The influence of epidural anesthesia on the hearing system after normal labor.

OBJECTIVE: The purpose of our study was to evaluate the influence of epidural anesthesia on the hearing system in women undergoing normal labor. DESIGN: We examined two groups of patients: women with epidural anesthesia underwent four tests of distortion product otoacoustic emissions(DPOAEs): on admission, and fifteen minutes, one hour, and three hours after the last epidural bolus of local anesthetic. Auditory brainstem response (ABR) tests were performed on admission, and one hour, and three hours after the last epidural bolus. Women who gave birth without epidural anesthesia underwent DPOAEs tests on admission, during a uterine contraction, during active delivery, and three hours after labor. ABR tests were performed on admission, during a uterine contraction, and three hours after labor. STUDY SAMPLE: twenty patients participated in the study. Twelve gave birth with epidural anesthesia and eight without anesthesia. RESULTS: No significant changes in DPOAEs and ABR recordings were found between the two groups. CONCLUSIONS: Epidural anesthesia does not impair the sensory or the neural elements of the hearing system and therefore does not influence hearing.

Intra-partum epidural analgesia in grandmultiparous women.

OBJECTIVE: The present study aimed to characterise grandmultiparous women receiving intra-partum epidural analgesia and investigate associations between this method of pain relief and labour outcomes in grandmultiparas. METHODS: A population-based study was conducted comparing obstetric and perinatal characteristics of grandmultiparous women with and without epidural analgesia. Deliveries occurred during the years 1988-2006. Multiple logistic regression models were constructed to find independent risk factors associated with epidural analgesia, cesarean section and 1st stage labour dystocia. RESULTS: Out of 41,488 deliveries to grandmultiparous women included in the study, intra-partum epidural analgesia was utilised in 877 (2.1%). Multivariate analysis revealed that grandmultiparas who received epidural pain relief were significantly older and more likely to suffer from pre-mature rupture of the membranes, polyhydramnion, oligohydramnion, labour induction and a macrosomic fetus. After controlling for potential confounding, use of epidural analgesia remained an independent risk factor for 1st stage labour dystocia (odds ratio (OR) = 1.5; 95% confidence interval (CI) = 1.08-2.2) and cesarean delivery (OR = 2.9; 95% CI = 2.4-3.5) in grandmultiparas. CONCLUSION: Grandmultiparous women who received intra-partum epidural analgesia have entirely different obstetric characteristics as compared with those who did not receive this method of pain relief. Although epidural use was demonstrated to be an independent risk factor for 1st stage labour dystocia and cesarean section in this population, residual confounding cannot be excluded.

The effect of epidural analgesia on labor progress and outcome in nulliparous women.

OBJECTIVE: The present study was designed to investigate the influence of epidural analgesia on labor progress and outcome in nulliparous women. METHODS: A population-based study comparing women with and without epidural analgesia was conducted. Deliveries occurred during 1988-2006 at the Soroka University Medical Center. A multivariable logistic regression model with backward elimination was constructed to control for confounders. RESULTS: During the study period there were 39 498 deliveries; epidural analgesia was given in 9960 (25.2%) of these. Using a multivariable analysis with backward elimination, the following conditions were significantly associated with the use of epidural analgesia: advanced maternal age, oligohydramnios, premature rupture of membranes, induction of labor, and Jewish (vs. Bedouin) ethnicity. These patients were more likely to deliver by cesarean delivery (CD; OR = 1.4, 95% CI 1.3-1.5; p < 0.001) and vacuum extraction (OR = 1.5, 95% CI 1.4-1.7; p < 0.001). After controlling for possible confounders such as macrosomia, failed induction, hypertensive disorders, gestational diabetes, maternal age, labor dystocia, and ethnicity, epidural analgesia was not found to be an independent risk factor for CD but rather a protective factor (OR = 0.9, 95% CI 0.8-0.9; p = 0.038). When vacuum extraction was the outcome variable, epidural analgesia was documented as an independent risk factor (OR = 1.1, 95% CI 1.01-1.3; p = 0.04). CONCLUSIONS: Epidural analgesia in nulliparous parturients increases the risk for labor dystocia and accordingly is an independent risk factor for vacuum extraction. Nevertheless, it does not pose an independent risk for cesarean delivery.

Development of abdominal pain and IBS following gynecological surgery: a prospective, controlled study.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) develops after bacterial enteritis that causes injury to the bowel mucosa. It's unclear whether abdominal pain or IBS results from gynecological surgery that could injure abdominopelvic nerves. The aim of this prospective, controlled study was to assess the incidence of pain or IBS in women undergoing elective gynecological surgery compared to non-surgical controls and to identify factors associated with their development. METHODS: One hundred thirty-two women without GI symptoms undergoing elective gynecological surgery for non-painful conditions were compared with 123 non-surgery controls without GI symptoms. Socio-demographic, psychosocial, and surgery-related variables were potential predictor variables of pain at 3 and/or 12 months. RESULTS: Three surgical patients (2.7%), but no controls, developed IBS at 12 months. Significantly more surgical patients had abdominal pain at 3 or 12 months (15.3% vs 3.6%, P=.003). No socio-demographic or surgery-related variables predicted pain development, but it was predicted by psychosocial factors including anticipation of difficult recovery from surgery (P=.01), perception of severity/constancy of illness (P=.04), and reduced sense of coherence (P=.01). CONCLUSIONS: Among women undergoing gynecological for non-pain indications the development of IBS was not significantly greater than controls. However, abdominal pain did develop in 17% of women in the surgical group, suggesting that surgery facilitated its development. Notably, only psychosocial variables predicted pain development, implying that pain development associated with central registration and amplification of the afferent signal (via cognitive and emotional input) must be considered along with the peripheral injury itself. These findings contribute to understanding the pathophysiology of functional GI pain.

Ketamine attenuates neutrophil activation after cardiopulmonary bypass.

UNLABELLED: Surgery is associated with activation of neutrophils and their influx into affected tissue. The pathogenic role of superoxide production generated by activated neutrophils has been documented repeatedly. Ketamine suppresses neutrophil oxygen radical production in vitro. In the present study, we compared the effect of adding small-dose ketamine to opioids during the induction of general anesthesia on superoxide production by neutrophils after coronary artery bypass grafting (CABG). Thirty-five patients undergoing elective CABG were randomized to one of two groups and prospectively studied in a double-blinded manner. The patients received either ketamine 0.25 mg/kg or a similar volume of saline in addition to large-dose fentanyl anesthesia. Blood samples were drawn before the operation, immediately after cardiopulmonary bypass, 24 and 48 postoperative h, and on postoperative Days 3-6. Functional capacity of neutrophils was assessed by superoxide generation after stimulation with phorbol 12-myristate 13-acetate, opsonized zymosan, or formyl-methionyl-leucyl-phenylalanine. The addition of small-dose ketamine to general anesthesia attenuates increased production of the superoxide anion (O2-) by neutrophils without chemical stimulation and after stimulation with phorbol 12-myristate 13-acetate, formyl-methionyl-leucyl-phenylalanine, and opsonized zymosan for 4-6 days after CABG. In addition, ketamine attenuated the percentage of neutrophils on postoperative Days 2-6. In the Control group, superoxide production significantly increased compared with the baseline value. By contrast, in the Ketamine group, this difference was not significant. IMPLICATIONS: In a randomized, double-blinded, prospective clinical study, we compared the effect of adding small-dose ketamine to opioids during general anesthesia on superoxide production and showed that ketamine suppressed the increase of superoxide anion production by neutrophils after coronary artery bypass grafting.