M. Pitkänen

Comparison of analgesic efficacy of oxycodone and morphine in postoperative intravenous patient-controlled analgesia

Background: Morphine has been the standard opioid in patient‐controlled analgesia (PCA). Oxycodone, the analgesic potency of which in i.v. administration has been suggested to be slightly greater than that of morphine, has not yet been studied for its efficacy in PCA.

Efficacy of epidural blood patch for postdural puncture headache

This prospective investigation was conducted to evaluate the efficacy of different volumes of epidural blood patch (EBP) for treatment of postdural puncture headache (PDPH) in 81 consecutive patients. In the first part of the investigation (Study part I), 10 ml of blood was injected for EBP in 28 patients. In the second randomized part of the investigation (Study part II), the patients were allocated to receive for EBP either 10 ml (27 patients) or 10–15 ml (26 patients), according to the height of the patient. The procedure was considered initially successful if PDPH disappeared completely during the 2–h recovery room follow–up. To evaluate the long–term success, a questionnaire was mailed to all patients. The EBP performed 3.7± 2.9 days following the dural puncture was initially successful in 88–96% of the patients in the different study groups. In the questionnaire, only 50–68% of the patients reported that PDPH had disappeared immediately without recurrence. In 16–36% of the patients the PDPH returned at lesser intensity and in 14–17% PDPH was reported to have continued, disappearing gradually in all patients. Despite this, 87% of all patients were satisfied with the EBP treatment. There were no statistically significant differences between the groups. The results indicate that a larger, height–adjusted volume of blood for EBP in adults does not produce a better effect on PDPH compared to a standard 10–ml volume. Despite the excellent initial effect (91%) seen in our patients, a permanent effect of the blood patch was only achieved in 61%.

Postoperative pain relief and bupivacaine plasma levels during continuous interscalene brachial plexus block

Interscalene brachial plexus block was performed on 40 patients for prophylactic pain relief after shoulder surgery. A dose of 1.25 mg/kg of 0.5%, bupivacaine was injected for the block (Group 1) and continued with an infusion of 0.25%, bupivacaine 0.25 mg/kg/h (Group 2). If the postoperative analgesia was insufficient, the patients received i.m. oxycodone 0.15 mg/kg. In Group 1, one patient managed without oxycodone supplementation during the 24‐h observation period compared with eight patients in Group 2 [P < 0.01). The rest of the patients received 3.8 ± 1.6 doses (Group 1) and 2.5 ± 1.2 doses (Group 2) of oxycodone (P < 0.05). At 30 min, the mean bupivacaine plasma concentration was 1.0 pg/ml in Group 1 and 0.9 pg/ ml in Group 2. The mean plasma level of bupivacaine increased from 0.7 μg/ml after 180 min to 1.1 μg/ml (P < 0.01) after 24 h of infusion, providing some evidence of accumulation during infusion. The dizziness and confusion experienced by three patients could be associated with the local anaesthetic, as they obtained relief after the infusion was stopped.

Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function

Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the effect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double‐exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double‐exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPo2) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty‐one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 4–37% of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in ls (FEV1) and peak expiratory flow (PEF) 3 and 8 h after the block without signs of dyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.

A low dose of plain or hyperbaric bupivacaine for unilateral spinal anesthesia.

Background and Objectives Unilateral spinal anesthesia may be advantageous, especially in the outpatient setting. A low dose of anesthetic solution, pencil-point needle, low speed of intrathecal injection, and a lateral position have been reported to facilitate the production of unilateral distribution of spinal anesthesia. We compared the effects of plain and hyperbaric bupivacaine in attempting to obtain a unilateral spinal anesthesia for patients undergoing outpatient knee arthroscopy. Methods Sixty patients were randomly allocated to 2 groups to receive either 1.2 mL (6 mg) of plain 0.5% bupivacaine (group 1; n = 30) or 1.2 mL (6 mg) of hyperbaric 0.5% bupivacaine in 8% glucose (group 2; n = 30). Drugs were administered at the L2-3 interspace with the patient in the lateral position. Patients remained in this position for 20 minutes before being turned supine for the operation. Spinal block was assessed by pinprick and modified Bromage scale and compared between the operated and nonoperated sides. Results There was a significant difference between the operated and nonoperated side in both groups at all testing times, but a more unilateral spinal block was achieved with hyperbaric bupivacaine. Unilateral motor and sensory block was observed in 25 patients in group 2 (83%) and in 11 patients in group 1 (37%) (P < .01). The hemodynamic changes were minimal, since hypotension occurred only in 5.0% and bradycardia in 1.7% of all patients. Conclusion In conclusion, the spinal anesthesia in both groups are suitable alternatives for adult outpatient knee arthroscopies, but hyperbaric bupivacaine provides us with a more unilateral spinal block.

The Use of Bupivacaine and Fentanyl for Spinal Anesthesia for Urologic Surgery

We evaluated the effect of 25 &mgr;g of fentanyl added to bupivacaine on sensory and motor block. By using a double-blinded study design, 80 men undergoing urologic surgery were randomized into the following four groups: Group I, bupivacaine 10 mg; Group II, bupivacaine 10 mg + fentanyl 25 &mgr;g; Group III, bupivacaine 7.5 mg + fentanyl 25 &mgr;g; Group IV, bupivacaine 5 mg + fentanyl 25 &mgr;g. The final volume of intrathecal injectate was adjusted to 2.5 mL with sterile distilled water. Spinal anesthesia was administered with the 27-gauge Whitacre needle at the L2-3 interspace with the patient in the sitting position. Neural block was assessed by using pinprick and a modified Bromage scale. The degree of motor block was more profound in Group II compared with Group I at the end of operation. In Group IV, there was no motor block at the end of operation in any of the patients. The median level of the upper limit of the sensory block was higher than T7 in all groups before the start of surgery. The addition of 25 &mgr;g of fentanyl to 5 mg of bupivacaine resulted in short-acting motor block. When 25 &mgr;g of fentanyl was added to 10 mg of bupivacaine, it increased the intensity and duration of motor block. Only 5 (6.3%) of the patients needed supplemental analgesia during the operation. {abs} Implications Bupivacaine 5 mg with 25 &mgr;g of fentanyl for spinal anesthesia resulted in short-acting motor block. On the contrary, the addition of 25 &mgr;g of fentanyl to 10 mg of bupivacaine resulted in an increase in the motor block intensity and duration.

Comparison of hypotensive epidural anaesthesia and spinal anaesthesia on blood loss and coagulation during and after total hip arthroplasty Note

Background: Hypotensive epidural anaesthesia (HEA) is a technique for reducing peroperative blood loss by significantly lowering mean arterial pressure (MAP).

Intraarticular morphine for pain relief after knee arthroscopy performed under regional anaesthesia

Eighty patients scheduled to undergo knee arthroscopy were studied in random and double blind fashion. Spinal anaesthesia with hyperbaric 0.5% bupivacaine was selected for 40 overnight–in–patients. At the end of arthroscopy, 1 mg morphine or saline was injected intraarticularly. Local anaesthesia with 1% lidocaine plus adrenaline, was selected for another 40 out–patients. At the end of the arthroscopy either 1 mg morphine or saline was injected intraarticularly. As a rescue medication the spinal anaesthesia patients received oxycodone 0.14 mg kg‐1 i.m. or ketoprofen 100 mg p.o. and the local anaesthesia patients received ketoprofen 100 mg p.o. The need for additional postoperative analgesic was almost similar in both spinal anaesthesia groups. The patients having local anaesthesia and given intraarticular morphine needed fewer doses of ketoprofen (22 doses) postoperatively than the control group (39 doses) (P < 0.05). Duration of analgesia was slightly longer after morphine than in the control group (ns). There was no difference between the morphine patients and the control patients in the two studies regarding the incidence of side effects. We conclude that postoperative analgesia in patients undergoing knee arthroscopy under local anaesthesia, but not under bupivacaine spinal anaesthesia, can be improved with a single intraarticular injection of 1 mg morphine.

Patient-controlled epidural analgesia versus continuous epidural analgesia after total knee arthroplasty

Background: Patient‐controlled epidural analgesia (PCEA) has been found to be an effective method for pain relief during labour and after surgery. The goal of this study was to compare the efficacy of bupivacaine–fentanyl PCEA and continuous epidural infusion with the same mixture for treatment of pain after total knee arthroplasty.

Technical aspects and postoperative sequelae of spinal and epidural anesthesia: A prospective study of 3,230 orthopedic patients

Background and Objectives Major complications after spinal or epidural anesthesia are extremely rare. The occurrence of less serious and transient sequelae and complaints may be underestimated if there is no established organization for the systematic and continuous surveillance of patients after anesthesia. This study was designed to evaluate the possible relationship between various block-related occurrences and the intra- and postoperative side effects and complaints. Methods This prospective study included 3,230 orthopedic patients operated on under neuraxial block. The block was performed by single-dose (single-shot spinal anesthesia [SPIN], 80.6%), continuous spinal anesthesia (CSA, 10.3%), or combined spinal and epidural anesthesia (CSE, 9.1%) technique. The patient position during surgery and a detailed description of block performance and equipment, as well as all intraoperative problems, were immediately recorded. Every patient was given a standardized questionnaire to be completed and returned after 1 week. Results The overall incidence of paresthesia was 12.8%, being most frequent during spinal catheter insertion with multiple attempts. Postoperative sensory disturbances (numbness, dysesthesia) occurred unrelated to paresthesia elicited by the puncture or catheterization. The failure rates (SPIN, 1.0%; CSA, 1.5%; and CSE, 1.0%) were quite low. Asystole with successful resuscitation, occurred in 1 patient with CSE but, overall, hemodynamic perturbations were more common with the continuous techniques. On the first postoperative day, decreased sensation of the skin was significantly more frequent after the continuous techniques, still present in 6.5% of SPIN patients, 6.1% of CSA patients, and 17.2% of CSE patients 1 week after surgery. These disturbances were also related to the use of a tourniquet and lateral position of the patient during surgery. The frequency of postdural puncture headache (PDPH) was similar for the different techniques (SPIN, 0.9%; CSA, 1.5%; and CSE, 1.7%). About one third of the patients reported strong postoperative pain on the day after the operation, and 5.6% continued to report this at 1 week. Conclusions Although sensory changes were quite frequent, they were mild and transient. Rather than having been caused by the anesthetic technique, per se, a “nonanesthetic” reason (position, tourniquet, immobilization) should also be considered as their origin. Sensory disturbances, as well as strong pain for at least a week, were reported by several patients, and to become aware of these problems and improve the quality of treatment, a universal regional anesthesia follow-up system is recommended.