Analgesic effects of interpleural bupivacaine with fentanyl for post-thoracotomy pain

OBJECTIVE: The analgesic effect of bupivacaine/fentanyl with epinephrine given interpleurally after thoracotomy was investigated in a randomized placebo and intravenous controlled study. DESIGN: Prospective clinical study. SETTING: University teaching hospital. PARTICIPANTS: Sixty American Society of Anesthesiologists physical status II and III patients scheduled for posterolateral thoracotomy with general anesthesia. INTERVENTIONS: Patients were randomly divided into 4 groups to receive either 0.5% bupivacaine/1.5 microg/kg of fentanyl with 5 microg/mL of epinephrine (n = 15, group IPBF), 0.5 % bupivacaine with 5 microg/mL of epinephrine (n = 15, group IPB), or saline (n = 15, group IPS) in a total volume of 15 to 20 mL in 60 seconds by an interpleural catheter placed at the end of surgery by direct vision. The same volume of bupivacaine 0.25% and 1.5 microg/kg of fentanyl with 5 microg/mL of epinephrine to group IPBF, bupivacaine 0.25% with 5 microg/mL of epinephrine to group IPB or saline to group IPS was injected through the interpleural catheter every 6 hours for 48 hours postoperatively. Intravenous fentanyl (n = 15, group IVF) and interpleural saline groups received 1.5 microg/kg of fentanyl intravenously at the first complaint of pain. All patients also received patient-controlled analgesia (PCA) with fentanyl for 48 hours postoperatively. Metamizol sodium was used as a rescue analgesic. MEASUREMENTS and MAIN RESULTS: Adequacy of pain relief was evaluated with the "Prince Henry Pain Scale" and visual analog pain scale. Fentanyl consumption via PCA and complications were evaluated for 48 hours. Visual analog scale scores were significantly higher in the interpleural saline group at 4 and 12 hours (6.6 +/- 1.2 and 5.0 +/- 2.1, respectively) postoperatively. Significantly more patients in the IPBF group had lower pain scores during coughing and deep breathing. Fentanyl consumption via PCA device was significantly higher in the intravenous fentanyl group (1,069 +/- 96.9 microg) than the interpleural groups (577.3 +/- 72.2 microg, 651.1 +/- 61.9 microg, and 601.0 +/- 22.6 microg in IPBF, IPB, and IPS groups, respectively). CONCLUSION: It is concluded that total fentanyl consumption via PCA decreased in all interpleural groups, but pain during coughing and deep breathing was significantly reduced in only the interpleural bupivacaine/fentanyl with epinephrine group.     

A randomized, double-blind comparison of the effects of interpleural bupivacaine and saline on morphine requirements and pulmonary function after cholecystectomy

The effect of interpleural bupivacaine and saline placebo on morphine requirements and pulmonary function after cholecystectomy was investigated. Twenty-six patients were randomly assigned on postoperative day 1 to receive either 20 ml preservative-free saline (group 1) or 20 ml 0.5% bupivacaine with epinephrine, 5 micrograms/ml (group 2) through an interpleural catheter. Adequacy of pain relief was determined by the amount of morphine used by the patient following interpleural injection. Morphine use via a patient-controlled analgesia (PCA) system was recorded for several hours before and after interpleural injection. All patients had a forced vital capacity (FVC) and FEV1 measurement immediately before and 1 h after interpleural injection. Mean hourly PCA morphine use ranged from 1.6 to 2.8 mg for the 6 h prior to interpleural treatment for groups 1 and 2. There was no difference in PCA use between the groups during this time. Group 1 patients did not reduce PCA morphine use after interpleural saline. Patients in group 2, however, significantly reduced PCA morphine use after interpleural bupivacaine. Mean PCA morphine use for group 2 was 0.38 +/- 0.15 mg/h (mean +/- SE) (81% reduction vs. control) for the first 2 h after bupivacaine (P less than 0.05). Mean PCA use in group 2 was 0.52 +/- 0.2 mg/h (73% reduction vs. control) for the third hour after bupivacaine (P less than 0.05). At the fourth and fifth hours after bupivacaine injection, mean PCA morphine use was not significantly different from that in group 1. FVC and FEV1 did not improve after interpleural saline.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of epinephrine and clonidine on plasma concentrations of spinal bupivacaine

ASA II-III patients, scheduled for peripheral vascular surgery, were included in a study designed to assess the effect of spinal epinephrine and clonidine on plasma concentrations of spinally administered 0.5% glucose-free bupivacaine. Patients were allocated randomly to three groups to receive via a spinal catheter 22.5 mg (4.5 ml) of bupivacaine alone (Group B, 9 patients) or combined with 0.3 mg epinephrine (Group BE, 10 patients) or 0.15 mg clonidine (Group BC, 10 patients). Sensory blockade was assessed by pin-prick and motor blockade on the Bromage scale. Bupivacaine plasma concentrations were measured by gas chromatography. A trend to prolongation of local anaesthetic blockade was documented in patients receiving bupivacaine plus epinephrine or clonidine. (Time to regression of sensory blockade to L2: 170 +/- 75 min in Group B, 230 +/- 50 min in Group BE, 232 +/- 64 min in Group BC.) The maximum peak concentration (Cmax), the time to reach Cmax (Tmax) and the time-concentration curve from 0-180 min (AUC) were not different for the three groups (Cmax 228 +/- 112 ng.ml-1 in Group B, 215 +/- 103 ng.ml-1 in Group BE, 234 +/- 159 ng.ml-1 in Group BC; Tmax 41 +/- 34 min in Group B, 59 +/- 31 min in Group BE, 68 +/- 32 min in Group BC; AUC 31.0 +/- 1.7 mg.ml-1.min-1 in Group B, 27.3 +/- 1.1 mg.ml-1.min-1 in Group BE, 27.0 +/- 1.1 mg.ml-1.min-1 in Group BC). The results of this study suggest that epinephrine and clonidine do not decrease blood resorption of spinal bupivacaine.     

Bupivacaine 0.125% produces motor block and weakness with fentanyl epidural analgesia in children

PURPOSE: Epidural infusions of fentanyl (2 micrograms.ml-1) alone or combined with bupivacaine 0.125% were compared for perioperative analgesia, motor block and other side-effects in children who underwent urological surgery. METHODS: In a prospective, double-blind study, 42 children, ASA I-II, 1-16 yr, were randomly allocated to receive either epidural F (fentanyl bolus 2 micrograms.kg-1 in 0.5 ml.kg-1 saline followed by 2 micrograms.ml-1 fentanyl infusion) or epidural F-B (fentanyl bolus 2 micrograms.kg-1 in 0.5 ml.kg-1 bupivacaine 0.25% followed by 2 micrograms.ml-1 fentanyl infusion in bupivacaine 0.125%) after induction of general anaesthesia. Adequacy of analgesia, lower limb motor block and side-effects were assessed four hourly postoperatively. RESULTS: Both infusion regimens provided excellent analgesia (median objective pain scores = 0). Epidural infusion rates were similar in the F (0.29 +/- 0.07 ml.kg-1.hr-1) and F-B (0.26 +/- 0.05 ml.kg-1.hr-1) groups. Three children in the F group and all children in the F-B group developed lower limb weakness. (P < 0.05) Bromage scores were different in the F group (median 0, range 0-0.66) compared with the F-B group (median 0.33, range 0-1) (P < 0.001). Other side-effects did not differ. CONCLUSION: Postoperative epidural fentanyl infusion provides equipotent analgesia to administration of a solution including both fentanyl and bupivacaine 0.125% and causes less lower limb weakness. No reduction in the fentanyl requirement resulted from the addition of bupivacaine 0.125%.     

Continuous interpleural infusion of bupivacaine for postoperative analgesia after surgery with flank incisions: a double-blind comparison of 0.25% and 0.5% solutions.

Postoperative analgesia, as assessed by visual analogue scale scores (0-10) and patient-controlled analgesia morphine requirements, pulmonary function (forced vital capacity and forced expiratory volume in 1 s), and plasma bupivacaine concentrations were studied in patients receiving interpleural blockade with bupivacaine after surgery with a flank incision. Two groups of 10 patients received either 0.5% or 0.25% bupivacaine, both with epinephrine (5 micrograms/mL). Pain relief was initiated when patients had visual analogue scale scores greater than or equal to 4. Patients received 21 mL of bupivacaine 0.25% or 0.5% in a double-blind fashion. One hour later, a continuous infusion of 5 mL/h of the study solution was started. At the same time, patient-controlled analgesia became accessible to the patients. The onset time of pain relief and the area under the visual analogue scale score-time curves over the first 8 h were similar in both groups. Patient-controlled analgesia morphine use was also similar in the 0.25% (21.3 +/- 14.6 mg) and 0.5% (21.0 +/- 16.0 mg) groups (mean +/- SD). In both groups, forced vital capacity and forced expiratory volume in 1 s improved significantly within 60 min (P less than 0.05). Peak plasma concentrations (Cmax) and the area under the plasma concentration-time curve (AUC) over 24 h were higher (P less than 0.001) in the 0.5% group (Cmax, 1.47 +/- 0.37 micrograms/mL; AUC, 1511 +/- 323 micrograms.mL-1.min) than those in the 0.25% group (Cmax, 0.55 +/- 0.22 micrograms/mL; AUC, 680 +/- 118 micrograms.mL-1.min) (mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)     

Interpleural administration of 1.0% and 1.5% lidocaine with epinephrine for pain relief after thoracotomy

Pain relief following thoracotomy and arterial concentration profiles after interpleural administration of lidocaine were studied in 23 adult patients. They were allocated to three groups and given interpleural injection of 20 ml each of 1.0% (group 1, N = 9, non-pneumonectomy patients), 1.5% (group 2, N = 10, non-pneumonectomy patients), and 1.5% (group 3, N = 4, pneumonectomy patients) lidocaine with epinephrine (5 micrograms.ml-1). Complete pain relief was obtained within 20 min after injection in all patients. The mean duration of analgesia was 2.8 hr, 3.1 hr, and 5.1 hr in group 1, 2, and 3, respectively. The maximum plasma concentrations of lidocaine (Cmax) were 1.7 +/- 1.0 (mean +/- SD) microgram.ml-1, 2.2 +/- 0.6 micrograms.ml-1, and 0.7 +/- 0.2 micrograms.ml-1 in group 1, 2, and 3, respectively. The mean duration of analgesia was significantly longer in group 3 than in group 2 (P less than 0.01). Cmax was significantly lower in group 3 than in group 2 (P less than 0.01). In conclusion, we consider interpleural injection of lidocaine with epinephrine to be an effective method of providing postoperative analgesia after thoracotomy. Our data also suggest that the duration of analgesia may increase and the plasma levels of lidocaine may remain quite low in total pneumonectomy patients, because local anesthetic solution is not absorbed through the visceral pleura but absorbed only through the parietal pleura alone in these patients.     

Continuous block of the femoral nerve after surgery of the knee: pharmacokinetics of bupivacaine

Ten ASA Class 1 and 2 patients, aged from 16 to 56 years (mean +/- SD: 37 +/- 17 years), scheduled for knee surgery were studied. At the end of the surgical procedure under general anesthesia, an epidural catheter was inserted in the femoral space. After X-ray opacification, a bolus of 2.5 mg.kg-1 of 0.5% bupivacaine with epinephrine was injected. A maintenance infusion was performed during 48 hours with 0.25 mg.kg-1.h-1 of 0.125% bupivacaine without epinephrine. Pain score recorded with an visual analogue scale was 5.0 +/- 1.9 before femoral block. Pain score decreased significantly from 6 to 48 hours. Plasma bupivacaine levels at 24, 36 and 48 hours were significantly higher than the levels obtained at 30 min, 1, 6 and 12 hours. Mean plasma bupivacaine level at steady state was 1.78 +/- 0.59 micrograms.ml-1. Clearance of bupivacaine was 2.59 +/- 0.91 ml.min-1.kg-1. No neurologic complications have been recorded.     

Lidocaine hydrocarbonate and lidocaine hydrochloride for cesarean section: transplacental passage and neonatal effects

Twenty-six patients, ASA physical status 1, scheduled for elective cesarean section, were divided at random into two groups and received via an epidural catheter 20 ml of 2.2% lidocaine hydrocarbonate (17.3 mg.ml-1 lidocaine base) with 5 micrograms.ml-1 epinephrine freshly added (Group CO2 = 13 patients) or 20 ml of 2% lidocaine hydrochloride (17.3 mg.ml-1 lidocaine base) also with 5 micrograms.ml-1 epinephrine freshly added. Following clampage of the umbilical cord (at 40.1 +/- 4.9 min after the injection of lidocaine for the CO2 group and at 41.0 +/- 5.4 min for the HCl group), serum concentrations of lidocaine were measured both in the mother and in the umbilical vein. All newborns were examined by the same blinded pediatrician with Apgar scores at 1, 5 and 10 min and with Neurobehavioral Adaptive Capacity Scores (NACS) at 15 min, 2 h and 24 h. The concentrations of lidocaine in the serum were comparable in both groups: in the mothers 8.61 +/- 1.48 mumol.l-1 for the CO2 group vs 8.04 +/- 2.36 mumol.l-1 for the HCl group and in the newborns 3.86 +/- 0.84 mumol.l-1 for the CO2 group vs 3.92 +/- 0.95 mumol.l-1 for the HCl group. The ratio of umbilical vein to maternal vein concentrations of lidocaine was also similar in both groups: 0.45 +/- 0.07 for the CO2 group vs 0.54 +/- 0.24 for the HCl group. The percentage of newborns with a normal NACS (score > or = 35/40) was equal in both groups, i.e. 91% at 15 min and 2 h of life and 100% at 24 h of life.(ABSTRACT TRUNCATED AT 250 WORDS)     

The clinical effectiveness of epidural bupivacaine, bupivacaine with lidocaine, and bupivacaine with fentanyl for labor analgesia

STUDY OBJECTIVE: To examine the efficacy of bupivacaine alone and in combination with lidocaine or fentanyl for epidural analgesia during labor. DESIGN: Randomized, single-blind study. SETTING: Labor and delivery unit at a university medical center. PATIENTS: Forty-five primiparas requesting epidural analgesia. INTERVENTIONS: Following epidural placement at L3-4 interspace, patients received either bupivacaine 0.5% (Group 1, n = 15), bupivacaine 0.25% with lidocaine 1% (Group 2, n = 15), or bupivacaine 0.5% with fentanyl 50 micrograms in 10 ml of saline (Group 3, n = 15). Patients in Groups 1 and 2 received 6 to 10 ml of local anesthetic depending on patient height, while patients in Group 3 received 5 ml of local anesthetic plus 50 micrograms of fentanyl in 10 ml of saline. All solutions contained epinephrine 1:200,000. MEASUREMENTS AND MAIN RESULTS: Patients were assessed at regular intervals following administration of the epidural solution. Visual analog scale (VAS) scores were used to measure onset of analgesia, time to complete pain relief, duration of analgesia, and patient satisfaction with therapy. The frequency of shivering and pruritus and the extent of sensory/motor block also were evaluated. There were no intragroup differences in time to complete pain relief or patient satisfaction. However, patients in Group 3 noted the most rapid onset and longest duration of pain relief. Patients in Group 3 also experienced significantly less shivering and had the lowest degree of motor block. Two patients in Group 3 experienced mild pruritus. CONCLUSIONS: Epidurally administered fentanyl safely extended the duration of labor analgesia while reducing bupivacaine dose requirements and magnitude of motor block. In this setting, the combination of bupivacaine and lidocaine offered no clinical advantage over bupivacaine alone.     

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)     

Epidural epinephrine and the systemic circulation during peripheral vascular surgery

This study was designed to determine the haemodynamic effects of epidural epinephrine, 5 micrograms.ml-1, added to bupivacaine, 0.75 per cent, in elderly patients with cardiac disease undergoing peripheral vascular surgery (PVS). The effect of epidural epinephrine on the plasma concentration of bupivacaine was also measured. Twenty patients with a history and/or ECG evidence of myocardial ischaemia requiring PVS were randomly assigned to two groups. The patients were monitored with a modified V5 ECG, oscillometric BP monitor and a PA catheter. After control haemodynamic measurements, 12 ml of bupivacaine, 0.75 per cent, +/- epinephrine, 5 micrograms.ml-1, was injected over five minutes into the epidural space at L3-4. Supine haemodynamic measurements were repeated at 15 and 45 min after injection. At 15 min after epidural injection, compared with control values, patients receiving epidural epinephrine showed a significantly greater decrease in mean blood pressure and systemic vascular resistance, and a significantly greater increase in cardiac output than patients receiving plain epidural bupivacaine (79.3 +/- 11.6 per cent vs 94.6 +/- 16.8 per cent, 61.6 +/- 9.0 vs 91.6 +/- 19.2 per cent, 130.8 +/- 23 vs 105 +/- 20.8 per cent, respectively). These differences were not present at 45 min after epidural injection. Heart rate was not significantly different between groups at either time. The presence of epidural epinephrine reduced the peak plasma concentration of bupivacaine from 0.86 +/- 0.20 to 0.64 +/- 0.33 micrograms.ml-1 and increased the time to achieve this concentration from 16.1 +/- 11.2 to 33.7 +/- 20.1 min.     

Spinal anesthesia for arthroscopic knee surgery

BACKGROUND AND OBJECTIVE: The purpose of the study was to compare the effects of adding 50 microg of morphine, 25 microg of fentanyl or saline to 6 mg of hyperbaric bupivacaine on postoperative analgesia and time to urination in patients undergoing arthroscopic knee surgery under spinal anesthesia. METHODS: The study was designed in a prospective, randomized, double-blinded and placebo-controlled manner. Sixty ASA I-II patients were randomized into the following three groups: Group BM: 6 mg of bupivacaine and 50 microg of morphine, Group BF: 6 mg of bupivacaine and 25 microg of fentanyl, and Group BS: 6 mg of bupivacaine and saline. Selective spinal anesthesia was performed in a lateral decubitus position, with the operative knee dependent for 10 min. RESULTS: In all groups satisfactory anesthesia was provided during the operation. There was a statistically significant difference between all the groups in times to voiding [Group BM 422 +/- 161 min; Group BF 244 +/- 163 min; Group BS 183 +/- 54 min (mean +/- SD)]. The incidence of pruritus was significantly greater in Group BM (80%) and BF (65%) in comparison with Group BS (no pruritus) (P < 0.05). The incidence of nausea was significantly increased in Group BM (35%) in comparison with Group BF (10%) and Group BS (P < 0.05). Analgesic consumption was significantly greater in Group BS in comparison with Groups BM and BF (P < 0.01). CONCLUSIONS: We conclude that during spinal anesthesia even mini-dose intrathecal morphine is not acceptable for outpatient surgery due to side-effects, especially severely prolonged time to urination.     

A combination of sufentanil and 0.25% bupivacaine administered epidurally for obstetrical analgesia. Comparison with fentanyl and placebo

The study reported was designed to determine whether 15 micrograms sufentanil would provide analgesia comparable in duration and quality with that given by 75 micrograms fentanyl, when associated with plain 0.25% bupivacaine for extradural analgesia for labour. Patients (n = 124) in labour and at full term were randomly divided into 3 groups. Group 1 (n = 41) were given 12 ml of 0.25% plain bupivacaine with saline, group 2 (n = 41) 12 ml of 0.25% plain bupivacaine with 75 micrograms fentanyl and group 3 (n = 42) 12 ml of 0.25% plain bupivacaine with 15 micrograms sufentanil. 11 cases were excluded from the study (8 Caesarean sections, 3 technical failures). The duration of analgesia obtained with the two opioids was similar (group 2: 126.7 +/- 6.5 min, p less than 0.01; group 3: 114.9 +/- 5.8 min, p less than 0.01; group 1: 93.6 +/- 5.4 min) as well as the quality of pain relief. There were no differences between the three groups with regard to Apgar scores. The only side-effect seen with sufentanil and fentanyl was pruritus (group 2: 21.9%, p less than 0.05; group 3: 21.4%, p less than 0.05; group 1: 2.4%). These results showed that 15 micrograms sufentanil could replace 75 micrograms fentanyl for extradural pain relief of labour with plain 0.25% bupivacaine. However, the use of opioids with local anaesthetics would seem to be of interest only if labour is likely to be prolonged.     

Analgesic and pulmonary effects of continuous intercostal nerve block following thoracotomy

This study examined the beneficial effects and potential systemic toxicity from continuous intercostal nerve block by repeated bolus injections of bupivacaine. In this double-blind, randomized study, 20 post-thoracotomy patients were assigned to receive four doses of either: 20 ml 0.5% bupivacaine with epinephrine 5 micrograms.ml-1 (bupivacaine group, n = 10), or 20 ml preservative-free saline (placebo group, n = 10) through two indwelling intercostal catheters every six hours. Patients receiving intercostal bupivacaine injections had greater decreases in visual analogue pain scores (VAS) (P less than 0.05) and lower 24 hr morphine requirements, 16.6 +/- 4.6 mg vs 35.8 +/- 7.2 mg, than patients in the placebo group (P less than 0.05). Higher post-injection values of forced expiratory volume in one second, forced vital capacity and peaked expiratory flow rate were also observed in the bupivacaine group (P less than 0.01). Repeated intercostal bupivacaine administration did lead to systemic accumulation, but the peak bupivacaine level after 400 mg was low at 1.2 +/- 0.2 microgram.ml-1. Thus, the technique of continuous intercostal nerve block described in this study is an effective treatment for the control of post-thoracotomy pain.     

Epidural fentanyl plus bupivacaine 0.125 per cent for labour: analgesic effects

Ninety-five healthy nulliparous women, ASA physical status I-II with an uncomplicated pregnancy and single fetus in vertex position were given lumbar epidural analgesia. Patients in Group A (n = 35) received bupivacaine 0.125 per cent with epinephrine 1:800.000; Groups B (n = 30) and C (n = 30) received the same agents as Group A but with the addition to the initial dose of 50 or 100 micrograms of fentanyl respectively. All patients were evaluated for duration and quality of analgesia, duration of labour, method of delivery and total dose of bupivacaine used. The addition of either 50 or 100 micrograms of fentanyl resulted in longer duration of analgesia (93 +/- 9 min and 106 +/- 8 min respectively vs 55 +/- 7) and reduced bupivacaine total doses (64 +/- 0.03 and 55 +/- 1.5 respectively vs 109.5 +/- 1.3). Only the addition of 100 micrograms of fentanyl improved significantly the quality of analgesia (43.3 per cent of excellent scores vs 6.6 per cent in Group B and 5.7 per cent in Group A). Addition of fentanyl did not affect the duration of labour, the method of delivery and the neonatal neurobehaviour scores.     

Extradural pain relief in labour: bupivacaine sparing by extradural fentanyl is dose dependent

The minimum local analgesic concentration (MLAC) of bupivacaine in labour is defined as the effective concentration in 50% of subjects (EC50). We have used the technique of double-blinded sequential allocation to quantify the bupivacaine sparing effect of the addition of four different doses of extradural fentanyl in 223 labouring women. There were five groups: (1) plain bupivacaine (control); (2) bupivacaine with fentanyl 1 microgram ml-1; (3) bupivacaine with fentanyl 2 micrograms ml-1; (4) bupivacaine with fentanyl 3 micrograms ml-1; and (5) bupivacaine with fentanyl 4 micrograms ml-1. The MLAC of bupivacaine were 0.069% w/v, 0.057% w/v, 0.048% w/v, 0.031% w/v and 0.015% w/v, respectively. We observed a reduction in MLAC of 18%, 31% (P = 0.03%), 55% (P < 0.0001) and 72% (P < 0.0001) with fentanyl 1, 2, 3 and 4 micrograms ml-1, respectively, demonstrating a significant negative linear trend (P < 0.0001) with increasing fentanyl dose. The incidence of pruritus was increased significantly with fentanyl 4 micrograms ml-1 (P = 0.0015). Because of this, fentanyl 3 micrograms ml- 1 may be the optimal dose when the aim is bupivacaine sparing extradural analgesia during labour.      

The effect of intrathecal epinephrine on epidural infused analgesics during labor

BACKGROUND AND OBJECTIVES: In order to prolong labor analgesia, one may add intrathecal epinephrine to the combination of bupivacaine and fentanyl. In this study, we tested the hypothesis that the addition of intrathecal epinephrine would lessen the requirement for a rescue dose of epidural analgesia during labor. METHODS: One hundred-eight parturients randomly received intrathecal bupivacaine 2.5 mg and fentanyl 25 microgram with epinephrine 100 microgram (Group BFE) or without (Group BF). Analgesia was assessed by visual analogue pain score (VAPS) 15 and 30 minutes after drug administration. Then, epidural analgesia (0.1% bupivacaine with 0.0002% fentanyl and 1:250,000 epinephrine at 10 mL/h) was initiated. If the patient requested additional analgesia and VAPS was over 30 mm, we added 8 mL epidural bupivacaine 0.125%. The requirement for additional analgesia, the incidence of motor block assessed by a modified Bromage score, hypotension, nausea, and pruritus was noted. RESULTS: Except for 3 parturients in Group BF, satisfactory analgesia was achieved in all parturients 30 minutes after intrathecal drug administration. Following 30 minutes of intrathecal drug administration, VAPSs (mean +/- SD) were 0 +/- 4 mm in Group BFE and 4 +/- 11 mm in Group BF. The number of patients who required additional labor analgesia in Group BFE (11 patients, 20%) was significantly less than in Group BF (26 patients, 48%) (P =.003). The incidence of motor block 30 minutes after spinal analgesia in Group BFE (12 patients, 22%) was significantly higher than in Group BF (3 patients, 6%) (P =.024). Nausea and pruritus were similar in both groups. CONCLUSION: The addition of epinephrine to intrathecal bupivacaine-fentanyl lessened the requirement for additional epidural analgesia without increasing hypotension, nausea, or pruritus. However, the incidence of motor block may be increased without labor prolongation.     

A double-blind comparison of intrathecal S(+) ketamine and fentanyl combined with bupivacaine 0.5% for Caesarean delivery

BACKGROUND: In this prospective, randomized, double-blind, controlled study, we investigated the sensory, motor and analgesic block characteristics of S(+) ketamine, fentanyl and saline given intrathecally (IT) in addition to 0.5% plain bupivacaine (10 mg) for spinal analgesia. METHODS: Ninety ASA I or II adult patients undergoing Caesarean section were randomly allocated to receive 1.0 mL of 0.9% saline in Group S (n = 30), 0.05 mg kg-1 of S(+) ketamine (1.0 mL) in Group K (n =30) or 25 microg (1.0 mL) of fentanyl in Group F (n =30) following 10 mg of plain bupivacaine 0.5% IT. We recorded onset and duration of sensory and motor block, time to reach the maximal dermatomal level of sensory block and duration of spinal analgesia. RESULTS: The onset time of sensory and motor block was significantly shorter in Groups K and F than in Group S (P < 0.014). Their duration was significantly longer in Group F than in Groups K and S (P < 0.009). The time to reach the maximal dermatomal level of sensory block was significantly shorter in Groups K and F than in Group S (P < 0.001). The duration of spinal analgesia was significantly longer in Group F than in Groups K and S (P < 0.001). CONCLUSION: In patients undergoing Caesarean section with spinal analgesia, the addition of S(+) ketamine (0.05 mg kg-1) IT to 10 mg of spinal plain bupivacaine (0.5%) led to rapid onset of both sensory and motor blockade and enhanced the segmental spread of spinal block without prolonging the duration of spinal analgesia, whereas fentanyl provided prolonged analgesia.     

Post-tonsillectomy infiltration with bupivacaine reduces immediate postoperative pain in children

Pain management after tonsillectomy in children remains a dilemma for the anaesthetist. A previous study demonstrated that the administration of lidocaine 1% topical spray to the peritonsillar fossae before tracheal extubation provided considerable immediate postoperative pain relief in infants and children. However, the pain relief was of short duration. We were hopeful that the use of bupivacaine would offer more prolonged pain relief because of its pharmacological characteristics. Therefore, this study was designed to compare the effects of bupivacaine 0.5% with 1:200,000 epinephrine administered after tonsillectomy either as topical spray or submucosal infiltration on postoperative pain in children. Forty-three patients aged two to ten years were randomized into three groups after tonsillectomy was performed. Group (1) received 0.5 ml · kg^?1 normal saline spray; (2) received 2 mg · kg^?1 bupivacaine 0.5% with 1:200,000 epinephrine peritonsillar infiltration in a similar volume to Group 1 and; (3) received 2 mg · kg^?1 bupivacaine 0.5% with 1:200,000 epinephrine spray to both tonsillar beds. The patients in each group were compared postoperatively with regard to the quality of pain control using the Objective Pain Score, and their analgesic requirements. Peritonsillar infiltration of bupivacaine provided superior immediate postoperative analgesia as reflected by lower recovery room pain scores (P < 0.05) and opioid requirements (P < 0.01). Ward pain scores and analgesic requirements were similar among groups. Peritonsillar infiltration of bupivacaine 0.5% with 1:200,000 epinephrine provides better post-tonsillectomy pain control in the immediate postoperative period than bupivacaine spray or placebo.     

Does the addition of fentanyl to bupivacaine in caudal epidural block have an effect on the plasma level of catecholamines in children?

We evaluated the effect of adding fentanyl to bupivacaine, compared with bupivacaine alone, on the stress response. The effect was evaluated by determining blood levels of epinephrine (E) and norepinephrine (NE) in pediatric patients receiving caudal epidural blocks. Sixty children, 1-8 yr of age, scheduled for elective herniorrhaphy, were randomly allocated to two groups of 30 patients each. Group A received inhaled anesthesia and caudal epidural block with bupivacaine 0.25% alone, 1.0 mL/kg. Group B received identical anesthesia; however, fentanyl 1 microg/kg was added to the bupivacaine in the caudal block. Blood samples for E and NE plasma levels were drawn at induction time (H(0)), at the end of surgery (H(1)), and in the postanesthesia care unit (H(2)). In both groups, there was a significant decrease in the E and NE plasma levels, when comparing H(1) and H(2) with H(0) within the same group (P < 0.001). There were no significant differences in the E and NE plasma levels between the two groups at H(0), H(1), and H(2) (P = 0.5, P = 0.12, P = 0.5, respectively). Pain scores (modified Children's Hospital of Eastern Ontario Pain Score) were also similar in both groups (P = 0. 19). This study suggests that adding fentanyl 1 microg/kg to bupivacaine in the caudal epidural block in children does not influence plasma levels of E and NE, nor does it improve the analgesic intensity of the caudal block.