Dr. John Oyston MB BS, FFARCS.
Authors Brownridge P Title Spinal Anaesthesia Revisited: An Evaluation of Subarachnoid Block in Obstetrics Source Anaesth Intens Care (1984) 12:334-342. Abstract A review of the use of subarachnoid block in 442 women, including 275 Caesarean sections. Using #25 and #26 guage needles 15 (5.4%) of women developed spinal headaches after Caesarean section. Of these, 8 were mild, 5 moderate, and 2 severe (requiring epidural blood patch). Conclusion: "Spinal anaesthesia does not deserve to remain in the doldrums in obstetrical practice". Authors Riley ET. Cohen SE. Macario A. Desai JB. Ratner EF. Title Spinal versus epidural anesthesia for cesarean section: a comparison of time efficiency, costs, charges, and complications . Source Anesthesia & Analgesia. 80(4):709-12, 1995 Apr. Abstract Spinal anesthesia recently has gained popularity for elective cesarean section. Our anesthesia service changed from epidural to spinal anesthesia for elective cesarean section in 1991. To evaluate the significance of this change in terms of time management, costs, charges, and complication rates, we retrospectively reviewed the charts of patients who had received epidural (n = 47) or spinal (n = 47) anesthesia for nonemergent cesarean section. Patients who received epidural anesthesia had significantly longer total operating room (OR) times than those who received spinal anesthesia (101 +/- 20 vs 83 +/- 16 min, [mean +/- SD] P < 0.001); this was caused by longer times spent in the OR until surgical incision (46 +/- 11 vs 29 +/- 6 min, P < 0.001). Length of time spent in the postanesthesia recovery unit was similar in both groups. Supplemental intraoperative intravenous (i.v.) analgesics and anxiolytics were required more often in the epidural group (38%) than in the spinal group (17%) (P < 0.05). Complications were noted in six patients with epidural anesthesia and none with spinal anesthesia (P < 0.05). Average per-patient charges were more for the epidural group than for the spinal group. Although direct cost differences between the groups were negligible, there were more substantial indirect costs differences. We conclude that spinal block may provide better and more cost effective anesthesia for uncomplicated, elective cesarean sections. Authors Chadwick HS, L Brian Ready Brian L Title Intrathecal and Epidural Morphine Sulfate for Postcesarean Analgesia - A Clinical Comparison. Source Anesthesiology (1988) 68:925-929. Abstract A retrospective, non-randomised, analysis of 442 patients (like Brownridge!). Conclusion: "...intrathecal MS 0.3 - 0.5 mg provides a similar degree of high-quality post-cesarean analgesia as does epidural MS 3.0 - 5.0 mg. The duration of analgesia ... was longer with intrathecal administration... the side effects are no more severe ... than ...with epidural MS". Authors Oyston, JP Title Obstetrical anaesthesia in Ontario. Source Canadian Journal of Anaesthesia (1995) 42:1117-25. Abstract A postal survey of 100% of the 142 hospitals in the Canadian province of Ontario which had designated obstetrical beds in the fall of 1994. For Caesarean section, all hospitals used general anaesthesia sometimes. In 7 hospitals it was the only option. Epidural anaesthesia was used in 93% and spinal anaesthesia in 48%. For postoperative analgesia, 31% used PCA and 28% used spinal opioids. 66 hospitals relied exclusively on IM or IV narcotics. In labour, IM or IV opioids were used in 96%, nitrous oxide in 75%, epidural analgesia in 75%, TENS in 52% and PCA in 10%. The overall epidural rate was 38%. Authors Beilin Y, Bodian CA, Haddad EM, Leibowitz AB. Title Practic Patterns of Anesthesiologists Regarding Situations in Obstetric Anesthesia Where Clinical Management is Controversial. Source Anesthesia & Analgesia (1996) 83:735-41. Abstract A survey of 47 questions was mailed to 153 academic and 153 private obstetric anesthesiologists. Topics included preoperative testing, pre-eclampsia and coagulopathy, epidurals in patients with "spinal problems" and epidural opioids and IV supplements. There was a 61 - 74 % response rate, with little difference between private and academic practice. 88% of academic and 80% of private anesthesiologists "would use a spinal anesthetic for a patient presenting for an emergent cesarean section". If IV supplementation was needed, 64-76% would use ketamine, 44-65% would use fentanyl, and 16-31% would use midazolam. 98-99% used epidural infusions in labour, and 93-94% added opioids. Authors Smedstad KF, Cramb R, Morison DH. Title Pulmonary hypertension and pregnancy: a series of eight cases Source Canadian Journal of Anaesthesia (1994) 41:502-12. Abstract A review of eight cases of pulmonary hypertension, five due to Eisenmenger's. Seven delivered vaginally with epidural anaesthesia, and one died after general anaesthesia for Caesarean section. General discussion of issues, with references to two successful C-sections under epidural in patients with Eisenmenger's. Authors Wallace DH. Leveno KJ. Cunningham FG. Giesecke AH. Shearer VE. Sidawi JE. Title Randomized comparison of general and regional anesthesia for cesarean delivery in pregnancies complicated by severe preeclampsia. Source Obstetrics & Gynecology. 86(2):193-9, 1995 Aug. Abstract OBJECTIVE: To evaluate the maternal and fetal effects of three anesthetic methods used randomly in women with severe preeclampsia who required cesarean delivery. METHODS: Eighty women with severe preeclampsia, who were to be delivered by cesarean, were randomized to general (26 women), epidural (27), or combined spinal-epidural (27) anesthesia. The mean preoperative blood pressure (BP) was approximately 170/110 mmHg, and all women had proteinuria. Anesthetic and obstetric management included antihypertensive drug therapy and limited intravenous (IV) fluid and drug therapy. RESULTS: The mean gestational age at delivery was 34.8 weeks. All infants were born in good condition as assessed by Apgar scores and umbilical arterial blood gas determinations. Maternal hypotension resulting from regional anesthesia was managed without excessive IV fluid administration. Similarly, maternal BP was managed without severe hypertensive effects in women undergoing general anesthesia. There were no serious maternal or fetal complications attributable to any of the three anesthetic methods. CONCLUSION: General as well as regional anesthetic methods are equally acceptable for cesarean delivery in pregnancies complicated by severe preeclampsia if steps are taken to ensure a careful approach to either method. Authors Rout CC. Rocke DA. Levin J. Gouws E. Reddy D. Title A reevaluation of the role of crystalloid preload in the prevention of hypotension associated with spinal anesthesia for elective cesarean section [published erratum appears in Anesthesiology 1994 Aug;81(2):529]. Source Anesthesiology. 79(2):262-9, 1993 Aug. Abstract BACKGROUND: Hypotension after spinal anesthesia for cesarean section remains a common and serious complication despite the use of uterine displacement and volume preloading. The current study revaluated the role of crystalloid volume preloading in this context. METHODS: In a two-stage open sequential design, patients presenting for elective repeat cesarean section were allocated to receive either no preload or 20 ml/kg crystalloid administered over 15-20 min before spinal anesthesia. Hypotension was defined as a decrease in systolic pressure to less than 100 mmHg and to less than 80% of baseline value, and the study was designed to detect a 20% difference in the incidence of hypotension between the groups, with statistical significance at the 10% (alpha = 0.1) level, one-tailed. RESULTS: One hundred forty patients were studied. Hypotension occurred in 43 (55%, 95% CI 43.4-66.4) preloaded and 44 (71%, 95% CI 58-81.8) unpreloaded subjects, a difference in incidence of 16% (95% CI 0.04-31.6), which was statistically significant. There were no significant differences in the severity, timing, or duration of hypotension; the dose requirement for ephedrine; or the clinical and biochemical status of neonates between the groups. The only difference seen was a lower mean base excess (-3.4, SD 2.81 mM-1) in the neonates of hypotensive mothers compared to neonates of nonhypotensive mothers (-2.4, SD 1.99 mM-1). CONCLUSIONS: The study confirms that hypotension associated with spinal anesthesia for cesarean section cannot be eliminated by volume preloading in the supine wedged patient. The relatively small reduction in incidence of hypotension challenges our perception of the value of crystalloid preload. Though volume preload in the elective cesarean section is advocated, the requirement for a mandatory administration of a fixed volume before spinal anesthesia for urgent cases has been abandoned. Authors Inglis A. Daniel M. McGrady E. Title Maternal position during induction of spinal anaesthesia for caesarean section. A comparison of right lateral and sitting positions. Source Anaesthesia. 50(4):363-5, 1995 Apr. Abstract Forty women presenting for elective Caesarean section under spinal anaesthesia were randomly assigned to have anaesthesia induced in either the sitting or right lateral positions; 2.5 ml 0.5% hyperbaric bupivacaine was injected over 10 s before the mother was placed in a supine position with a 20 degree lateral tilt. The onset time and height of the subsequent analgesic and anaesthetic block was measured. It took longer to site spinal needles in the lateral position (240 vs 115 s, p < 0.001). There was a faster onset of sensory block to the sixth thoracic dermatomal level (8 vs 10 min, p < 0.001), in the lateral group, although onset time to T4 was comparable. There was no difference in maximum block height or degree of motor block. Mothers in the lateral group required more ephedrine in the first 10 m after siting the spinal (13.5 vs 10.5 mg, p < 0.05). Authors Morgan P Title Spinal anaesthesia in obstetrics Source Canadian Journal of Anaesthesia (1995) 42:1145-63. Abstract A detailed review of the history and current practice of spinal anaesthesia in obstetrics, including effects, techniques, indications and contra-indications, complications, and conclusions. Different needles are illustrated. Tables summarise the data on needle size and post dural-puncture headache, and offer a range of doses for both vaginal delivery and Caesarean section under spinal anaesthesia. Highly recommended. 134 references. Author Mayer DC. Quance D. Weeks SK. Title Headache after spinal anesthesia for cesarean section: a comparison of the 27-gauge Quincke and 24-gauge Sprotte needles . Source Anesthesia & Analgesia. 75(3):377-80, 1992 Sep. Abstract A high incidence of postdural puncture headache (PDPH) occurs after spinal anesthesia for cesarean section. To examine this problem, a study was conducted with the recently developed 24-gauge Sprotte and 27-gauge Quincke needles in patients undergoing elective and emergency cesarean section (n = 298). The needle to be used was assigned in a random manner: group I, 27-gauge Quincke (n = 147); group II, 24-gauge Sprotte (n = 151). During the postoperative period, patients were visited daily and asked specifically about the presence and severity of headache. The overall incidence of PDPH was 2% (n = 6), five in the Quincke group (3.5%) and one in the Sprotte group (0.7%). There was no significant difference in the incidence of PDPH between the two groups. Five headaches were classified as mild, and only one was moderate to severe. All headaches resolved quickly with conservative management and without blood patch. The authors conclude that the choice between a 27-gauge Quincke and a 24-gauge Sprotte needle does not influence the incidence of PDPH after spinal anesthesia for cesarean section. Author Smith EA. Thorburn J. Duckworth RA. Reid JA. Title A comparison of 25 G and 27 G Whitacre needles for caesarean section. Source Anaesthesia. 49(10):859-62, 1994 Oct. Abstract Spinal needles with a pencil-point tip and those of a finer gauge are known to be associated with a lower incidence of postdural puncture headache. This study set out to determine if fine pencil-point needles were acceptably easy to use in routine clinical practice. Two hundred and twelve women undergoing elective Caesarean section were randomly allocated to receive a subarachnoid block using either a 25 G or 27 G Whitacre needle. Factors determining ease of needle use, adequacy of block, incidence of postdural puncture headache, backache and neurological sequelae were assessed. Successful intrathecal injection was achieved in all patients in the 25 G group. Using the 27 G needle, the anaesthetist failed to reach the subarachnoid space in eight patients of which seven subsequently had a successful intrathecal injection with a larger needle. These failures were attributed to excessive needle flexibility which was the only significant difference in ease of use between the 25 G and 27 G needles. In the 25 G group, there was one severe postdural puncture headache which required an epidural blood patch and three mild headaches which resolved spontaneously. There were no postdural puncture headaches in the 27 G group. We conclude that the final choice of needle is a compromise between the ease of use and lower failure rate of the 25 G needle and the, as yet unproven, possibility of a lower incidence of postdural puncture headache with the 27 G needle.
Ritorna a Guida all’uso dell’anestesia Spinale per il taglio cesareo