Left Lateral Table Tilt for Elective Cesarean Delivery under Spinal Anesthesia Has No Effect on Neonatal Acid-Base Status: A Randomized Controlled Trial.

BACKGROUND: Current recommendations for women undergoing cesarean delivery include 15° left tilt for uterine displacement to prevent aortocaval compression, although this degree of tilt is practically never achieved. We hypothesized that under contemporary clinical practice, including a crystalloid coload and phenylephrine infusion targeted at maintaining baseline systolic blood pressure, there would be no effect of maternal position on neonatal acid base status in women undergoing elective cesarean delivery with spinal anesthesia. METHODS: Healthy women undergoing elective cesarean delivery were randomized (nonblinded) to supine horizontal (supine, n = 50) or 15° left tilt of the surgical table (tilt, n = 50) after spinal anesthesia (hyperbaric bupivacaine 12 mg, fentanyl 15 µg, preservative-free morphine 150 µg). Lactated Ringer's 10 ml/kg and a phenylephrine infusion titrated to 100% baseline systolic blood pressure were initiated with intrathecal injection. The primary outcome was umbilical artery base excess. RESULTS: There were no differences in umbilical artery base excess or pH between groups. The mean umbilical artery base excess (± SD) was -0.5 mM (± 1.6) in the supine group (n = 50) versus -0.6 mM (± 1.5) in the tilt group (n = 47) (P = 0.64). During 15 min after spinal anesthesia, mean phenylephrine requirement was greater (P = 0.002), and mean cardiac output was lower (P = 0.014) in the supine group. CONCLUSIONS: Maternal supine position during elective cesarean delivery with spinal anesthesia in healthy term women does not impair neonatal acid-base status compared to 15° left tilt, when maternal systolic blood pressure is maintained with a coload and phenylephrine infusion. These findings may not be generalized to emergency situations or nonreassuring fetal status.

Aortocaval Compression Syndrome: Time to Revisit Certain Dogmas.

More than 70 years ago, the phenomenon of "postural shock" in the supine position was described in healthy women in late pregnancy. Since then, avoidance of the supine position has become a key component of clinical practice. Indeed, performing pelvic tilt in mothers at term to avoid aortocaval compression is a universally adopted measure, particularly during cesarean delivery. The studies on which this practice is based are largely nonrandomized, utilized a mix of anesthetic techniques, and were conducted decades ago in the setting of avoidance of vasopressors. Recent evidence is beginning to refine our understanding of the physiologic consequences of aortocaval compression in the context of contemporary clinical practice. For example, magnetic resonance imaging of women at term in the supine and tilted positions has challenged the dogma that 15° of left tilt is sufficient to relieve inferior vena cava compression. A clinical investigation of healthy term women undergoing elective cesarean delivery with spinal anesthesia found no difference in neonatal acid-base status between women randomized to be either tilted to the left by 15° or to be in the supine position, if maternal systolic blood pressure is maintained at baseline with a crystalloid coload and prophylactic phenylephrine infusion. This review presents a fresh look at the decades of evidence surrounding this topic and proposes a reevaluation and appraisal of current guidelines regarding entrenched practices.

Validating Parallel-Forms Tests for Assessing Anesthesia Resident Knowledge.

We created a serious game to teach first year anesthesiology (CA-1) residents to perform general anesthesia for cesarean delivery. We aimed to investigate resident knowledge gains after playing the game and having received one of 2 modalities of debriefing. We report on the development and validation of scores from parallel test forms for criterion-referenced interpretations of resident knowledge. The test forms were intended for use as pre- and posttests for the experiment. Validation of instruments measuring the study's primary outcome was considered essential for adding rigor to the planned experiment, to be able to trust the study's results. Parallel, multiple-choice test forms development steps included: (1) assessment purpose and population specification; (2) content domain specification and writing/selection of items; (3) content validation by experts of paired items by topic and cognitive level; and (4) empirical validation of scores from the parallel test forms using Classical Test Theory (CTT) techniques. Field testing involved online administration of 52 shuffled items from both test forms to 24 CA-1's, 21 second-year anesthesiology (CA-2) residents, 2 fellows, 1 attending anesthesiologist, and 1 of unknown rank at 3 US institutions. Items from each form yielded near-normal score distributions, with similar medians, ranges, and standard deviations. Evaluations of CTT item difficulty (item p values) and discrimination (D) indices indicated that most items met assumptions of criterion-referenced test design, separating experienced from novice residents. Experienced residents performed better on overall domain scores than novices (P < .05). Kuder-Richardson Formula 20 (KR-20) reliability estimates of both test forms were above the acceptability cut of .70, and parallel forms reliability estimate was high at .86, indicating results were consistent with theoretical expectations. Total scores of parallel test forms demonstrated item-level validity, strong internal consistency and parallel forms reliability, suggesting sufficient robustness for knowledge outcomes assessments of CA-1 residents.

Development and Implementation of a Clinician-Educator Track for Residents in Anesthesiology.

Background: Clinician-educators in academic settings have often had no formal training in teaching or in giving feedback to trainees. We implemented a Clinician-Educator Track within the Department of Anesthesiology with the initial goal of improving teaching skills through a didactic curriculum and experiential opportunities for a broad audience of faculty, fellows, and residents. We then assessed our program for feasibility and effectiveness. Methods: We developed a 1-year curriculum focusing on adult learning theory, evidence-based best teaching practices in different educational settings, and giving feedback. We recorded the number of participants and their attendance at monthly sessions. The year culminated in a voluntary observed teaching session using an objective assessment rubric to structure feedback. Participants in the Clinician-Educator Track then evaluated the program through anonymous online surveys. Qualitative content analysis of the survey comments was performed using inductive coding to generate relevant categories and identify the main themes. Results: There were 19 participants in the first year of the program and 16 in the second year. Attendance at most sessions remained high. Participants appreciated the flexibility and design of scheduled sessions. They very much enjoyed the voluntary observed teaching sessions to practice what they had learned throughout the year. All participants were satisfied with the Clinician-Educator Track, and many participants described changes and improvements in their teaching practices due to the course. Conclusions: The implementation of a novel, anesthesiology-specific Clinician-Educator Track has been feasible and successful, with participants reporting improved teaching skills and overall satisfaction with the program.

Ultrasound assessment of the vertebral level of the intercristal line in pregnancy.

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.

Severe transfusion-related acute lung injury managed with extracorporeal membrane oxygenation (ECMO) in an obstetric patient.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality in the United States. Management is usually supportive, including supplemental oxygen, intravenous fluids, and mechanical ventilation if necessary. Most patients recover within 72 hours. We present a nearly fatal case of TRALI in an obstetric patient, which was successfully managed with extracorporeal membrane oxygenation (ECMO).

Infection associated with central venous or epidural catheters: how to reduce it?

PURPOSE OF REVIEW: Central venous catheters are a leading source of nosocomial bloodstream infection with an estimated 10% mortality. Infection associated with epidural catheterization is an uncommon but devastating complication. Diagnosis of spinal epidural abscess requires a high index of suspicion and imaging techniques such as MRI. Early diagnosis and treatment will minimize permanent damage, but primary prevention should be the aim, which depends on proper patient evaluation and use of full aseptic precautions. RECENT FINDINGS: Recent studies suggest that epidural infection is no longer as rare a complication as once thought and may be increasing. It is not clear whether this increase is related to an increase in reporting, an overall increase in the total number of epidurals (especially extended use) being performed, or a true increase in infection rate. Implementation of multistep prevention programs has been shown to decrease central venous catheter-related bloodstream infection rate. Antiseptic or antibiotic-impregnated central venous catheters are effective in decreasing central venous catheter-related bloodstream infections. SUMMARY: Healthcare worker education and training are essential to create standardization of aseptic care. Continuous surveillance is necessary for identifying lapses in infection-control practices.

Development of a Multiple-Choice Test for Novice Anesthesia Residents to Evaluate Knowledge Related to Management of General Anesthesia for Urgent Cesarean Delivery.

BACKGROUND: Teaching trainees the knowledge and skills to perform general anesthesia (GA) for cesarean delivery (CD) requires innovative strategies, as they may never manage such cases in training. We used a multistage design process to create a criterion-referenced multiple-choice test as an assessment tool to evaluate CA1's knowledge related to this scenario. METHODS: Three faculty created 33 questions, categorized as: (1) physiologic changes of pregnancy (PCP), (2) pharmacology (PHA), (3) anesthetic implications of pregnancy (AIP), and (4) crisis resource management principles (CRM). A Delphi process (3 rounds) provided content validation. In round 1, experts (n = 15) ranked questions on a 7-point Likert scale. Questions ranked ≥ 5 in importance by ≥ 70% of experts were retained. Five questions were eliminated, several were revised, and 1 added. In round 2, consensus (N = 14) was reached in all except 7 questions. In round 3 (N = 14), all questions stabilized. A pilot test of the 29-question instrument evaluating internal consistency, reliability, convergent validity, and item analysis was conducted with the July CA1 classes at our institution after a lecture on GA for CD (n = 26, "instructed group") and another institution with no lecture (n = 26, "uninstructed group"), CA2s (N = 17), and attendings (N = 10). RESULTS: Acceptable internal consistency and reliability was demonstrated (ρ = 0.67). Convergent validity coefficients between the CA1 uninstructed and instructed group suggested theoretical meaningfulness of the 4 sub-scales: PCP correlated at 0.29 with PHA, 0.35 with CRM, and 0.25 with AIP. PHA correlated with CRM and AIP at 0.23 and 0.28, respectively. The correlation between CRM and AIP was 0.29. CONCLUSION: The test produces moderately reliable scores to assess CA1s' knowledge related to GA for urgent CD.

Ultrasound-guided bilateral transversus abdominis plane blocks in conjunction with intrathecal morphine for postcesarean analgesia.

STUDY OBJECTIVE: To determine whether transversus abdominis plane (TAP) blocks administered in conjunction with intrathecal morphine provided superior analgesia to intrathecal morphine alone. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Operating room of a university hospital. PATIENTS: 51 women undergoing elective Cesarean delivery with a combined spinal-epidural technique that included intrathecal morphine. INTERVENTIONS: Subjects were randomized to receive a bilateral TAP block with 0.5% ropivacaine or 0.9% saline. Postoperative analgesics were administered on request and selected based on pain severity. MEASUREMENTS: Patients were evaluated at 2, 24, and 48 hours after the TAP blocks were performed. Verbal rating scale (VRS) pain scores at rest, with movement, and for colicky pain were recorded, as was analgesic consumption. Patients rated the severity of opioid side effects and their satisfaction with the procedure and analgesia. MAIN RESULTS: 51 subjects received TAP blocks with ropivacaine (n = 26) or saline (n = 25). At two hours, the ropivacaine group reported less pain at rest and with movement (0.5 and 1.9 vs 2.8 and 4.9 in the saline group [VRS scale 0 - 10]; P < 0.001) and had no requests for analgesics; there were several requests for analgesia in the saline group. At 24 hours, there was no difference in pain scores or analgesic consumption. At 48 hours, the ropivacaine group received more analgesics for moderate pain (P = 0.04) and the saline group received more analgesics for severe pain (P = 0.01). CONCLUSIONS: Transversus abdominis plane blocks in conjunction with intrathecal morphine provided superior early postcesarean analgesia to intrathecal morphine alone. By 24 hours there was no difference in pain scores or analgesic consumption.

Bilateral multi-injection iliohypogastric-ilioinguinal nerve block in conjunction with neuraxial morphine is superior to neuraxial morphine alone for postcesarean analgesia.

STUDY OBJECTIVE: To determine whether bilateral iliohypogastric and ilioinguinal (IHII) peripheral nerve blocks, given in conjunction with neuraxial morphine, reduce postcesarean analgesic requirements and side effects, resulting in improved maternal satisfaction. DESIGN: Randomized, prospective, double-blinded, placebo-controlled study. SETTING: Labor and delivery suite at Johns Hopkins Hospital. PATIENTS: 34 women scheduled for elective cesarean delivery. INTERVENTIONS: Patients were randomized to receive IHII nerve blocks bilaterally, with either total 24 mL of 0.5% bupivacaine or normal saline, following cesarean delivery via Pfannensteil incision with a standard intrathecal dose of 12 mg of 0.75% bupivacaine with 10 µg of fentanyl and 200 µg of preservative-free morphine. MEASUREMENTS: Patients were assessed at 0, 6, 12, 18, and 24 hours postoperatively. Visual analog scale (VAS) pain scores at rest were recorded at each time period. Analgesic use, patients' perception of nausea, vomiting, pruritus, and their overall satisfaction with their analgesia were recorded for the first 24 hours. MAIN RESULTS: Lower VAS pain scores were seen in the bupivacaine group at 6, 12, 18, and 24 hours postoperatively (P = 0.01, P < 0.01, 0.02, and 0.04, respectively). A longer mean time to first rescue dose of ketorolac was noted in the bupivacaine group (14.3 ± 1.8 hrs) than the saline group (mean 5.6 ±1.1 hrs), (P < 0.01). Fewer patients in the bupivacaine group made requests for acetaminophen 500 mg/oxycodone 5 mg in the first 24 hours. Satisfaction was greater in the bupivacaine group. No difference in side effects was noted between groups. CONCLUSIONS: Bilateral multilevel injection IHII nerve blocks result in lower resting VAS pain scores, lower analgesic requirements, and greater satisfaction following cesarean delivery in patients who received neuraxial morphine.

Cardiac output assessed by invasive and minimally invasive techniques.

Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC.