An analysis of transfusion practice and the role of intraoperative red blood cell salvage during cesarean delivery.

BACKGROUND: We sought to determine to what extent intraoperative salvaged red blood cells (RBC) might theoretically reduce exposure to appropriately transfused allogenic erythrocytes in Cesarean delivery patients. METHODS: Medical records of Cesarean delivery patients requiring blood transfusions from January 1, 1992 to June 30, 1996 and June 1, 1998 to June 30, 2003 were reviewed. For each patient, we calculated the number of allogenic RBC units that could have theoretically been avoided had intraoperative autotransfusion been performed, based upon estimated blood loss, preoperative hematocrit, and the amount of retrieved blood needed to yield a single RBC unit. RBC transfusion appropriateness was determined using the recommended guideline of transfusing RBCs if the hemoglobin is <7 gm/dL in a patient with continuing bleeding. RESULTS: A small percentage of Cesarean delivery patients (1.8%) received blood product transfusions. Of 207 patients receiving blood transfusions, salvaged erythrocytes could have theoretically decreased exposure to allogenic RBCs in 115 (55.6%) patients. Only 75.7% of these 115 patients were appropriately transfused with erythrocytes. CONCLUSION: Theoretically, based on best, average, and worst RBC salvage recovery calculations, 25.1%, 21.2%, or 14.5% of the appropriately transfused patients, respectively, could have completely avoided allogenic RBC transfusion.

Changes in cerebrospinal fluid neurochemistry during pregnancy.

BACKGROUND: Little is known about changes in brain function that may occur during pregnancy. Studies in rodents and sheep suggest that several brain neurotransmitter and neurohormonal systems known to modulate anxiety may be altered during pregnancy. METHODS: Cerebrospinal fluid (CSF) and plasma samples were obtained from 21 women (during weeks 38-39 of pregnancy) who were undergoing elective cesarean section and from 22 healthy nonpregnant women. RESULTS: The CSF levels of g-aminobutyric acid (GABA) and 3-methoxy-4-hydroxyphenylglycolwere reduced in pregnant women. There were no changes in CSF glutamate, 5-hydroxyindoleactic acid, and homovanillic acid. There was a large increase in CSF prolactin in pregnant women and also a trend toward an elevation in CSF oxytocin. Levels of prolactin, but not oxytocin, in CSF and plasma were correlated in pregnant women. CONCLUSIONS: These results suggest that pregnancy alters regulation of brain GABA, norepinephrine, and prolactin, which may play a role in changes in vulnerability to anxiety and depression during pregnancy and postpartum. Prolactin circulating in the bloodstream seems to be the major source of CSF prolactin during pregnancy.

The descent curve of the grand multiparous woman.

OBJECTIVE: The purpose of this study was to compare the descent curves and second-stage length among grand multiparous, nulliparous, and lower parity multiparous women. STUDY DESIGN: Retrospective cohorts of spontaneously laboring, vertex-presenting, term, grand multiparous women (parity >or=5) from two medical centers over 5.5 years were matched randomly to nulliparous women and lower parity multiparous women controlled for age, hospital, and year of delivery. Descent curves were modeled from serial cervical examination data by the estimation of the probability of a given station occurring at a given time before delivery with the use of ordinal logistic regression. Curves were compared by Wald tests and adjusted for possible confounders. Second-stage lengths were compared by a Cox proportional hazards model. A probability value of <.05 was considered significant. RESULTS: Grand multiparous women and lower parity multiparous women maintain a high station up to 1.5 hour before delivery and then rapidly transition to delivery. Nulliparous women transition to lower stations at a more gradual rate throughout the first and second stages. Descent curves differ among parity groups, with grand multiparous women maintaining a higher station for a longer time compared with either lower parity multiparous women or nulliparous women (P<.001). Once full dilation is reached, the median length of the second stage is 0.75, 0.85, and 1.75 hours for grand multiparous women, lower parity multiparous women, and nulliparous women, respectively (hazard ratios were 0.39 for nulliparous women vs grand multiparous women and 0.9 for lower parity multiparous women vs grand multiparous women). CONCLUSIONS: Compared with lower parity multiparous women or nulliparous women, grand multiparous women maintain a higher station for a longer time before delivery but transition rapidly to delivery once full dilation is reached.

Injecting saline through the epidural needle decreases the iv epidural catheter placement rate during combined spinal-epidural labour analgesia.

PURPOSE: To determine if injecting 10 mL saline before epidural catheter threading (pre-cannulation epidural fluid injection) can decrease the incidence of iv epidural catheter placement during combined spinal-epidural (CSE) labour analgesia. METHODS: One hundred healthy women requesting CSE labour analgesia with either fentanyl 20 microg or sufentanil 10 microg were prospectively randomized to receive either no epidural injection (dry group, n = 50) or epidural 10 mL saline injection (saline group, n = 50) before epidural catheter placement. A nylon multiport catheter was then threaded 3-5 cm into the epidural space and the needle was removed. We diagnosed iv catheter placement if blood was freely aspirated, if the mother became tachycardic after injection of epinephrine 15 microg, or if intracardiac air was heard (using ultrasound) after injection of air 1.5 mL. RESULTS: Intravenous epidural catheter placement occurred in one saline and ten dry group patients (P < 0.01). No complications of excessive cephalad intrathecal opioid spread (i.e., difficulty swallowing, hypoxemia, or respiratory arrest) occurred. CONCLUSIONS: Injecting 10 mL or saline through the epidural needle after intrathecal opioid injection and before threading the catheter significantly decreased accidental venous catheter placement without any apparent increase in complications from excessive cephalad intrathecal opioid spread.

The labor curve of the grand multipara: does progress of labor continue to improve with additional childbearing?

OBJECTIVE: Our purpose was to test the hypothesis that progress of labor slows as parity exceeds 4 by comparing labor curves of grand multiparous women (para 5 and over) (GMs) with those of nulliparous and lower-parity multiparous women. STUDY DESIGN: Retrospective cohorts of spontaneously laboring, vertex-presenting, term GMs who were admitted to two medical centers during the period from January 1990 through June 1995 were randomly computer-matched to a nulliparous and a lower-parity multiparous control subject, matched for age, hospital, and year of delivery. Cervical examination data were graphed retrospectively from the time of full dilatation. Curves were compared by pairwise likelihood ratio tests, by using a random effects model to adjust for obstetric interventions, with significance set at P <.05. RESULTS: Pregnancies in 1095 GMs, 1174 lower-parity multiparous women, and 908 nulliparous women were studied. GMs exhibit a longer initial phase of labor than either nulliparous women or lower-parity multiparous women, begin to dilate rapidly at a greater dilatation than nulliparous women, and experience acceleration of labor at a rate no faster than lower-parity multiparous women. The average labor curve of GMs resembles that of nulliparous women before dilatation of 4 cm is attained, then transitions to the typical curve of the lower-parity multiparous women until dilatation of 6 cm is attained and thereafter is indistinguishable from that of the lower-parity multiparous women (P <.001). CONCLUSIONS: Once parity exceeds 4, progress of labor slows. "Poor progress" beyond dilatation of 4 cm should not be considered abnormal for a GM, because she is likely still in the latent phase until dilatation of 6 cm is attained. Nor should she be expected to progress through her active phase any faster than lower-parity multiparous women.