Double-masked randomized trial comparing alternate combinations of intraoperative anesthesia and postoperative analgesia in abdominal aortic surgery.

BACKGROUND: Improvement in patient outcome and reduced use of medical resources may result from using epidural anesthesia and analgesia as compared with general anesthesia and intravenous opioids, although the relative importance of intraoperative versus postoperative technique has not been studied. This prospective, double-masked, randomized clinical trial was designed to compare alternate combinations of intraoperative anesthesia and postoperative analgesia with respect to postoperative outcomes in patients undergoing surgery of the abdominal aorta. METHODS: One hundred sixty-eight patients undergoing surgery of the abdominal aorta were randomly assigned to receive either thoracic epidural anesthesia combined with a light general anesthesia or general anesthesia alone intraoperatively and either intravenous or epidural patient-controlled analgesia postoperatively (four treatment groups). Patient-controlled analgesia was continued for at least 72 h. Protocols were used to standardize perioperative medical management and to preserve masking intraoperatively and postoperatively. A uniform surveillance strategy was used for the identification of prospectively defined postoperative complications. Outcome evaluation included postoperative hospital length of stay, direct medical costs, selected postoperative morbidities, and postoperative recovery milestones. RESULTS: Length of stay and direct medical costs for patients surviving to discharge were similar among the four treatment groups. Postoperative outcomes were similar among the four treatment groups with respect to death, myocardial infarction, myocardial ischemia, reoperation, pneumonia, and renal failure. Epidural patient-controlled analgesia was associated with a significantly shorter time to extubation (P = 0.002). Times to intensive care unit discharge, ward admission, first bowel sounds, first flatus, tolerating clear liquids, tolerating regular diet, and independent ambulation were similar among the four treatment groups. Postoperative pain scores were also similar among the four treatment groups. CONCLUSIONS: In patients undergoing surgery of the abdominal aorta, thoracic epidural anesthesia combined with a light general anesthesia and followed by either intravenous or epidural patient-controlled analgesia, offers no major advantage or disadvantage when compared with general anesthesia alone followed by either intravenous or epidural patient-controlled analgesia.

A randomized, double-blind, dose-response comparison of epidural fentanyl versus sufentanil analgesia after cesarean section.

This study was designed to determine and compare the dose-response characteristics, speed of onset, and relative potency of single-dose epidural fentanyl (F) and sufentanil (S) for postoperative pain relief. Eighty women undergoing cesarean section (C/S) with epidural 2% lidocaine with epinephrine (1:200,000) were randomly assigned to receive double-blind epidural administration of F (25, 50, 100, or 200 microg) or S (5, 10, 20, or 30 microg) (n = 10 per group) upon complaint of pain postoperatively. Visual analog scales (VAS, 0-100 mm) were used to assess pain and sedation at baseline; at 3, 6, 9, 12, 15, 20, 25, 30, 45, and 60 min; and every 30 min until further analgesia was requested. The study was terminated at 30 min if satisfactory analgesia was not achieved. Side effects were recorded. A dose-response was demonstrated for both opioids. F 25 microg and S 5 microg were ineffective, with significantly fewer women achieving VAS scores <10 mm (P < 0.05 compared with F 100 or 200 microg and S 20 or 30 microg). F 100 and 200 microg and S 20 and 30 microg all achieved VAS scores <10 mm in all women with no differences in time to 50% reduction in VAS (mean 11-16 min) and no differences in duration of analgesia (mean 117-138 min). The 50% and 95% effective dose values for each opioid to achieve a VAS score <10 mm were F 33 microg and 92 microg and S 6.7 microg and 17.5 microg. There were no differences among groups in sedation scores or side effects. Our data suggest that the relative analgesic potency of epidural S:F is approximately 5 and that there are no differences between the opioids in the onset, duration, and effectiveness of analgesia when equianalgesic doses are administered postoperatively after lidocaine anesthesia for C/S.

Double-blind randomized evaluation of intercostal nerve blocks as an adjuvant to subarachnoid administered morphine for post-thoracotomy analgesia.

BACKGROUND AND OBJECTIVES: Thoracotomy is associated with pain and compromised pulmonary function. Intercostal nerve blocks (INB) and subarachnoid morphine (SM) act on different portions of the pain pathway. Each is effective for post-thoracotomy pain relief. The combination of these two modalities in relieving post-thoracotomy pain and improving postoperative pulmonary function has not been investigated. METHODS: In a double-blind study, 20 patients undergoing lateral thoracotomy for lung resection were randomized to receive 0.5 mg SM preoperatively and INB with bupivacaine (INB+) prior to wound closure or 0.5 mg SM with INB using saline (INB-). Visual analog scale pain scores at rest, with cough, and with movement of the ipsilateral arm, forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC) were measured at 4, 24, 48, and 72 hours after the operation. Opioid use was measured during the initial 24 hours after the operation. RESULTS: At 4 hours, the INB+ group demonstrated better FEV1 (56.6% vs. 40.4% of baseline, P < .05) and FVC values (54.6% vs. 39.6% of baseline, P < .05) and less resting and cough pain (P < .05). However, FEV1 continued to decline in the INB+ group at 24 hours to lower than the INB- group although pain scores were similar beyond 4 hours. Opioid usage during the first 24 hours was similar (INB-, 16.7 mg vs. INB+, 13.2 mg, P = .7). CONCLUSIONS: Although postoperative INB provided modest improvements in pain and pulmonary function when used as an adjuvant to 0.5 mg SM for post-thoracotomy analgesia, the benefits were transient. The authors do not recommend adding INB for patients undergoing lateral thoracotomy who receive 0.5 mg SM.

Patients' versus nurses' assessments of pain and sedation after cesarean section.

OBJECTIVE: To compare nurses' and patients' assessments of pain and sedation in patients receiving epidural or intravenous patient-controlled analgesia (PCA) after cesarean section. DESIGN: Prospective, randomized study. SETTING: The perinatal unit and labor and delivery unit in a 1,036-bed university hospital in the mid-Atlantic region. PARTICIPANTS: Twenty-six patients receiving epidural PCA or intravenous PCA. Nurses participating in the study were assigned as caregivers to the 26 patients. MAIN OUTCOME MEASURES: Pain and sedation were assessed using 10-cm visual analogue scales completed by both the patient and the patient's nurse twice daily on the day of surgery and on the 1st and 2nd postoperative days. RESULTS: No significant correlation was found between the nurses' and patients' pain or sedation scores. Chi-square analysis showed that the nurse was as likely to underestimate as to overestimate the patient's pain score. The nurse underestimated the patient's sedation score 85% of the time. CONCLUSIONS: The results suggest that nurses' and patients' assessments of pain and sedation differ. The routine use of a standardized self-assessment tool, such as the visual analogue scale, is recommended to ensure that analgesic treatment is based on the subjective nature of the patient's pain experience rather than the nurse's judgment.

The effects of bedrest on circadian changes in hemostasis.

Venous stasis occurs when people are at bedrest, because of altered venous flow characteristics. This is commonly believed to be one etiology behind the development of deep venous thrombosis (DVT). The hemostatic effects of bedrest and their possible role in DVT development have not been fully examined. We hypothesized that bedrest would lead to increases in hemostatic function and that these increases could be important in the development of DVT. Twelve non-smoking volunteers were studied during supine positioning for 36 hours. Platelet reactivity and plasma concentrations of fibrinogen, alpha 2-antiplasmin, plasminogen, thromboxane beta 2, plasminogen activator inhibitor-1, tissue plasminogen activator and neuroendocrine hormones (cortisol, epinephrine and norepinephrine) were measured at 8:00 a.m., 10:00 a.m., 4:00 p.m. and 8:00 a.m. Cortisol demonstrated an early morning increase while catecholamines were unchanged throughout. Fibrinogen, alpha 2-antiplasmin, plasminogen and platelet reactivity were no different at any time point. Fibrinolytic proteins changed over time, manifested by decreased PAI-1 antigen and activity levels at 24 h. Based upon the parameters measured, bedrest causes no increase in hemostatic function. In fact, bedrest causes the potential for enhanced fibrinolysis, that differs from that previously reported for normal activity over 24 h. This may represent a protective mechanism to counter the effects of stasis from bedrest.

Assessment of ketorolac as an adjuvant to fentanyl patient-controlled epidural analgesia after radical retropubic prostatectomy.

BACKGROUND: Opioids, although effective postoperative analgesics, are associated with undesirable side effects. In an attempt to determine whether adjuvant, nonopioid medication would permit a reduction of the amount of fentanyl required for postoperative analgesia, the efficacy of ketorolac, an injectable nonsteroidal antiinflammatory drug, was studied as an adjuvant to fentanyl patient-controlled epidural analgesia (PCEA) for postoperative pain management following radical retropublic prostatectomy. METHODS: Forty patients were randomized into two groups to receive fentanyl PCEA and either ketorolac 30 mg intramuscularly every 6 h after an initial dose of 60 mg (n = 20) or placebo (n = 20) for 72 h. Visual analogue scale pain scores (0-100 mm; 0 mm = no pain; 100 mm = worst pain), sedation, fentanyl usage, gastrointestinal function, complications, blood loss, and temperature were assessed four times each day. RESULTS: Visual analogue scale (VAS) pain scores at rest were lower in the ketorolac group during the first 4 h (P < 0.01), but were similar thereafter. Global VAS pain scores with activity were lower in the ketorolac group on postoperative day 1 (23 +/- 4 vs. 39 +/- 6; P < 0.05) and postoperative day 2 (17 +/- 3 vs. 29 +/- 4; P < 0.05). Bladder spasm pain occurred less frequently in the ketorolac group (1 vs. 9 patients; P < 0.05). Fentanyl usage was less in the ketorolac group throughout the study (33 +/- 3 vs. 50 +/- 6 micrograms/h, 0-24 h; 20 +/- 2 vs. 36 +/- 6 micrograms/h, 24-48 h; 12 +/- 2 vs. 24 +/- 6 micrograms/h, 48-72 h; P < 0.05). Sedation scores and side effects were similar, except on postoperative day 3 when nausea was less frequent in the ketorolac group (0 vs. 6 patients; P < 0.05). Recovery of gastrointestinal function occurred sooner in the ketorolac group as determined by first bowel sounds (26 +/- 3 vs. 38 +/- 4 h; P < 0.05), first clear liquids (51 +/- 2 vs. 65 +/- 3 h; P < 0.01), and first regular meal (95 +/- 4 vs. 110 +/- 4 h; P < 0.05). There was no significant difference in blood loss, transfusion requirement, hematocrit, platelet count, or temperature. There was high overall satisfaction in both groups, but fewer patients in the ketorolac group rated pain with walking as usually or always painful (1 vs. 9 patients; P < 0.05). CONCLUSIONS: Ketorolac is a beneficial adjuvant to fentanyl PCEA for postoperative pain management after radical retropubic prostatectomy.

Lack of coupling between adrenal cortical metabolic activity and blood flow in anesthetized dogs.

To determine whether adrenal O2 consumption and cortical blood flow (CBF) increase during stimulation of cortical secretory activity, exogenous adrenocorticotrophic hormone (ACTH) was infused at 0, 2, and 10 ng.kg-1.min-1 (groups 1, 2, and 3, respectively) into dexamethasone-pretreated, pentobarbital-fentanyl-anesthetized, ventilated dogs. ACTH levels of approximately 20, 100, and 500 pg/ml were obtained in groups 1, 2, and 3, respectively. Cortisol secretion increased after 20 min in groups 2 and 3 (from 0.016 +/- 0.004 to 2.25 +/- 1.36 and from 0.02 +/- 0.01 to 5.32 +/- 1.23 microgram.min-1.g cortex-1, respectively) while adenosine 3',5'-cyclic monophosphate (cAMP) secretion increased after 20 min only in group 3 (from 5.7 +/- 2.8 to 61.3 +/- 18.6 micrograms.min-1.g cortex-1). Whole adrenal gland O2 consumption increased after 20 min in group 3 animals (from 0.89 +/- 0.16 to 1.77 +/- 0.27 ml O2.min-1.100 g tissue-1) but not in the other two groups. CBF measured with radiolabeled microspheres was unaffected by ACTH infusion while O2 extraction increased from a baseline of 5.9 +/- 1.4 to 13.0 +/- 2.4% after 30 min in group 3. These data demonstrate that in anesthetized dogs increases in adrenal cortical secretory activity are associated with increases in O2 consumption, and this increase in O2 consumption is met by increasing O2 extraction, not by increasing cortical blood flow.