A comparison of the efficacy, safety, and patient satisfaction of ondansetron versus droperidol as antiemetics for elective outpatient surgical procedures. S3A-409 and S3A-410 Study Groups.

UNLABELLED: Two identical, randomized, double-blind, placebo-controlled studies enrolled 2061 adult surgical outpatients at high risk of postoperative nausea and vomiting (PONV) to compare i.v. ondansetron 4 mg with droperidol 0.625 mg and droperidol 1.25 mg for the prevention of PONV. The antiemetic drugs or placebo were administered i.v. 20 min before the induction of anesthesia with a barbiturate compound, followed by maintenance with N2O/isoflurane/enflurane. Nausea, emetic episodes, adverse events, and patient satisfaction were analyzed for the 0 to 2 h and 0 to 24 h postoperative periods. In the 0 to 2 h postoperative period, there was a complete response (no emesis or rescue antiemetic) in 46% of subjects given placebo (P < 0.05 versus antiemetic groups), in 62% given ondansetron, in 63% given droperidol 0.625 mg, and in 69% given droperidol 1.25 mg (P < 0.05 versus ondansetron). In the 0 to 24-h postoperative period, there were no significant differences in complete response between the ondansetron and droperidol 0.625 or 1.25 mg groups; all groups remained superior to placebo. The proportion of patients without nausea during the 0 to 24 h postoperative period was greater in the antiemetic groups compared with the placebo group; however, droperidol 1.25 mg was more effective than ondansetron 4 mg or droperidol 0.625 mg (43% vs 29% or 29%, respectively). Headache incidence was higher in the ondansetron group compared with either droperidol group. Patient satisfaction scores did not differ significantly among antiemetic treatment groups, although all were superior to placebo. In conclusion, all antiemetic treatment regimens were superior to placebo for the prevention of PONV in the immediate postoperative period; however, droperidol 1.25 mg was more efficacious than ondansetron during the early recovery period (0-2 h). There were no significant differences between ondansetron and either droperidol dose for emesis prevention during the 0 to 24 h postoperative period. IMPLICATIONS: More than 2000 patients at high risk of postoperative nausea and vomiting were given either placebo, ondansetron 4 mg, or droperidol 0.625 mg or 1.25 mg i.v. before the administration of general anesthesia. After surgery, the incidence of nausea, vomiting, medication side effects, and patient satisfaction were evaluated for 24 h. Droperidol 0.625 or 1.25 mg i.v. compared favorably with ondansetron 4 mg i.v. for the prevention of postoperative nausea and vomiting after ambulatory surgery.

Eutectic mixture of local anaesthetics is not effective for extracorporeal shock wave lithotripsy.

PURPOSE: Eutectic mixture of local anaesthetics (EMLA) produces cutaneous analgesia. This randomized, double blind, placebo controlled study evaluated the efficacy of EMLA cream during extracorporeal shock wave lithotripsy (ESWL) using the Dornier MFL 5000 lithotripter. METHODS: Patients scheduled to undergo lithotripsy of renal or pelviureteric junction stones were randomized to receive either 30 g EMLA cream (E) or placebo (P) over the kidney area 60-90 min before the procedure. During lithotripsy all patients received alfentanil via a PCA machine (dose--10 mu.kg-1, lockout time--three minutes, no basal infusion). Additional bolus doses of 5 micrograms.kg-1 alfentanil were administered by the anaesthetist if analgesia was inadequate. Visual analogue scores (VAS) for pain were documented prior to application of the cream. On arrival in the post anaesthesia care unit VAS pain scores were documented for maximum pain and average pain felt during the procedure as well as for satisfaction of the analgesic technique used. Total time spent in the PACU and the Aldrete scores on arrival were compared. RESULTS: Eighty-three patients completed the study. Demographic data were similar between the two groups. Also, VAS for maximal pain, average pain and satisfaction and the total number of shock waves were similar although the EMLA group received more shock waves at the lower energy level (kV) (P < 0.0001). Total dose of alfentanil, dose as boluses, rate of alfentanil use, total number of PCA attempts and missed attempts were similar. The incidence of adverse events such as bradypnoea, airway obstruction, transient hypoxaemia, pruritus and nausea were small and similar. There was a slightly higher incidence of inadequate analgesia documented by the anaesthetist in the EMLA group. There was no difference between the groups with regards to duration of stay in the PACU, incidence of nausea or Aldrete scores on admission to PACU. CONCLUSIONS: During lithotripsy EMLA cream does not modify the pain perceived nor does it have any opioid sparing effect. It does not facilitate early discharge from the PACU.

Postoperative cognitive impairment in the elderly. Choice of patient-controlled analgesia opioid.

This study evaluated the safety and cognitive impact of patient-controlled analgesia with fentanyl compared to patient-controlled analgesia with morphine among elderly postoperative patients. In addition, two screening tests for cognitive impairment, the Mini Mental Status Exam and the Short Portable Mental Status Questionnaire, were compared. Ninety-six elderly patients were randomly allocated to receive patient-controlled analgesia with either fentanyl or morphine following hip or knee arthroplasty. Patients were evaluated postoperatively for clinical confusion, cognitive function test results, adequacy of analgesia, drug use and complications. Fentanyl produced less depression in postoperative cognitive function compared to morphine. The incidence of clinical confusion was not statistically different between groups (4.3% for fentanyl versus 14.3% for morphine). Fentanyl patients used more opioid based on a dose ratio of 100:1 suggesting that this dose ratio is inadequate. The incidence of urinary retention was lower in the fentanyl group. A poor agreement between the two tests of cognitive impairment mandates caution when peri-operative cognitive function is compared using different tests.

Postoperative pain management--back to basics.

Butscher describes a common-sense approach to pain management which is simple, safe and effective. A wide variety of national and international organization devoted to the management of pain have universally adopted these simple measures. Current guidelines advocate both regular dosing and rescue analgesia. These guidelines were produced by an army of international experts and have been available for a decade. Although the information is widely published, it is rarely adopted in clinical practice. It is any wonder that leaders in the field of pain management ask: "Is education enough?" "Will guidelines make a difference?" They continue to lament the "tragedy of needless pain" and in despair they have called for "national initiatives on pain." Bonica stated so elegantly, "for nearly 30 yr I have studied the reasons for inadequate management of postoperative pain, and they remain the same...inadequate or improper application of available information and therapies is certainly the most important reason for inadequate analgesia does not require futuristic high tech solutions. In fact, as the economic crunch continues we may find that we cannot afford some of these new, improved and more expensive techniques. If we can provide safe and effective analgesia for only pennies a day, this option cannot be ignored. The new way may be the old way.

The prevention of postoperative pain.

Patients want safe and effective analgesia. Our goal is to prevent postoperative pain in an efficient and cost effective manner. For most patients, the pain can be managed using simple, non-invasive and inexpensive analgesic techniques. Given the current economic climate, cost will become increasingly important. There will be financial pressure to expand the scope of ambulatory surgery. There will be pressure to discharge patients as soon as they are able to take oral medications. Outpatient analgesia is the oldest and most widespread form of patient-controlled analgesia--We already have the knowledge and the analgesics necessary to prevent postoperative pain. What we need now is logical, rational, and universal application of this information.

Techniques for post-op pain management in the adult.

Nurse-administered analgesia is simple, universally accessible, and cost-effective. This route of administration must be fully explored and exploited to gain maximal analgesia at minimal cost. Combined, balanced multimodal analgesia with NSAIDs and opioids used preoperatively to prevent pain should be encouraged. Intraoperative analgesia should not consist solely of opioids, but also local anaesthetics and NSAIDs. Postoperatively, balanced analgesia should continue and when the patient is able to tolerate fluids the oral route of administration should be used. The solution to improved postoperative analgesia lies in exploitation and liberalization of traditional analgesic drugs and techniques. We do not need new pharmacology or new technology. We need to use the drugs and techniques we already have in a much more effective and efficient fashion. Anaesthetists have been at the forefront of delivering superb analgesia to patients after extensive major surgical procedures using epidural analgesia and patient-controlled analgesia. We must focus on postoperative pain management of all patients to ensure that optimal analgesia is provided throughout the institution. This requires a multi-disciplinary team of health care professionals and a multi-modal array of analgesics. This approach represents a change from current practice. Considerable time and energy has been invested in the development of the clinical practice guidelines and they deserve our consideration as we manage patients now and in the future.

Efficacy of nonsteroidal anti-inflammatory drugs in the management of postoperative pain.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are very effective for the management of acute postoperative pain. These agents can be used in combination with opioid analgesics and local anaesthetics for the relief of severe postoperative pain, when the combination results in reduced narcotic requirements and improved analgesia compared with opioids and/or local anaesthetics. NSAIDs have been shown to be effective in a wide variety of postoperative pain states, including thoracotomy, major orthopaedic surgery such as hip arthroplasty, upper and lower abdominal surgery and minor outpatient surgery. The benefits of combining NSAIDs with opioid analgesics in the immediate postoperative period include not only improved analgesia but also the benefits associated with narcotic sparing (improved respiratory function, reduction in nausea and vomiting, reduced sedation) and there is a suggestion that NSAIDs may improve not only the quality but also the speed of recovery. By adding the NSAIDs to a routine analgesic armamentarium the goal of preventing or eliminating postoperative pain, rather than treating or reducing postoperative pain, is achieved. To use these agents more effectively, further research is required to distinguish the differences between the various NSAIDs, the optimal dosage schedules and route of administration, and, finally, the cost-effectiveness and impact on the quality and speed of postoperative recovery of NSAIDs.

Efficacy and safety of potassium infusion therapy in hypokalemic critically ill patients.

OBJECTIVE: To evaluate the efficacy and safety of potassium replacement infusions in critically ill patients. DESIGN: Prospective cohort study. SETTING: Multidisciplinary critical care unit. PATIENTS: Forty-eight critically ill adult patients, age 25 to 86 yrs. Patients entered the study when hypokalemia (potassium less than 3.5 mmol/L) was noted on routine laboratory blood analysis. Most common primary diagnoses on ICU admission included postoperative cardiac surgery (n = 9), sepsis and multiple organ system failure (n = 9), complicated myocardial infarction (n = 7), and respiratory failure (n = 5). INTERVENTION: Potassium chloride infusions (20, 30, or 40 mmol in 100 mL normal saline over 1 hr) were administered to patients for serum potassium levels of less than 3.5 but greater than 3.2 mmol/L (n = 26), 3.0 to 3.2 mmol/L (n = 11), and less than 3.0 mmol/L (n = 11), respectively. Serum and urine potassium levels were monitored during and for 1 hr after the infusion. MEASUREMENTS AND RESULTS: All patients tolerated the infusions without evidence of hemodynamic compromise, ECG change, or new dysrhythmia requiring treatment. The mean maximum potassium increase was 0.5 +/- 0.3 mmol/L, 0.9 +/- 0.4 mmol/L, and 1.1 +/- 0.4 mmol/L in the 20-, 30-, and 40-mmol groups, respectively. The increase in serum potassium was maximal at the completion of the infusion and was significant (p less than .05) compared with baseline in all groups. Peak potassium levels were the same in patients with normal renal function (n = 33) compared with those with renal insufficiency (n = 15). Urinary excretion of potassium increased in all groups during the infusion and was significant (p less than .05) in the 30- and 40-mmol groups, but was no greater in those patients who had received diuretics (n = 8) compared with those patients who had not (n = 40). CONCLUSIONS: In the select group of hypokalemic patients studied, potassium infusions of 20 to 40 mmol delivered over 1 hr were safe to administer and effectively increased serum potassium levels in a dose-dependent and predictable fashion. Furthermore, these results were independent of the patient's underlying renal function or associated diuretic administration.

Comparison of integrated evoked EMG between the hypothenar and facial muscle groups following atracurium and vecuronium administration.

In 17 healthy patients undergoing O2.N2O.isoflurane anaesthesia, following atracurium or vecuronium administration, we compared simultaneous integrated evoked electromyograms (IEEMGs) during spontaneous recovery of the adductor digiti minimi (ADM) and orbicularis oris (OOM) muscle groups in response to train-of-four (TOF) stimulation of the ulnar and facial nerves, respectively. In all patients, the onset of neuromuscular recovery occurred first in the OOM. The time required to recover to a T4/T1 = 0.70 +/- 0.01 (SD) was earlier in the OOM compared with the ADM muscles in both the atracurium (33.4 +/- 5 vs 46.5 +/- 8, P less than 0.005) and vecuronium (46.5 +/- 12 vs 60.3 +/- 20, P less than 0.005) groups. When the OOM attained a T4/T1 = 0.70 +/- 0.01, the simultaneous T4/T1 in the ADM was 0.29 +/- 0.15 (P less than 0.05) in the atracurium group and 0.41 +/- 0.16 (P less than 0.01) in the vecuronium group. We conclude that (1) the facial muscles (OOM) recover earlier than the hypothenar muscles (ADM) and (2) an EMG T4/T1 = 0.70 in the facial muscles may not indicate adequate recovery of neuromuscular function.

Low-dose bupivacaine does not improve postoperative epidural fentanyl analgesia in orthopedic patients.

Epidural infusions of 10 micrograms/mL fentanyl combined with low-dose bupivacaine (0.1%) were compared with epidural infusions of fentanyl alone for postoperative analgesia after total knee joint replacement. There were no detectable differences between the two groups in analgesia (visual analogue scale ranging between 15 and 40 mm), infusion rates (which averaged 7-9 mL/h), or serum fentanyl levels (which reached 1-2 ng/mL). The incidence of side effects, including nausea, vomiting, and pruritus, was also similar. Of the patients receiving fentanyl and low-dose bupivacaine, one developed a transient unilateral motor and sensory loss, and one developed significant hypotension and respiratory depression. The addition of low-dose bupivacaine does not improve epidural fentanyl infusion analgesia after knee surgery and may increase morbidity.

Anesthesia with abdominal surgery leads to intense REM sleep during the first postoperative week.

Characteristics of nocturnal sleep were investigated in six patients after anesthesia and cholecystectomy and in another six after anesthesia and gastroplasty. All night polysomnographic recordings were obtained while each patient slept in a private surgical ward room through two nights before and five or six nights after operation. Anesthesia included thiopental, N2O, isoflurane, and fentanyl. Postoperative analgesia was provided with parenteral morphine. Other aspects of care were routine. Nocturnal sleep was markedly disturbed after both surgical procedures. Throughout the operative night and subsequent one or two nights, sleep was highly fragmented with the usual recurring cycles of sleep stages completely disrupted. Slow wave sleep was suppressed and rapid eye movement (REM) sleep virtually eliminated. During the following 2-4 nights, as other aspects of sleep recovered, REM sleep reappeared and then increased to greater than the preoperative amount. This increased REM sleep was marked by a heavy density of eye movement activity along with frequent patient reports of unusually distressing dreams or vivid nightmares. It is concluded that anesthesia with upper abdominal surgery leads to a severe disruption of nocturnal sleep followed by the release of highly intense REM sleep about the middle of the first postoperative week.

Perioperative monitoring of the electrocardiogram during cerebral aneurysm surgery.

Electrocardiographic (ECG) abnormalities occur frequently following a subarachnoid hemorrhage and may also occur intraoperatively and postoperatively in patients undergoing neurovascular procedures. The aim of this study was to assess the relationship between ECG changes and the neurological status of the patient, the size and the location of the aneurysm, and the influence of these changes on the cardiac and neurological outcome. The preoperative ECG was analyzed in 270 patients. Forty-five patients had intraoperative Holter monitoring. An immediate postoperative ECG was recorded in 120 patients and 60 patients had three consecutive postoperative ECGs. Preoperatively, 52% of the patients had an abnormal ECG and the incidence was highest in patients with a poorer neurological status. Most of the ECG changes involved the T wave or the ST segment. Intraoperative and postoperative changes occurred in 35 and 65% of the patients, respectively, and were independent of the studied factors. There were no documented cardiac events. The presence of an abnormal preoperative ECG did not influence the neurological outcome of the patient, but fluctuating postoperative changes were associated with a worse outcome.

Isoflurane anesthesia causes a transient alteration in nocturnal sleep.

Nocturnal sleep was studied in eight healthy young volunteers before and after isoflurane anesthesia. All night polysomnographic recordings were obtained for seven consecutive nights from approximately 2300 to 0700 h. On the morning after the third night each subject was anesthetized with isoflurane 1.1 MAC for approximately 3 h. The stages and indices of nocturnal sleep were calculated for each night of study according to standard criteria. The effects of anesthesia on nocturnal sleep were confined to the first postanesthetic night. Slow wave sleep (Stages 3 and 4) was moderately suppressed from 16 +/- 1% to 6 +/- 1%, and Stage 2 sleep reciprocally increased from 52 +/- 2% to 60 +/- 2% (mean +/- SEM, P less than 0.05). There were no detectable changes in the sleep onset latency, the total quantity of sleep, or the proportion of rapid eye movement (REM) sleep. Anesthesia was followed by daytime napping in six of the eight volunteers. Nocturnal sleep was similar in the subjects who napped and those who did not. It is concluded that anesthesia with isoflurane leads to a modest and a transient change in the architecture of nocturnal sleep.

Ventilatory compensation for continuous inspiratory resistive and elastic loads during halothane anesthesia in humans.

Inspiratory mechanical loads were applied to the airway continuously for 5 min in healthy young adult volunteers maintained in a near steady-state of halothane anesthesia 1.1 MAC. The loads, both flow resistive and elastic in nature, had been selected to reduce the first loaded tidal volume approximately 10, 30 or 50%--these being designated "small," "medium," and "large" loads, respectively. The actual magnitudes of resistive load were 8 +/- 1, 21 +/- 3, and 48 +/- 6 cmH2O X l-1 X s, and of elastic load 6 +/- 1, 18 +/- 1, and 41 +/- 5 cmH2O X l-1 (mean +/- SEM). All loads caused an immediate reduction of ventilation proportional to the size of the load. This was followed by a gradual recovery of ventilation toward control values over approximately 2 min and then nearly stable ventilation for the rest of the loading period. Respiratory frequency was unchanged throughout. At 5 min of loading, ventilation and PaCO2 had been nearly steady for 3 min and O2 uptake and CO2 output at the airway were unchanged from control, suggesting the establishment of a near steady respiratory state. With the small and medium loads of both types, ventilation and PaCO2 in this near steady-state were not detectably different from control. With the large loads, however, ventilation was significantly reduced and PaCO2 slightly increased. The end-expiratory position of the chest wall and the relative contributions of the rib cage and abdomen-diaphragm to ventilation, as estimated by anteroposterior chest wall magnetometers, were not consistently altered by any load.(ABSTRACT TRUNCATED AT 250 WORDS)