Anesthesia In High-risk Patients Research Articles

Outcome after general or regional anaesthesia in high-risk patients

This review is a critical analysis of research design for studies of outcome comparing epidural anaesthesia and analgesia with general anaesthesia and alternative postoperative analgesia regimens. If important advances in knowledge are to be made, appropriately designed multicentre randomized controlled trials are essential. These trials must incorporate strict controls on patient entry, a comprehensive range of carefully defined and clinically significant morbidity endpoints and the previous determination of sample size through a proper analysis of statistical power.

Thoracoscopic Operation for Secondary Pneumothorax Under Local and Epidural Anesthesia in High-Risk Patients

Background. Video-assisted thoracic operations usually require single-lung ventilation under general anesthesia. However, for high-risk patients with other underlying pulmonary diseases, one has to consider risks of general anesthesia itself. Methods. Four high-risk patients (4 men; mean age, 73 years) with intractable secondary pneumothorax and other underlying pulmonary diseases were treated by video-assisted thoracic operations under local and epidural anesthesia. Absorbable polyglycolic acid sheets and fibrin glue were used to control the air leakage. Results. The mean duration of the procedure was 108 minutes. Pain and cough reflex were well controlled, and spontaneous breathing and hemodynamics were well maintained during the operation. The mean duration of the postoperative chest drainage was 5 days. No significant postoperative complication was encountered. No pneumothorax had recurred at a mean follow-up of 16 months. Conclusions. Video-assisted thoracic operations can be performed safely under local and epidural anesthesia for the treatment of intractable secondary pneumothorax in high-risk patients. The air leakage can be controlled with the use of polyglycolic acid sheets and fibrin glue without bullectomy.

Local Anesthesia for Laser Prostatectomy

The technique of visual laser-assisted prostatectomy (VLAP) with a noncontact right-angle delivery system (Urolase) under local anesthesia is described. The advantages of local anesthesia include the facilitation of early patient discharge (2-3 hours after the procedure), avoidance of the risks of spinal and general anesthesia in high-risk patients, and, potentially, the enabling of VLAP as an outpatient office procedure. This technique was employed in 52 men with symptomatic benign prostatic hyperplasia (BPH) as an outpatient procedure without significant morbidity. The mean AUA Symptom Scores and uroflow measures all improved significantly with 1-year follow-up. Outpatient VLAP under local anesthesia is a promising treatment alternative for men with BPH.

Awake epidural anesthesia is effective and safe in the high-risk colectomy patient

This study was designed to examine the feasibility and safety of performing open colectomy using awake epidural anesthesia in high-risk patients with comorbid illnesses. We retrospectively compared 15 high-risk patients who underwent colectomy using awake epidural anesthesia with 17 lower risk colectomy patients who received conventional general endotracheal anesthesia. All patients were operated on consecutively during the same time period by the same surgeon. Based on the number of coexisting diseased organ systems and by a weighted multifactorial index of operative risk, the patients receiving awake epidural anesthesia were significantly more ill than the patients receiving general anesthesia. No differences in complications, length of operative procedure, or number of lymph nodes in cancer specimens were found between the two groups. There was a trend favoring the epidural technique when operative blood loss, length of postoperative hospital stay, and return of bowel function were considered. Awake epidural anesthesia is a safe and effective technique in high-risk patients undergoing colectomy and achieves an operative risk that compares favorably with healthier patients receiving general anesthesia.

Regional versus general anesthesia in high-risk surgical patients: The need for a clinical trial

Regional anesthesia is often preferred over general anesthesia for patients with cardiovascular disease because of presumed decreased risk of perioperative myocardial ischemia. However, few studies have addressed this issue directly. To determine whether the type of anesthesia is independently associated with myocardial ischemia, records of 134 patients undergoing peripheral vascular grafting under general or regional anesthesia were examined. There were no significant differences preoperatively between groups in ASA class, age, sex, or prevalence of angina, diabetes, or hypertension. Twelve patients developed myocardial ischemia or infarction within 7 days of operation; 11 of these 12 patients had received regional anesthesia ( p < 0.015). The association between anesthetic approach and perioperative myocardial ischemia or infarction remained after adjustment for preoperative factors associated with ischemia or with type of anesthesia. General anesthesia does not appear to be associated with increased risk of myocardial ischemia, and stringent recommendations to avoid it in this population may be unfounded. A clinical trial is needed to define more clearly the risks and benefits of different types of anesthesia in high-risk patients.

Primary surgery for hyperparathyroidism: The lateral approach after preoperative ultrasonographic localization

Increasing experience and improving equipment has made ultrasonography the localizing test of choice before neck exploration for hyperparathyroidism is carried out. A study of 16 patients who were examined with ultrasonography before exploration showed that the sensitivity for finding enlarged parathyroid glands was 80 percent, the specificity 95 percent, and the diagnostic accuracy 91 percent. Our operative technique was altered from the classic midline exploration, with bilateral division of the strap muscles, to a lateral approach on the basis of our experience with a high-risk patient who had undergone unilateral exploration under local anesthesia after successful ultrasonographic localization. We found the results with the lateral approach to be equivalent to the results using the midline approach. The lateral approach appeared to be more direct, efficient, and less traumatic than the classic midline approach. This technique is well suited for parathyroid exploration with local anesthesia in high-risk patients who have multiple system failure.

EXPERIMENTAL STUDIES OF THE BREAKDOWN OF EPONTOL: DETERMINATION OF PROPANIDED IN HUMAN SERUM

SUMMARY The concentration of propanidid in human serum was determined and was found to depend on the rate of injection. None was found 25 minutes after injection over a 20-second period. Propanidid passed the placental barrier, the umbilical vein concentration depending on the dose injected. Serum cholinesterase was inhibited by propanidid both in vivo and in vitro; the red-cell esterase was also inhibited. The concentration in umbilical vein blood was highest in mothers with reduced cholinesterase activity. The duration of anaesthesia appears to be influenced by serum cholinesterase activity. In vitro, enzymatic hydrolysis in human serum was slow but occurred rapidly in purified concentrated cholinesterase. When suxamethonium was injected after Epontol the period of apnoea was increased and this is ascribed to enzyme inhibition. The e.e.g. was useful in determining the duration of anaesthesia. Prolongation of anaesthesia in subjects with low enzyme activity corresponded with the e.e.g. findings. Propanidid is bound to plasma proteins and it is recommended that a dose of 3–4 mg/kg of Epontol is sufficient for induction of anaesthesia in high-risk patients.