Puerperal seizures after post-dural puncture headache.

OBJECTIVE: To describe eight cases of postpartum women who developed seizures associated with post-dural puncture headache. METHODS: Between the years 1982-1991, more than 19,000 women at our institution underwent subarachnoid analgesia for delivery or puerperal tubal sterilization. In eight of these women, grand mal seizures developed after spinal headache. RESULTS: In all eight women, typical post-dural puncture headaches were followed by visual disturbances that progressed to cortical blindness in three. These headaches and visual disturbances culminated in generalized tonic-clonic seizures 2-7 days after dural puncture. Although some of these women had transient hypertension at the time of seizure, none had preeclampsia. In three of the women evaluated, there was evidence of regional blood flow changes; two had diffuse cerebral artery vasospasm seen on angiography, and the third had diminished blood flow detected by a xenon-flow study. CONCLUSION: We propose that cerebral vasoconstriction is the mechanism for post-dural puncture headaches and seizures. Anatomic brain displacement may incite this vasospasm. This mechanism could also be the cause of cranial nerve palsies that have been described after dural puncture.

Randomized comparison of general and regional anesthesia for cesarean delivery in pregnancies complicated by severe preeclampsia.

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.

Airway management for patients with penetrating neck trauma: a retrospective study.

Airway management in patients with penetrating neck trauma is controversial. We reviewed the records of 107 patients with penetrating neck trauma from 1989 through 1991 for primary intubation technique, mechanism of injury, zone of injury, and structures injured. Six patients (6%) received a surgical airway as the primary choice, 89 (83%) had direct laryngoscopies after rapid sequence induction of anesthesia, eight (7%) had awake fiberoptic bronchoscopies, and four (4%) had awake blind nasotracheal intubation. The success rates for primary surgical were 100%, fiberoptic 100%, direct laryngoscopy 98%, and blind nasal 75%. Two (2%) of the patients in the direct laryngoscopy group required a secondary emergency surgical airway. One failed blind nasal attempt (25%) resulted in the patient's death due to loss of airway during a secondary attempt at an emergency surgical airway. A second patient died as a result of hemorrhage not related to airway management. Success rates were not statistically different with any of the four airway management techniques chosen primarily. However, the one death in the awake nasal intubation group and the technical and time constraints of fiberoptic intubation cause us to prefer rapid sequence induction of anesthesia with direct laryngoscopy or a primary surgical airway in patients with penetrating neck trauma who need an emergency airway.

Cervical spine movement during orotracheal intubation: comparison of the Belscope and Macintosh blades.

This study was designed to compare the degree of cervical spine movement during laryngoscopy and tracheal intubation using the Belscope and Macintosh laryngoscope blades. Twenty ASA 1 and 2 patients scheduled for elective surgery requiring tracheal intubation were studied. Following induction of anaesthesia and muscle relaxation, a neutral cross-table lateral cervical spine X ray was taken. Laryngoscopy was then performed in each patient using both the Belscope and Macintosh blades. After visualisation of the vocal cords and tracheal intubation the cervical spine X ray was repeated. Movement of the cervical spine was evaluated by tracing bony landmarks on each film and then superimposing the neutral and intubating films. We were unable to demonstrate a difference in the amount of cervical spine movement comparing the two blades. Using the Belscope blade, intubation took longer (median 18 s) than the Macintosh blade (median 12 s, p < 0.01) and was unsuccessful in two patients despite adequate visualisation of the vocal cords.

Clinical audit of anaesthesia practice and adverse peri-operative events at Parkland Memorial Hospital, Dallas, Texas.

A study was undertaken to compare the quantity and nature of adverse event data collected during two equivalent time periods in 1990-1991 and 1991-1992 respectively. During the first period adverse event data were collected and reviewed sporadically, critical incidents were not specifically identified and no formal mechanism for regular presentation of these data existed. During the second period a new and detailed data collected from was introduced. The resulting data were analysed and presented to trainee and senior anaesthetists during formal clinical education sessions. Adverse incident reporting was significantly increased during the later period. Unsafe clinical practices and common errors were also more easily identified.

Comparison of prophylactic angiotensin II versus ephedrine infusion for prevention of maternal hypotension during spinal anesthesia.

OBJECTIVE: Our purpose was to study the efficacy of ephedrine versus angiotensin II prophylactic infusions to counter maternal hypotension that occurs during spinal anesthesia at cesarean delivery. STUDY DESIGN: Healthy pregnant women undergoing elective repeat cesarean delivery at term with spinal anesthesia were randomized either to a control group (n = 10) or to one of two prophylactic infusion groups: angiotensin II (n = 10) or ephedrine (n = 10). Prophylactic infusions were titrated to a maternal diastolic blood pressure 0 to 10 mm Hg above baseline. Maternal and fetal blood samples for angiotensin II levels and acid-base status were obtained. Student's t test, chi 2, and analysis of variance were used. RESULTS: Mean arterial pressures were maintained after spinal anesthesia in the ephedrine and angiotensin II groups but decreased (p < 0.05) in the control group. Maternal angiotensin II levels rose with angiotensin II infusions but were unaltered in the other groups. Umbilical artery and vein angiotensin II levels were unaltered by angiotensin II infusions. Mean umbilical artery blood pH was lower (p < 0.05) in the ephedrine group than in the angiotensin II and control groups. CONCLUSIONS: In the healthy term fetus there is an advantage in using angiotensin II to maintain maternal blood pressure during regional anesthesia.

Fetal effects of prophylactic ephedrine and maternal hypotension during regional anesthesia for cesarean section.

The purpose of this study was to evaluate the effects of a prophylactic intravenous bolus of ephedrine on the incidence and severity of maternal hypotension and on neonatal outcome. Term healthy parturients (n = 122) scheduled for elective repeat cesarean section under regional anesthesia were studied. Ninety-two women received 10 mg ephedrine as a prophylactic intravenous bolus prior to intrathecal epidural local anesthesia. Thirty parturients who served as controls did not receive prophylactic ephedrine. Maternal blood pressures, Apgar scores, and umbilical cord blood acid-base status were evaluated. Sixty-three of 92 women (69%) who received intravenous prophylactic ephedrine prior to regional anesthesia developed hypotension compared to 21 (70%) controls. The mean (+/- SD) lowest systolic blood pressure was similar in both groups (95.6 +/- 12.9 vs. 96 +/- 8.9 mmHg; P = 0.86). The mean (+/-SD) fetal pH was significantly lower with prophylactic ephedrine than controls (7.24 +/- 0.07 vs. 7.28 +/- 0.05; P = 0.001). The frequency of umbilical artery blood pH < 7.20 was 10.6% for the ephedrine group vs. 3.2% for controls (P = 0.024). Among newborns of hypotensive mothers, the frequency of umbilical artery blood pH < 7.20 was 30.2% and 4.6% for the ephedrine and control groups, respectively (P = 0.018). Intravenous prophylaxis with ephedrine did not significantly decrease the frequency of hypotension in women receiving regional anesthesia and resulted in a greater proportion of umbilical artery blood pH values < 7.20.

Comparison of adenosine and remifentanil infusions as adjuvants to desflurane anesthesia.

BACKGROUND: Because adenosine has been alleged to produce both anesthetic and analgesic sparing effects, a randomized, double-blinded study was designed to compare the perioperative effects of adenosine and remifentanil when administered as intravenous adjuvants during general anesthesia for major gynecologic procedures. METHODS: Thirty-two women were assigned randomly to one of two drug treatment groups. After premedication with 0.04 mg/kg intravenous midazolam, anesthesia was induced with 2 micro/kg intravenous fentanyl, 1.5 mg/kg intravenous propofol, and 0.6 mg/kg intravenous rocuronium, and maintained with desflurane, 2%, and nitrous oxide, 65%, in oxygen. Before skin incision, an infusion of either remifentanil (0.02 microg x kg(-1) x min(-1)) or adenosine (25 microg x kg(-1) x min(-1)) was started and subsequently titrated to maintain systolic blood pressure, heart rate, or both within 10-15% of the preincision values. RESULTS: Adenosine and remifentanil infusions were effective anesthetic adjuvants during lower abdominal surgery. Use of adenosine (mean +/- SEM, 166+/-17 microg x kg(-1) x min(-1)) was associated with a significantly greater decrease in systolic blood pressure and higher heart rate values compared with remifentanil (mean +/- SEM, 0.2+/-0.03 microg kg(-1) x min(-1)). Total postoperative opioid analgesic use was 45% and 27% lower in the adenosine group at 0-2 h and 2-24 h after surgery, respectively. CONCLUSIONS: Adjunctive use of a variable-rate infusion of adenosine during desflurane-nitrous oxide anesthesia was associated with acceptable hemodynamic stability during the intraoperative period. Compared with remifentanil, intraoperative use of adenosine was associated with a decreased requirement for opioid analgesics during the first 24 h after operation.