Journal of cardiothoracic anesthesia
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J Cardiothorac Anesth · Jun 1989
Comparative StudyMyocardial oxygen balance and cardiopulmonary bypass in patients undergoing coronary artery bypass grafting.
The frequency of anaerobic myocardial metabolism was studied in 14 patients undergoing coronary artery bypass surgery during enflurane-supplemented high-dose fentanyl anesthesia and compared with other clinical monitors of myocardial ischemia including the configuration of the pulmonary capillary wedge pressure (PCWP) and electrocardiographic findings. Hemodynamic parameters, coronary sinus blood flow, myocardial oxygen and lactate extractions, and a seven-lead ECG were recorded before and after cannulation of the aorta and vena cava, during total cardiopulmonary bypass (CPB) in a vented heart, during rewarming after global myocardial ischemia and cold cardioplegia, and 15 minutes after coming off bypass. The cannulation for CPB induced no changes in the central or coronary hemodynamics, but four patients had abnormal lactate metabolism. ⋯ Two patients had ECG evidence of a perioperative myocardial infarction, but they had no significant clinical consequences. Four patients had a fascicular block at discharge. These results indicate that anaerobic myocardial metabolism is common during and after CPB, and that associated myocardial ischemia cannot always be reliably detected by changes in the ECG or the PCWP tracings.
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J Cardiothorac Anesth · Jun 1989
Comparative StudyA comparison of two pulmonary artery mixed venous oxygen saturation catheters during the changing conditions of cardiac surgery.
Continuous mixed venous oxygen saturation (SvO2), using modified pulmonary artery (PA) catheters, can assist in the management of cardiac surgery patients. Two FDA-approved catheters are available for SvO2 monitoring. One system uses two wavelengths of light and the other is a three-wavelength system. ⋯ Two-wavelength determinations varied inconsistently from cooximeter values, while three-wavelength measurements did not differ significantly. Changes in hematocrit were responsible in part for the variability in two-wavelength measurements. In summary, three-wavelength measurements by the Shaw system were more accurate than two-wavelength measurements by the Edwards system.
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J Cardiothorac Anesth · Jun 1989
Brachial plexus lesions following cardiac surgery with median sternotomy and cannulation of the internal jugular vein.
There are many possible complications after cannulation of the internal jugular vein (IJV) including injury to the brachial plexus. Neurologic injuries can also occur from sternal splitting. The present study looked at the incidence of brachial plexus lesions after cardiac surgery with and without IJV cannulation. ⋯ No posterior first rib fractures could be detected by radiographs. The brachial plexus lesions were transient but the Horner's syndromes were longer-lasting. It is concluded that the injuries are due to compression and traction of the plexus due to stretching and possibly from hematoma formation from the IJV punctures.
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J Cardiothorac Anesth · Apr 1989
Randomized Controlled Trial Clinical TrialIntrapleural bupivacaine v saline after thoracotomy--effects on pain and lung function--a double-blind study.
The effects of intrapleural (IP) bupivacaine on pain, morphine requirement, and pulmonary function were evaluated in 15 patients for 24 hours after thoracotomy. An IP catheter was placed during surgery. Patients were randomized in a double-blind fashion to receive 1.5 mg/kg of 0.5% bupivacaine IP or saline on two occasions, eight hours apart. ⋯ The analgesic effect was shortlived (two to five hours), possibly because of loss of bupivacaine in the chest drains. No differences were seen between the two groups after the effect of IP bupivacaine had worn off. Plasma bupivacaine levels had a Cmax of 0.44 to 1.50 micrograms/mL, with a Tmax at 5 to 30 minutes with levels well below 2 to 4 micrograms/mL where increasing toxicity is seen.
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Thoracic epidural fentanyl has been used successfully for postoperative analgesia in patients undergoing thoracic surgery. Prior investigators have suggested that increasing the administered dosage and volume of lumbar epidural fentanyl may increase the spread of analgesia. The feasibility of injecting a high volume (20 mL) of fentanyl into the lumbar epidural space for post-thoracic surgery analgesia was studied in 17 patients undergoing elective thoracotomy or sternotomy. ⋯ All patients experienced pain relief within 15 minutes of injection. No significant respiratory depression or hypercarbia was noted. Lumbar epidural fentanyl is a safe and practical alternative to thoracic epidural analgesia in the post-thoracic surgical patient.