Melatonin treatment has consistent but transient beneficial effects on sleep measures and pain in patients with severe chronic pain: the DREAM-CP randomised controlled trial.

BACKGROUND: Sleep disturbance is a major issue for patients with chronic pain. Melatonin has been shown to improve symptoms of fibromyalgia, but its efficacy in other chronic non-malignant pain conditions is not fully known. Hence, we determined the effect of melatonin in patients with severe noncancer chronic pain. METHODS: This was a randomised double-blinded crossover trial of modified-release melatonin as Circadin™ compared with placebo. Sixty male and female subjects with chronic severe pain were randomised to receive either 2 mg of Circadin™ or placebo before sleep for 6 weeks, followed by a >4 week washout, then crossing over to the other treatment. Sleep disturbance, quality, and latency were measured using three different validated sleep assessment tools. The primary outcome measure was self-reported sleep disturbance after 6 weeks of treatment. Adverse events were also recorded. RESULTS: Sleep disturbance after 6 weeks was not significantly altered by melatonin treatment, but differences between melatonin and placebo treatment periods after 3 weeks were seen: sleep disturbance (P=0.014), latency (P=0.04), overall sleep quality (P=0.004), and effect of pain on sleep (P=0.032). Pain intensity scores improved during both treatment periods (both P<0.001). There were no differences in adverse events between treatment periods. CONCLUSIONS: Circadin™ treatment did not improve sleep disturbance in patients with severe chronic pain compared with placebo at 6 weeks, but there were consistent improvements in aspects of sleep in the shorter term. Given its favourable safety profile, it could be beneficial for some patients with chronic pain. CLINICAL TRIAL REGISTRATION: ISRCTN12861060.

Critical care, maternal and neonatal outcomes of pregnant women with COVID-19 admitted to eight intensive care units during the wildtype, alpha and delta waves of the pandemic across the North West of England-a retrospective review.

INTRODUCTION: Few studies have described obstetric and critical care outcomes in pregnant women with COVID-19 needing intensive care unit (ICU) admission. MATERIAL AND METHODS: Obstetric and critical care outcomes of COVID-19 women admitted to eight ICUs from April 1, 2020 to September 15, 2021, in the North West of England were retrospectively analyzed. Women admitted to ICU were assigned to three groups: antepartum women discharged from ICU prior to delivery (antepartum ICU-discharged group), antepartum women who had expedited delivery (antepartum ICU-delivered group) and a postpartum group. Our aims were to describe maternal characteristics and assess how delivery influenced the obstetric and critical care outcomes in these women. RESULTS: During the study period, 615 women tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), of whom 62 (10.1%) needed ICU admission due to symptomatic COVID-19. Pregnancy loss (3.2%) was recorded in two women. Detailed obstetric and critical outcomes from 60 women are reported. Nine antepartum women (15%) admitted to ICU were discharged and continued their pregnancy, 13 antepartum women (21.7%) had expedited delivery by cesarean birth after ICU admission and 38 (63.3%) women were admitted to ICU during the postpartum period. Antepartum ICU-discharged women contracted the SARS-CoV-2 at an earlier median gestational age (23 weeks; p = 0.0003) and needed ICU admission at an earlier median gestational age (28 weeks, p = 0.03) compared with antepartum ICU-delivered (28 and 32 weeks) and postpartum women (35.5 and 36 weeks). Antepartum ICU-discharged women had the lowest rate of mechanical ventilation receipt (11.1%) compared with antepartum ICU-delivered women (52.3%) and postpartum women (44.3%) but the difference was not statistically significant (p = 0.13). No significant differences were observed in the frequency and severity of critical care complications in the antepartum ICU-discharged, antepartum-ICU delivered and postpartum women. CONCLUSIONS: Of the women admitted to ICU antepartum, 40% were discharged while remaining pregnant and 60% had expedited delivery. Antepartum women who were discharged from ICU without giving birth may receive lower rates of mechanical ventilation than those who delivered in ICU or admitted postpartum; however, further studies are needed to confirm or refute this association.

Good clinical research practice (GCRP) in pharmacodynamic studies of neuromuscular blocking agents III: The 2023 Geneva revision.

The set of guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents was developed following an international consensus conference in Copenhagen in 1996 (Viby-Mogensen et al., Acta Anaesthesiol Scand 1996, 40, 59-74); the guidelines were later revised and updated following the second consensus conference in Stockholm in 2005 (Fuchs-Buder et al., Acta Anaesthesiol Scand 2007, 51, 789-808). In view of new devices and further development of monitoring technologies that emerged since then, (e.g., electromyography, three-dimensional acceleromyography, kinemyography) as well as novel compounds (e.g., sugammadex) a review and update of these recommendations became necessary. The intent of these revised guidelines is to continue to help clinical researchers to conduct high-quality work and advance the field by enhancing the standards, consistency, and comparability of clinical studies. There is growing awareness of the importance of consensus-based reporting standards in clinical trials and observational studies. Such global initiatives are necessary in order to minimize heterogeneous and inadequate data reporting and to improve clarity and comparability between different studies and study cohorts. Variations in definitions of endpoints or outcome variables can introduce confusion and difficulties in interpretation of data, but more importantly, it may preclude building of an adequate body of evidence to achieve reliable conclusions and recommendations. Clinical research in neuromuscular pharmacology and physiology is no exception.

Magnetic resonance imaging of cerebrospinal fluid spread in the epidural space and postdural puncture headache in obstetrics: A proof-of-concept study.

BACKGROUND: Currently, performing an epidural blood patch (EBP) for postdural puncture headache (PDPH) remains a subjective clinical decision. An evidence-based protocol may be of value in identifying women at high risk of developing a severe PDPH. OBJECTIVE: To investigate a potential correlation between the extent of CSF spread in the epidural space, as noted on Magnetic Resonance Imaging (MRI), and the likelihood of development of severe PDPH in obstetric patients. DESIGN: A prospective double-blind quasi-observational study. SETTING: Eight tertiary obstetric units, from NHS hospitals. PATIENTS: Parturients with accidental dural puncture (ADP) underwent T1 and T2-weighted MRI scans of the brain and lumbar spine within 48 h after delivery. All women were followed up, daily, for 1 week. MAIN OUTCOME MEASURES: For each woman, a PDPH severity score was calculated using a four-point Verbal Reporting Scale (none = 0, mild = 1, moderate = 2, severe = 3), with additional points awarded for visual, auditory and emetic symptoms. MRIs were reported by a neuroradiologist, blind to the patient details, using a predefined MRI score. RESULTS: Twenty-two parturients were recruited; 86% (n=19) developed PDPH and 10 of these (53%) required an EBP. The median (range) time for the onset of PDPH was 24 (4 to 126) hours. The median (range) cumulative PDPH severity score was 10 (0 to 21), whereas, the median (range) MRI score was 2.5 (0 to 12). Spearman (rs) analysis identified a significant positive correlation (rs = 0.46; P = 0.024) between cumulative PDPH severity and MRI scores. Of all the radiological features identified in an MRI (lumbar dural shift, caudal brain displacement, epidural or intrathecal blood), the presence of intrathecal blood was most strongly correlated with PDPH severity (P = 0.043). CONCLUSION: Following an ADP, the extent of CSF spread in the epidural space correlates with the severity of subsequent PDPH. CLINICAL TRIAL NUMBER AND REGISTRY URL: ISRCTN14959004, https://www.isrctn.com/.

Effect of rectus sheath block vs. spinal anaesthesia on time-to-readiness for hospital discharge after trans-peritoneal hand-assisted laparoscopic live donor nephrectomy: A randomised trial.

BACKGROUND: The role of spinal anaesthesia in patients having a transperitoneal hand-assisted laparoscopic donor nephrectomy in an enhanced recovery setting has never been investigated. OBJECTIVE: We explored whether substituting a rectus sheath block (RSB) with spinal anaesthesia, as an adjunct to a general anaesthetic technique, influenced time-to-readiness for discharge in patients undergoing hand-assisted laparoscopic donor nephrectomy. DESIGN: Prospective randomised open blinded end-point (PROBE) study with two parallel groups. SETTING: Tertiary University Hospital. PATIENTS: Ninety-seven patients undergoing a trans-peritoneal hand-assisted laparoscopic donor nephrectomy. INTERVENTION: Patients (n=52) were randomly assigned to receive a general anaesthetic and a surgical RSB with 2 mg kg-1 of levobupivacaine at the time of surgical closure or a spinal anaesthetic with hyperbaric bupivacaine 12.5 mg and diamorphine 0.5 mg (n=45) before general anaesthesia. PRIMARY OUTCOME: The primary outcome was the time-to-readiness for discharge following surgery. RESULTS: Median [IQR] times-to-readiness for discharge were 75 [56 to 83] and 79 [67 to 101] h for RSB and spinal anaesthesia and there was no significant difference in times-to-readiness for discharge (median difference 4 (95% CI, 0 to 20h; P  = 0.07)). There were no significant differences in pain scores at rest (P  = 0.91) or on movement (P = 0.66). Median 24-h oxycodone consumptions were similar (P  = 0.80). Nausea and vomiting scores were similar (P = 0.57) and urinary retention occurred in one vs. four patients with RSB and spinal anaesthesia, respectively (P  = 0.077). CONCLUSION: Substitution of RSB with spinal anaesthesia using 12.5 mg hyperbaric bupivacaine and 0.5 mg diamorphine, together with a general anaesthetic failed to confer any benefit on time-to-discharge readiness following transperitoneal hand-assisted laparoscopic donor nephrectomy. RSB provided similar analgesia in the immediate postoperative period with a low frequency of side-effects in this cohort. TRIAL REGISTRATION: ClinicalTrial.gov identifier: NCT02700217.

Generic versus reference listed ropivacaine for peripheral nerve blockade: A randomised, triple-blinded, crossover, equivalence study in volunteers.

BACKGROUND: Generic drug preparations do not require the same degree of scrutiny as the originally licensed preparation before they can be approved for clinical use. The permitted tolerance limits for bioequivalent preparations might be associated with clinically relevant differences for drugs with a narrow therapeutic index, such as local anaesthetics. OBJECTIVE: We compared pharmacokinetic and pharmacodynamic characteristics of generic and reference listed or original preparations of ropivacaine. DESIGN: The current healthy volunteer study used a randomised, triple-blinded, cross-over equivalence design. SETTING: Tertiary university hospital, Medical University of Vienna. SUBJECTS: Healthy male volunteers (N=18) aged 18 to 60 years. INTERVENTIONS: A series of three ultrasound-guided ulnar nerve blocks separated by at least 6 days were carried out on each volunteer. Reference listed ropivacaine (NaropinTM) was used for two blocks and a generic preparation of ropivacaine was used for the other block. Sensory block onset and duration were evaluated using loss of pinprick sensation. MAIN OUTCOME MEASURES: Duration of sensory block was the primary outcome. Secondary outcomes included time-to-onset of sensory block, ropivacaine pharmacokinetics from venous blood samples and pH of the preparations. Equivalence was evaluated using the ratios of means and 90% confidence intervals (CIs) of log transformed data. RESULTS: Equivalence was demonstrated for the primary outcome measure, the duration of sensory block [original : generic ratio 1.01 (90% CI 0.87 to 1.16); P < 0.007] and all pharmacokinetic variables. Equivalence could not be concluded for time-to-onset of sensory block [reference : generic ratio 0.80 (90% CI 0.63 to 1.03); P = 0.27], although reproducibility of this variable using our experimental model was lower than for other variables. The generic preparation was significantly more alkaline [difference 0.06 pH units (95% CI 0.04 to 0.07); P < 0.0001]. CONCLUSION: Our finding of equivalence for sensory block duration and key pharmacokinetic variables between a generic and original preparation of ropivacaine is reassuring. The significant, but small, difference in pH is not clinically important. TRIAL REGISTRATION: EudraCT 2019-003148-61, German Clinical Trials Register (DRKS 00017750).

A national survey of anaesthetists' preferences for their own end of life care.

OBJECTIVES: To describe individual views, wishes, and preferences for end of life care and to report UK anaesthetists' personal perspectives. METHODS: The 'bigconversations' questionnaire was developed by modifying an existing framework for end of life discussions. An online cross-sectional survey of UK anaesthetists was then conducted using the questionnaire in January 2019. RESULTS: The bigconversations questionnaire was validated as measuring the important aspects of end of life care by an expert panel and was found to have moderate test-retest reliability. Responses were received from 760/1913 (40%) of those invited to take part. Overall, 698/760 (92%) of respondents wished to be well informed about their condition and prognosis and 518/760 (68%) wanted to be heavily involved in decision-making about their health. Meanwhile, 639/760 (84%) of respondents would choose to forego treatment aimed at prolonging life should that life be of poor quality. The desire to spend time with family was a theme which arose from the qualitative analysis. CONCLUSION: This study provides the first systematic description of UK doctors', specifically anaesthetists', personal preferences for end of life care. Broad trends were identified: to be well informed; to avoid high-intensity medical treatments if terminally unwell; to spend remaining time with family and friends; and to be symptom-free and well cared for. However, a substantial minority expressed different, indeed opposite, opinions. This variation highlights that good quality end of life care must be driven by discussion of an individual's values, wishes, and preferences.

Dexamethasone as an adjuvant for peripheral nerve blockade: a randomised, triple-blinded crossover study in volunteers.

BACKGROUND: The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine. METHODS: Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome. RESULTS: All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85-7.62) h in the control group, 7.37 (5.78-7.93) h in the perineural group and 7.37 (6.10-7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups. CONCLUSION: Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve. CLINICAL TRIAL REGISTRATION: DRKS, 00014604; EudraCT, 2018-001221-98.

Mortality and morbidity in oesophageal atresia.

BACKGROUND: Several classification systems exist to predict mortality in oesophageal atresia, the most widely quoted of these being over 20 years old. No classification system exists to predict morbidity. We sought to test whether these classification systems remain relevant and to determine whether they can be useful to predict morbidity. In addition, we aimed to identify independent risk factors for predicting mortality and morbidity. METHODS: Neonates presenting with oesophageal atresia over a 20-year period (1990-2010) were retrospectively reviewed. Discriminative statistical analysis compared the performance of current classification systems. Stepwise logistic regression analysis of the influence of perioperative risk factors on mortality and duration of ventilatory support and intensive care unit stay were performed. RESULTS: All classification systems predicted mortality in this series of 248 neonates. Birth weight, cardiac anomalies and pre-operative pneumonia were independent risk factors for predicting mortality in oesophageal atresia. The Waterston classification is the most useful classification for predicting post-operative morbidity in terms of length of hospital stay and time spent ventilated. CONCLUSION: Despite advances in the neonatal care of the very low birth weight infant and those with congenital cardiac disease, these conditions remain relevant in predicting mortality and morbidity in oesophageal atresia.

The impact of biological sex in peripheral nerve blockade: A prospective pharmacodynamic, pharmacokinetic and morphometric study in volunteers.

STUDY OBJECTIVE: The impact of biological sex in peripheral regional anaesthesia is largely unknown. We therefore designed a prospective study in volunteers to investigate the impact of biological sex on pharmacodynamic, pharmacokinetic and morphometric characteristics for peripheral nerve blockade. METHODS: The initial study plan was powered to include 90 volunteers to find a difference of 35 min in duration of sensory block (primary outcome variable) with 80% power and alpha error at 5%. After discussions in ethical review, a pilot study of 2 x 12 volunteers from each sex were studied. Female and male volunteers received ultrasound guided nerve blockade with 3.0 mL ropivacaine 7.5 mg mL-1. Sensory duration of blockade, as the primary outcome, was evaluated by pinprick testing. Secondary outcomes were sensory onset time of blockade, pharmacokinetic characteristics and the visibility of ulnar nerves using ultrasound. Analyses included Mann-Whitney U-statistics with P<0.05 (two-sided) as significant. RESULTS: After 24 participants, the median (IQR) duration of sensory blockade was 450 (420; 503) min in women and 480 (450; 510) min in men (P = 0.49). Sensory onset time of blockade, and ultrasound visibility of nerves were also similar between the study groups. The total drug exposure across time (AUC0-infinity) was significantly higher in women (P = 0.017). After a the planned power re-analysis after these 24 study paticipants, which suggested that > 400 subjects would be required with 80% power and alpha error of 5% to find significance for the primary outcome parameter for marginal differences, we terminated the study at this point. CONCLUSIONS: We did not detect significant differences between female and male study participants in terms of pharmacodynamic and morphometric characteristics after ultrasound guided ulnar nerve blocks. Women did show significantly greater pharmacokinetic ropivacaine exposures. The results of this study indicate that peripheral regional block pharmacodynamic characteristics are independent of the biological sex, whereas pharmacokinetic parameters are sex-dependent.

Supraneural versus Infraneural Approach to transforaMinal Epidural StEroid injection for unilateral lumbosacral radicular pain (SIAMESE): a study protocol for a randomised non-inferiority trial.

Background: Lumbosacral radicular pain is commonly treated by transforaminal steroid epidural injection. There are two methods: the supraneural and the infraneural approaches. The supraneural approach can result in rare but catastrophic consequences from injury to the radiculomedullary artery. The infraneural technique avoids the artery; both approaches show efficacy and are used locally. Methods: This is a protocol for a randomised, single-blinded, non-inferiority trial of infraneural vs supraneural transforaminal epidural injection for lumbosacral radicular pain at a tertiary referral pain management clinic. Adult patients (n=92) with moderate-to-severe lumbosacral radicular pain of >3 months duration, scheduled for transforaminal epidural steroid injection, will be randomised to epidural by either the infraneural or supraneural approach. Only the treating physicians will know which route is used. The primary outcome measure is the differential impact on pain intensity score at 3 months. Secondary outcome measures will include disability and function scores, sleep and activity measures, and adverse events. Participants will be followed up for 12 months. Conclusions: This study will determine whether the techniques are comparable and, if so, will enable recommendations for the use of an approach without risk of artery damage and catastrophic injury. Clinical trial registration: ISRCTN 36195887.

Breast-Q sensory outcomes of non-neurotized, autologous, unilateral breast reconstruction with a minimum of 3-year follow-up.

INTRODUCTION: Sensory reinnervation of autologous breast tissue after free flap reconstruction is highly variable. There is no long-term follow-up data exploring spontaneous reinnervation and how this affects patients' quality of life nor the nerve-related symptoms they experience. To address this issue, we invited patients with a minimum of 3 years after non-neurotized, free flap breast reconstruction to complete patient-reported outcome measures exploring sensation, quality of life and breast-related symptoms. METHODS: We performed a retrospective cohort study of patients undergoing unilateral Muscle-Sparing Transverse Rectus Abdominus Muscle (MS-TRAM) or deep inferior epigastric artery perforator (DIEP) flap breast reconstruction between 01-01-2015 and 31-12-2019 in the Department of Plastic and Reconstructive Surgery at Manchester University NHS Foundation Trust. We invited participants to complete the recently developed Breast-Q© Breast Sensation Module. RESULTS: All patients had undergone unilateral immediate (n = 85) or delayed (n = 82) breast reconstruction after mastectomy using either a free DIEP (n = 150) or TRAM (n = 17) flap reconstruction a minimum of 3 years prior. The median age at operation was 48. Sensation after reconstruction was significantly reduced in the reconstructed breast compared with the contralateral breast (P < 0.0001) with a reduction in reported quality of life (immediate (68.0 [54.0, 89.0]) and delayed (68.0 [62.0, 83.8])). The sensation was significantly better in immediate vs delayed procedures (P = 0.024). Sensory scores after reconstruction increased with age (P = 0.036). DISCUSSION: Breast sensation after non-neurotized reconstruction with autologous tissue is significantly reduced at long-term follow-up with a reduction in quality of life. A minimum outcome set for quantification of breast sensation is required and future research into the cost-benefit of neurotized, autologous breast reconstruction is needed.

The incidence and management of peripheral nerve injury in England (2005-2020).

Peripheral nerve injury (PNI) is a significant health problem that confers lifelong impact on those injured. Current interventions are purely surgical; however, outcomes remain poor. There is a lack of high-quality epidemiological data that is needed to identify populations involved, current healthcare demands, and ensure resources are distributed to the greatest effect, to reduce the injury burden. METHODS: Anonymized hospital episode statistical (HES) data on admitted patient care was obtained from NHS Digital for all National Health Service (NHS) patients sustaining PNI of all body regions between 2005 and 2020. Total numbers of finished consultant episodes (FCEs) or FCEs/100,000 population were used to demonstrate changes in demographic variables, anatomical locations of injury, mechanisms of injury, speciality, and main operation. RESULTS: There was a mean national incidence of 11.2 (95% CI 10.9, 11.6) events per 100,000 population per year. Males were at least twice as likely (p < 0.0001) to sustain a PNI. Upper limb nerves at or distal to the wrist were most commonly injured. Knife injuries increased (p < 0.0001), whereas glass injuries decreased (p < 0.0001). Plastic surgeons increasingly managed PNI (p = 0.002) as opposed to orthopaedic surgeons (p = 0.006) or neurosurgeons (p = 0.001). There was an increase in neurosynthesis (p = 0.022) and graft procedures (p < 0.0001) during the study period. DISCUSSION: PNI is a significant national healthcare problem predominantly affecting distal, upper limb nerves of men of working age. Injury prevention strategies, improved targeted funding and rehabilitation pathways are needed to reduce the injury burden and improve patient care.

Plasma interleukin responses as predictors of outcome stratification in patients after major trauma: a prospective observational two centre study.

Background and objectives: There is a need to develop objective risk stratification tools to define efficient care pathways for trauma patients. Biomarker-based point of care testing may strengthen existing clinical tools currently available for this purpose. The dysregulation of pro- and anti-inflammatory cytokines in the pathogenesis of organ failure is well recognised. This study was carried out to evaluate whether blood concentrations of IL-6, IL-10, and IL-6:IL-10 ratios in the early stages of the illness are significantly different in patients with worsening organ function. Materials and methods: In this prospective observational cohort study, plasma concentrations of IL-6 and IL-10 on days 1, 3 and 5 were measured in 91 major trauma patients using a multiplexed cytometric bead array approach. A composite measure of adverse outcome - defined as SOFA ≥ 2 or mortality at 7 days, was the primary outcome. IL-6 and IL-10 concentrations in early samples (days 1, 3 & 5) in patients who developed SOFA ≥ 2 on day 7 were compared against those who did not. Similar composite outcome groups at day 5 and in groups with worsening or improving SOFA scores (ΔSOFA) at days 7 and 5 were undertaken as secondary analyses. Results: Stratification on day 7, 44 (48%) patients showed adverse outcomes. These adverse outcomes associated with significantly greater IL-6 concentrations on days 1 and 5 (Day 1: 47.65 [23.24-78.68] Vs 73.69 [39.93 - 118.07] pg/mL, P = 0.040 and Day 5: 12.85 [5.80-19.51] Vs 28.90 [8.78-74.08] pg/mL; P = 0.0019). Similarly, IL-10 levels were significantly greater in the adverse outcome group on days 3 and 5 (Day 3: 2.54 [1.76-3.19] Vs 3.16 [2.68-4.21] pg/mL; P = 0.044 and Day 5: 2.03 [1.65-2.55] Vs 2.90 [2.00-5.06] pg/mL; P <0.001). IL-6 and IL-10 concentrations were also significantly elevated in the adverse outcome groups at day 3 and day 5 when stratified on day 5 outcomes. Both IL-6 and IL-6:IL-10 were found to be significantly elevated on days 1 and 3 when stratified based on ΔSOFA at day 5. This significance was lost when stratified on day 7 scores. Conclusions: Early IL-6 and IL-10 concentrations are significantly greater in patients who develop worsening organ functions downstream. These differences may provide an alternate biomarker-based approach to strengthen risk stratification in trauma patients.

Cardiac index in term pregnant women in the sitting, lateral, and supine positions: an observational, crossover study.

BACKGROUND: Aortocaval compression may affect maternal hemodynamic indices and fetal well-being in various maternal positions. There has been much debate regarding the optimal position for performing neuraxial blockade for labor analgesia and cesarean delivery. We hypothesized that in pregnant women at term, cardiac index (CI) may be improved in the lateral positions as compared with the flexed sitting position. Our primary outcome was to measure CI as assessed by suprasternal Doppler. METHODS: A prospective, observational, crossover study was conducted in 25 ASA physical status I/II women with uncomplicated pregnancies presenting for elective cesarean delivery at term. Hemodynamic indices were measured in 4 positions in random order: supine with a 15-degree left tilt, sitting with neck and hips flexed, and flexed left lateral and flexed right lateral positions. Maternal CIs were measured using a noninvasive suprasternal Doppler device and upper arm noninvasive arterial blood pressure. Umbilical Dopplers were performed simultaneously to measure the fetal heart rate and umbilical artery pulsatility and resistivity indices. RESULTS: CI differed by position (P = 0.01); it was higher in the right lateral position compared with the sitting and supine positions (by 8.8% and 8.1%, respectively) and in the left lateral compared with sitting position (by 7.8%) (P < 0.05). Maternal stroke volume index, heart rate, and systolic blood pressure were higher in the lateral positions compared with the sitting and supine-tilt positions. We found no significant differences in fetal heart rate, pulsatility index, or resistivity index among positions. CONCLUSION: Positioning for neuraxial anesthesia may influence maternal hemodynamic variables. We found no difference in healthy fetal blood flow indices among positions, suggesting that these changes are not clinically significant. This study provides new physiological information on the changes that occur in a group in whom it has not been practical to study previously. Further study is necessary to determine whether these changes are significant in the presence of neuraxial anesthesia or in the high-risk parturient.