Simultaneous bilateral obturator nerve stimulation during transurethral electrovaporization of the prostate.

Transurethral vaporization of the prostate is a new method of electrosurgery used for treating benign prostatic hypertrophy. We observed simultaneous obturator nerve stimulation during spinal anesthesia while the middle lobe of the prostate was being resected. A discussion of why electrovaporization is different from traditional electrocautery devices is presented. Due to the increased power required during electrovaporization, and the arcing at the electrode, a large amount of demodulated, low-frequency current is produced that can stimulate the obturator nerve. This can occur even if the electrode is not close to the lateral bladder wall. The solution to the problem of obturator nerve stimulation, including bilateral obturator nerve blocks using a lower power setting during resection and converting from a regional to general anesthetic with neuromuscular blockade, is discussed.

Preoperative cardiac evaluation.

A thorough history and a complete physical examination will detect most cardiac problems that can affect perioperative management or outcome. Further diagnostic tests, including an electrocardiogram, a chest radiograph and more sophisticated studies, should be performed if indicated by the history and physical examination. Congestive heart failure and a myocardial infarction within the six months before surgery are the most important risk factors for postoperative cardiac events, but almost all cardiovascular diseases have some impact on perioperative management and risk stratification. Regional anesthesia is no safer than general anesthesia, except under a few circumstances.

Transcutaneous pacing in patients undergoing coronary artery bypass grafting: effect of previous cardiac surgery.

Temporary transcutaneous pacing thresholds were measured in 10 patients undergoing primary coronary artery bypass grafting (CABG) operations and 10 patients having reoperative CABG operations 7 months to 14 years after their previous cardiac surgery. All surgeries were performed via median sternotomy. After anesthetic induction using either fentanyl or sufentanil in combination with enflurane, the pacing stimulation thresholds were determined. There was no significant difference (P less than 0.05) between the pacing thresholds of the reoperative group and the primary procedure group (78.2 +/- 6.2 v 79.2 +/- 4.8 mA, respectively). Transcutaneous pacing was successful in all 20 patients. Therefore, transcutaneous pacing thresholds appear unaffected by previous cardiac surgery.

Comparison of direct and indirect methods of measuring arterial blood pressure, part II.

Blood pressure measurements can be obtained in the clinical setting by a variety of methods, direct and indirect, but with varying results. Disparities between direct and indirect blood pressure measurements are due in part to physiological considerations, but are largely conditioned by the frequency response of the recording system. In this, the second of three part, the authors conclude that there is no easy solution to the problems confronting direct measurement of blood pressure, and that the interim course seems to be insistence upon definition of the characteristics of measurement systems employed in producing investigative data. Part I (Med. Instrum. January-February 1981) concluded that comparative studies of direct and indirect blood pressure fall into two groups--those resulting in close agreement between methods, and those that do not. In part III (May-June 1981), the authors will examine their own study of a group of patients undergoing surgery.

Comparison of direct and indirect methods of measuring arterial blood pressure, part III.

Blood pressure measurements can be obtained in the clinical setting by a variety of methods, direct and indirect, but with varying results. Disparities between direct and indirect blood pressure measurements are due in part to physiological considerations, but are largely conditioned by the frequency response of the recording system. In this, the final part of a three-part series comparing blood pressure measuring techniques, the authors examine their own study of a group of patients undergoing surgery, and conclude that their study confirmed that was already known: direct measurements of systolic pressure correlate rather poorly with indirect measurements. In part I (Med. Instrum. January-February 1981), the authors concluded that comparative studies of direct and indirect blood pressure fall into two groups-those resulting in close agreement between methods, and those that do not. In part II (Med. Instrum. March-April 1981), they concluded that there is no easy solution to the problems confronting direct measurement of blood pressure, and that the, interim course seems to be insistence upon definition of the characteristics of measurement system employed in producing investigative data.

Comparison of direct and indirect measuring arterial blood pressure.

Blood pressure measurements can be obtained in the clinical setting by a variety of methods, direct and indirect, but with varying results. Disparities between direct and indirect blood pressure measurements are due in part to physiological considerations, but are largely conditioned by the frequency of the recording system. In this, the first of three parts, the authors conclude that comparative studies of direct and indirect blood pressure fall into two groups, those resulting in close agreement between methods, and those that do not. Subsequent issues will include recommendations for further study (part II, March-April 1981), and will examine their own study of a group of patients undergoing surgery (part III, May-June 1981).