The roles of acute and chronic pain in regression of sensory analgesia during continuous epidural bupivacaine infusion

The purpose of this study was to investigate whether regression of sensory analgesia during constant epidural bupivacaine infusion was different in postoperative patients with acute pain than in patients with chronic nonsurgical pain. Sensory levels of analgesia (to pinprick) and pain (on a five-point scale) were assessed hourly for 16 hours during continuous epidural infusion of 0.5% plain bupivacaine (8 ml/hr) in 12 patients with chronic nonsurgical pain and in 30 patients after major abdominal surgery performed under combined bupivacaine and halothane--N2O general anesthesia. No opiates were given. If sensory analgesia decreased more than five segments from the initial level or if the pain score reached 2 (moderate pain), the patient was removed from the study. Initial levels of sensory analgesia after loading doses of 21.8 +/- 0.5 and 19.3 +/- 0.8 ml bupivacaine 0.5% were similar (T3.8 +/- 0.3 and T3.8 +/- 0.5) in the surgical and chronic pain patients, respectively (mean +/- SEM). Of the surgical patients, only 4 of the 30 (13%) maintained the initial level of sensory analgesia, and a pain score below 2 throughout the study compared with 7 of the 12 patients with chronic pain (58%) (P less than 0.01). Mean duration of sensory blockade was significantly longer (P less than 0.005) in the patients with chronic pain than in surgical patients (13.1 +/- 1.2 and 8.5 +/- 0.7 hours, respectively). Thus, surgical injury hastens regression of sensory analgesia during continuous epidural bupivacaine infusion. The underlying mechanism remains to be determined.     

The effect of 0.5 % ropivacaine on epidural blood flow

Twenty patients scheduled for elective abdominal surgery received epidural analgesia with 20 ml 0.5% ropivacaine or 0.5% bupivacaine. Epidural blood flow was measured by an epidural 133Xe clearance technique on the day before surgery (no local anaesthetic) and again 1 h before surgery, 30 min after injection of the local anaesthetic during continuous infusion (8 ml/h). Median initial blood flow was 5.0 ml/min and 6.0 ml/min per 100 g tissue in patients receiving ropivacaine and bupivacaine, respectively. After epidural bupivacaine, blood flow increased in 8 of 10 patients to 6.9 ml/min per 100 g tissue (P less than 0.05) in contrast to a decrease in 9 of 10 patients to 3.3 ml/min per 100 g tissue after ropivacaine (P less than 0.05), (P less than 0.01 between groups). The median level of sensory analgesia was T3.5 and T4.5 in the ropivacaine and bupivacaine group, respectively (P greater than 0.05). The demonstrated vasoconstrictor effect of epidural ropivacaine may influence the duration of its local anaesthetic effect.     

Epidural morphine improves pain relief and maintains sensory analgesia during continuous epidural bupivacaine after abdominal surgery

Twenty patients scheduled for elective major abdominal surgery were matched into two groups with regard to age, sex, height, body weight, and surgical procedure. Both groups received general anesthesia plus lumbar epidural analgesia with similar loading doses of bupivacaine 0.5% (23.1 +/- 1.0 and 23.3 +/- 0.8 ml) (mean +/- SEM) followed by continuous infusion of plain bupivacaine 0.5% (8 ml/hr) plus, in one group, epidural morphine (0.5 mg/hr). Pain score on a 5-point scale and sensory analgesia (pin prick) were assessed hourly for 16 hours after skin incision. If sensory analgesia decreased more than 5 segments from preoperative levels or if pain scores reached 2 (moderate pain), the patients were removed from the study, and pain was treated with other methods. Preoperative mean (+/- SEM) sensory levels of analgesia were similar in the bupivacaine and the bupivacaine-morphine groups (T3.4 +/- 0.5 and T3.3 +/- 0.4, respectively). In the group receiving only bupivacaine, sensory analgesia regressed over time with a simultaneous increase in pain score. Thus, within 10 hr after skin incision, seven patients in this group were discharged from the study, and 16 hr after incision only one patient maintained initial level of sensory analgesia. In contrast, each patient receiving bupivacaine plus morphine had stable sensory analgesia and was completely free of pain as indicated by a mean pain score of zero during the 16-hr observation period. Thus epidural morphine may improve pain relief and maintain analgesia during continuous epidural bupivacaine administration after abdominal surgery.     

Advantage of ropivacaine for postoperative epidural analgesia following leg orthopedic surgery

BACKGROUND: Epidural administration of local anesthetics may lead to effective pain relief. However, tachyphylaxis or other problems following prolonged epidural anesthesia may develop and in many cases difficulties exist in the maintenance of the similar degree of sensory blockade. The present study was therefore performed to investigate the analgesic effect of continuous postoperative epidural infusion of ropivacaine with fentanyl in comparison with that of bupivacaine or ropivacaine alone. METHODS: After leg orthopedic surgery with lumbar combined spinal-epidural anesthesia, thirty-six patients were randomized to one of the three postoperative epidural infusion groups: bupivacaine 0.125%, ropivacaine 0.2%, or ropivacaine 0.2% with 2.2 microg x ml(-1) (400 microg x 180 ml(-1)) of fentanyl. Continuous epidural infusion was started at a rate of 6 ml x h(-1) with possibility of an additional bolus injection of 3 ml at least every 60 min. Pain was assessed using a 10-cm visual analog scale (VAS) just before and 15 min after epidural bolus injections, and 15-20 h after the start of continuous epidural infusion as the severe at pain through the observation. The spread of analgesia (loss of sharpness in pinprick perception) and motor block (Bromage scale) were evaluated bilaterally. Systolic and diastolic blood pressure and heart rate were also measured. RESULTS: The epidural bolus infusion was associated with a significant decrease of VAS (P < 0.001) and stable blood pressure and heart rate in all groups. The maximal VAS in patients receiving 0.2% ropivacaine+fentanyl was significantly less compared to that in the other two groups. The regression of sensory blockade was significantly prolonged in patients treated with ropivacaine+fentanyl. There was no significant difference in the spread of sensory analgesia between 20 min and 15-20 h after the continuous epidural anesthesia in this group. None of the patients developed adverse effects such as respiratory depression, nausea, and pruritis. CONCLUSIONS: Epidural injection of ropivacaine with fentanyl decreased postoperative pain with stable vital signs in patients undergoing leg orthopedic surgery, as compared to bupivacaine or ropivacaine alone, possibly because of the maintenance of sensory blockade by ropivacaine and enhancement of this sensory blockade by fentanyl.     

Patient-controlled epidural analgesia during labor: a comparison of three solutions with a continuous infusion control

This study examined the efficacy of patient-controlled epidural analgesia (PCEA) during labor and compared the suitability of three different PCEA solutions. After establishing effective epidural analgesia with 12 ml of 0.25% bupivacaine, 72 parturients in active labor were randomly assigned to one of four groups: physician-controlled continuous epidural infusion using 0.125% bupivacaine (CEI); PCEA using 0.125% bupivacaine (B); PCEA using 0.125% bupivacaine with fentanyl 1 micrograms/ml (BF); and PCEA using 0.125% bupivacaine with fentanyl 1 micrograms/ml and 1:400,000 epinephrine (BFE). The CEI infusion was begun at 12-16 ml/h and adjusted to maintain a T10 sensory level and adequate pain relief. PCEA pumps were programmed to deliver a 6 ml/h basal infusion, 4 ml on-demand boluses, 10-min lockout intervals between doses, and a 20 ml hourly limit. Hemodynamic parameters, sensory level, quality of analgesia, duration of labor, overall satisfaction, and Apgar scores did not differ among groups. Compared with CEI, PCEA with plain bupivacaine did not decrease total local anesthetic usage or average hourly infusion rates during labor. However, addition of fentanyl (groups BF and BFE) decreased hourly infusion requirements. Average hourly infusion rates were 13.0 +/- 1.1 ml/h (B), 10.6 +/- 0.6 ml/h (BF), and 9.6 +/- 0.5 ml/h (BFE); group B differs from others (P less than 0.05). No instance of respiratory depression or complication secondary to PCEA was observed. Mild pruritus occurred only with fentanyl-containing solutions, whereas dense motor block developed more frequently with the epinephrine-containing solution.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidural clonidine added to a bupivacaine infusion increases analgesic duration in labor without adverse maternal or fetal effects

Purpose Many obstetric patients receiving epidural analgesia are encouraged to ambulate. This current study was designed to determine the potential for maximizing the time to first epidural supplement when adding clonidine to a 0.625 mg·ml⁻¹ bupivacaine continuous epidural infusion following epidural fentanyl bolus in early labor for patients allowed to ambulate. Maternal and fetal effects secondary to clonidine were also evaluated. Methods Sixty-eight laboring primigravid women received a 3-ml epidural test dose of lidocaine with epinephrine, followed by a fentanyl 100-μg bolus (in a 10 ml-volume). The patients then received a 0.625 mg·ml⁻¹ bupivacaine continuous epidural infusion, either with or without clonidine (5 μg·ml⁻¹), at a rate of 10 ml·h⁻¹. Pain scores and side effects were recorded for each patient. Results The overall quality of analgesia was similar in both groups. The mean duration prior to request for additional analgesia was significantly longer in the clonidine group (269 ± 160 min), compared to the control group (164 ± 64 min). No patient in either group experienced any detectable motor block; one patient (clonidine group) complained of mild thigh numbness and was not allowed to ambulate. While mean blood pressure was approximately 6 mmHg lower in the clonidine group at 1, 1.5, and 3.5 h, this was not clinically significant. No adverse effects on maternal heart rate or fetal heart rate were noted. Conclusion In early laboring patients, addition of clonidine prolongs the analgesia duration of a 0.625 mg·ml⁻¹ bupivacaine continuous epidural infusion following 100 μg epidural fentanyl (after a lidocaine-epinephrine test dose) without a clinically significant increase in side effects.     

Postoperative analgesia using continuous lumbar epidural infusion of ropivacaine in comparison with bupivacaine

BACKGROUND: Epidural bupivacaine infusion is a commonly used technique for postoperative analgesia because of its motor-sparing properties. Recently a new long acting local anesthetic, ropivacaine, has become available. The aim of this study was to investigate the efficacy of ropivacaine and bupivacaine with regard to postoperative analgesia when administered continuously into the lumbar epidural space. METHODS: All patients were ASA I II and undergoing ipsi-lateral leg orthopedic surgery with epidural or combined spinal-epidural anesthesia. Patients were randomly assigned to following three groups: 0.1% ropivacaine (0.1 R); 0.2% ropivacaine (0.2 R); 0.125% bupivacaine (0.125 B). At the end of surgery, continuous infusion was begun at a rate of 6 ml.hr 1 after a bolus epidural administration of 5 ml of 0.2% ropivacaine in R groups and 0.25% bupivacaine in B group. Sensory and motor block, blood pressure, pulse rate, verbal pain score (VPS), analgesic consumption were assessed at 20 min, 1, 3, 10-20 hrs following the beginning of continuous infusion. RESULTS: Vital signs were stable at every measuring point in all groups. In 0.1 R group (n = 20), the spread of sensory block at 3 hrs after infusion was lower than 0.2 R group (n = 19), and VPS during the study was higher than 0.125 B group (n = 17). Bromage scale after 3 hrs was higher in 0.2 R group compared with 0.125 B group. The degree of sensory and motor block gradually decreased, resulting in little difference between the groups. When epidural anesthesia was spread over the surgical area throughout the study, 0.2 R or 0.125 B was sufficiently relieved from postoperative pain. CONCLUSIONS: After leg orthopedic surgery, 6 ml.hr-1 of 0.2 R or 0.125 B provided enough postoperative analgesia when the spread of anesthesia covered the operated area. 0.2 R would be better compared to 0.125 B in continuous epidural infusion for postoperative analgesia due to less systemic toxicity, even though it accompanies a little more intense motor block.     

Epidural Fentanyl Produces Labor Analgesia by a Spinal Mechanism

Background: The purpose of this study was to determine if epidural fentanyl produces analgesia in laboring patients by a primary spinal or supraspinal action.

Methods: Fifty-four parturients were randomized to receive epidural 0.125% bupivacaine plus one of three treatments: epidural saline-intravenous saline, epidural fentanyl (20 [micro sign]g/h)-intravenous saline, or epidural saline-intravenous fentanyl (20 [micro sign]g/h). The study treatments were administered by continuous infusion, whereas epidural bupivacaine use was patient controlled.

Results: Epidural bupivacaine use was significantly reduced by epidural (11.5 +/- 4.6 ml/h) but not by intravenous fentanyl (15.9 +/- 4.5 ml/h) compared with saline control (16 +/- 5.9 ml/h). Analgesia characteristics and side effects were similar among groups.     

Postoperative analgesia by combined continuous infusion and patient-controlled epidural analgesia (PCEA) following hip replacement: ropivacaine versus bupivacaine

BACKGROUND: Ropivacaine is a new local anaesthetic, which compared to bupivacaine is less toxic and shows greater sensory and motor block dissociation. We hypothesised that treatment of postoperative pain with a combined regimen of continuous epidural infusion and Patient-Controlled Epidural Analgesia (PCEA) using ropivacaine could have given better results compared with those we had obtained using bupivacaine. METHODS: Patients undergoing total hip replacement were randomly assigned to two groups. They received epidural analgesia for postoperative pain treatment using ropivacaine, 2 mg x ml(-1) or bupivacaine 2 mg x ml(-1). Both drugs were administered as a constant infusion of 6 ml x h(-1) supplemented by PCEA bolus doses of 2 ml. Patients in both groups received morphine intravenously on demand from a patient-controlled analgesia (PCA) device. An independent observer recorded pain scores, intensity of motor block and morphine consumption at regular intervals during the first 24 h after surgery. RESULTS: Fifty-one patients were evaluated. Ropivacaine and bupivacaine, in similar amounts, provided similar results assessed as adequate to very good postoperative analgesia, whereas motor block was significantly more intense in patients treated with bupivacaine. CONCLUSIONS: Despite similar analgesic effects, epidural infusion of ropivacaine combined with PCEA provides higher patient satisfaction than equal doses of bupivacaine due to lack of motor block.     

Effectiveness of ropivacaine and fentanyl for postoperative epidural analgesia following thoracic surgery

BACKGROUND: Epidural ropivacaine is now a common drug used for postoperative analgesia. However, little information is available concerning regression of sensory blockade and analgesia following prolonged epidural infusion of ropivacaine. We investigated the efficacy of ropivacaine and fentanyl for postoperative analgesia after thoracic surgery. METHODS: Thirty patients undergoing thoracic surgery were enrolled. After surgery with general and thoracic epidural anesthesia, continuous epidural infusion of 0.2% ropivacaine+fentanyl (1.67 microg x ml(-1)) was started at a rate of 6 ml x h(-1) for patients whose height was more than 155 cm and 4 ml x h(-1) for those below 155 cm with possibility of an additional bolus injection of 3 ml at least every 60 min. RESULTS: An additional epidural injection of 3 ml produced a decrease in VAS without significant changes of vital signs. The greatest VAS was 10+/-25 mm in the incision site and 36+/-38 mm in the ipsilateral shoulder. Sensory blockade was sustained until the morning after the day of surgery. Also blood pressure and heart rate were stable throughout the observation period. There were no adverse effects except for slight nausea in three patients. CONCLUSIONS: A bolus of 3 ml with continuous 4-6 ml x h(-1) epidural injection of ropivacaine plus a small dose of fentanyl would decrease postoperative pain with stable vital signs in patients after thoracic surgery.     

Comparison of ropivacaine and bupivacaine for epidural analgesia during labor]

OBJECTIVES: To compare the analgesic efficacy and level of motor block using two local anesthetics, ropivacaine and bupivacaine, during labor. MATERIAL AND METHODS: Sixty nulliparous women were enrolled during labor after full-term pregnancies. They were randomly assigned to receive epidural analgesia with ropivacaine (group R) or bupivacaine (group B). Group R patients received 10 ml of 0.18% ropivacaine with 5 microgram/ml of fentanyl followed by continuous epidural infusion of 0.1% ropivacaine with 2 microgram/ml of fentanyl at a rate of 10 ml/h. Group B patients received 10 ml of 0.15% bupivacaine with 5 microgram/ml of fentanyl followed by continuous epidural perfusion of 0.0625% bupivacaine with 2 microgram/ml of fentanyl at the same rate. Pain intensity was assessed on a visual analog scale, motor blockade on a Bromage scale, and level of sensory block at different moments. We also recorded total doses of local anesthetic employed during continuous epidural infusion, manner of final delivery, Apgar score, degree of maternal satisfaction and side effects. RESULTS: The demographic and delivery characteristics were similar in both groups. We found no statistically significant differences between the two groups for level of motor blockade, which was nil for 29 patients (96.66%) in group R and 28 patients (93.33%) in group B. No differences in degree of pain or level of sensory block (T8-T10 in both groups) were observed.The total doses of local anesthetic used were similar at 23.7 +/- 11.6 mg in group R and 16.5 +/- 7.3 mg in group B (non-significant difference). Nor did we find differences in manner of delivery, neonatal Apgar scores, degree of maternal satisfaction or side effects. CONCLUSION: Ropivacaine and bupivacaine are equally effective for epidural analgesia during labor at the doses used and they do not cause a relevant level of motor blockade.     

Spinal mechanisms contribute to analgesia produced by epidural sufentanil combined with bupivacaine for postoperative analgesia

When used alone, lipid-soluble epidural opioids are thought to produce analgesia supraspinally via systemic absorption. However, spinal opioids and local anesthetics have been shown to act synergistically at the spinal level in animal studies. We, therefore, tested the hypothesis that sufentanil requirements will be less when given epidurally than IV in patients simultaneously given epidural bupivacaine after major abdominal surgery. Forty patients were anesthetized with isoflurane and epidural bupivacaine for major abdominal surgery. After surgery, each was given a continuous epidural infusion of bupivacaine at a rate of 5 mg/h and sufentanil patient-controlled analgesia (PCA). In a randomized, double-blinded fashion, the sufentanil was given either epidurally or IV. PCA settings were the same in each group. For 60 hrs after surgery, the following variables were measured: pain scores at rest, during mobilization, and during coughing; extension of sensory block; side effects; and sufentanil consumption. Pain scores, extension of sensory block, and the incidence of side effects did not differ between the two groups. Consumption of sufentanil in the epidural group was half that of the IV group (48 h after surgery: 107 +/- 57 microg versus 207 +/- 100 microg for the epidural and IV groups, respectively; P < 0.05). We conclude that spinal mechanisms contribute to the analgesia produced by epidural sufentanil in combination with a local anesthetic. IMPLICATIONS: When combined with epidural bupivacaine, the sufentanil requirement was 50% less when given epidurally than IV. Epidural sufentanil thus appears to have a spinal mechanism of action.     

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml/h + 0.2 mg/h, respectively for 8 h postoperatively. Mean initial spread of sensory analgesia on the right side was the same (Th3,4-Th11 versus Th2,6-Th11), but decreased (P less than 0.05) postoperatively in the paravertebral group. All patients in the epidural group had bilateral blockade, compared with three patients in the paravertebral group. In both groups only minor insignificant changes in blood pressure and pulse rate were seen postoperatively. Pain scores were significantly higher in the paravertebral group, as was the need for systemic morphine (P less than 0.05). Pulmonary function estimated by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients.     

Comparison of continuous epidural bupivacaine infusion plus either continuous epidural infusion or patient-controlled epidural injection of fentanyl for postoperative analgesia.

We compared the postoperative epidural analgesia provided by the continuous epidural infusion of bupivacaine supplemented with patient-controlled injection (PCA) of epidural fentanyl with that provided by a continuous infusion of bupivacaine supplemented with a continuous epidural infusion of fentanyl. Our patient population comprised 16 ASA physical status I or II patients undergoing laparotomy with a midline incision under general anesthesia combined with bupivacaine epidural analgesia. Post-operatively, a continuous epidural infusion of bupivacaine (0.1 mg.kg-1.h-1) was combined with epidural fentanyl given by either (a) PCA (15-micrograms bolus with a lockout interval of 12 min, n = 8) or (b) continuous infusion (1 microgram.kg-1.h-1, n = 8). In the case of inadequate pain relief in the latter group, the fentanyl infusion rate was increased by 10 micrograms/h. Analgesia evaluated by a visual analogue pain score and by a verbal pain score was similarly effective in both groups. The sedation score was also similar in both groups. The total dose of epidural fentanyl administered during the first 24 h was significantly lower in the PCA group than in the continuous infusion group (405 +/- 110 micrograms vs 1600 +/- 245 micrograms, P less than 0.001). The dose of fentanyl given during each 4-h interval ranged between 40 and 160 micrograms in the PCA group and 251 and 292 micrograms in the continuous infusion group. Clinically detectable respiratory depression was not observed in either group. In conclusion, epidural administration of 0.1 mg.kg-1.h-1 bupivacaine combined with fentanyl provides effective postoperative analgesia with a total dose of fentanyl required that is lower when fentanyl is administered by epidural PCA rather than by continuous epidural infusion.     

Continuous epidural infusion of 0.075% bupivacaine for pain relief in labour

Seventy-three women who requested epidural analgesia during labour were randomly allocated in a prospective study to receive either a continuous epidural infusion of 0.075% bupivacaine at a rate of 12-18 ml/hour (38 mothers) or intermittent top-ups of 0.5% bupivacaine (35 mothers). Both groups received an initial dose of 6-8 ml bupivacaine 0.5%. Patients were asked to score their pain using a 10-cm linear scale prior to insertion of the epidural, 30 minutes after its insertion and hourly thereafter. The quality of analgesia in the continuous infusion group was significantly better than in the intermittent top-up group (p less than 0.025). There was no significant difference in the total dose of bupivacaine given to the two groups.     

RETRACTED ARTICLE: Hemodynamics, intra-mucosal pH and regulators of circulation during perioperative epidural analgesia

PURPOSE: To evaluate the effects of perioperative epidural analgesia on hemodynamics, splanchnic perfusion and regulators of circulation. METHODS: Twenty patients undergoing aortic surgery were randomised into two groups: epidural analgesia group (EAG): epidural analgesia with bupivacaine (15 ml, 0.125%) was started before surgery. Eight and 16 hr postoperatively 10 ml bupivacaine 0.125% and 1 mg morphine were given. Control group (COG): patients received no epidural catheter. Monitoring included pulmonary artery catheter and gastric tonometer. Norepinephrine, epinephrine, renin, ADH, ANP and endothelin were measured: before epidural analgesia (T0), before aortic clamping (T1), 20 min after aortic clamping (T2), after declamping the first leg (T3), at end of surgery (T4), one hour (T5) and 24 hr postoperatively (T6). RESULTS: At T5 mean arterial blood pressure decreased in EAG compared with baseline (86 +/- 16 to 75 +/- 8 mmHg) and compared with COG (75 +/- 8 vs 84 +/- 11 mmHg). At T2 pulmonary capillary wedge pressure and cardiac index increased and at T6 decreased in both groups. Systemic vascular resistance decreased at T I and at T3-T5 in EAG compared with COG and at T1 and T3-T6 to baseline (1472 +/- 448 to 1027 +/- 184 dyn x sec x cm(-5) x m(-2)). In EAG and in COG, pHi decreased compared with baseline but without group differences. In both groups, epinephrine, norepinephrine, renin, and ADH levels increased from baseline. Endothelin and ANP levels showed no changes. CONCLUSIONS: Perioperatively administrated epidural bupivacaine has no beneficially effects on hemodynamics, pHi or release of regulators of circulation.     

Continuous epidural infusion of morphine for treatment of pain after thoracic surgery: a new technique

We evaluated postoperative pain relief and the incidence of side effects of three methods of thoracic epidural analgesia. Ninety patients, divided into three equal groups, received postoperative analgesia after thoracic surgery either as intermittent epidural injections of bupivacaine (25 mg/5 ml, 0.5% solution) as needed, or, intermittent epidural injections of morphine (5 mg/5 ml of normal saline, 0.1% solution) as needed, or continuous epidural infusion of morphine (0.1 mg, in 1 ml of normal saline) per hour supplemented with intravenous morphine (2 mg) upon request. Pain relief was evaluated by each patient on a pain scale visual analogue and by pain relief questionnaire for a period of 72 hr. Postoperative pain relief was achieved equally with these three methods of epidural analgesia in all patients with no significant difference between groups. Intermittent epidural injection of bupivacaine relieved pain for 4.9 +/- 1.9 (SD) hr/injection and was associated with urinary retention in all patients, with numbness and weakness of the hands in 12 patients, and with severe hypotension in 7 patients. Intermittent epidural injection of morphine relieved pain for 5.8 +/- 2.3 hr/injection and was associated with urinary retention in all patients, with pruritus in 12 patients, and with central narcosis and respiratory depression in 8 patients. Continuous epidural infusion of morphine with occasional intravenous morphine (2 mg) supplementation also effectively relieved postoperative pain and was associated with minimal systemic side effects. One patient complained of pruritus, and two patients developed urinary retention.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous infusion epidural analgesia for obstetrics: bupivacaine versus bupivacaine-fentanyl mixture

Continuous infusion epidural analgesia (CIEA) using a mixture of bupivacaine and fentanyl was evaluated in this randomized, double-blind study involving 75 nulliparous women by comparing the mixture (Group I, Bupivacaine 0.125% and fentanyl 4 micrograms.ml-1 -24 patients) with two concentrations of bupivacaine alone (Group II, bupivacaine 0.25% - 24 patients; and Group III, bupivacaine 0.125% - 27 patients). Epidural anaesthesia was established in Group I with 6 ml 0.125% bupivacaine with fentanyl 50 micrograms and in both Groups II and III with 6 ml 0.25% bupivacaine. In the women whose pain score (Visual Analogue Scale) decreased by at least 50% within 15 min, CIEA was given until delivery. The initial infusion rate in all three groups was set at 7 ml.hr-1, but was decreased in the event of motor block or excessive sensory level. For inadequate analgesia, bupivacaine 0.25% in 3 ml supplements was given every 30 min, as required. During the first stage of labour, 88% of women in Group I reported excellent or good analgesia compared with 92% of women in Group II (NS) and with 59% in Group III (P less than 0.05). The proportion of women reporting excellent/good analgesia during the second stage was approximately 65% in all three groups. The total cumulative dose of bupivacaine in Group I was 54 +/- 36 mg, compared with 107 +/- 47 mg for Group II (P = 0.001), and 71 +/- 41 mg for Group III (NS). Group I patients required less supplementation with bupivacaine than either Group II or III patients during the first stage but only with Group III patients during the second stage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Double-blind evaluation of patient-controlled epidural analgesia during labor

A double-blind randomized study was designed to compare the efficacy of patient-controlled epidural analgesia (PCEA) with continuous epidural analgesia (CEA) with regards to patient satisfaction with analgesia, analgesic efficacy, and local anesthetic usage. After establishing effective epidural analgesia with 8 ml of 0.25% bupivacaine, 39 parturients were randomized to 1 of 2 groups. The CEA group received a continuous infusion of 12 ml/h of 0.125% bupivacaine. The PCEA group received a background infusion of 4 ml/h of 0.125% bupivacaine and were able to self-administer additional boluses of 3 ml of 0.25% bupivacaine every 10 min up to 15 ml/h. In both groups, when patients complained of inadequate analgesia, supplemental doses of 5 ml of 0.25% bupivacaine were administered by a physician. The 2 groups were similar in age, height, weight, gravidity, labor duration, motor block, sensory block, and infant Apgar scores. The 2 groups also did not differ significantly in terms of patient satisfaction, pain assessment, or total drug usage. However, the PCEA group required significantly fewer supplemental doses (15%) compared with the CEA group (40%). The decreased need for supplemental doses in the PCEA group may suggest a potential advantage in consistency of analgesia and possibly decreased man-power needs.