Published in The Cochrane Database of Systematic Reviews. 2006 Oct 18;(4): at www.interscience.wiley.com

Techniques for preventing hypotension during spinal anaesthesia for caesarean section

Thrombocytopenia in critically ill patients receiving thromboprophylaxis: frequency, risk factors, and outcomes.

Lung cancer is the leading cause of cancer-related death in the United States, accounting for over 30% of cancer deaths in men and 25% in women. Small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) are uniformly aggressive tumors, with rates of regional or distant metastases at diagnosis as high as 70%. Because the majority of these tumors are unresectable, patients with relatively good performance status receive platinum-based chemotherapy. Although no treatment consensus exists, currently recommended regimens for SCLC include PE (cisplatin and etoposide), CAV (cyclophosphamide, doxorubicin, and vincristine), CAE (cyclophosphamide, doxorubicin, and etoposide), and CAVE (cyclophosphamide, doxorubicin, vincristine, and etoposide). Of these, the PE regimen has been widely accepted in the United States, although CE (carboplatin and etoposide) provides better tolerability. For NSCLC, standard chemotherapy regimens have included platinum-based therapy (cisplatin and a vinca alkaloid or PE). Data from recent studies suggest that the addition of paclitaxel to platinum modestly improves tumor response and survival in NSCLC. Although SCLC and NSCLC are both responsive to first-line chemotherapy, most patients relapse and die from their disease, with 5-year survival rates of approximately 15%. Given the disappointing survival rates associated with SCLC and NSCLC, the introduction of new cytotoxic agents has been eagerly anticipated. Evidence of improved response and extended survival is mounting for various combinations of established regimens (e.g., PE) with newer drugs exhibiting novel mechanisms of action and single-agent antitumor activity, such as gemcitabine, paclitaxel, docetaxel, vinorelbine, and topotecan. This article reviews the current standards of care in SCLC and NSCLC, and introduces the potential role of newer agents given in combination with standard chemotherapy.

Current standards of care in small-cell and non-small-cell lung cancer

Summary Spinal anaesthesia is the preferred anaesthetic technique for elective Caesarean deliveries. Hypotension is the most common side-effect and has both maternal and neonatal consequences. Different strategies have been attempted to prevent spinal-induced hypotension, including the use of low-dose bupivacaine. We conducted a systematic search for randomized controlled trials comparing the efficacy of spinal bupivacaine in low dose (LD ≤8 mg) with conventional dose (CD >8 mg) for elective Caesarean delivery. Thirty-five trials were identified for eligibility assessment, 15 were selected for data extraction, and 12 were finally included in the meta-analysis. We investigated sources of heterogeneity, subgroup analysis, and meta-regression for confounding variables (baricity, intrathecal opioids, lateral vs sitting position, uterine exteriorization, and study population). Sensitivity analysis was performed to test the robustness of the results. In the LD group, the need for analgesic supplementation during surgery was significantly higher [risk ratio (RR)=3.76, 95% confidence interval (95% CI)=2.38–5.92] and the number needed to treat for an additional harmful outcome (NNTH) was 4 (95% CI=2–7). Furthermore, the LD group exhibited a lower risk of hypotension (RR=0.78, 95% CI=0.65–0.93) and nausea/vomiting (RR=0.71, 95% CI=0.55–0.93). Conversion to general anaesthesia occurred only in the LD group (two events). Neonatal outcomes (Apgar score, acid–base status) and clinical quality variables (patient satisfaction, surgical conditions) showed non-significant differences between LD and CD. This meta-analysis demonstrates that low-dose bupivacaine in spinal anaesthesia compromises anaesthetic efficacy (risk of analgesic supplementation: high grade of evidence), despite the benefit of lower maternal side-effects (hypotension, nausea/vomiting: moderate grade of evidence).

Efficacy of low-dose bupivacaine in spinal anaesthesia for Caesarean delivery: systematic review and meta-analysis

Multimodal therapy in perioperative analgesia

Conservative management of postoperative bronchopleural fistulas.

BACKGROUND: Spinal anaesthesia for caesarean section exposes to high incidence of arterial hypotension which can result in maternal and neonatal morbidity. We hypothesized that the reduction of this dose from 10 mg to 7.5 mg would minimize hypotension without altering pain relief. METHODS: In this double-blind prospective study, 80 ASA1 women scheduled for elective caesarean section were randomized into two groups A and B receiving respectively 10 and 7.5 mg of isobaric bupivacaine both with 25 microg of fentanyl and 100 microg of morphine in spinal anaesthesia. Intravenous ephedrine was administered for each episode of hypotension. We recorded sensory and motor block, intraoperative pain, nausea and vomiting. In postanaesthesia care unit, sensory and motor recoveries were measured and maternal satisfaction rate was assessed. RESULTS: In group A, a larger dose of ephedrine was needed (32 +/- 23 vs 19 +/- 16 mg; p = 0.004). Incidence of sensory block above T4 (52 vs 10%; p < 0.001), nausea (52 vs 22%; p = 0.005) and vomiting (25 vs 8%; p = 0.03) were all higher than in group B. Arterial hypotension was less frequent in group B (68 vs 88%; p = 0.03). The time required for recovery to T10 sensory level and motor regression were shorter than in group A (p < 0.001) and the satisfaction rate was higher than in group A (excellent and good in 90% vs 67%; p = 0.03). There was no difference in pain relief. CONCLUSION: A dose of 7.5 mg of isobaric bupivacaine reduced incidence of hypotension, nausea and vomiting and improved patient satisfaction.

Reduction of bupivacaine dose in spinal anaesthesia for caesarean section may improve maternal satisfaction by reducing incidence of low blood pressure episodes.

Background We investigated whether intrathecally magnesium sulphate added to morphine and fentanyl reduces patients’ postoperative analgesia requirements and prolongs spinal opioid analgesia after thoracotomy. Methods In a single-center, prospective, placebo-controlled, double-blind trial, we enrolled 58 adult patients undergoing elective posterolateral thoracotomy. Patients were randomized to receive either 25 μg of fentanyl citrate (0.5 mL) + 300 μg of morphine + 1.0 mL of preservative-free 0.9% sodium chloride (Group S) or 25 μg of fentanyl citrate (0.5 mL) + 300 μg of morphine + 50 mg of magnesium sulphate 5% (1.0 mL) (Group MgSO4) for intrathecal analgesia. Opioid consumption and postoperative pain were assessed for 36 hours. Results VAS pain scores at rest and on coughing were similar in all groups. The total 36-h intravenous morphine requirements were significantly lower in group MgSO4 (14 [9.50–26.50] mg vs. 33 [30–41] mg, p  Conclusion We found that in patients undergoing pulmonary resection with elective posterolateral thoracotomy, magnesium sulphate (50 mg), when added to spinal morphine analgesia reduces postoperative morphine requirements, the number of patients requiring morphine titration without increasing opioid side effects.

The effect of adding intrathecal magnesium sulphate to morphine-fentanyl spinal analgesia after thoracic surgery. A prospective, double-blind, placebo-controlled research study

The polypharmacological approach to the treatment of postoperative pain has become routine in an attempt to minimize the adverse side effects of opioids. Magnesium sulphate is a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) receptor and thus can modify nociceptive modulation. Intravenous administration of magnesium sulphate can improve postoperative analgesia and decrease the requirement for postoperative opiates, but the effects are inconsistent and have not been reliably accompanied by a reduction in the incidence of morphine-related adverse events. Several studies have shown that the administration of magnesium by the intrathecal route is safe and, in combination with opiates, extends the effect of spinal anaesthesia in both animal and human studies. The analysis of these studies justifies further investigation of the use of magnesium sulphate by the intrathecal route.

Is magnesium sulfate by the intrathecal route efficient and safe

BACKGROUND AND OBJECTIVE Spinal anaesthesia for caesarean section is commonly associated with hypotension and crystalloid preload is widely recommended. Low-dose spinal appears to cause less hypotension. The aim of this study was to investigate whether the combined use of crystalloid preload and low dose spinal anaesthesia might further reduce the rates of hypotension. METHODS Sixty-two patients were randomly assigned to two groups: crystalloid preload anaesthesia (P): received a rapid infusion of 20 mL/kg lactated Ringer's solution (LR), and no preload anaesthesia (N). The incidence of hypotension and the amount of ephedrine used to treat it were compared. Spinal anaesthesia was performed with 0.5% isobaric bupivacaine 7.5 mg and fentanyl 10 microg and morphine 100 microg. RESULTS The incidence of hypotension was similar in the P and N groups. Same doses of ephedrine were required to treat hypotension in the two groups. CONCLUSION Crystalloid preload combined with low-dose spinal anaesthesia do not reduce the incidence of hypotension nor its severity.

Combined use of crystalloid preload and low dose spinal anesthesia for preventing hypotension in spinal anesthesia for cesarean delivery: a randomized controlled trial.

Taher Mestiri

Papers

Conservative management of postoperative bronchopleural fistulas.

Reduction of bupivacaine dose in spinal anaesthesia for caesarean section may improve maternal satisfaction by reducing incidence of low blood pressure episodes.

The effect of adding intrathecal magnesium sulphate to morphine-fentanyl spinal analgesia after thoracic surgery. A prospective, double-blind, placebo-controlled research study

Is magnesium sulfate by the intrathecal route efficient and safe

Combined use of crystalloid preload and low dose spinal anesthesia for preventing hypotension in spinal anesthesia for cesarean delivery: a randomized controlled trial.