Bolus Of Bupivacaine Research Articles

Use of a double epidural catheter provides effective postoperative analgesia after spine deformity surgery

Spine deformity surgery is a painful procedure in which pain control is difficult to obtain. The aim of this study was to evaluate the efficacy of double epidural catheters in this setting. Twenty-three patients scheduled for an elective spine deformity surgery were included prospectively. At the end of surgery, the surgeon inserted two epidural catheters, one cranial, one caudal to the surgical field. In the recovery room the catheters were both injected with a bolus of bupivacaine 0.0625%. In the absence of any neurological abnormality a continuous infusion of bupivacaine 0.0625%, fentanyl 2 microg.mL(-1) and clonidine 3 microg.mL(-1) was administered at a rate of 10 mL.hr(-1) through each catheter for 48 hr. Pain score, sedation level, motor block and side-effects were checked regularly. Complete analgesia (VAS=0) was obtained at rest in all patients. During mobilization and physiotherapy four patients (17%) had a VAS 30. No motor block was observed. Four patients (17%) had nausea and vomiting. No excessive sedation, pruritus or respiratory depression were observed. Early mobilization was possible in all patients. Postoperative epidural analgesia by means of a double catheter is an effective technique to control pain after spine deformity surgery and is associated with a low incidence of side-effects.

Walking With Labor Epidural Analgesia: The Impact of Bupivacaine Concentration and a Lidocaine-Epinephrine Test Dose

BACKGROUND Regional analgesia techniques for labor that permit ambulation are popular among parturients. This study evaluated the influence of bupivacaine bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic effectiveness and the ability to walk after block placement. METHODS Using a randomized double-blind study design, epidural analgesia was initiated in 60 parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125 received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15 ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10 microg sufentanil. Bupivacaine, 0.0625%, with 0.33 microg/ml sufentanil was infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception, motor block, and patient ability to stand and walk were evaluated at various intervals. RESULTS A bolus of 0.125% bupivacaine containing sufentanil, without a previous test dose, proved to be optimal with respect to analgesia and early ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with or without a test dose, provided inadequate analgesia, necessitating additional bupivacaine, which impaired the ability to walk. A high percentage of women in all groups (73-93%) walked at some stage during labor. CONCLUSIONS Omitting a lidocaine-epinephrine test dose and using 0.125% bupivacaine for the initial bolus should permit ambulation in the early postblock period for most parturients who elect this option.

A comparison of the effects on postoperative pain relief of epidural analgesia started before or after surgery

In a randomized, prospective clinical study pain relief and pulmonary function were compared after upper abdominal surgery when thoracic epidural analgesia was instituted either before or after surgery. Twenty-six patients admitted for surgery to treat gastro-oesophageal reflux received thoracic epidural analgesia as an adjunct to general anaesthesia either before or after surgery. Twelve patients received epidural mepivacaine 20 mg mL−1 and morphine perioperatively. Another 14 patients received an epidural bolus of bupivacaine 2.5 mg mL−1 and morphine after skin closure. Bupivacaine 2.5 mg mL−1 with morphine was adminstered to all patients for three postoperative days. No intergroup differences were found regarding pain at rest and mobilization. The requirement for additional analgesics was similar in both groups as well as peak expiratory flow. Thoracic epidural analgesia that had already been induced before surgery, and was continued into the postoperative period, does not seem to add any advantage regarding pain relief and lung function compared with thoracic epidural analgesia instituted in the immediate post-operative period.

Epidural Analgesia for Pain Relief After Scoliosis Surgery in a Patient with Rett's Syndrome

Epidural Analgesia for Pain Relief After Scoliosis Surgery in a Patient with Rett's Syndrome

SOAP 30th Annual Meeting

SOAP 30th Annual Meeting

Epidural pain relief in labour: potencies of levobupivacaine and racemic bupivacaine

We have compared the minimum local analgesic concentrations (MLAC) of levobupivacaine relative to racemic bupivacaine in a prospective, randomized, double-blind, sequential allocation study. Women in labour were given a 20-ml bolus of epidural levobupivacaine or bupivacaine diluted to a concentration determined by up-down sequential allocation. The initial concentration was 0.07% w/v for both drugs. Efficacy was defined using a visual analogue pain score (VAPS) at 10 mm or less within 30 min. The MLAC of levobupivacaine was 0.083% w/v (95% CI 0.065-0.101) and the MLAC of bupivacaine 0.081% w/v (95% CI 0.055-0.108). In molar terms, the MLAC of levobupivacaine was 2.87 mmol litre-1 (95% CI 2.25-3.49) and the MLAC of bupivacaine 2.49 mmol litre-1 (95% CI 1.69-3.32). With regard to the commercial preparations, the potency ratio levobupivacaine: bupivacaine was 0.98 (95% CI 0.67-1.41), and this is unlikely to be of clinical relevance. In molar terms, the ratio was 0.87 (95% CI 0.60-1.25). With regard to toxicity, the evidence should be evaluated in the light of a possible 13% potency difference in molar concentration in favour of racemic bupivacaine.

Epidural analgesia with bupivacaine does not improve splanchnic tissue perfusion after aortic reconstruction surgery

Inadequate splanchnic tissue perfusion is relatively common during and after aortic surgery. We hypothesized that vasodilation caused by thoracic epidural analgesia improves splanchnic blood flow and tissue perfusion after aortic surgery. In this prospective, randomized, controlled study, we studied 20 patients undergoing elective aortic-femoral or aortic-iliac reconstruction surgery. Gastric and sigmoid colon mucosal PCO2 and pH were measured during surgery. An epidural bolus of bupivacaine 40 mg followed by infusion of 15 mg h-1 was started after operation in 10 patients. After operation, splanchnic blood flow and gastric and sigmoid colon mucosal PCO2 and pH were measured before and 2 h after the start of epidural analgesia. During surgery, the gastric mucosal-arterial PCO2 difference remained stable, whereas the sigmoid mucosal-arterial PCO2 difference increased during aortic clamping but returned to pre-clamping values after declamping. After operation, epidural analgesia had no effect on gastric or sigmoid mucosal-arterial PCO2 differences or on splanchnic blood flow.

Continuous Spinal Anesthesia for Hip Surgery in a Patient with Shy-Drager Syndrome

Continuous Spinal Anesthesia for Hip Surgery in a Patient with Shy-Drager Syndrome

Continuous parasacral sciatic nerve block: Two case reports

This study investigated the use of a continuous parasacral sciatic nerve block for anesthesia and postoperative analgesia for lower extremity surgery. A continuous parasacral sciatic nerve block was performed in two patients (triple ankle arthrodesis and below-knee amputation). The sacral plexus was identified using an insulated Tuohy needle and a nerve stimulator. A catheter was placed near the elements of the sacral plexus via the Tuohy needle. In both patients, surgical anesthesia was successfully established through the parasacral catheter with lidocaine 1% (1/200,000 epinephrine), and postoperative analgesia was successfully established with a bolus of bupivacaine 0.375% (1/200,000 epinephrine) and maintained with a continuous infusion of bupivacaine 0.1% (8 mL/h) for 48 hours. We conclude that continuous parasacral sciatic nerve block can provide anesthesia and long-term analgesia for operative procedures of the foot and leg.

Complication After Interpleural Analgesia

To the Editor: We report an unusual complication after interpleural analgesia. A 76-yr-old male patient was scheduled for a left ureteronephrectomy because of ureter carcinoma. General anesthesia was induced with thiopental, fentanyl, and atracurium and maintained with midazolam, fentanyl, atracurium, and low concentrations of isoflurane in air. At the end of the procedure, while the patient was still in the semilateral position, an interpleural catheter was introduced on the midaxillary line at the level of the fourth intercostal interspace. Subsequently, a bolus of 10 mL 0.5% bupivacaine with 1:200,000 adrenaline was injected. The trachea was eventually extubated, and the patient transferred to the recovery room. The recovery room nurse was instructed to connect the interpleural catheter to a pump that was to deliver plain 0.25% bupivacaine at a rate of 6 mL/h. The nurse prepared a 50-mL plastic syringe with 0.25% bupivacaine and connected it to the interpleural catheter. At this point, she was urgently called by another patient, so she just put the syringe on the patient's bed without fixing it within the driving pump. When she came back 10 min later, she was struck by the fact that the syringe now contained only 10 mL. Checks were made, and it turned out that nobody had touched the syringe. The most likely explanation is that the syringe was emptied due to the negative interpleural pressure generated by the patient's breathing. Our patient was not affected by the two bupivacaine boluses (150 mg in 20 min) and made an uneventful recovery. N. Milliet, MD W. Studer, MD Department of Anesthesia Kantonsspital Basel, Switzerland

A.330 Optimal concentration for an initial bolus of bupivacaine for extradural analgesia during labour

A.330 Optimal concentration for an initial bolus of bupivacaine for extradural analgesia during labour

Epidural fibrosis after permanent catheter insertion and infusion

Forty-six permanent epidural catheters and life-port units were implanted in 43 patients with severe, recurrent low back pain who had been considered not to be candidates for surgical intervention and in whom other therapeutic modalities had failed. Eight cases developed epidural fibrosis (EF). For analgesia, patients received either infusions with preservative-free solutions of fentanyl and bupivacaine or daily boluses of morphine and bupivacaine. Catheters remained from 75 days to 433 days. Signs of EF appeared from 21 days to 320 days after implantation. Pain at injection or resistance to injection were initial manifestations of EF, followed by poor, and eventually, nil analgesic effect. The epidural catheters were made of either polyamide, silicone, or polyurethane. Epidurograms revealed encapsulation, narrowing, and loculation of epidural space with gradually reduced spread of the contrast material. The occurrence of EF limits the permanency of implanted epidural catheters. The infusate does not cause this complication, which appears to be a foreign body reaction due to the presence of the catheter in the epidural space.

Effects of Perioperative Analgesic Technique on Rate of Recovery after Colon Surgery

Choice of perioperative analgesia may affect the rate of recovery of gastrointestinal function and thus duration and cost of hospitalization after colonic surgery. Fifty-four patients undergoing partial colectomy surgery were randomized into four groups. All groups received a standardized general anesthetic. Group MB received a preoperative bolus of epidural bupivacaine and morphine followed by an infusion of morphine and bupivacaine. Group M received a preoperative bolus of epidural morphine followed by an infusion of morphine. Group B received a preoperative bolus of bupivacaine followed by an infusion of bupivacaine. Group P received a preoperative bolus of intravenous morphine followed by intravenous patient-controlled morphine postoperatively. All patients participated in a standardized recovery program to minimize the influence of nonanalgesic factors on recovery of gastrointestinal function. All epidural groups were double-blinded. All patients were deemed ready for discharge according to prospectively defined criteria. Groups B and MB reported superior analgesia with activity (P < 0.01). Group M had a greater incidence of pruritus (P < 0.05). Group B had a greater incidence of orthostatic hypotension (P = 0.04). Groups B and MB recovered gastrointestinal function and fulfilled discharge criteria approximately 1.5 days earlier than groups M and P (P < 0.005). Epidural analgesia with bupivacaine and morphine provided the best balance of analgesia and side effects while accelerating postoperative recovery of gastrointestinal function and time to fulfillment of discharge criteria after colon surgery in relatively healthy patients within the context of a multimodal recovery program.

Acute pain management in patients with prior opioid consumption: a case-controlled retrospective review

The patient with a history of current opioid consumption presenting in the acute postoperative setting presents a challenge for pain management. Standard treatment dosages and strategies are often ineffective in providing pain relief. This retrospective case-control study reviews 4 years' experience of the Acute Pain Service (APS) at our institution providing care for 202 chronic pain and opioid-consuming (CPOC) patients, 6.6% of 3058 patients undergoing urologic, gynecologic, orthopedic and general surgical procedures. Controls matched for age, gender, date and type of surgery, and postoperative pain relief modality were found for 180 (89%) of these patients. Patients were provided patient-controlled analgesia (PCA), or epidural opioid analgesia (EOA with boluses of preservative-free morphine or bupivacaine (1:16% + 2 μg/ml fentanyl (B/F)). Records were reviewed for patient demographics, diagnoses, surgical procedures, pre-operative opioid use, days-on-service, analgesic requirement, pain scores and incidence of moderate/severe side effects. Patient demographics were similar between CPOC and control groups. When considering PCA alone, mean 24-h usage in controls was 42.8 (32.0) mg morphine (MS) equivalents differing significantly from CPOC patients' use of 135.8 (68.5) mg MS equivalents ( P = 0.0001). EOA and B/F case studies showed similar results. Moderate sedation was experienced by 50% of CPOC patients receiving PCA. Differences in opioid usage, side effects, pain scores, sedation and prescribed treatment with anxiolytics were shown between CPOC patients and matched controls. Treatment implications suggested by the data include: (1) PCA use by the patient with prior opioid consumption can be expected to be significantly increased beyond mere replacement; (2) pain scores will be higher in patients with prior opioid exposure; and (3) pruritic and emetic symptoms are less likely to be experienced by patients with prior opioid use.

Extrapleural bupivacaine for amelioration of multiple rib fracture pain.

The pain associated with multiple rib fractures can be surprisingly variable. The objective of this study was to determine the efficacy of an indwelling, percutaneously placed intercostal catheter in relieving the pain associated with multiple rib fractures. Prospective nonrandomized study setting: Surgical intensive care unit in a level 1 trauma center. Fifteen blunt chest trauma patients with a minimum of three rib fractures who had failed an intravenous patient controlled analgesia protocol. Insertion of an epidural catheter within the intercostal space. Bupivacaine 0.25% with epinephrine was injected in a volume of 20 mL. Subsequent doses were limited to a total of 400 mg per 24 hours. Severity of injury was estimated by using the Injury Severity Score. For each patient a preinjection visual analogue scale (VAS) and incentive spirometry (IS) lung volume were determined. Fifteen minutes following injection of 0.25% bupivacaine with epinephrine the VAS and IS were repeated. The Injury Severity Score ranged from 9 to 32 (mean 19.0 +/- 1.6). Overall, mean VAS pain scores improved significantly following the initial bolus of bupivacaine (before VAS = 7.5 +/- 0.6, after VAS = 3.5 +/- 0.5, p < 0.05) and this was associated with significant increase in IS lung volumes (before IS = 0.77 +/- 0.09, after IS = 1.3 +/- 0.13, p < 0.05). No patient experienced either insertion-related or drug administration complications. These results confirm that an indwelling intercostal catheter provides a continuous nerve block resulting in a simple, safe procedure that can ameliorate the pain and splinting associated with multiple rib fractures. Although we experienced no complications, additional investigation is clearly needed.

Clonidine Pretreatment Reduces the Systemic Toxicity of Intravenous Bupivacaine in Rats

Clonidine prolongs the duration of sensory and motor block induced by bupivacaine, and this association, in constant infusion by the epidural route, is used for postoperative analgesia. After a near-fatal intravenous bolus of bupivacaine in dogs, clonidine improves ventricular electrophysiologic parameters, but probably worsens bupivacaine-induced bradycardia and depression of the myocardial contractility. The current study, using a rodent animal model, evaluated the influence of clonidine pretreatment on the systemic toxic effects of bupivacaine overdose induced by a constant intravenous infusion. Twenty Wistar male rats were anesthetized with thiopental, and controlled ventilation was started with an equal mixture of O2 and N2O. Electrocardiogram (ECG), electroencephalogram (EEG), and invasive arterial blood pressure were continuously recorded. Clonidine (5 micrograms/kg) or saline was injected intravenously in a randomized fashion. After 15 min, an intravenous infusion of bupivacaine was started at 2 mg.kg-1 x min-1. The time of occurrence of the bupivacaine-induced toxic events was recorded and the doses were calculated. Ten (five in each group) additional rats, pretreated according to the same protocol, were killed at the time of the first dysrhythmia, for blood sampling and plasma bupivacaine concentration measurement. Clonidine reduced heart rate and arterial blood pressure before bupivacaine infusion (P < 0.05). The threshold doses at the first QRS modification (11.3 +/- 5.6 vs. 2.1 +/- 0.9 mg/kg) and the first dysrhythmia (40.6 +/- 15.3 vs. 8.48 +/- 3.7 mg/kg), the increase in EEG total spectral power (33.3 +/- 21.9 vs. 8.2 +/- 5.1 mg/kg), the 25 and 50% reduction in baseline mean arterial pressure and heart rate, the isoelectric EEG (58.6 +/- 14 vs. 22 +/- 6.6 mg/kg), and the final systole (99 +/- 16 vs. 51.8 +/- 14.5 mg/kg) were significantly greater in the clonidine group than in the saline group (P < 0.01). The time between the first dysrhythmia and 50% reduction of baseline mean arterial blood pressure was not different between the groups. In the additional series, the first dysrhythmia occurred later (10.9 +/- 4.5 vs. 3.2 +/- 1.0 min, P < 0.01) and plasma bupivacaine levels were greater (18.7 +/- 8.0 vs. 7.8 +/- 3.2 micrograms/ml, P < 0.01) in the clonidine group than in the saline group. In this model, clonidine given prophylactically delays the toxic manifestations of bupivacaine overdose and does not accentuate the subsequent hypotension.

Displacement of lidocaine from the lung after bolus injection of bupivacaine

The purpose of this study was to determine whether lidocaine was displaced from the lung after bolus injection of bupivacaine. Fourteen anesthetized rabbits were randomly assigned to either a bupivacaine or a control group. Lidocaine was infused at a rate of 10 mg.kg-1 x hr-1. After one hour of infusion, a bolus of bupivacaine (1 mg.kg-1) in normal saline (0.2 ml.kg-1) was injected into the central venous circulation in the bupivacaine group. The control group was injected with normal saline. After bolus injection, arterial blood samples were collected serially from an internal carotid artery at 1.2-sec intervals for 24 sec. The baseline concentration of lidocaine was 3.0 +/- 0.1 micrograms.ml-1 in the bupivacaine group and 3.2 +/- 0.1 micrograms.ml-1 in the control group (NS). Arterial concentrations of lidocaine increased to a maximum of 4.7 +/- 0.2 micrograms.ml-1 in the bupivacaine group (P = 0.0001). No increases were seen in the control group. These findings indicate that lidocaine was displaced from the lung into the blood after bolus injection of bupivacaine. The amount of lidocaine displaced during the first passage of bupivacaine through the lung was calculated to be 92.3 +/- 9.7 micrograms. It is concluded that lidocaine is displaced from the lung after bolus injection of bupivacaine.

The Uptake of Bupivacaine in an in situ Isolated Perfused Rabbit Lung Preparation

A double indicator technique has been used in an in situ isolated perfused rabbit lung model to examine the first pass effect of the lung on systemic bupivacaine concentrations. Bupivacaine (0.5 mg/kg) was given in two consecutive boluses to six in situ isolated perfused New Zealand White rabbit lung preparations. The mean recovery (first bolus) of bupivacaine was 62.6% +/- 6.3 (S.E.M.), and 63.7% +/- 10.2 (second bolus), suggesting bupivacaine accumulation in the lung. The average mean transit time for bupivacaine was 280.5% +/- 24.1 and 264.8% +/- 36.7 longer than ICG (Indocyanine Green) following the first and second boluses respectively (P less than 0.01). There were no differences in the first pass effect of the lung between the first and second boluses of bupivacaine. The profiles of the bupivacaine concentrations suggest that uptake is followed by accumulation and later back diffusion. This has implications for conditions that decrease the uptake and therefore increase the risk of systemic toxicity.

Nicardipine reduces the cardio-respiratory toxicity of intravenously administered bupivacaine in rats

The purpose of our study was to examine the effect of intravenous (IV) nicardipine pretreatment (30 micrograms.kg-1), given three minutes before an IV bolus of bupivacaine to determine its effect on the incidence of fatal bupivacaine cardio-respiratory toxicity in adult male Sprague Dawley rats anaesthetized with intraperitoneal pentobarbital. Fifty rats were divided into four groups. Groups I and II (n = 10 each) received 3.5 mg.kg-1 0.5 per cent bupivacaine and Groups III and IV (n = 15 each) received 5.0 mg.kg-1, 0.5 per cent bupivacaine. Groups I and III received pretreatment with normal saline before bupivacaine, whereas Groups II and IV were given pretreatment with nicardipine, 30 mg.kg-1. There was no difference in the incidence of survival between the nicardipine pretreatment group and the saline placebo pretreatment group given 3.5 mg.kg-1, 0.5 per cent bupivacaine (no fatalities in either group). However, there was significant protection by nicardipine pretreatment in the group given 5 mg.kg-1, 0.5 per cent bupivacaine (13 of 15 survived, compared with only 4 of 15 in the saline pretreatment group, P less than 0.001). In conclusion, our data demonstrate that in rats given 0.5 per cent bupivacaine, 5 mg.kg-1, nicardipine pretreatment protected against fatal cardio-respiratory toxicity.

Blood levels of bupivacaine after arthroscopy of the knee joint

Toxic levels of bupivacaine have been reported in other types of surgery, but have not been previously noted in arthroscopic procedures. The purpose of this study was to evaluate bupivacaine levels after an intraarticular bolus of bupivacaine administered after arthroscopic surgery. Blood levels of bupivacaine were found to be significantly higher in patients in whom synovial surgery had been performed compared with those patients in whom the procedure involved only meniscal or articular cartilage surgery. A reduction in the bupivacaine dosage when the synovium has been resected or divided is recommended to keep the serum level below the potentially toxic range.