Efficacy of Bupivacaine Delivered by Wound Catheter for Post-Caesarean Section Analgesia

Summary: A prospective, randomized, double-blind trial was conducted to assess contribution to postoperative analgesia of intermittent instillation of 0.25% bupivacaine beneath the rectus sheath in 70 women delivered by lower uterine segment Caesarean section. The operations were performed via a Pfannenstiel incision under spinal anaesthesia. Background intravenous narcotic analgesia was provided with a patient controlled analgesia system (PCAS) using a standard morphine regimen.
Overall (44 hr) mean morphine consumption was significantly greater in the placebo (saline) group compared to the treatment group (84.2 mg versus 63.3 mg. Two tailed t test p<0.001). The most significant intergroup differences in narcotic use were found in the first 4 hours and between 24 and 36 hours after commencing PCAS (Two tailed t test p=0.014 and 0.003 respectively).
Subjective pain scores were assessed with a 10 cm visual analogue scale (VAS). The mean peak VAS score was greater in controls (5.37) than the treatment group (4.25) between 18 and 24 hours postoperatively (Mann-Whitney U=424, p=0.027). There were no intergroup differences in pain scores for any other time period. The overall incidence of nausea was lower in the treatment group compared to the control group (Chi squared with Yates' correction p=0.046) and a lower degree of sedation was seen in those receiving bupivacaine between 4 and 8 hours after commencing PCAS (Mann-Whitney U=427, p=0.028). No differences in other narcotic related side-effects (vomiting and pruritus) were shown between groups.
Regular instillation of 0.25% bupivacaine beneath the rectus sheath of women delivered by Caesarean section reduces their morphine requirements by 25% in the 44 hours after operation, with an associated reduction in both nausea and early sedation.     

Chronic Widespread Pain Drawn on a Body Diagram is a Screening Tool for Increased Pain Sensitization,Psycho‐Social Load,and Utilization of Pain Management Strategies

The aim of this study was to investigate the hypothesis that chronic widespread pain, (CWP) drawn by patients on a body diagram, could be used as a screening tool for increased pain sensitization, psycho‐social load, and utilization of pain management strategies. The triage questionnaires of 144 adults attending a chronic pain outpatients' clinic were audited and the percentage pain surface area (PPSA) drawn on their body diagrams was calculated using the “rule of nines” (RON) method for burns area assessment. Outcomes were measured using the painDETECT Questionnaire (PD‐Q) and other indices and compared using a nonrandomized, case–control method. It was found that significantly more subjects with CWP (defined as a PPSA ≥ 20%) reported high (≥ 19) PD‐Q scores (suggesting pain “sensitization” or neuropathic pain) (P = 0.0002), “severe” or “extremely severe” anxiety scores on the Depression, Anxiety and Stress Scale‐21 Items Questionnaire (P = 0.0270), ≥ 5 psycho‐social stressors (P = 0.0022), ≥ 5 significant life events (P = 0.0098), and used ≥ 7 pain management strategies (PMS) (P < 00001), compared to control subjects with a lower PPSA. A Widespread Pain Index score ≥ 7 (OR = 11.36), PD‐Q score ≥ 19 (OR = 4.46) and use of ≥ 7 PMS (OR = 5.49) were independently associated with CWP. This study demonstrates that calculating PPSA on a body diagram (using the RON method) is a valid and convenient “snapshot” screening tool to identify patients with an increased likelihood of pain sensitization, psycho‐social load, and utilizing pain management resources.     

Can There be a Place for Intraoperative Salvaged Blood in Spine Tumor Surgery?

Background

Intraoperative cell salvage (IOCS) has been used in musculoskeletal surgery extensively. However, it has never found its place in musculoskeletal oncologic surgery. We have conducted the first-ever study to evaluate the feasibility of IOCS in combination with a leucocyte-depletion filter (LDF) in metastatic spine tumor surgery. This was to pave the path for use of IOCS-LDF in musculoskeletal oncologic surgery.

Methods

Patients with a known primary epithelial tumor, who were offered surgery for metastatic spinal disease, were recruited. Blood samples were collected at three different stages during the surgery: from the operative field before IOCS processing, after IOCS processing, and after IOCS-LDF processing. Three separate samples (5 mL each) were taken at each stage. Samples were examined using immunohistochemical monoclonal antibodies to identify tumor cells of epithelial origin.

Results

Of 30 patients in the study, 6 were excluded for not fulfilling the inclusion criteria, leaving 24 patients. Malignant tumor cells were detected in the samples from the operative field before IOCS processing in eight patients and in the samples from the transfusion bag after IOCS processing in three patients. No viable malignant cell was detectable in any of the blood samples after passage through both IOCS and LDF.

Conclusions

The findings support the notion that the IOCS-LDF combination works effectively in eliminating tumor cells from salvaged blood, so this technique can be applied successfully in spine tumor surgery. This concept can then further be extended to whole musculoskeletal tumor surgery and other oncologic surgeries with further appropriate clinical studies.