Beneficial impact of epidural anesthesia on recovery after outpatient arthroscopy

The ideal outpatient anesthetic provides analgesia, is readily reversible, has minimal complications, and allows for a prompt hospital discharge. Iatrogenic side effects, such as nausea/vomiting and pain, however, may hamper patient recovery and delay discharge. The influence of anesthesia [general (G) versus epidural (E)] was assessed in 260 patients (G = 181, E = 79) undergoing ambulatory knee arthroscopic surgery. Patients were studied before discharge and on follow-up (24 h) to evaluate the effect of the anesthetic technique. Discharge times were shorter in the E group (159 +/- 6 min SEM E, compared with 208 +/- 8 min SEM G), as was the incidence of pain (24.1% versus 49.7%), and nausea/vomiting (8.9% versus 32%) before discharge. Patient satisfaction was equal in the two groups. Our study shows that in select patients, epidural anesthesia is a viable alternative to general anesthesia for knee arthroscopy, offering the advantages of fewer side effects and earlier discharge times.

Bioimpedance hemodynamics compared to pulmonary artery catheter monitoring during orthotopic liver transplantation

Simultaneous cardiac output measurements were obtained using bioimpedance (BI) and thermodilution (TD) methods in 10 patients undergoing orthotopic liver transplantation (OLT). BI and TD data were collected during five intraoperative phases of OLT. Linear regression revealed significant correlation between BI and TD (r = 0.8, P = 0.001) with a slope of regression of 0.64. Bias analysis demonstrated a negative of BI (-0.26) when compared with TD.Sv-O2 correlated poorly with cardiac index determined by TD (r = 0.41) or BI (r = .47). BI is an accurate reproducible method for measuring cardiac output and may be a useful adjunct to the pulmonary artery catheter for hemodynamic monitoring during OLT.

Differential effects of advanced age on neurologic and cardiac risks of coronary artery operations

Two thousand patients undergoing coronary artery bypass grafting with cardiopulmonary bypass were prospectively studied to compare the influence of age on the incidence of neurologic, cardiac, and other complications. Postoperative neurologic events were found in 56 (2.8%) patients, with an incidence in patients > or = 75 years (8.9%) more than twice that of patients 65 to 74 (3.6%) and nine times larger than in patients < 65 (0.9%). Cardiac complications did not differ between age groups except for low cardiac output state, which occurred 1.7 times more frequently in patients > or = 75 years compared with those < 65. Patients with postoperative neurologic events had a ninefold increase in mortality--35.7% versus 4.0%. Logistic regression analysis demonstrate the most important predictors of a postoperative neurologic event to be age, preoperative neurologic abnormality, recent myocardial infarction, and duration of cardiopulmonary bypass. The risk of neurologic complications increases disproportionately to the risk of cardiac complications in the elderly undergoing coronary artery bypass grafting with cardiopulmonary bypass. Despite neurologic improvement (32 of 56 patients), a postoperative neurologic event was second only to low cardiac output state as the postoperative complication most highly associated with in-hospital death. These results are important for decisions regarding selection of candidates for coronary artery bypass grafting and for prediction of surgical outcome.

Morbidity and duration of ICU stay after cardiac surgery. A model for preoperative risk assessment

Although risk factors for mortality after cardiac surgery have been identified, there is no widely applicable method for readily determining risk of postoperative morbidity based on preoperative severity of illness. The goal of this study was to develop a model for stratifying the risk of serious morbidity after adult cardiac surgery using readily available and objective clinical data. After univariate analysis of risk factors in 3,156 operations, 11 variables were identified as important predictors by logistic regression (LR) analysis and used to construct an additive model to calculate the probability of serious morbidity. Reliable correlation was found between a simplified additive model for clinical use and the LR model. The clinical and logistic models were then tested prospectively in 394 patients and demonstrated a pattern of increasing morbidity with ascending scores similar to that predicted by the reference group. Increasing clinical risk score was also associated with a greater frequency of individual complications as well as prolongation of ICU stay. This study demonstrates that it is feasible to design a simple method to stratify the risk of serious morbidity after adult cardiac surgery. With further prospective multicenter refinement and testing, such a model is likely to be useful for adjusting severity of illness when reporting outcome statistics as well as planning resource utilization.

Autologous blood donation: hemodynamics in a high-risk patient population

Transfusion practices have changed dramatically in recent years as a result of the acquired immune deficiency syndrome crisis. The use of preoperative donation of autologous blood units has gained popularity. Healthy individuals tolerate phlebotomy well, experiencing a 2- to 5-percent incidence of vasovagal reactions. However, no systematic study of hemodynamic function during phlebotomy exists for patients who have major cardiovascular or multiple organ disease (high-risk patients). The following protocol examines blood pressure, heart rate, cardiac output, lead II electrocardiogram, and pulse oximetry in 123 patients donating a total of 224 units of blood in a new high-risk autologous blood donation program that was conducted in a postanesthesia care unit over the past 18 months. Changes in hemodynamic variables during phlebotomy were consistent with mild volume depletion; the changes did not result in overall differences in the courses of the groups. Significant numbers of patients exhibited systolic or diastolic hypotension, dysrhythmias, syncope, and tachycardia. Because tolerance for hypotension (vasovagal reactions) is decreased in patients with coronary artery disease, appropriate monitoring may be warranted to maximize the safety of elective phlebotomy. Further study is required to stratify risks and to determine which hemodynamic variables are predictive of adverse events.

Effects of epidural anesthesia and analgesia on coagulation and outcome after major vascular surgery

To examine the interaction of epidural anesthesia, coagulation status, and outcome after lower extremity revascularization, 80 patients with atherosclerotic vascular disease were prospectively randomized to receive general anesthesia combined with postoperative epidural analgesia (GEN-EPI) or general anesthesia with on-demand narcotic analgesia (GEN). Demographics did not differ between groups except that the GEN-EPI group had a higher incidence of diabetes mellitus and of previous myocardial infarction. Coagulation status was monitored using thromboelastography. An additional 40 randomly selected patients without atherosclerotic vascular disease undergoing noncardiovascular procedures served as controls for coagulation status. Vascular surgical patients were hypercoagulable compared with control patients before operation and on the first postoperative day. Postoperatively, this hypercoagulability was attenuated in the GEN-EPI group and was associated with a lower incidence of thrombotic events (peripheral arterial graft coronary artery or deep vein thromboses). The rates of cardiovascular, infectious, and overall postoperative complications, as well as duration of intensive care unit stay, were significantly reduced in the GEN-EPI group. Stepwise logistic regression demonstrated that the only significant predictors of postoperative cardiovascular complications were preoperative congestive heart failure and general anesthesia without epidural analgesia. We conclude that in patients with atherosclerotic vascular disease undergoing arterial reconstructive surgery (a) thromboelastographic evidence of increased platelet-fibrinogen interaction is associated with early postoperative thrombotic events, and (b) epidural anesthesia and analgesia is associated with beneficial effects on coagulation status and postoperative outcome compared with intermittent on-demand opioid analgesia.

Patient-controlled analgesia for postoperative pain

The use of PCA for the treatment of pain is a valuable and growing practice. The technique for PCA initiation and management has been described. This mode of therapy should be in the therapeutic armamentarium of every clinician managing postoperative pain because PCA provides better analgesia than conventional IM or IV narcotic therapy and is generally associated with fewer side effects.

Postoperative epidural analgesia

Epidural analgesia is an important advance in the treatment of postoperative pain. Improved pain relief and decreased patient morbidity have combined to make this technique more desirable than the use of traditional intramuscular narcotics. Optimal patient care and satisfaction, however, can only be achieved with the education and assistance of experienced nursing staff familiar with postoperative epidural analgesia therapy.

Sufentanil-midazolam anesthesia for coronary artery surgery

The combination of benzodiazepines and high-dose narcotics has been reported to produce hypotension in patients undergoing coronary artery surgery. This study was performed to evaluate the cardiovascular effects of lower doses of the narcotic sufentanil administered with the benzodiazepine midazolam. Thirty adult patients with good ventricular function undergoing elective coronary revascularization received sufentanil, 2.5 micrograms/kg, and midazolam, 0.1 mg/kg, followed by infusions of sufentanil, 0.7 to 1.5 micrograms/kg/h, and midazolam, 0.07 to 0.15 mg/kg/h. Overall, stable hemodynamics were achieved before and after cardiopulmonary bypass (CPB). Patients who were not receiving preoperative beta-adrenergic blockade (n = 15) had increases from baseline heart rate and rate-pressure product after sternotomy, during aortic dissection, and after CPB that were not clinically significant. Five patients developed hypertension (increases greater than 20% over the baseline value), which was controlled with additional sufentanil or a vasodilator. Hypertension requiring vasodilator therapy did not occur in patients taking beta-adrenergic blockers. Blood pressure decreases exceeding 20% of the baseline value did not occur. Two of 15 patients receiving beta-blockers, versus 3 of 15 not receiving beta-blockers, developed ischemic electrocardiographic changes before CPB (NS); one of these patients without beta-blockade had a postoperative myocardial infarction. The results of this study show that the infusion of low doses of sufentanil with midazolam provides a hemodynamically safe and stable anesthetic for coronary artery surgery and avoids the hypotension seen when a high-dose narcotic is combined with a benzodiazepine.

Comparison of anesthetic techniques in patients undergoing heart valve replacement

A prospective study of 324 adult patients undergoing operations requiring cardiopulmonary bypass for heart valve replacement was undertaken to determine the effect of anesthetic technique on outcome. Patients received one of three primary techniques: fentanyl (40-100 micrograms/kg), sufentanil (4-8 micrograms/kg), or diazepam (0.4-1 mg/kg) with ketamine (3-6 mg/kg). Supplemental inhalation anesthesia with enflurane, halothane, or isoflurane was used in 43.8% of cases. Patients in these anesthetic groupings had similar perioperative demographic and risk classifications. Although there were differences in the requirements for vasopressors postoperatively among the intravenous anesthetic agents, neither mortality rates, length of ICU stay, nor incidence of postoperative heart failure showed the advantage of any intravenous or inhalational agent. There were also no significant differences in the incidences of serious pulmonary, renal, or neurologic morbidity among primary anesthetic techniques nor among supplemental inhalation agents. Multivariate discriminant analysis of these data suggests that many factors are significantly more important than anesthetic technique as determinants of outcome after heart valve replacement.

Intraspinal narcotics for treatment of cancer pain

Inadequate pain relief remains a problem for many patients with cancer. Narcotic administration by the epidural or subarachnoid route is a relatively recent innovation and is indicated when pain is poorly controlled with high doses of systemic narcotics, or when patients experience limiting narcotic side effects. When given by the epidural or intrathecal route, narcotics have a longer duration of action and a lower dose is effective. These techniques involve personnel trained in catheter insertion and maintenance. Epidural and intrathecal administration of narcotics is an alternative when oral narcotics are ineffective. In this report the term "intraspinal" refers to epidural and/or subarachnoid placement of catheters and drugs.

Isotonic hyponatremia following transurethral prostate resection

The proper treatment of hyponatremia during transurethral resection of the prostate continues to be controversial. Two cases of isotonic hyponatremia are reported here, and the literature regarding the incidence and treatment of hyponatremia during transurethral resection of the prostate is reviewed. In each case, the patient developed neurologic changes during complicated transurethral prostate resection. Despite the rapid decrease in the serum sodium concentration, serum osmolality remained normal due to the resorption of the bladder irrigant glycine. Therefore, etiologies other than cerebral edema are postulated as the cause of the neurologic manifestations. Also, the role of the osmolar gap in directing appropriate therapy is emphasized in an effort to avoid unnecessary use of hypertonic saline. Finally, an appropriate differential diagnosis of the neurologic changes seen during the transurethral resection of the prostate syndrome is discussed.