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Shock index and continuous non-invasive haemoglobin monitoring (SpHb) have both been proposed for the timely recognition of postpartum haemorrhage (PPH). We sought to determine, in parallel, the association of each of shock index and SpHb with blood loss after vaginal delivery.Sixty-six women were recruited to this prospective observational study. Shock index and SpHb were recorded postpartum for 120 min. The association between each of shock index and SpHb with quantitative blood loss (QBL) at 30, 60 and 120 min postpartum was determined using linear mixed models. Area-under-the-receiver-operator-characteristic (AUROC) curves were constructed to evaluate the diagnostic ability of shock index and SpHb to detect PPH (defined as QBL ≥1000 mL).Shock index trend was associated with QBL over the first 30 min (r=0.37, P=0.002), but not over 60 or 120 min. There was an association of SpHb trend with QBL over the first 30 min (P=0.06), but not over 60 min (r=-0.32, P=0.009) or 120 min (r=-0.26, P=0.03). Maximum shock index within 60 min correlated with QBL (r=0.54, P0.001) and was a predictor of PPH (P=0.0012, AUROC 0.796). Maximum change in SpHb within 60 min negatively correlated with QBL (r=-0.4, P0.001) and was a predictor of PPH (P=0.048, AUROC 0.761).The trend of shock index and its peak values are associated with blood loss after vaginal delivery and are early indicators of PPH. Negative trend of SpHb is a late sign of PPH and has a weaker association with blood loss than shock index.

Objective The objective of this study was to determine the pattern of uterotonic drug usage in obstetric units of university-affiliated hospitals in Canada. Methods This was a prospective observational study conducted in the form of an electronic survey. The target group consisted of chiefs or directors of Obstetrics and Anaesthesia at university-affiliated hospitals across Canada. The survey was sent out between November 2016 and January 2017, using the program ‘SurveyMonkey’. Data on institutional obstetric practices and usage of uterotonic agents were collected. Results The survey was sent to 92 obstetricians and anesthesiologists from 46 institutions, of which 33 clinicians from 24 institutions responded. About 65% of clinicians were unaware of the rate of postpartum hemorrhage in their institution. The first-line agent for vaginal deliveries was reported as oxytocin by 94% and carbetocin by 6% of physicians. For women at low-risk for postpartum hemorrhage when undergoing cesarean deliveries (CD), 66% reported oxytocin as the first-line uterotonic, while 34% reported carbetocin. For CDs at high-risk of postpartum hemorrhage, 60% of physicians reported oxytocin and 40% reported using carbetocin initially. The use of second-line uterotonics was also variable. The choice of uterotonic was mainly based on perceived efficacy and Society of Obstetricians and Gynaecologists of Canada guidelines. Conclusion There is a lack of a unified approach to the use of uterotonic drugs for postpartum hemorrhage management in Canada. To improve the management of postpartum hemorrhage due to uterine atony, an evidence-based approach to usage and consensus between obstetricians and anesthesiologists is warranted.

It is routine to give a uterotonic drug following delivery of the neonate during caesarean section. However, there is much heterogeneity in the relevant research, which has largely been performed in low-risk elective cases or women with uncomplicated labour. This is reflected in considerable variation in clinical practice. There are significant differences between dose requirements during elective and intrapartum caesarean section. Standard recommended doses are higher than required, with the potential for acute cardiovascular adverse effects. We recommend a small initial bolus dose of oxytocin, followed by a titrated infusion. The recommended doses of oxytocin may have to be increased in women with risk factors for uterine atony. Carbetocin at equipotent doses to oxytocin has similar actions, while avoiding the requirement for a continuous infusion after the initial dose and reducing the need for additional uterotonics. As with oxytocin, carbetocin dose requirements are higher for intrapartum caesarean sections. A second-line agent should be considered early if oxytocin/carbetocin fails to produce good uterine tone. Women with cardiac disease may be very sensitive to the adverse effects of oxytocin and other uterotonics, and their management needs to be individualised.

Prophylactic oxytocin administration at the third stage of labour reduces blood loss and the need for additional uterotonic drugs. Obesity is known to be associated with an increased risk of uterine atony and postpartum haemorrhage. It is unknown whether women with obesity require higher doses of oxytocin in order to achieve adequate uterine tone after delivery. The purpose of this study was to establish the bolus dose of oxytocin required to initiate effective uterine contraction in 90% of women with obesity (the ED90 ) at elective caesarean delivery. We conducted a double-blind dose-finding study using the biased coin up-down design method. Term pregnant women with a BMI ≥ 40 kg.m-2 undergoing elective caesarean delivery under regional anaesthesia were included. Those with conditions predisposing to postpartum haemorrhage were not included. Oxytocin was administered as an intravenous bolus over 1 minute upon delivery of the fetus. With the first woman receiving 0.5 IU, oxytocin doses were administered according to a sequential allocation scheme. The primary outcome measure was satisfactory uterine tone, as assessed by the operating obstetrician 2 minutes after administration of the oxytocin bolus. Secondary outcomes included the need for rescue uterotonic drugs, adverse effects and estimated blood loss. We studied 30 women with a mean (SD) BMI of 52.3 (7.6) kg.m-2 . The ED90 for oxytocin was 0.75 IU (95%CI 0.5-0.93 IU) by isotonic regression and 0.78 IU (95%CI 0.68-0.88 IU) by the Dixon and Mood method. Our results suggest that women with a BMI ≥ 40 kg.m-2 require approximately twice as much oxytocin as those with a BMI < 40 kg.m-2 , in whom an ED90 of 0.35 IU (95%CI 0.15-0.52 IU) has previously been demonstrated.

The optimum time interval for 10 ml boluses of bupivacaine 0.0625% + fentanyl 2 μg.ml-1 as part of a programmed intermittent epidural bolus regimen has been found to be 40 min. This regimen was shown to be effective without the use of supplementary patient-controlled epidural analgesia boluses in 90% of women during the first stage of labour, although with a rate of sensory block to ice above T6 in 34% of women. We aimed to determine the optimum programmed intermittent epidural bolus volume at a 40 min interval to provide effective analgesia in 90% of women (EV90 ) during the first stage of labour, without the use of patient-controlled epidural analgesia. We performed a prospective double-blind dose-finding study using the biased coin up-and-down sequential allocation method in 40 women. The estimated EV90 was 11.0 (95%CI 10.0-11.7) ml with the isotonic regression method and 10.7 (95%CI 10.3-11.0) ml with the truncated Dixon and Mood method. Overall, 18 women had a sensory block above T6, and 37 women exhibited no motor block. No women required treatment for hypotension. In conclusion, it is not possible to reduce the programmed intermittent epidural bolus volume from 10 ml, used in our current regimen, without compromising the quality of analgesia. Using this regimen, a high proportion of women will develop a sensory block above T6.

Primary immune thrombocytopenia (ITP) is an autoimmune condition affecting women of childbearing age that is characterized by diminished platelet quantity with preserved function. Although pregnant women with ITP are often denied obstetric neuraxial anesthesia (OBNA) with low platelet counts for fear of neuraxial hematoma, the true magnitude of neuraxial hematoma for ITP parturients is unknown. The aim of this systematic review and meta-analysis was to examine OBNA outcomes in ITP parturients with platelet counts below 100 x 109·L-1. Articles published in MEDLINE, Embase, Web of Science, Scopus, Cochrane, and PubMed in process until May 14, 2018 were searched. Two reviewers independently screened 954 articles by title and abstract, reviewed 62 full-texts, extracted data, and assessed risk of bias for 26 articles. Of 291 pregnant women with ITP and platelet counts below 100 x 109·L-1, 166 received OBNA and 61 of these had platelet counts below 80 x 109·L-1. No neuraxial hematomas were reported. Meta-analysis of six studies showed higher platelet counts in those with OBNA than without (mean difference [MD], 19 x 109·L-1; 95% confidence interval [CI], 11 to 26; P < 0.001), with no difference between epidural and spinal anesthesia (MD, 0.4 x 109·L-1; 95% CI, -4 to 4; P = 0.86). Our study highlights continued reluctance to offer OBNA below the commonly quoted 80 x 109·L-1 platelet count, based largely on consensus and theoretical presumption of risk. This further negatively influences the accrual of large-scale data. The evidence of no neuraxial hematoma after OBNA provided herein offers support for considering neuraxial anesthesia at lower platelet count thresholds. Each patient should be afforded individualized discussion of risk and benefit relative to other analgesic measures. PROSPERO (CRD42018059220); registered 2 August, 2018.

Obstetricians and anesthesiologists may interpret medical evidence differently, which could potentially generate conflict and compromise patient care. We sought to identify the most important controversial topics involving obstetricians and anesthesiologists on the labour ward that had the potential to affect patient outcome. We conducted a consensus-building study based on the Delphi technique. A panel of experts comprised of obstetric anesthesiologists and obstetricians responded to a series of four parallel sequential questionnaires interspersed with feedback. The first round consisted of an open questionnaire: Which topics in patient management would rouse a difference of opinion between anesthesiologists and obstetricians that may interfere with patient outcome, and why? The second round sought agreement on the topics, and the third round sought to rank the topics, and their underlying reasons, that scored at least 60% agreement. The final round allowed each discipline insight into the controversies gathered by the other discipline. Ten anesthesiologists and ten obstetricians participated in the study. Anesthesiologists identified twice as many controversial topics as the obstetricians (six vs three, respectively). The obstetricians agreed with all topics identified by the anesthesiologists, but agreed with only five of the 18 (28%) reasons to support them. Anesthesiologists agreed with all topics raised by the obstetricians, but agreed with only three of the six (50%) reasons to support them. Both the obstetricians and the anesthesiologists identified several controversial topics that may influence clinical practice on the labour ward. This information could serve as the basis to develop educational programs and strategies to improve communication between the two disciplines.

Bedside gastric ultrasonography can be performed reliably by anaesthetists to assess gastric content in the peri-operative period. We aimed to study the relationship between gastric cross-sectional area, assessed by ultrasound, and volumes of clear fluids ingested by pregnant women. We recruited 60 non-labouring third-trimester pregnant women in a randomised controlled and assessor-blinded study. A standardised scanning protocol of the gastric antrum was performed in the 45° semirecumbent and 45° semirecumbent-right lateral positions. Subjects were randomly allocated to drink one out of six predetermined volumes of apple juice (0 ml, 50 ml, 100 ml, 200 ml, 300 ml, 400 ml). Qualitative and quantitative assessments at a baseline period after an 8-h fast, and immediately after the drink, were used to establish the correlation between antral cross-sectional area and volume ingested. A predictive model to estimate gastric volume was developed. Antral cross-sectional area in the semirecumbent right lateral position significantly correlated with the ingested volume (Spearman rank correlation = 0.7; p < 0.0001). A cut-off value of 9.6 cm2 discriminated ingested volumes ≥ 1.5 ml.kg-1 with a sensitivity of 80%, a specificity of 66.7%, and an area under the curve of 0.82. A linear predictive model was developed for gastric volume based only on antral cross-sectional area (Volume (ml) = -327.1 + 215.2 × log (cross-sectional area) (cm2 )). We conclude that in pregnant women in the third trimester of gestation, the antral cross-sectional area correlates well with volumes ingested, and this cut-off value in the semirecumbent right lateral position discriminates high gastric volumes.

JUSTIFICATIVA E OBJETIVOS: O monitoramento da pressão arterial oferece uma compreensão limitada das consequências hemodinâmicas da raquianestesia para cesariana. O objetivo deste estudo foi avaliar, com o auxílio do monitor de débito cardíaco não invasivo baseado na biorreatância, as alterações hemodinâmicas durante cesariana eletiva sob raquianestesia, na qual doses intermitentes de fenilefrina foram utilizados para prevenir e tratar a hipotensão. MÉTODOS: Este estudo observacional foi realizado após aprovação da comissão de ética na pesquisa e assinatura do consentimento informado. Pacientes saudáveis marcadas para cesariana eletiva sob raquianestesia foram avaliadas. Doses intermitentes de fenilefrina foram administrados para manter a pressão arterial sistólica nos níveis basais e as pacientes foram avaliadas com o monitor de débito cardíaco não invasivo baseado na biorreatância. Os dados hemodinâmicos foram colhidos continuamente no momento basal e durante os períodos pós-raquianestesia e pós-nascimento do feto. Os dados foram analisados usando ANOVA para modelos mistos e um p < 0,05 foi considerado significativo. RESULTADOS: A pressão arterial sistólica foi mantida entre 79,2% ± 14,2 e 105,9% ± 10,0 dos valores basais durante o período pós-raquianestesia e 78,4% ± 11,13 e 100,9% ± 10,7 dos valores basais no período pós-nascimento do feto (média ± DP). Flutuações significativas foram observadas na pressão arterial sistólica, frequência cardíaca e débito cardíaco no período pós-nascimento. CONCLUSÕES: Um novo monitor não invasivo, baseado na biorreatância, revelou flutuações hemodinâmicas significativas durante a cesariana sob raquianestesia, a despeito das tentativas de manter a pressão arterial nos níveis basais com doses intermitentes de fenilefrina. BACKGROUND AND OBJECTIVES: Blood pressure monitoring offers a limited understanding of the hemodynamic consequences of spinal anesthesia for cesarean delivery. The purpose of this study was to assess, with the aid of a non-invasive cardiac output monitor based on bioreactance, the hemodynamic changes during elective cesarean delivery under spinal anesthesia in which intermittent boluses of phenylephrine were used to prevent and treat hypotension. METHODS: This observational study was conducted with the Research Ethics Board approval, and all participants provided written informed consent. Healthy patients undergoing elective cesarean delivery under spinal anesthesia were enrolled. Intermittent boluses of phenylephrine were administered in an attempt to maintain systolic blood pressure at baseline levels, and patients were assessed with a non-invasive cardiac output monitor based on bioreactance. Hemodynamic data was collected continuously at baseline, and during the postspinal and postdelivery periods. Data was analyzed using a mixed model ANOVA, and a p < 0.05 was considered significant. RESULTS: Systolic blood pressure was maintained within 79.2 ± 14.2 and 105.8 ± 10.0 percent of baseline during the postspinal period, and 78.4 ± 11.3 and 100.9 ± 10.7 percent of baseline in the postdelivery period (mean ± SD) There were significant fluctuations in systolic blood pressure, heart rate, and cardiac output during the postspinal period, and significant fluctuations in systolic blood pressure and cardiac output in the postdelivery period. CONCLUSIONS: A new non-invasive monitor based on bioreactance reveals significant hemodynamic fluctuations during cesarean delivery under spinal anesthesia, despite attempts to maintain blood pressure at baseline levels with intermittent boluses of phenylephrine. JUSTIFICATIVA Y OBJETIVOS: La monitorización de la presión arterial ofrece una comprensión limitada de las consecuencias hemodinámicas de la raquianestesia para la cesárea. El objetivo de este estudio fue evaluar, con la ayuda del monitor de débito cardíaco no invasivo y con base en la biorreactancia, las alteraciones hemodinámicas durante la cesárea electiva bajo raquianestesia, en la cual bolos intermitentes de fenilefrina fueron utilizados para prevenir y tratar la hipotensión. MÉTODOS: Este estudio observacional fue realizado posterior a la aprobación de la comisión de ética en investigación y de la firma del consentimiento informado. Se evaluaron los pacientes sanos con cesárea electiva programada bajo raquianestesia. Bolos intermitentes de fenilefrina fueron administrados para mantener la presión arterial sistólica en los niveles basales, y las pacientes fueron evaluadas con la ayuda del monitor de débito cardíaco no invasivo con base en la biorreactancia. Los datos hemodinámicos se recopilaron continuamente en el momento basal y durante los períodos postraquianestesia y después del nacimiento del feto. Los datos se analizaron usando ANOVA para modelos mixtos, y un p < 0,05 fue considerado significativo. RESULTADOS: La presión arterial sistólica se mantuvo entre 79,2 (14,2) y 105,9 (10,0) por ciento de los valores basales durante el período postraquianestesia, y 78,4 (11,13) y 100,9 (10,7) por ciento de los valores basales en el período postparto promedio ± de. Las fluctuaciones significativas se observaron en la presión arterial sistólica, en la frecuencia cardíaca y en el débito cardíaco en el período postparto. CONCLUSIONES: Un nuevo monitor no invasivo, con base en la biorreactancia, reveló fluctuaciones hemodinámicas significativas durante la cesárea bajo la raquianestesia, pese a los intentos de mantener la presión arterial a niveles basales con bolos intermitentes de fenilefrina.

Objective To determine if intravenous infusion of a combination of oxytocin and ergometrine maleate is better than oxytocin alone to decrease blood loss at caesarean delivery for labour arrest. Design Prospective, double-blinded, randomised controlled trial. Setting Mount Sinai Hospital, Toronto, Canada. Population Women undergoing caesarean deliveries for labour arrest. Methods Forty-eight women were randomised to receive infusion of either ergometrine maleate 0.25 mg + oxytocin 20 iu or oxytocin 20 iu alone, diluted in 1 l of lactated Ringer’s Solution, immediately after delivery of the infant. Unsatisfactory uterine contractions after delivery were treated with additional boluses of the study solution or rescue carboprost. Blood loss was estimated based on the haematocrit values before and 48 hours after delivery. Main outcome measures The primary outcome was the estimated blood loss, while the secondary outcomes included the use of additional uterotonics, need for blood transfusion and the incidence of adverse effects. Results The estimated blood loss was similar in the oxytocin–ergometrine and oxytocin-only groups; 1218 ± 716 ml and 1299 ± 774 ml, respectively (P= 0.72). Significantly fewer women required additional boluses of the study drug in the oxytocin–ergometrine group (21 and 57%; P= 0.01). Nausea (42 and 9%; P= 0.01) and vomiting (25 and 4%; P= 0.05) were significantly more prevalent in the oxytocin–ergometrine group. Conclusions In women undergoing caesarean delivery for labour arrest, the co-administration of ergometrine with oxytocin does not reduce intraoperative blood loss, despite apparently superior uterine contraction.