Preventing nausea and vomiting in women undergoing regional anesthesia for cesarean section: challenges and solutions.

BACKGROUND: Intraoperative nausea and vomiting (IONV) or postoperative nausea and vomiting (PONV) affecting women undergoing regional anesthesia for cesarean section is an important clinical problem since these techniques are used widely. There are burdens of literature about IONV/PONV and several in parturient and cesarean. However, it needs more attention. The underlying mechanisms of IONV and PONV in the obstetrical setting mainly include hypotension due to sympathicolysis during neuraxial anesthesia, bradycardia owing to an increased vagal tone, the visceral stimulation via the surgical procedure and intravenously administered opioids. METHODS: Given the high and even increasing rate of cesarean sections and the sparse information on the etiology, incidence and severity of nausea and vomiting and the impact of prophylactic measures on the incidence of PONV/IONV, this article aims to review the available information and provide pragmatic suggestions on how to prevent nausea and vomiting in this patient cohort. Current literature and guidelines were identified by electronic database searching (MEDLINE via PubMed and Cochrane database of systematic reviews) up to present, searching through reference lists of included literature and personal contact with experts. DISCUSSION AND CONCLUSION: Taking into account the current guidelines and literature as well as everyday clinical experience, the first step for decreasing the incidence of IONV and PONV is a comprehensive management of circulatory parameters. This management includes liberal perioperative fluid administration and the application of vasopressors as the circumstances require. By using low-dose local anesthetics, an additional application of intrathecal or spinal opioids or hyperbaric solutions for a sufficient controllability of neuraxial distribution, maternal hypotension might be reduced. Performing a combined spinal-epidural anesthesia or epidural anesthesia may be considered as an alternative to spinal anesthesia. Antiemetic drugs may be administered restrainedly due to off-label use in pregnant women for IONV or PONV prophylaxis and may be reserved for treatment.

Protection against CD95-induced apoptosis by chlamydial infection at a mitochondrial step.

Chlamydiae are obligate intracellular bacteria that infect human epithelial and myeloid cells. Previous work has established that chlamydiae are able to protect a cell against apoptosis induced by certain experimentally applied stimuli. Here we provide an analysis of this protective activity against the signal transduction during CD95-induced apoptosis. In HeLa cells overexpressing CD95, infection with Chlamydia trachomatis inhibited the appearance of apoptotic morphology, effector caspase activity, the activation of caspase-9 and -3, and the release of cytochrome c from mitochondria. However, caspase-8-processing and activity (measured as cleavage of Bid) were unaffected by the chlamydial infection. Similarly, infection with the species C. pneumoniae did not prevent the activation of caspase-8 but inhibited the appearance of effector caspase activity upon signaling through CD95. Furthermore, infection with C. trachomatis was able to inhibit CD95-induced apoptosis in Jurkat lymphoid cells, where a mitochondrial contribution is required, but not in SKW6.4 lymphoid cells, where caspase-8 directly activates caspase-3. Taken together, these data show that chlamydial infection can protect cells against CD95-induced apoptosis but only where a mitochondrial signaling step is necessary for apoptotic signal transduction.