Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Oct 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of thoracic and lumbar epidural infusions of bupivacaine and fentanyl for post-thoracotomy analgesia.
Epidural analgesia, via either a thoracic or lumbar route, is commonly used to provide postoperative analgesia following thoracotomy for pulmonary resection, but little data indicate which location is better in terms of postoperative analgesia, side effects, or associated complications. In this study, 45 patients, who were scheduled to have epidural analgesia and undergo a lateral thoracotomy, were randomized to receive either a thoracic or a lumbar catheter. ⋯ This study found no statistical difference in pain relief or side effects between lumbar and thoracic epidural analgesia for post-thoracotomy pain. An increased infusion rate (6.4 +/- 1.9 v 5.1 +/- 1.4 mL/h, P = 0.02) was required in the lumbar group to achieve equivalent analgesic levels.
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J. Cardiothorac. Vasc. Anesth. · Oct 1993
The effect of preoperative beta-blocker therapy on cardiovascular responses to weaning from mechanical ventilation and extubation after coronary artery bypass grafting.
The hemodynamic and electrocardiographic changes during weaning from mechanical ventilation and tracheal extubation were studied in 75 patients after elective coronary artery bypass surgery. Transfer from synchronized intermittent mandatory ventilation to spontaneous respiration through a T-piece was associated with an increase greater than 20% over baseline in systolic (SBP) and diastolic (DBP) blood pressure in 27% of patients, and in heart rate (HR) in 5% of patients. Although baseline SBP, DBP, and HR differed significantly between the patients taking chronic beta-blocker therapy and those not on beta-blockers (P values all < 0.003), there were no differences between these groups in their response to transfer to the T-piece. (P values: SBP = 0.98; DBP = 0.46; HR = 0.20). ⋯ However, there were significant differences between the chronically beta-blocked and non-beta-blocked groups, both in baseline values for SBP, DBP, and HR (P values all < 0.001), and also in the SBP response (P = 0.007) and HR response (P = 0.02) to extubation. Extubation was associated with a greater than 20% increase in SBP in 8.2% and DBP in 12.2% of chronically beta-blocked patients, compared to 40% and 23% of non-beta-blocked patients, although the DBP response was not statistically different (P = 0.14) between the groups. Similar proportions of patients in both groups increased their HR more than 20% above baseline, but the increase was much greater in the non-beta-blocked group (P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiothorac. Vasc. Anesth. · Oct 1993
Mechanical ventilation in the prone position for acute respiratory failure after cardiac surgery.
Ten patients with acute respiratory failure (ARF) after coronary artery bypass grafting were studied during conventional mechanical ventilation in the supine and in the prone position. Impaired gas exchange was defined as an inspired oxygen fraction (FIO2) greater than 0.5 to maintain an arterial oxygen tension (PaO2) > or = 70 mmHg, an alveolar-arterial PaO2 gradient (PA-aO2) > 200 mmHg and a venous admixture (QVA/QT) > 15% during mechanical ventilation with a tidal volume (VT) = 10 to 12 mL/kg, frequency (f) = 10 to 15 VT/min, inspiratory-expiratory (I:E) ratio = 0.5, and positive end-expiratory pressure (PEEP) of 5 to 7.5 cm H2O. In the supine position, systemic and pulmonary hemodynamics were in the normal range, but oxygenation was severely impaired. ⋯ CO2 elimination was not severely affected. The patients were turned into the prone position after an average of 30.6 +/- 5.4 hours postoperatively and ventilated with unchanged VT, f, PEEP, and inspiratory-expiratory ratio for 26.7 +/- 11.7 hours (range, 10 to 42 hours). A second cardiopulmonary status was obtained within 2 to 5 hours of ventilation in the prone position.(ABSTRACT TRUNCATED AT 250 WORDS)