropic or mechanical support after bypass. In-hospital mortality was lower in Group T than in Group O (1.2% vs 9.5%, P = 0.034). CONCLUSION: High-dose thiopentone delays extubation after open-chamber procedures. However, the technique appears safe, and further prospective investigation is justifiable.

A comparison of cyclosporine A and cyclosporine G in a rabbit heterotopic cardiac transplant model: graft outcome and histological findings.

Cervical heterotopic heart transplants were performed on 20 male New Zealand white rabbits comprising 4 treatment groups. Animals in each group were injected daily via the marginal ear vein and received one of the following regimes: Cyclosporine A, 10 mg/kg/day; Cyclosporine G, 15 mg/kg/day; cremophor-El, 3ml/day; or normal saline. Measurement of 24 hour trough blood concentrations revealed no significant differences between the average concentrations of Cyclosporine A and Cyclosporine G. Animals were examined daily and the cervical allografts assessed by palpation for viability/rejection. The duration of the study ended for each animal when the graft stopped beating at which time the animals were euthanized and the transplanted heart and native kidneys harvested and processed for light microscopy evaluation of rejection and drug toxicity, respectively. Graft survival in the Cyclosporine A group significantly surpassed that seen in the Cyclosporine G group as well as the control groups, whereas in animals treated with Cyclosporine G, graft survival was not different from controls. In the native kidney, there were no differences in glomerular tuft area or volume density amongst drug-treated or control animals. In contrast, tubule atrophy and interstitial fibrosis were markedly greater in Cyclosporine A-treated vs Cyclosporine G-treated animals. The results of this study indicate that, whereas Cyclosporine G is less nephrotoxic than Cyclosporine A, given equivalent blood concentrations Cyclosporine A delays rejection of a cardiac allograft significantly longer than Cyclosporine G in this animal species.

Late recurrence of testicular cancer.

Late recurrence of nonseminomatous germ cell tumours of the testis is rare. The authors report on a 35-year-old man treated initially for embryonal cell carcinoma of the testis with metastases, who presented 12 years later with an increasing serum alpha-fetoprotein level and a biopsy-proven embryonal cell cancer in the hilus of the left lung. Because the tumour was highly resistant to two separate courses of cis-platinum-based chemotherapy and one course of radiotherapy, surgical resection for salvage was carried out. The patient was free of disease 3.5 years after the second operation. The possible reasons for the occurrence of this highly resistant metastatic testicular cancer are discussed. They include a second primary tumour and malignant degeneration of the original tumour. In this patient the latter cause was the most plausible.

The relationship of blood concentrations of rapamycin and cyclosporine to suppression of allograft rejection in a rabbit heterotopic heart transplant model.

Heterotopic heart transplants were performed on 50 New Zealand white rabbits. Groups of 5 rabbits were randomly assigned to receive, through an intravenous route, rapamycin (RAPA) or cyclosporine at the following doses: RAPA (0.05, 0.1, 0.5, and 1.0 mg/kg/day); CsA (5.0, 10.0, and 15.0 mg/kg/day). Drug vehicle and saline controls were also included. Trough blood concentrations were monitored in both RAPA- and CsA-treated groups on a weekly basis throughout the study. Biochemical assessment of renal and liver function was performed at the beginning and end of the study. Animals receiving RAPA exhibited excellent allograft survival; only two animals in the lowest dosage group (0.05 mg/kg/day) rejected their grafts. In contrast, no rejection occurred in the CsA-treated groups. Animals that rejected their grafts were maintained on the drug until the endpoint of the study was reached at 60 days posttransplant to monitor drug induced side-effects. In some instances animals were sacrificed prior to this time due to infectious and other complications. No significant changes in renal or liver function were noted in the RAPA-treated group, while in the group of animals receiving the highest dose of CsA (15.0 mg/kg/day) a significant decrease in creatinine clearance was noted. A correlation was shown to exist between dose and the trough concentrations of both drugs. The whole-blood concentrations of RAPA that resulted in maximal efficacy with minimal toxicity was in the range of 10-60 micrograms/L. Rabbits having trough whole-blood concentrations of < 10 micrograms/L rejected their grafts. A much wider therapeutic range for CsA (50-300 micrograms/L) was noted. The results suggest that RAPA is as efficacious as CsA in prevention of allograft rejection in the animal model tested. The therapeutic monitoring of trough blood concentrations of RAPA, as with CsA, may be useful in guiding dosage adjustments to maximize the immunosuppressive efficacy while minimizing drug-induced side-effects.

Annulo-aortic ectasia extending to the arch: composite graft repair with circulatory arrest.

OBJECTIVE: To examine the results of surgery performed in patients with annulo-aortic ectasia extending to the arch. DESIGN: Retrospective hospital record review. SETTING: A Canadian teaching hospital. PATIENTS: Five patients (mean age 57 years) had annulo-aortic ectasia with severe aortic insufficiency, a maximum aneurysmal diameter ranging from 6.5 to 13 cm at the root or ascending aortic level, and extending into the arch with a diameter of at least 5 cm at the innominate artery level. They all had reconstruction with a composite prosthetic valve and Dacron tube graft employing standard techniques of aortic root replacement as well as aortic arch reconstruction with a single bevelled anastomosis in a state of profound hypothermia and circulatory arrest. MAIN RESULTS: No perioperative deaths, neurological complications nor significant cardiac complications. At a median follow-up period of 46 months all patients are alive, free from cardiovascular symptoms and show no evidence of aortic aneurysmal disease. CONCLUSIONS: This safe, effective and durable repair should be applied to selected patients with annulo-aortic ectasia which extends to the arch.

Expression of transferrin receptors on lymphocytes: its correlation with T-helper/T-suppressor cytotoxic ratio and rejection in heart transplant recipients.

Forty-one heart transplant recipients were monitored serially for the expression of transferrin receptors and T-helper/T-suppressor cytotoxic ratios on circulating lymphocytes during the hospitalization periods after heart transplantations (60.5 +/- 18.9 days). These values were retrospectively correlated with the patients' clinical status with respect to rejection and infection. During clinically stable periods the average values of percentage of transferrin receptor-positive lymphocytes and T-helper/T-suppressor cytotoxic ratios were 5.9 +/- 4.3 and 1.5 +/- 1.0, respectively. The percentage of transferrin receptor-positive lymphocytes increased to a level of 12.0 +/- 5.4 (p less than 0.001) during the early prerejection phase and remained at this level throughout the rejection period. T-helper/T-suppressor cytotoxic ratios increased to 1.96 +/- 0.92 during the early prerejection phase (p less than 0.05), peaked at 2.30 +/- 1.21 during the late prerejection phase (p less than 0.01), but began to decline by the rejection period. After rejection treatment percentage of transferrin receptor-positive lymphocytes decreased to 8.4 +/- 5.3 (p less than 0.05), and T-helper/T-suppressor cytotoxic ratios decreased to normal levels. In contrast, in patients with infectious complications, a remarkably elevated percentage of transferrin receptor-positive lymphocytes (20.7 +/- 11.7) and relatively low T-helper/T-suppressor cytotoxic ratios (1.3 +/- 0.5) were noted. The data show an association between the clinical status, such as rejection and infection, and these immunologic measurements as transferrin receptor-positive lymphocytes and T-helper/T-suppressor cytotoxic ratios in heart transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)