Lois L. Bready

The Prevention of Injuries of the Brachial Plexus Secondary to Malposition of the Patient During Surgery

Brachial plexus injuries that occur secondary to malposition of the patient during general anesthesia have been described in the medical literature for nearly a century. However, little can be found in the orthopedic literature. Of the peripheral nerve groups, the brachial plexus may be the most vulnerable to injury from malpositioning. This study presents three such cases of brachial plexus injury and reviews the literature concerning the subject. Pertinent anatomy, etiology, and pathogenesis of injury to the brachial plexus reveal that injury can occur from stretch or compression of nerves and is usually caused by a combination of the two. With awareness of risk factors and the positions which are likely to cause injury to the brachial plexus, careful positioning of the upper extremity can prevent injury and potential disability to the patient.

Acute digitalis toxicity during turp

Water entrainment into opened prostate venous sinuses during transurethral resection of the prostate (TURP) may lead to dilution of serum electrolytes. Dilutional hypokalemia may precipitate digitalis toxicity in the digitalized patient. Successful resuscitation of such a patient is reported.

Anesthesia for Thoracoscopy

Thoracoscopy has become a widely used method of achieving minimally invasive thoracic surgery. The anesthesiologist providing perioperative care for VATS is challenged to evaluate the patient carefully; to design a safe anesthetic regimen, taking into account preexisting disorders; to ameliorate physiologic alterations associated with one-lung ventilation and CO2 insufflation; and to provide safe, effective perioperative anesthesia and postoperative pain control.

Gas exchange in low-compression HFPPV is maintained at low distending pressures in the pig

The fact that collateral ventilation normally occurs in the human lung has led to the suggestion that it might contribute to the successful clinical effects of low‐compression high‐frequency positive‐pressure ventilation (HFPPV). As the pig has poor collateral ventilation, pulmonary vasoconstriction has to be part of the regulatory mechanisms matching ventilation‐perfusion. A study was made on nine pigs anesthetized with ketamine hydrochloride intravenously to elucidate the maintenance of ventilation‐perfusion balance during mechanical ventilation. Comparisons were made between the ventilatory patterns provided by a conventional ventilator (Servo‐Ventilator 900C) and an improved prototype of a low‐compression system for volume‐controlled ventilation (system H). A ventilatory frequency of 20 breaths per min (bpm) with SV‐900C (SV‐20) and system H (H‐20) and of 60 bpm with system H (H‐60) was used. The experimental conditions were otherwise identical. Positive end‐expiratory pressures (PEEP) were applied to maintain the same mean airway pressure with the three systems. The tidal volume required for normoventilation differed significantly between the three ventilatory patterns, but there were no differences in circulatory and oxygen‐transport variables. By measurements of airway pressure and intrapleural liquid surface pressure, it was demonstrated that the distending pressure (at end‐inspiration) was significantly lower with a low‐compression system (H‐20 versus SV‐20), especially at a high ventilatory frequency (H‐60 versus H‐20). Consequently, although the mean airway pressure was set at the same level for the three different ventilatory modalities, the distending pressures required for the same alveolar ventilation and arterial oxygenation differed significantly. H‐20 and H‐60, and especially H‐60 (= HFPPV) provided ventilation with the lowest distending pressure. Thus the barotrauma of mechanical ventilation was lower during H‐60 than SV‐20. The present results show that low‐compressive patterns of ventilation and HFPPV allow adequate gas exchange in animals without collateral ventilation.

Perioperative management in undiagnosed pheochromocytoma

Pheochromocytoma which is diagnosed intraoperatively carries a high morbidity and mortality. Successful management of the patient with unsuspected pheochromocytoma requires a high index of suspicion and aggressive pharmacologic intervention.

ECG changes with electroconvulsive therapy

Recently, Loper et al. reported celiac plexus block for hepatic artery embolization to be superior to analgesia with intravenous (IV) morphine (1). We would like to report the use of IV sedation in patients receiving intrahepatic artery chemotherapy consisting of carmustine in lipiodol. Lipiodol is a radiopaque oil used in hepatic artery chemotherapy (2,3) to aid drug binding to tumor sites and allow fluoroscopic visualization of the chemotherapeutic drug infusion. It is poorly soluble in blood, causing a transient embolization of the hepatic arteries. During infusion of carmustine in lipiodol, temporary but severe upper right quadrant pain develops that is related to hepatic ischemia caused by the lipiodol. The treatment is useful in patients who are poor surgical risks or in those with unresectable disease (1,4,5). With institutional approval, and after obtaining individual informed consents, we studied eight adults having chemotherapy with hepatic arterial embolization who were managed during the procedure with IV sedation. The six men and two women had either an unresectable primary hepatoma or metastatic liver disease. All patients were given 1530 mL of sodium citrate orally before treatments. Monitoring included electrocardiogram, indirect blood pressure, pulse oximetry, and precordial stethoscope. All patients received 3 4 L/min of oxygen by nasal cannulae. During cannulation of the femoral artery mild sedation was provided with midazolam (1-3 mg in divided doses) and fentanyl (25-100 pg) intravenously. After arterial patency in the portal circulation had been established by angiogram, the level of sedation was increased with additional midazolam (14 mg) and fentanyl (50-100 Pg). Just before infusion of the chemotherapeutic/ embolizing agent, ketamine 10-20 mg was given intravenously. The infusions were completed in 10-15 min. With this technique, only one patient had recall of discomfort during the procedure, and this discomfort was only minimal. The combination of midazolam, fentanyl, and ketamine intravenously provides adequate amnesia and analeesia for patients undergoing intrahepatic artery chemotherapeutic embolization. None of our patients developed oxygen desaturation during the procedure or required support of the airway. There were no episodes of emergence delirium. We report our experience as an alternative to celiac plexus block or high-dose IV narcotics to provide analgesia in patients in whom a temporary hepatic artery embolization is produced with an infusion of chemotherapeutic agents in lipiodol. Stephen A. Vitkun, MD Departments of Anesthesiology and Medicine Stefan Madajewicz, MD Department of Medicine Juan Madariaga, MD Department of Surgery John A. Ferretti, MD Joseph M. Carrucciu, MD Department of Radiology Paul J. Poppers, MD Department of Anesthesiology State University of Npw York at Stony Brook Stony Brook, NY 11 794-8480