[Efficacy of low-dose oxytocin during elective cesarean section]

BACKGROUND AND OBJECTIVE

In cesarean section, the optimal dose of oxytocin to reduce the risk of hemorrhage with the least risk of adverse effects has yet to be defined. We studied the effects of using 2 different doses of oxytocin in women undergoing elective cesarean section under spinal anesthesia. The women had had no prior labor.

MATERIAL AND METHODS

Randomized multicenter trial enrolling 104 patients classified as ASA 1. Following fetal extraction and coinciding with umbilical cord clamping, a group of 52 women received 1 IU of oxytocin followed by an infusion of 2.5 IU x h(-1); a second group of 52 women received a continuous infusion of 20 IU at a rate of 700 mlU x min(-1) followed by 10 IU x min(-1). We compared uterine contractility (assessed as absent, moderate, satisfactory), postoperative vaginal bleeding (absent, light, moderate, heavy), hemodynamics, and adverse effects after administration of oxytocin and fetal extraction (electrocardiographic abnormalities, nausea, vomiting, discomfort, headache, blushing, trembling, chills, or chest pain).

RESULTS

No significant between-group differences in patient, obstetric, or anesthetic variables were detected. Uterine contraction was satisfactory in over 90% of the patients in both groups on initial assessment during surgery. After surgery, vaginal bleeding was absent or light in over 90% of the women. No significant differences in adverse events were detected between groups.

CONCLUSIONS

The incidence of obstetric bleeding is not higher when a lower dose of oxytocin is used; the rate of postoperative adverse events also does not increase.

[Paresthesia and spinal anesthesia for cesarean section: comparison of patient positioning]

OBJECTIVE

To determine the incidence of paresthesia during lumbar puncture performed with the patient in different positions.

MATERIAL AND METHODS

A single-blind prospective study of patients scheduled for elective cesarean section, randomized to 3 groups. In group 1 patients were seated in the direction of the long axis of the table, with heels resting on the table. In group 2 they were seated perpendicular to the long axis of the table, with legs hanging from the table. In group 3 they were in left lateral decubitus position. Lumbar punctures were performed with a 27-gauge Whitacre needle.

RESULTS

One hundred sixty-eight patients (56 per group) were enrolled. Paresthesia occurred most often in group 3 (P = .009). We observed no differences in blood pressure after patients moved from decubitus position to the assigned position. Nor did we observe between-group differences in blood pressure according to position taken during puncture.

CONCLUSION

Puncture undertaken with the patient seated, heels on the table and knees slightly bent, is associated with a lower incidence of paresthesia than puncture performed with the patient seated, legs hanging from the table. Placing the patient's heels on the table requires hip flexion and leads to anterior displacement of nerve roots in the dural sac. Such displacement would increase the nerve-free zone on the posterior side of the sac, thereby decreasing the likelihood of paresthesia during lumbar puncture. A left lateral decubitus position would increase the likelihood of paresthesia, possibly because the anesthetist may inadvertently not follow the medial line when inserting the needle.

[Is oxygen therapy truly useful and necessary during elective cesarean section under spinal anesthesia?]

OBJECTIVE

To analyze maternal and fetal well-being with and without the application of oxygen therapy.

MATERIAL AND METHODS

Randomized trial of full-term parturients who had received prenatal care during pregnancy. The women were healthy and classified as ASA 1. They were scheduled for delivery by cesarean section under spinal anesthesia and randomized to 2 groups to breathe room air or air providing an inspired oxygen fraction of 40% through a face mask. We assessed the well-being of the neonate immediately after birth with the Apgar test and by measuring umbilical cord blood gases.

RESULTS

One hundred thirty women were enrolled. Both groups were similar, with no differences in demographic or hemodynamic variables, time from uterine incision to fetal extraction, neonatal birth weight, presence of umbilical cord abnormalities, type of resuscitation required by the neonate, or Apgar score in the first or fifth minute. Oxygen saturation in maternal blood by pulse oximetry was higher after 10 minutes in the group of women who received supplemental oxygen through face masks. We also observed significant differences in umbilical cord arterial blood between the room air and supplemental oxygen groups, respectively, as follows: PaCO2, 51.14 mm Hg vs 54.33 mm Hg (P=.016); bicarbonate, 22.19 mEq L(-1) vs 23.23 mEq L(-1) (P=.012); lactate, 1.85 mmol L(-1) vs 1.64 mmol L(-1) (P=.038). The PO2 in venous blood also differed significantly: 25.53 mm Hg vs 28.13 mm Hg, respectively (P=033).

CONCLUSIONS

Breathing supplemental oxygen or not during elective cesarean delivery of healthy parturients under spinal anesthesia does not have a significant effect on neonatal well-being.

[Continuous subarachnoid analgesia and anesthesia for labor and cesarean section in a patient who had previously undergone surgery for ependymoma]

We report the case of a 38-year-old primipara who had undergone surgery 2 years earlier for an intradural ependymoma at L2-L3 and who was currently asymptomatic. A combined epidural-subarachnoid block was performed for analgesia during labor but this technique was only effective for the first 2 hours. When analgesia via epidural cannula was no longer adequate, it was decided to perform a continuous subarachnoid block. Later, the fetus's head was seen to be too large to fit through the pelvis; for cesarean section, the mother was administered fractionated doses of local anesthetic via the subarachnoid cannula until analgesia reached T4. The patient did not develop postdural puncture headache. Continuous subarachnoid anesthesia may be considered the technique of choice where the patient has a history of spinal surgery.

[Air embolism during elective cesarean section, and uterine atony due to fetal macrosomia]

We report the case of a paradoxical air embolism during a scheduled cesarean section for fetal macrosomia (7.010 kg) in a 38-year-old woman with a history of gestational diabetes and preeclampsia. Spinal anesthesia was satisfactory and well tolerated. After approximately 30 minutes (coinciding with uterine exteriorization), the patient presented a sudden episode of dyspnea, confusion, hypotension, and ST segment depression. The episode lasted approximately 10 minutes and resolved spontaneously with no sequelae. Neurological status and the electrocardiogram were normal at the end of surgery and no postoperative lesions were observed. In the immediate postoperative period, the patient presented a massive hemorrhage due to uterine atony. Echocardiography revealed a patent foramen ovale. The clinical signs in this patient are highly suggestive of a paradoxical cerebral and coronary air embolism.

[Remifentanil bolus for cesarean section in high-risk patients: study of 12 cases]

OBJECTIVES

To evaluate the utility and safety of remifentanil for hemodynamic control during cesarean section in high-risk patients ineligible for spinal anesthesia.

METHODS

One minute before induction we injected a bolus of 1 microg x kg(-1) of remifentanil, followed by propofol (2.5 mg x kg(-1)), succinylcholine (1 mg x kg(-1)), cisatracurium, sevoflurane in oxygen and nitrous oxide, and fentanyl (5 microg x kg(-1)) after clamping the umbilical cord. We recorded maternal hemodynamic variables, pulse oximetry, capnography, bispectral index, and presence of muscular rigidity. In the neonate we assessed fetal wellbeing, weight, and requirement for naloxone. Hemodynamic stability was defined as no more than 15% variation in arterial pressure with respect to baseline.

RESULTS

Twelve patients undergoing surgery because of placenta abruptio, subarachnoid hemorrhage, HELLP syndrome, or preeclampsia were enrolled. Hemodynamic variables were consistently stable during surgery in all patients. No cases of neonatal rigidity were noted and there was no need for naloxone. The mean Apgar score was 6.42 (1.5) at 1 minute and 8.42 (0.9) at 5 minutes.

CONCLUSION

Bolus injection of 1 microg x kg(-1) of remifentanil may be useful for maintaining maternal hemodynamic stability in high-risk obstetric cases. Given the risk of neonatal depression, this resource should be used selectively and the means for neonatal resuscitation should be available.

[Experience with uterine artery embolization in the treatment of massive postpartum hemorrhage]

OBJECTIVE

To analyze our experience with uterine artery embolization in the management of massive hemorrhage in obstetric patients.

PATIENTS AND METHODS

This observational, retrospective study analyzed all deliveries requiring a blood transfusion that were performed in the maternity unit of Hospital Universitario La Paz between January 1, 2000 and December 31, 2005.

RESULTS

A total of 57,835 deliveries were performed with an incidence of postpartum hemorrhage of 0.7% (406 episodes). Uterine artery embolization was performed on 51 patients and 45 patients underwent obstetric hysterectomy. Both procedures were performed on 11 patients. Ten of the patients who underwent obstetric hysterectomy subsequently required uterine artery embolization, whereas only 1 patient required an obstetric hysterectomy following embolization because the hemorrhage was not resolved. The mean consumption of blood products for patients who underwent obstetric hysterectomy was twice that for patients who underwent uterine artery embolization. There were no complications secondary to embolization.

CONCLUSIONS

Uterine artery embolization is a safe and effective procedure for managing massive postpartum hemorrhage.

[Cesarean section in a woman with acute blood-stage malaria]

Malaria infection during pregnancy is a serious health problem in most of the world's tropical regions. The disease has also been imported into Western countries, however, as an increasing number of infected women, who may become pregnant, emigrate from areas where malaria is endemic. Infection during pregnancy can have serious repercussions for both mother and fetus. Early diagnosis and multidisciplinary management are essential. We report the case of a woman from Guinea who debuted with severe, acute blood-stage malaria in the 32nd week of pregnancy and was admitted to the recovery care unit.

[Emergency cesarean in a patient with Coffin-Siris syndrome]

Coffin-Siris syndrome is a rare genetic disease characterized by coarse facial features, sparse scalp hair, hirsutism, hypoplasia of the distal phalanges, hypoplastic nail in the fifth digit, and mental retardation and delayed growth evident in both weight and height. Most cases are sporadic, but the possibility of recessive or dominant autosomal inheritance has been suggested. Facial abnormalities that make intubation difficult and mental retardation that interferes with cooperation are aspects of this disease that can affect the choice of type of anesthesia. We report the case of a parturient with Coffin-Siris syndrome who refused epidural analgesia for labor pain and for whom the obstetrician later decided that an emergency cesarean was necessary due to fetal distress.

[Acute myocardial infarction during tocolytic treatment with ritodrine]

Ritodrine, a beta2-adrenergic agonist with a selective effect on the uterine muscle, is prescribed to prevent premature labor and to treat a hypertonic uterus. At therapeutic doses ritodrine has chronotropic and peripheral vasodilator effects. At high doses it has been related to sporadic cases of subendocardial necrosis, pulmonary edema, and death in pregnancy. We report the case of a pregnant woman who had a non-Q wave acute myocardial infarction after administration of ritodrine.

[Comparison of 2 techniques for combined spinal-epidural analgesia for advanced labor in childbirth]

OBJECTIVES

To assess whether using a needle-locking device in combined spinal-epidural analgesia leads to better quality of pain relief for advanced stages of obstetric labor than can be achieved with conventional materials.

PATIENTS AND METHODS

A total of 230 women in advanced labor were randomized to 2 groups. In both groups the needle-through-needle technique was used. In group N we used a new technique with a Tuohy needle and a system for locking the spinal needle (27-gauge, pencil-point design). The conventional technique (group C) made use of the same Tuohy needle and spinal needle without the needle-locking device. The variables considered were patient characteristics, anesthesiologist, number of attempts and level of difficulty in carrying out the procedure, pain on a simple verbal visual analog scale before the procedure and 5 minutes later, latency, motor block, duration of spinal analgesia, complications, type of expulsion, and maternal satisfaction.

RESULTS

The 2 groups were similar with respect to all studied variables except duration of spinal analgesia (longer in group N, P<0.001); VAS after 5 minutes (lower in group N, P<0.010); latency (shorter in group N, P<0.001); lateralization (less in group N, P=0.034), and maternal satisfaction (greater in group N, P=0.037).

CONCLUSIONS

The use of devices specifically designed for administering combined spinal-epidural analgesia in advanced stages of labor provides faster pain relief, longer duration of analgesia, and greater maternal satisfaction without increasing the incidence of complications.

[Postpartum seizures in 2 epileptic patients]

We report the cases of 2 women with epilepsy who suffered generalized postpartum seizures on the first day after giving birth. The first had a history of febrile convulsions in childhood and had a seizure in the 36th week of gestation due to sleep deprivation. She had received epidural analgesia for labor pain. The second patient had had her most recent crisis at the beginning of the third trimester of pregnancy. Both patients had low serum levels of antiepileptic drugs. The pharmacokinetics of antiepileptic drugs can change during pregnancy, making seizures more difficult to control. Serum levels of these drugs should therefore be monitored more often, given that a generalized maternal seizure can have devastating consequences for the fetus. More careful planning and management of pregnancy is necessary for epileptic patients to ensure successful outcomes for both mother and fetus.

[Amniotic fluid embolism: review]

The amniotic fluid embolism, is a very uncommon syndrome but because of its severity and high mortality, it is interesting to study and to get a deep knowledge of its etiopathogenia and physiopathology. In this article, we revise the actually purposed pathogenic mechanisms, specially the humoral mechanisms in front of mechanical, as it was defended a few years ago. The diagnostic of this syndrome, is an interesting question, because it is not only pathology, actually it trends to immunologic diagnosis. The amniotic fluid embolism, interests to anesthesiologist and its differences in cardiopulmonary resuscitation in the pregnant woman too. All these data are discussed in our article, as much as treatment, that is based upon haemodinamics and cardiopulmonary resuscitation.

[Anesthesia for vertebral osteoclasis in a patient with severe predominantly cervical spondylitis ankylopoietica]

We present a patient suffering severe, mainly cervical, ankylopoietic spondylitis who was scheduled for posterior vertebral osteoclasis under local anesthesia. We describe handling of anesthesia, particularly airway control by flexible bronchoscopy in an awake, locally anesthetized patient sedated with benzodiazepines and inhalational anesthetics as compared with other alternatives: an awake patient who is not intubated, under local anesthesia and sedated with narcotics and gaseous anesthetics, or a patient under general anesthesia with placement of a flexible bronchoscope and neurological monitoring by evoked potentials. The surgical technique was Simmons' posterior vertebral osteoclasis, with the column extended and immobilized with wire.