Ketamine for labour analgesia

Challenges of Providing Optimal and Safe Intrapartum Analgesia in Patients With HELLP Syndrome: A Case Report and Literature Review

HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets) Syndrome is a rare but serious complication of pregnancy that can lead to disseminated intravascular coagulation, pulmonary edema, respiratory failure, hepatic and renal injury, and death if not recognized and treated promptly. A 36-year-old nulligravid (G0) active duty Marine at 36 weeks and 1 day gestation with dichorionic diamniotic twins presented to triage for routine cervical examination found to have elevated blood pressures and symptomatic thrombocytopenia, with a suspected diagnosis of HELLP. A multidisciplinary decision was made by anesthesiology, obstetrics and gynecology, and pediatrics to deliver the twins to avoid any further complications. The twins were in cephalic presentation and the patient desired to attempt a vaginal delivery. Due to the patient's thrombocytopenia, neuraxial anesthesia (spinal and/or epidural) left the patient at a high risk of developing catastrophic complications such as an epidural hematoma, and the subsequent motor block/weakness would likely lessen the patient's ability to participate in active labor for a vaginal delivery. A Cesarean section under general anesthesia was also to be avoided as the patient's elevated risk of catastrophic hemorrhage would be worsened by volatile anesthetic agents which cause significant uterine vascular relaxation and reduced uterine muscular tone. Ultimately, the decision was made to provide analgesia through a remifentanil PCA (patient-controlled analgesia) for labor and a ketamine bolus for delivery. The mother delivered both twins vaginally in the operating room without perioperative complication. This case demonstrates the safety of alternate forms of anesthesia for delivery when neuraxial anesthesia is contraindicated.

Low-dose ketamine infusion for labor analgesia: A double-blind, randomized, placebo controlled clinical trial

Background:

Most primary and secondary level hospitals in developing countries provide inadequate labor analgesia due to various medical, technical and economic reasons. This clinical trial was an effort to study the efficacy, safety and feasibility of intravenous (IV) ketamine to provide labor analgesia.

Materials and Methods:

A total of 70 parturients were consented and randomly assigned to receive either IV ketamine or 0.9% saline. A loading dose of ketamine (0.2 mg/kg) was followed-by an infusion (0.2 mg/kg/h) until the delivery of the neonate. Similar volume of saline was infused in the placebo-group. Intramuscular meperidine was the rescue analgesic in both groups. The pain score, hemodynamic parameters of mother and fetus and the anticipated side-effects of ketamine were observed for. The newborn was assessed by the Neonatologist.

Results:

The pain score showed a decreasing trend in the ketamine group and after the 1^st h more than 60% of women in the ketamine group had pain relief, which was statistically significant. There was no significant clinical change in the maternal hemodynamics and fetal heart rate. However, 17 (48.5%) of them had transient light headedness in the ketamine group. All the neonates were breast fed and the umbilical cord blood pH was between 7.1 and 7.2. The overall satisfaction was significantly high in the intervention group (P = 0.028).

Conclusion:

A low-dose ketamine infusion (loading dose of 0.2 mg/kg delivered over 30 min, followed-by an infusion at 0.2 mg/kg/h) could provide acceptable analgesia during labor and delivery.

Analgesia for childbirth: modern insights into an age-old challenge and the quest for an ideal approach

SUMMARY It is widely recognized that childbirth may be the most painful experience in a woman’s lifetime and that women have a right to relief. There are many options, but the efficacy of only a few is supported by robust evidence. Many influences determine which method of pain relief is chosen, including social and cultural factors, availability, cost and personal preference. Due to human diversity and the differing perspectives of consumers, obstetric care providers and health administrators, there is no such thing as ‘an ideal approach’. In resource-rich societies, major advances in parturient safety and outcome flow from technique development and better monitoring. Greater awareness of the negative impact of untreated pain and of the relevance of genetic, cultural and social factors motivates research into better predictive models, novel therapies and optimization of existing methods.

Ketamine-induced neuroapoptosis in the fetal and neonatal rhesus macaque brain

BACKGROUND

Exposure of rhesus macaque fetuses for 24 h or neonates for 9 h to ketamine anesthesia causes neuroapoptosis in the developing brain. The current study clarifies the minimum exposure required for and the extent and spatial distribution of ketamine-induced neuroapoptosis in rhesus fetuses and neonates.

METHOD

Ketamine was administered by IV infusion for 5 h to postnatal day 6 rhesus neonates or to pregnant rhesus females at 120 days' gestation (full term = 165 days). Three hours later, fetuses were delivered by cesarean section, and the fetal and neonatal brains were studied for evidence of apoptotic neurodegeneration, as determined by activated caspase-3 staining.

RESULTS

Both the fetal (n = 3) and neonatal (n = 4) ketamine-exposed brains had a significant increase in apoptotic profiles compared with drug-naive controls (fetal n = 4; neonatal n = 5). Loss of neurons attributable to ketamine exposure was 2.2 times greater in fetuses than in neonates. The pattern of neurodegeneration in fetuses was different from that in neonates, and all subjects exposed at either age had a pattern characteristic for that age.

CONCLUSION

The developing rhesus macaque brain is sensitive to the apoptogenic action of ketamine at both a fetal and neonatal age, and exposure duration of 5 h is sufficient to induce a significant neuroapoptosis response at either age. The pattern of neurodegeneration induced by ketamine in fetuses was different from that in neonates, and loss of neurons attributable to ketamine exposure was 2.2 times greater in the fetal than neonatal brains.