Spinal Anesthesia and Severe Gestational HypertensionDr. Alison Macarthur Department of Anesthesia University of TorontoOutlinetReview of population / current obstetric practicestMethods of anesthesia for cesarean delivery (past / present)tSuggestions for future practiceClassification of PIHIncidence of Complicated Gestational HypertensiontIncidence of GH: (U.S. 1979 - 86) 26 / 1000 live births tcontrast this with other nations:20.3 / 1000 live births (Taiwan 1993-97)103 / 1000 live births (Turkey 1986)tIncidence of severe disease:5.2 / 1000 live births (U.S. 1986)7.8 / 1000 live births (Taiwan 1993-7)Incidence of Gestational HypertensiontIncidence of eclampsia:0.56 / 1000 live births (U.S.)19 / 1000 live births (Turkey)tMortality: (U.S. 1979 - 92) 1.5 / 100,000 live birthsSpinal anesthesia - introduction into practice tObstetric anesthesiologists started using spinal anesthesia for cesarean delivery (1990s) in mild - moderate diseasetchange from 1st to 2nd ed. Chestnuts Obstetric Anesthesia:“Some anesthesiologists consider spinal anesthesia contraindicated in preeclampsia because of the risk of severe hypotension.”Old EvidenceHood - Hemodynamic resultsEpiduralSpinalWallace - Hemodynamic resultsKarinen - Fetal Outcome (Pulsatility index)New EvidenceSOAP 2001; A34Spinal Anesthesia for EclampticstNo. of antepartum eclamptic parturients requiring immediate delivery: 1505 / 1846 (81.5%)tNo. of cesarean deliveries:1185 / 1505 (78.7%)Spinal Anesthesia for EclampticstMethod of anesthesia for cesarean delivery:915 / 1185 spinal anesthesia (77.2%) 270 / 1185 general anesthesia (22.8%)Spinal Anesthesia for EclampticstNo. of deaths amongst women requiring LSCS delivery:58 / 1505 (3.9%)total deaths = 176 / 1846 (9.5%) Spinal Anesthesia for EclampticstNo. of deaths by method of anesthesia:spinal = 31 / 915 (3.4%)general = 27 / 270 (10%)tOdds Ratio (general / spinal)3.17 (95% C.I. 1.86, 5.41)Spinal Anesthesia for Eclamptics - Remaining Questions?1. What factors determined type of anesthetic?2. What were the causes of death in each group?3. Where there complications in each group?4. Not all the women with antepartum eclampsia (1846) delivered (1505). What happened to these women?New EvidenceRegional Anesthesia and Pain Medicine 2001; 26: 46-51Ramanathan - Study MethodstDesign: case series of 46 women, severe preeclampsia receiving CSE for cesarean deliverytIntervention: intrathecal bupivicaine 7.5 mg + fentanyl 25 mcg (+ epidural lidocaine 2%)Ramanathan - Study MethodstOutcomes: BP, Ephedrine doses, Apgar score, umb ABGtResults: 8% epidural supplementation / 34% prior to closuremedian sensory level T4 (T2-T5)52% reqd ephedrine use, nadir w/i 5 min of spinalRamanathan - Hemodynamic changesSBPDBPMAPComments: Dr. HoodtOral exam preparation: does the clinical scenario leave time for an epidural?tUrgent clinical scenario: spinal anesthetictResidents taught to use spinal anesthesiat2/3 attendants 2000 OAA meeting use spinal anestheticsPersonal PearlstChoosing patient: consider airway, bleeding diathesis, neurological status, urgency tMethods:hyperbaric bupivicaine 0.75% 11.25-13.5mgpreservative-free morphine 0.1-0.2mgtConsider intra-arterial monitortPre-determine % change in MAP or systolic bp to respond with vasopressorConclusions Future research: Await RCT however.1. Changing obstetric practice:327 / 444 (73.6%) labored2. Lack of clinical equipoise:“.we could not do a randomised epidural versus spinal trial for severe pre-eclamptics.”Future StudiestSophisticated evaluation of fetal / neonatal wellbeing during course of regional anesthesiatContinued reporting of observational data (specifically: morbidity) Conclusiont are not to convince that spinal anesthesia should replace epidural anesthesiatinstead. to convince you that spinal anesthesia should be an option instead of general anesthesia