Summary Table 5Studies on the effectiveness and safety of neural blockade for acute pain (KQ2)

Author, YearStudy Design, settingSample sizeClinical category; baseline painIntervention/exposure of interestOutcomes measuredResults
Chudinov, 199921Randomized trial in orthopedic hospital, Israel40Hip fracture, undergoing surgeryPsoas compartment block using 2mg/kg/body weight of 0.25% bupivacaine with adrenaline (0.8 ml/kg) and supplementary doses as required via catheter vs. no blockLength of follow-up: perioperative period only (72 hours). Pain relief assessed by VAS. Adverse effects of the blockThe psoas compartment block resulted in significantly less pain at 8 and 16 hours pre-operatively, and also at 16, 24, and 32 hours post-operatively. Proportionally more patients who received the psoas block were satisfied with pain control compared with controls.
Haddad, 199522Randomised trial50Extracapsular hip fractureFemoral nerve block inserted at time of admission using 0.3ml/kg of 0.25% buipivacaine vs. control group (no injectionMean pain score using VAS: pre-block and at 15 mins, 2 hrs and 8 hrs. Amount of analgesic administration within first 24 hrs of co-codramol, voltarol, pethidine. Incidence of respiratory infections, CVA, pulmonary embolism, deep vein thrombosis, urinary tract infection, skin breakdown, mortality, failed nerve block.Femoral nerve block provided a greater reduction in the mean pain scores that was statistically significant at 15 minutes (mean change −2.6 v. −0.7) and at 2 hours (mean reduction −3.0 v. −1.2). The number of parenteral analgesic drugs administered in the 24 hrs from admission was reduced for the nerve block group. Local or systemic complications did not occur with the use of femoral nerve blocks.
Scheinin, 200023Randomized trial, orthopedic hospital in Finland59Hip fracture, undergoing surgeryLumbar epidural using bupivacaine and fentanyl inserted within 6 hrs of admission. Infusion rate adjusted according to patients requirements vs intramuscular opiate (oxycodone 0.1–0.15mg/kg) at 6 hourly intervals as necessary. All patients operated on using spinal anesthesiaLength of follow-up for clinical outcomes was 3 days. Mortality for 3 years was determined using central statistic register. Pain relief as assessed by VAS (scale 0–100). Ischemic episodes as determined by continuous electrocardiogram recording; nocturnal oxygen saturation; itching; nausea; quality of sleep; mortality.Pre-operative pain scores did not significantly differ (p=0.42) continuous epidural infusion of bupivacaine plus fentanyl (mean value 34) vs controls who received parenteral opiates IM (mean 42), although post-operative pain scores were significantly (p=0.006) reduced in the epidural group (mean 22) compared with intramuscular opiates (mean 35). No mention of complications specific to the treatment.
Halbert, 2002 #142824SR of 12 controlled trials that reported phantom pain as an outcomeIncluded 12 trials, total 375 patients (both men and women), ages 47–75.8 trials of treatment of acute phantom pain with preoperative, intra-operative, and early (<2 weeks) postoperative interventions8 trials on phantom limb pain studied epidural treatments (3 trials); regional nerve blocks (3); calcitonin (1); and transcutaenous electrical nerve stimulation (1). 4 trials on late postoperative pain studied transcutaneous electrical nerve stimulation (2) and Farablock (a metal threaded sock) and ketamine (1 trial each). In 8 preop/intraop/early post-op trials, the interventions included epidural anesthesia (3 trials), regional nerve blocks (3), intravenous calcitonin (1) and TENS. Controls received a placebo consisting of a saline infusion or epidural anesthesia consisting of on-demand opioid analgesia. 5 trials used opioid analgesia, and 1 trial used sham TENS with and without chlorpromazine. Trials that used epidural anesthesia commenced 18–72 hours before surgery. Blockade anesthesia commenced during the operation or postoperatively. 4 trials of late postop interventions included TENS, Farabloc, vibratory stimulation, and infused ketamine.Effect on phantom limb pain at various time points up to 12 months post-amputationUp to 70% of patients have phantom limb pain after amputation. There is little evidence from randomized trials to guide clinicans with treatment.
Evidence on preemptive epidurals, early regional nerve blocks, and mechanical vibratory stimulation provides inconsistent support for these treatments.
Knoop, 199425Randomized prospective, nonblinded clinical study, convenience sample; inner-city and community hospital ER30Patients had 3rd or 4th finger injuries including and distal to the proximalinterp halangeal joint that required digital anesthesia. Injuries included lacerations (67%) and infections (27%).Digital blocks and a metacarpal block were performed on each patient, in randomized order. Additional anesthesia was given and noted when required for all patients.
After a period of no less than 10 minutes, the patient was treated in a mannger consistent with the injury (ie, sutures, incision, and drainage).
Patients immediately rated pain associated with each technique on a nonsegmented VAS. Efficacy was assessed by requirement for additional anesthesia and anesthesia to pinprick. Time to anesthesia was assessed after each block in 23 patients. Patients were asked which technique they thought was more painful or if there was no difference between the 2 techniques. Responses were recorded for 10 minutes.Digital block was less painful than metacarpal block by both VAS and by verbal comparison, but the differences did not reach statistical significance. There were no sig. Diffs in the VAS scores of the first block compared with the second block. Mean VAS scores were 2.53 cm for digital block, and 3.35 cm for metacarpal block (p=ns).
40% of patients rated the digital block as more painful, and 7% noted no difference in pain between the blocks (p=ns).
Digital block was found to be more efficacious as metacarpal block failed anesthesia to pinprick in seven of 30 metacarpol blocks (23%) compared with one of 30 (3%) for digital block (p=0.02). When requirement for additional anesthesia was assessed, digital block was adequate 97% of the time (29 of 30 blocks), while metacarpal block was adequate 87% of the time (26 of 30 blocks, p=ns).
Time to anesthesia available in 23 patients was found to be significantly shorter for digital block compared with metacarpal block, with a mean of 2.82 minutes vs. 6.35 minutes (p<0.0001).

From: APPENDIX E, Evidence Summary Tables

Cover of Assessment and Management of Acute Pain in Adult Medical Inpatients
Assessment and Management of Acute Pain in Adult Medical Inpatients: A Systematic Review [Internet].
Helfand M, Freeman M.
Washington (DC): Department of Veterans Affairs (US); 2008 Apr.

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