Delayed bilateral spinal anaesthesia following interscalene brachial plexus block

Purpose

To present a case of delayed neuraxial blockade after interscalene brachial plexus block.

Clinical features

A 65-yr-old lady presenting for radial head excision underwent a right interscalene block using bupivacaine and lidocaine. She experienced excellent anaesthesia and had stable vital signs for the duration of surgery. However, after 65 min, she developed signs of bilateral neuraxial block, progressing over the following hour to involve the cervical to lumbar dermatomes, with sparing of the phrenic nerves. The patient remained alert and communicative throughout with haemodynamic stability. Two days following the block, the patient experienced severe frontal and occipital pain, typical of a post dural puncture headache, which responded to fluids and recumbency.

Conclusion

This example of delayed central neural blockade complicating interscalene block is presented in contrast to other reports, which have usually occurred promptly after injection, accompanied by complete sensory and motor block requiring cardio-respiratory support. The presumed mechanism of the delayed onset of bilateral neuraxial spread was a durai cuff puncture with slow CSF spread from a plexus sheath “depot” of local anaesthetic.     

Motor block in regional anaesthesia

A device based on a load cell was constructed to measure the strength of foot dorsiflexion and plantarflexion. Performance of the device was evaluated for both movements. The influence of foot position within the device, its use over a 30-min period at 30-s intervals and the effect of the removal and reapplication of the device on measured force of dorsiflexion and plantarflexion was studied in six volunteers. Both dorsiflexion and plantarflexion are suitable movements on which to base a device to quantify the density of motor block during the onset and offset of neuraxial block. Dorsiflexion has a number of advantages: muscle strength is independent of knee position, and therefore a below-knee device can be constructed; strength of dorsiflexion is less affected by the foot position; we found the device easier to apply using dorsiflexion as the heel tended to self-locate; innervation of the muscles responsible for dorsiflexion involves fewer spinal segments.     

Pharmacokinetics of bupivacaine after bilateral ultrasound-guided transversus abdominis plane block following cesarean delivery under spinal anesthesia

BackgroundTransversus abdominis plane block is an effective method of post-cesarean analgesia. There are no data available about plasma bupivacaine levels after this block in adults. This study aimed to assess bupivacaine pharmacokinetic parameters after ultrasound-guided transversus abdominis plane blocks following cesarean delivery under spinal anesthesia.MethodsA prospective observational study in parturients undergoing elective cesarean delivery under hyperbaric bupivacaine spinal anesthesia was conducted. After surgery, patients received bilateral transversus abdominis plane block (50 mg bupivacaine each side). Venous blood samples were collected immediately before performing the block and at 10, 20, 30, 45, 60, 90, 120, 180, 240, 720 and 1440 minutes. High performance liquid chromatography was used to measure total plasma bupivacaine concentrations. Mean bupivacaine area under the curve (AUC) was calculated from 0 to 24 hours.ResultsData were collected from 17 parturients. Mean age and body mass index were 31 ± 6 y and 30 ± 4 kg/m² respectively. Mean plasma bupivacaine concentration before the block was 171 ng/mL. Mean peak concentration was 802.36 ng/mL (range 231.8 to 3504.5 ng/mL). Mean time to peak concentration was 30 min and mean area-under-the-curve (0–24 h) was 4505.4 h.ng/mL. Mean elimination half-life was 8.75 h. Three subjects had concentrations above the quoted toxic threshold and mild symptoms suggestive of neurotoxicity were reported by two subjects, but no treatment was required.ConclusionSingle-dose bilateral transversus abdominis plane block using 100 mg of bupivacaine, after spinal anesthesia for cesarean delivery, can result in toxic plasma bupivacaine concentrations.     

Fracture risk following bilateral orchiectomy

PURPOSE: Bone loss has been reported in patients with prostate cancer treated with androgen deprivation therapy. We assess fracture risk following bilateral orchiectomy. MATERIALS AND METHODS: Through the Rochester Epidemiology Project we identified 429 Olmsted County, Minnesota men who underwent bilateral orchiectomy in 1956 to 2000, almost all for prostate cancer. Fractures were ascertained from comprehensive medical records and compared with expected numbers based on local incidence rates (standardized incidence ratio, SIR). Potential risk factors were assessed with proportional hazards models. RESULTS: During 1961 person-years of followup 161 men experienced 267 fractures, for a cumulative incidence after 15 years of 40% compared to 19% expected (p <0.001). However, 42 were pathological fractures and 82 were found incidentally on radiological surveys for metastasis. Overall fracture risk was increased (SIR 3.42, 95% CI 2.91-3.99) but was reduced by excluding the pathological and incidental fractures (SIR 2.04, 95% CI 1.66-2.47). The increase was largely accounted for by the moderate trauma fractures of the hip, spine and distal forearm traditionally linked with osteoporosis (SIR 3.50, 95% CI 2.71-4.43). In multivariate analyses risk factors for fractures generally included patient age, inactivity, prior radiological diagnosis of osteoporosis, chemotherapy and use of nonsteroidal antiandrogens, while independent risk factors for the traditional osteoporotic fractures included age, inactivity and diagnosis of osteoporosis. CONCLUSIONS: Fractures are common in men with prostate cancer due to advanced age, occurrence of pathological fractures and enhanced skeletal surveillance but there remains a significant increase in osteoporotic fracture risk following bilateral orchiectomy.     

Shivering following retrobulbar block

A case of a severe but brief period of shivering following a retrobulbar block (RBB) is presented. The shivering occurred within two minutes after completion of the RBB and subsided gradually within five minutes, without specific treatment. The patient remained conscious during the episode of shivering. The shivering was so abrupt and severe as to be misjudged as a seizure, but its onset appeared to be slower than a seizure. The mechanism of shivering appeared to be the central spread of local anaesthetic solution into the brain stem, along the optic nerve. Shivering may be a warning sign of brain stem anaesthesia and demands special care to anticipate life-threatening complications.     

Iliac compartment block following ilioinguinal iliohypogastric nerve block

Transient femoral nerve palsy is a known complication associated with percutaneous ilioinguinal iliohypogastric nerve block. Excess volume and higher concentrations of local anesthetic have been implicated for transient femoral nerve palsy. We encountered partial iliac compartment block involving lateral cutaneous nerve of the thigh and femoral nerve with a lower concentration (0.25%) of bupivacaine administered in the smallest indicated volume of 0.25 ml.kg-1 using a double-shot technique.     

A comparison of bilateral infraorbital nerve block with intravenous fentanyl for analgesia following cleft lip repair in children

BACKGROUND: The efficacy of analgesia with bilateral infraorbital nerve block and intravenous (i.v.) fentanyl were compared for cleft lip surgery in children. METHODS: Eighty-two children aged 3 months to 10 years undergoing cleft lip repair were prospectively randomized to one of two groups: bilateral infraorbital nerve block (Group B), or i.v. fentanyl (Group F). Group B (n = 41) received bilateral infraorbital injection of 1 ml 0.25% bupivacaine and 2 ml i.v. saline as control. Group F (n = 41) received 2 microg x kg(-1) i.v. fentanyl, and bilateral infraorbital injection of 1 ml saline as control. Pain was evaluated by the incidence of tachycardia, hypertension, and/or modified pain score > or =4. The time to awakening, time to first cry and time to feeding were noted. RESULTS: Thirty four children (82.9%) in Group B had adequate analgesia compared with 15 (36.6%) in Group F (P < 0.0001, RR of failure 0.27 for Group B). Group B had a mean time to awakening of 5.65 +/- 2.52 min (Group F: 9.37 +/- 4.50 min; P < 0.0001), time to first cry 32.14 +/- 18.22 min (Group F: 28.00 +/- 16.27 min; P = 0.3), time to feed 62.05 +/- 20.06 min (Group F: 72.44 +/- 17.72; P = 0.015), and pain score 2.81 +/- 1.38 (Group F: 4.71 +/- 1.89; P < 0.0001). There were no major complications. CONCLUSIONS: Bilateral infraorbital block is superior to fentanyl in terms of analgesia, and time to awakening and feeding.