BACKGROUND The intercristal line is known to most frequently cross the L4 spinous process or L4-5 interspace; however, it is speculated to be positioned higher during pregnancy because of the exaggerated lumbar lordosis. Clinical estimation of vertebral levels relying on the use of the intercristal line has been shown to often be inaccurate. We hypothesized that the vertebral level of the intercristal line determined by palpation would be higher than the level determined by ultrasound in pregnant women. METHODS Fifty-one term pregnant patients were recruited. Two experienced anesthesiologists performed estimates of the position of the intercristal line by palpation. Using ultrasound, another anesthesiologist who was blinded to the clinical estimates, determined the position of the superior border of the iliac crest in the transverse and longitudinal planes and then identified the lumbar vertebral levels. The vertebral level at which the clinical estimates of the intercristal line crossed the spine was recorded and compared with the ultrasound-determined level of the superior border of the iliac crest. RESULTS The clinical estimates of the spinal level of the intercristal line agreed with the ultrasound measurement 14% of the time (14 of 101; 95% confidence interval [CI]: 8%, 22%). The clinical estimates were 1 level higher than the ultrasound measurement 23% of the time (23 of 101; 95% CI: 16%, 32%) and >1 level higher 25% of the time (25 of 101; 1-tailed 95% CI:>18%). The distribution of the clinical estimates found clinicians locating the intercristal line at L3 or L3-4 54% of the time (54 of 101; 95% CI: 44%, 63%) and at L2-3 or higher 27% of the time (27 of 101; 1-tailed 95% CI:>20%). CONCLUSION The anatomical position of the intercristal line was at L3 or higher in at least 6% of term pregnant patients using ultrasound. Clinical estimates were found to be ≥1 vertebral level higher than the anatomical position determined by ultrasound at least 40% of the time. This disparity may contribute to misidentification of lumbar interspaces and increased risk of neurologic injury during neuraxial anesthesia.

PURPOSE: To ensure that the endotracheal tube (ETT) is ideally placed for proper ventilation, radiographic confirmation of ETT placement is frequently used to supplement clinical examination in the intensive care unit setting. However, fluoroscopy rarely serves the same role during surgery, despite the fact that portable units are often present in the operating room. The purpose of this study was to ascertain the value of fluoroscopy in determining ETT malposition among the pediatric surgical population. METHODS: Chest radiographs from 257 children (age 12 days-12 yr), who presented for a total of 446 individual procedures in the fluoroscopy suite, were studied to determine the incidence of ETTs placed too shallow (above the inferior clavicular border) or too deep (at or below the carina). A logistic regression with outcomes of correct and incorrect was used to analyze the data points. RESULTS: Eighteen percent of all the radiographs showed initial improper ETT placement, despite clinical evidence suggesting the contrary. The peak incidence of malposition, which occurred in patients under one year old, reached 35%. Incidence decreased with advancing age, but remained over 10% until the age of ten. A second attempt at positioning the tube, based on information from the chest radiograph, was successful in 95% of the cases. The remaining 5% required placement of the ETT under continuous fluoroscopic guidance. CONCLUSION: Fluoroscopy, when readily available in the operating room, is a safe and useful technique to ensure proper ETT placement among the pediatric population.

Objective:To test the psychometric soundness of a teamwork climate survey in labor and delivery, examine differences in perceptions of teamwork, and provide benchmarking data.Design:Cross-sectional survey of labor and delivery caregivers in 44 hospitals in diverse regions of the US, using the Safety Attitudes Questionnaire teamwork climate scale.Results:The response rate was 72%(3382 of 4700). The teamwork climate scale had good internal reliability (overall alpha=0.78). Teamwork climate scale factor structure was confirmed using multilevel confirmatory factor analyses (CFI=0.95, TLI=0.92, RMSEA=0.12, SRMR(within)=0.04, SRMR(between)=0.09). Aggregation of individual-level responses to the L&D unit-level was supported by ICC (1)=0.06 (P<0.001), ICC (2)=0.83 and mean r (wg(j))=0.83. ANOVA demonstrated differences between caregivers F (7, 3013)=10.30, P<0.001 and labor and delivery units, F (43, 1022)=3.49, P<0.001. Convergent validity of the scale scores was measured by correlations with external teamwork-related items: collaborative decision making (r=0.780, P<0.001), use of briefings (r=0.496, P<0.001) and perceived adequacy of staffing levels (r=0.593, P<0.001).Conclusion:We demonstrate a psychometrically sound teamwork climate scale, correlate it to external teamwork-related items, and provide labor and delivery teamwork benchmarks. Further teamwork climate research should explore the links to clinical and operational outcomes.Journal of Perinatology advance online publication 15 June 2006 doi:10.1038/sj.jp.7211556.

OBJECTIVE: Our primary objective was to examine the relationship between umbilical arterial gas analysis and decision-to-delivery interval for emergency cesareans performed for nonreassuring fetal status to determine if this would validate the 30-minute rule. STUDY DESIGN: For this retrospective cohort study, all cesarean deliveries performed for nonreassuring fetal status from September 2001 to January 2003 were reviewed. A synopsis of clinical information that would have been available to the clinician at the time of delivery and the last hour of the electronic fetal heart rate tracing prior to delivery were reviewed by three different maternal-fetal medicine specialists masked to outcome, who classified each delivery as either emergent (delivery as soon as possible) or urgent (willing to wait up to 30 minutes for delivery) since immediacy of the fetal condition is the key factor affecting the type of anesthesia used. RESULTS: Of 145 cesareans performed for nonreassuring fetal status during this period, 117 patients met criteria for entry, of which 34 were classified as emergent and 83 as urgent. Kappa correlation was 0.35, showing only fair/moderate agreement between reviewers. In the emergent group, general anesthesia was more common (35.3%, 10.8%, p=0.003), and the decision-to-delivery interval was 14 minutes shorter (23.0+/-15.3, 36.7+/-14.9 minutes, p<0.001). Linear regression showed a statistically significant relationship between increasing decision-to-delivery interval and umbilical arterial pH (r=0.22, p=0.02) and base excess (r=0.33, p<0.001) showing that delivery proceeded sooner for most of those with the worst cord gases, with a gradual improvement over time. For the 13 (11%) neonates with cord gases placing them at increased risk for long-term neurologic sequelae, the decision-to-delivery interval was 24.7+/-14.6 minutes (range 6 to 50 minutes), and 3/13 (23%) were classified as urgent rather than emergent. CONCLUSION: Electronic fetal monitoring shows considerable variation in interpretation among maternal-fetal medicine specialists and is not a sensitive predictor of the fetus developing metabolic acidosis. There is no deterioration in cord gas results after 30 minutes, and most neonates delivered emergently or urgently for nonreassuring fetal status even when born after 30 minutes have normal cord gases. The 30-minute rule is a compromise that reflects the time it takes the fetus to develop severe metabolic acidosis, our imprecision in its identification, and its rarity in the presence of nonreassuring fetal monitoring.

A 24-year-old woman at 37 weeks gestation, with an uncorrected atrioventricular canal defect and incipient congestive heart failure is presented. This rare defect is part of the larger group of endocardial cushion defects. The peripartum anesthetic management of this condition has not been described. Our patient had a large atrial septal defect, a common regurgitant atrioventricular valve, a large left-to-right shunt and a small ventricular septal defect. Her pregnancy was maintained until she developed symptoms of congestive heart failure. We discuss her peripartum management, monitoring and anesthetic choices.

Umbilical cord occlusion causes fetal hypoxemia which can result in brain injury including damage to cerebral white matter. Excessive glutamate release may be involved in the damage process. This study examined the relation between extracellular glutamate levels in the cerebral white matter of the ovine fetus during and after intermittent umbilical cord occlusion and the degree of resultant fetal brain injury. Fetal sheep underwent surgery for chronic catheterisation and implantation of an intra-cerebral microdialysis probe at 130 days of gestation (term approximately 147 days). Four days after surgery (day 1), seven fetuses were subjected to 5x2 min umbilical cord occlusions, and on the following day (day 2) they were subjected to either 4 or 5x4 min umbilical cord occlusions; seven fetuses served as controls. Microdialysis samples were collected before, during and after the umbilical cord occlusions to determine extracellular glutamate levels in the cerebral white matter. Fetal blood gas status was measured and the fetal electrocorticogram was recorded continuously. During the periods of umbilical cord occlusions on both days 1 and 2, fetal arterial oxygen saturation, arterial partial pressure of oxygen and arterial pH decreased (P<0.05) while arterial partial pressure of carbon dioxide increased (P<0.05). All fetuses showed episodes of isoelectric electrocortical activity during umbilical cord occlusions on both days 1 and 2. In fetuses with patent microdialysis probes there were marked increases of glutamate efflux in the cerebral white matter following umbilical cord occlusion. Fetal brains were removed at autopsy on day 5 and subjected to histological assessment. Brain damage was observed in all fetuses exposed to cord occlusion, particularly in the periventricular white matter, with the most extensive damage occurring in the fetuses with the greatest increases in glutamate levels. We conclude that, in the unanesthetised fetus in utero, glutamatergic processes are associated with umbilical cord occlusion-induced brain damage in the cerebral white matter.

PURPOSE: To examine if ilioinguinal-iliohypogastric nerve block could reduce the need for post-Cesarean delivery morphine analgesia and thus reduce the incidence of opioid related adverse-effects. METHODS: A multi-level technique for performing the nerve block with bupivacaine was developed and then utilized in this two-part study. Part one was a retrospective assessment of Cesarean delivery patients with and without ilioinguinal-iliohypogastric blocks to determine if the technique reduced patient controlled analgesia morphine use and thus would warrant further study. The second phase was a randomized double-blind placebo-controlled trial to compare post-Cesarean morphine use and the appearance of opioid-related side effects between the anesthetic and placebo-injected groups. RESULTS: Both phases demonstrated that our method of ilioinguinal-iliohypogastric nerve block significantly reduced the amount of iv morphine used by patients during the 24 hr following Cesarean delivery. In the retrospective assessment, morphine use was 49 +/- 30 mg in the block group vs 79 +/- 25 mg in the no block group (P = 0.0063). For the prospective trial, patients who received nerve blocks with bupivacaine had a similar result, self-administering 48 +/- 27 mg of morphine over 24 hr compared to 67 +/- 28 mg administered by patients who received infiltrations of saline. However, despite the significant decrease in morphine use, there was no reduction in opioid-related adverse effects: the incidences of nausea were 41% and 46%(P = 0.70) and for itching were 79% and 63%(P = 0.25) in the placebo and nerve block groups, respectively. CONCLUSION: A multi-level ilioinguinal-iliohypogastric nerve block technique can reduce the amount of systemic morphine required to control post-Cesarean delivery pain but this reduction was not associated with a reduction of opioid related adverse effects in our study group.

Progesterone modulates gamma-aminobutyric acid and excitatory amino acid neurotransmitter systems and has neuroprotective properties in models of hypoxia-ischemia. This study examined the in vitro effects of allopregnanolone, the active progesterone metabolite, in models of N-methyl-D-aspartate (NMDA)-induced necrosis and apoptosis. Cultured NT2 neurons were exposed to 1 mM NMDA. Lactate dehydrogenase (LDH) release was measured 24 h later. NMDA at a concentration of 1 mM produced a 39 +/- 19% release of total LDH. Exposure to 10 microM allopregnanolone prior to NMDA exposure reduced LDH release by 51%(P = 0.0028). NMDA stimulated apoptotic cell changes defined by terminal dUTP nick-end labeling (TUNEL) and 5,5', 6,6'-tetrachloro-1,1,3,3'-tetra ethlybenzimidazolycarbocyanide iodide staining were reduced to baseline values by both 10 microM allopregnanolone and 100 microM MK-801. Pretreatment with allopregnanolone (0-10 microM) reduced the percentage of TUNEL-positive cells in a dose-dependent manner (EC(50)= 2.7 +/- 0.1 nM). Physiologic concentrations of allopregnanolone provided protection against both necrotic and apoptotic injury induced by NMDA excitotoxicity.

A common but difficult task for a hospital when it decides to open a freestanding ambulatory surgery facility is how to decide which surgical procedures should be done at the new facility. This is necessary in order to determine how many operating rooms to plan for the new facility and which ancillary services are needed on-site. In this case study, we describe a novel methodology that we used to develop a comprehensive list of procedures to be done at a new ambulatory facility. The level of anesthetic complexity of a procedure was defined by its number of ASA Relative Value Guide basic units. Broad categories of procedures (e.g., eye surgery) were defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification. We identified 22 categories that are of a type that every procedure in the category has no more than seven basic units. In addition, by analyzing all procedures that the hospital being studied actually performed on an ambulatory basis, we identified six other categories of procedures that were of a type that all procedures eligible for surgery at the new facility had seven or fewer basic units. IMPLICATIONS: We describe a novel method to develop a comprehensive list of procedures that have a prespecified maximum level of anesthetic complexity to be performed at a new ambulatory surgery facility.