The effects of maternal position during induction of combined spinal-epidural anesthesia for cesarean delivery.

UNLABELLED: Combined spinal-epidural anesthesia (CSE) is a popular technique for cesarean delivery. Regional blocks in obstetrics are often performed with the parturient in the sitting position because the midline may be recognized more easily than in the lateral decubitus position. When conventional spinal anesthesia is performed in the sitting position, the patient is placed supine immediately after drug injection. In contrast, when CSE is performed with the woman sitting, there is a delay in assuming the supine position because of epidural catheter placement, which may affect the incidence of hypotension. Healthy women, at term of pregnancy, about to undergo an elective cesarean section under CSE, were randomly assigned to the sitting or lateral recumbent position for initiation of the block. All parturients were given 1000 mL of lactated Ringer's solution in the 15 min preceding induction and an additional 300-500 mL while the actual block was being performed. On completion of the CSE, they were turned to the supine position with left uterine displacement. A second anesthesiologist, blinded to the woman's position during CSE, evaluated the sensory level of anesthesia, maternal heart rate, blood pressure, oxygen saturation, need for ephedrine, and occurrence of nausea and vomiting. Results are expressed as mean +/- SD. Twelve women were studied in the sitting group and 10 were studied in the lateral recumbent group. The severity and duration of hypotension were greater in those parturients who had CSE induced in the sitting (47%+/-7% and 6+/-3 min, respectively) compared with the lateral recumbent position (32%+/-14% and 3+/-2 min, respectively). Women in the sitting group also required twice as much ephedrine (38+/-18 mg) to correct hypotension compared with the other group (17+/-12 mg). In conclusion, the severity and duration of hypotension were greater when CSE was induced in the sitting compared with the lateral decubitus position. IMPLICATIONS: We studied the induction of combined spinal-epidural anesthesia (CSE) in the sitting versus lateral recumbent positions in healthy women undergoing a scheduled cesarean delivery. The severity and duration of hypotension were greater when CSE was induced in the sitting position. Thus, the position used for induction of CSE should be among the factors considered when there is greater maternal or fetal risk from hypotension.

Complete recovery after near-fatal venous air embolism during cesarean section.

During replacement to the abdomen of the exteriorized uterus at cesarean section under epidural block, a previously healthy woman developed cardiorespiratory arrest. Tracheal intubation revealed low end-tidal carbon dioxide concentration suggesting embolization. Resuscitative efforts were successful. Uterine exteriorization - as well as the Trendelenburg position - significantly increase the risk of air embolization so that routine use of appropriate monitors is indicated to facilitate early diagnosis.

Fetal bradycardia resulting from maternal hypoglycemia. A report of two cases.

Two term-pregnant women presented in the obstetric unit with marked diaphoresis and tremulousness. Fetal heart rate monitoring revealed severe bradycardia. Both mothers had blood glucose levels consistent with the diagnosis of hypoglycemia. In both cases the fetal heart rate normalized with improvement in the mothers' glycemic state. The presence of maternal hypoglycemia should always be considered as a potential cause of fetal bradycardia.

The first spinal anesthesia. Who deserves the laurels?

BACKGROUND AND OBJECTIVES: One year after the discovery of the anesthetic properties of cocaine, the American neurologist Corning injected the drug between the spinous processes of the lower dorsal vertebrae, first in a young dog and then in a generally healthy man. He published the results in a paper entitled "Spinal Anaesthesia and Local Medication of the Cord." For many years, there has been controversy as to whether Corning's injection was a spinal or an extradural block. METHODS: To settle this controversy, a detailed review was undertaken, in the original language, of Corning's publication, as well as of two major initial articles describing authentic spinal anesthesia, namely that by the surgeon Bier of Germany and Tuffier of France. Mention of cerebrospinal fluid, dose of injected cocaine, onset of action, and height of sensory analgesia were compared. RESULTS: Corning's dose of local anesthetic was eight times higher than the doses of the same drug used by Bier and Tuffier; yet, the onset of analgesia in his patient was slower and the ultimate sensory level lower. Cerebrospinal fluid was not described in contrast to the other two publications. In addition, Corning proposed the action of cocaine to result from absorption into the venous circulation and subsequent transport to the cord. CONCLUSIONS: Corning's injection was extradural, and Bier deserves the laurels for introducing spinal anesthesia.

Changing Mallampati score during labour.

We present the case of a changing Mallampati score during the course of labour in a healthy primigravida. On admission to hospital, the airway was assessed as Mallampati class I-II. At 5 cm cervical dilation, the woman began to bear down strenuously and continued this despite being advised of the inherent hazard. At 8 cm dilation, Caesarean delivery was contemplated because of fetal heart rate decelerations. Repeat airway evaluation revealed marked oedema of the lower pharynx giving rise to a Mallampati score of III-IV. Improvement of the fetal heart rate tracing permitted vaginal delivery under local infiltration. Postpartum, the Mallampati score was still III-IV. However, 12 hr later it had returned to the admission classification of I-II. We recommend that, in addition to the usual airway evaluation on admission, the assessment be repeated in the obstetric patient before induction of general anaesthesia.

Successful spinal anesthesia after inadequate epidural block in a parturient with prior surgical correction of scoliosis.

BACKGROUND: Lumbar epidural anesthesia is safe in patients with previous spinal surgery, but it is not always successful or easily performed. METHOD: The authors present the case of a parturient with Harrington rod insertion, scheduled for cesarean delivery, whose epidural anesthetic could not be extended beyond the T10 level. RESULT: After letting the epidural block recede below the lumbar level, a successful spinal anesthetic was administered producing a sensory level to T4.

Automated blood pressure measurements in laboring women: are they reliable?

OBJECTIVE: In laboring women a consistent difference has become evident between measurements obtained with an automated blood pressure device and those obtained with the auscultatory method. A prospective study was designed to assess the concordance of these two methods. STUDY DESIGN: Three sets of brachial blood pressure measurements were made by both oscillatory and auscultatory techniques in 30 women in labor, 20 term pregnant women not in labor, and 20 nonpregnant volunteers. RESULTS: In the nonlaboring women and the nonpregnant controls there was satisfactory agreement between the results of the two methods of measurement. In the parturients systolic pressures were consistently and significantly higher and diastolic pressures consistently and significantly lower with the oscillatory compared with the auscultatory method, but mean arterial pressures were not different. CONCLUSION: In laboring women there is a discrepancy between systolic and diastolic pressures obtained by the auscultatory versus the oscillatory method of measurement, although mean pressures are not significantly different. We suggest that during labor the diagnoses of hypertension and hypotension be based on the mean rather than the systolic or diastolic pressure.

The introduction of nitrous oxide analgesia into obstetrics.

Nitrous oxide analgesia was introduced into obstetrics by a young Polish-Russian physician who manufactured the gas himself, mixed it with oxygen, humidified the mixture with water vapor, and devised a mouthpiece for self-administration. After assessing the results on himself, he evaluated the effects on pain relief, maternal emotion, and maternal and fetal heart rates, as well as on the frequency, duration, and strength of uterine contractions in 25 parturients. He recognized that, in contrast to chloroform, nitrous oxide did not alter uterine activity. He concluded that the advantages of nitrous oxide administration far outweighed its disadvantages.