International journal of obstetric anesthesia
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Int J Obstet Anesth · May 1992
Ephedrine and phenylephrine for avoiding maternal hypotension due to spinal anaesthesia for caesarean section. Effects on uteroplacental and fetal haemodynamics.
The effects of i.v. vasopressors on Doppler velocimetry of the maternal uterine and placental arcuate arteries and the fetal umbilical, renal and middle cerebral arteries were studied during spinal anaesthesia in 19 healthy parturients undergoing elective caesarean section. Fetal myocardial function was investigated at the same time by M-mode echocardiography. The patients were randomized into two groups, to be given either ephedrine or phenylephrine as a prophylactic infusion supplemented with minor boluses if systolic arterial pressure decreased by more than 10 mmHg from the control value. ⋯ The ephedrine group showed no significant differences in any of the Doppler velocimetry recordings relative to the baseline values, but during the phenylephrine infusion the blood flow velocity waveform indices for the uterine and placental arcuate arteries increased significantly and vascular resistance decreased significantly in the fetal renal arteries. Healthy fetuses seem to tolerate these changes in uteroplacental circulation well, however, since the Apgar scores for the newborns and the acid-base values in the umbilical cord were within the normal range in both groups. The results suggest that some caution is required when selecting the specific vasopressor agent, the dosage and the mode of administration for the treatment of maternal hypotension secondary to spinal anaesthesia for caesarean section.
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Int J Obstet Anesth · May 1992
Spinal or epidural anaesthesia for elective caesarean section? A Swedish experience.
Ninety seven women undergoing elective lower segment caesarean section were randomly divided into two groups, group 1 received spinal anaesthesia with hyperbaric bupivacaine and group 2 received mepivacaine 20 mg/ml with adrenaline 5 microg/ml via an epidural catheter. All patients were given a preload of Ringer acetate and Macrodex prior to onset of anaesthesia. Ephedrine 5 mg was given if the systolic blood pressure fell below 100 mmHg. ⋯ The Apgar scores at 1 and 5 min were similar in both groups. The results from our study suggest that spinal anaesthesia is a good alternative to epidural anaesthesia for elective caesarean section. A fall in blood pressure, which is equally possible in both groups of patients, should be prevented by adequate fluid preload and treated immediately by intravenous ephedrine.
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Int J Obstet Anesth · Jan 1992
Epidural insertion: how far should the epidural needle be inserted before testing for loss of resistance?
The aim of this study was to determine the depth to which an epidural needle can safely be inserted before testing for loss of resistance. This ensures that the epidural needle is advanced far enough to encounter ligament thus avoiding the confusion that can occur when testing for loss of resistance whilst still in subcutaneous tissues. A survey of the distance between the skin and the epidural space in 400 obstetric patients was performed. ⋯ Dividing the patient's pregnant weight by 25 will give this distance in centimetres. Seventy six paramedian approaches were performed and a less good correlation was found between the depth of the space and the woman's weight. There was no correlation with height or foot size.
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Int J Obstet Anesth · Jan 1992
The effectiveness of low dose droperidol in controlling nausea and vomiting during epidural anesthesia for cesarean section.
The antiemetic efficacy of 0.5 mg of droperidol was evaluated in 128 term parturients undergoing elective and non-urgent cesarean section with epidural anesthesia. Following delivery, parturients received intravenously either 0.5 mg of droperidol or normal saline in a double-blinded fashion. Droperidol decreased nausea after delivery from 41 to 13% (P=0.001). ⋯ Analysis of the data using logistic regression analysis showed that increasing age (P = 0.002), hypotension after delivery (P = 0.040), and vomiting prior to delivery (P = 0.017) were associated with increased nausea after delivery. No extrapyramidal symptoms or significant changes in pulse rate or blood pressure were associated with droperidol administration. We conclude that 0.5 mg of intravenous droperidol decreases nausea in term parturients undergoing non-urgent cesarean section with epidural anesthesia without producing unwanted side-effects.
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The effectiveness of postoperative pain relief and the frequency of side effects with three different doses of epidural diamorphine (2.0, 3.5 and 5 mg) was investigated. The study was carried out double-blind in 30 women undergoing awake elective caesarean section. Postoperative pain intensity was measured on a linear analogue scale. ⋯ Three patients in the 2 mg group failed to achieve scores of zero but were comfortable. No nausea or vomiting was seen but the incidence of itching was 0, 30% and 80% in the 2.0, 3.5 and 5 mg groups respectively. We conclude that epidural diamorphine 2 mg is adequate for relief of post-caesarean pain and higher doses may increase the incidence of unwanted side-effects.