Increased cerebrospinal fluid concentration of aspartate but decreased concentration of nitric oxide breakdown products in women experiencing visceral pain during active labour

The aim of the present study was to investigate some putative neurotransmitters involved in nociception and pain in parturients during active labour experiencing intense visceral pain. The concentration of the excitatory amino acid aspartate was significantly increased, and there was a tendency for an increase in glutamate, in lumbar cerebrospinal fluid (CSF) of parturients in active vaginal labour compared with control patients without pain subjected to elective caesarean section. The CSF concentration of the nitric oxide breakdown product nitrate was significantly decreased in parturients compared with control patients and healthy volunteers. No significant differences in the concentrations of substance P, substance P-endopeptidase or met-enkephalin were detected between parturients and controls. Our data suggest a paradoxical negative relationship between CSF concentrations of excitatory amino acids and nitric oxide in labour pain. The mechanisms behind this finding is unclear at present.

Anesthetic quality during cesarean section following subarachnoid or epidural administration of bupivacaine with or without fentanyl

BACKGROUND

It is often assumed that subarachnoid administration of local anesthetics produces a more profound blockade than epidural anesthesia. Furthermore, the addition of fentanyl has been reported to increase preferentially intraoperative analgesia. In the present study we set out to study these two issues in a randomized and controlled study with respect to perceived pain and discomfort during surgery and postoperative pain.

METHODS

In the present study, 100 parturients subjected to elective cesarean section, 34 nullipara and 66 multipara, received one out of four combinations of the local anesthetic bupivacaine and the opioid fentanyl; group A--bupivacaine 12.5 mg + 10 micrograms fentanyl subarachnoidally, group B--bupivacaine 12.5 mg + saline subarachnoidally, group C--bupivacaine 100 mg + 100 micrograms fentanyl epidurally, group D--bupivacaine 100 mg + saline epidurally; N = 25 in each group. Pain intensity and discomfort during surgery was assessed with a visual analogue scale (VAS). Postoperative pain intensity and need for analgesics postoperatively, ketobemidone, was registered for 24 h following surgery.

RESULTS

Intraoperative pain intensity and discomfort did not differ significantly between parturients in any of the four groups Postoperative pain was significantly more intense in parturients receiving local anesthetics subarachnoidally as compared to the epidural groups during the first 6-h period. This difference was also reflected in a significantly increased consumption of analgesics during this period. No significant differences between the groups were observed with regard to hemodynamics (blood pressure), respiration (oxygen saturation) or other effects such as nausea or itching. All neonates had normal Apgar and neonatal adaptive capacity scores (NACS).

CONCLUSION

We conclude that subarachnoidal (12.5 mg) and epidural (100 mg) injections with bupivacaine both produced adequate anesthetic quality in women undergoing elective cesarean section. The addition of fentanyl (10 micrograms subarachnoidally or 100 micrograms epidurally) did not significantly improve the quality of these already profound blockades.

Lack of analgesic effect of systemically administered morphine or pethidine on labour pain

OBJECTIVE

To evaluate the true analgesic effect of morphine and pethidine on labour pain.

DESIGN

The analgesic and sedative effects of intravenous morphine or pethidine and their effect on anxiety were compared in a prospective, double-blind, randomised dose-response study.

SETTING

A Stockholm teaching hospital obstetric unit.

PARTICIPANTS

Ten healthy nulliparous parturients in active labour were included in each group.

RESULTS

Even after repeated doses (up to 0.15 mg/kg body weight morphine and up to 1.5 mg/kg body weight pethidine) the findings were uniform, with very high pain scores maintained in each group as assessed with visual analogue scale. The parturients were all significantly sedated and several fell asleep but were awakened by pain during contractions.

CONCLUSION

It is concluded that labour pain is not sensitive to systemically administered morphine or pethidine. These drugs only cause heavy sedation. It therefore seems unethical and medically incorrect to meet parturients' requests for pain relief by giving them sedation. Considering the well documented negative effects on newborn infants we also believe systemic pethidine should be avoided in labour.

Analgesic efficacy of intravenous morphine in labour pain: a reappraisal

The aim of the present study was to investigate the dose-related analgesic effect of intravenous (i.v.) morphine during spontaneous term first stage labour. This was an open study in 17 parturients who requested analgesia for severe labour pain. All women were given morphine i.v. in repeated doses of 0.05 mg/kg following every third contraction until a final dose of 0.20 mg/kg was reached. The decrease in overall pain intensity, from median visual analogue scale (VAS) 85 (range 52-100) to median VAS 70 (range 46-99), was clinically insignificant. The number of women experiencing back pain, however, decreased significantly following morphine. The most striking effect of morphine (7.2-18 mg) was pronounced sedation. No adverse reactions related to morphine were noted in the neonates. We conclude that i.v. morphine does not significantly reduce overall labour pain intensity. Thus, if a real analgesic effect is desired, systemically given morphine seems inappropriate and other techniques should be used.

Peripartum cardiomyopathy--three cases

Three cases of peripartum cardiomyopathy (PPCM) are presented, each illustrating a clinically important aspect of the disorder. One patient survived despite extreme haemodynamic deterioration, one died suddenly 2 months post partum although clinically recovered, and one died during a subsequent pregnancy. The cases demonstrate the severity and the unpredictable course of PPCM, which remains a challenge both to scientists and to clinicians.