Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Aug 1994
Use of monitoring devices during anesthesia for cardiac surgery: a survey of practices at public hospitals within the United Kingdom and Ireland.
A questionnaire was sent to all 42 public hospitals, within the United Kingdom (UK) and Ireland, known to conduct elective cardiac surgery. Information was sought with regard to the availability of intraoperative monitoring equipment. ⋯ Similarly, continuous monitoring of arterial oxygen tension and oxygen fraction in the gas flow to the bypass machine was not conducted in 28 and 32 hospitals, respectively. This survey revealed that essential anesthetic monitoring devices, as defined by the United Kingdom Association of Anesthetists, are not in routine usage during the pre-bypass and post-bypass phases of anesthesia for cardiac surgery within the British Isles.
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J. Cardiothorac. Vasc. Anesth. · Aug 1994
Transesophageal pulsed-Doppler echocardiographic evaluation of transmitral and pulmonary venous flow during ventilation with positive end-expiratory pressure.
During mechanical ventilation with high levels of positive end-expiratory pressure (PEEP) several hemodynamic changes occur, the mechanism of which has been the subject of various previous studies. The effects of increasing levels of PEEP during mechanical ventilation were measured on left atrial and left ventricular filling dynamics, as assessed by pulmonary venous and transmitral flow velocities, respectively. Using transesophageal echocardiography in 12 patients, Doppler flow velocities of pulmonary venous and transmitral flow were studied at baseline (0 cmH2O PEEP) and at 5, 10, 15, and 20 cm H2O with 10-minute intervals, and once more after removal of PEEP. ⋯ In contrast, early and late diastolic velocities and velocity time integrals did not change. In regard to transmitral flow, both early and late diastolic velocities significantly decreased from 51 +/- 7 cm/s and 50 +/- 9 cm/s at baseline to 38 +/- 7 cm/s at 20 cmH2O PEEP, respectively (P < 0.01). Early and late diastolic velocity time integrals decreased from 6.1 +/- 1.8 cm and 4.7 +/- 1.0 cm to 4.5 +/- 1.0 cm (NS) and 3.4 +/- 0.7 cm (P < 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiothorac. Vasc. Anesth. · Aug 1994
Randomized Controlled Trial Comparative Study Clinical TrialThoracic epidural analgesia with bupivacaine and fentanyl for postoperative thoracotomy pain.
This study was designed to evaluate the potential fentanyl-sparing effect of a dilute local anesthetic, bupivacaine, administered in fixed combinations with fentanyl for post-thoracotomy analgesia via a continuous thoracic epidural infusion. Forty adult patients scheduled for thoracotomy were randomly allocated in a double-blind fashion to receive an epidural infusion containing 0, 0.03, 0.06, or 0.125% bupivacaine in combination with fentanyl (4 micrograms/mL). The epidural infusions were initiated in the operating room at 10 mL/hr. ⋯ Arterial blood gas measurements performed on the morning after surgery revealed significant reductions in PaCO2 values, 38 +/- 4, 36 +/- 4, 37 +/- 4 mmHg for 0.03, 0.06, and 0.125% bupivacaine groups respectively, versus 44 +/- 6 for the plain fentanyl group. Arterial pH values were significantly higher in all bupivacaine treatment groups. These findings suggest that the combination of dilute bupivacaine with fentanyl for thoracic epidural analgesia for post-thoracotomy pain may have beneficial effects on pulmonary gas exchange.
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J. Cardiothorac. Vasc. Anesth. · Aug 1994
Randomized Controlled Trial Comparative Study Clinical TrialSomatosensory evoked potential monitoring of the brachial plexus to predict nerve injury during internal mammary artery harvest: intraoperative comparisons of the Rultract and Pittman sternal retractors.
Brachial plexus injury after coronary artery bypass grafting (CABG) continues to be a common problem postoperatively. With the use of somatosensory evoked potential monitoring (SSEP), neurologic integrity of the brachial plexus during internal mammary artery (IMA) harvest was assessed and the Rultract and Pittman sternal retractors were compared to determine what effect they had on SSEP characteristics. Results showed that the Rultract and Pittman retractors caused large decreases in SSEP amplitudes after insertion, (1.25 +/- 0.14 versus 0.72 +/- 0.09, P < 0.05; and 1.64 +/- 0.27 versus 0.91 +/- 0.14, P < 0.05) respectively. ⋯ The nerve plexus seems to be most at risk for pathologic injury during retraction of the sternum for IMA harvest. Though the Rultract retractor caused greater changes in SSEP characteristics than the Pittman, no clinical outcome differences between the two could be ascertained. Using SSEP monitoring may reduce brachial plexus injury during IMA harvest by allowing early detection of nerve compromise and therapeutic interventions to alleviate the insult while under general anesthesia.