Pregnancy and COVID-19: pharmacologic considerations.

In this review, we summarize evidence regarding the use of routine and investigational pharmacologic interventions for pregnant and lactating patients with coronavirus disease 2019 (COVID-19). Antenatal corticosteroids may be used routinely for fetal lung maturation between 24 and 34 weeks' gestation, but decisions in those with critical illness and those < 24 or > 34 weeks' gestation should be made on a case-by-case basis. Magnesium sulfate may be used for seizure prophylaxis and fetal neuroprotection, albeit cautiously in those with hypoxia and renal compromise. There are no contraindications to using low-dose aspirin to prevent placenta-mediated pregnancy complications when indicated. An algorithm for thromboprophylaxis in pregnant patients with COVID-19 is presented, which considers disease severity, timing of delivery in relation to disease onset, inpatient vs outpatient status, underlying comorbidities and contraindications to the use of anticoagulation. Nitrous oxide may be administered for labor analgesia while using appropriate personal protective equipment. Intravenous remifentanil patient-controlled analgesia should be used with caution in patients with respiratory depression. Liberal use of neuraxial labor analgesia may reduce the need for emergency general anesthesia which results in aerosolization. Short courses of non-steroidal anti-inflammatory drugs can be administered for postpartum analgesia, but opioids should be used with caution due to the risk of respiratory depression. For mechanically ventilated pregnant patients, neuromuscular blockade should be used for the shortest duration possible and reversal agents should be available on hand if delivery is imminent. To date, dexamethasone is the only proven and recommended experimental treatment for pregnant patients with COVID-19 who are mechanically ventilated or who require supplemental oxygen. Although hydroxycholoroquine, lopinavir/ritonavir and remdesivir may be used during pregnancy and lactation within the context of clinical trials, data from non-pregnant populations have not shown benefit. The role of monoclonal antibodies (tocilizumab), immunomodulators (tacrolimus), interferon, inhaled nitric oxide and convalescent plasma in pregnancy and lactation needs further evaluation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Challenging authority and speaking up in the operating room environment: a narrative synthesis.

Multidisciplinary care teams exist throughout healthcare systems. In the operating room (OR), effective communication between teams is essential, especially during crisis situations where patient safety can be in acute danger. An often-neglected skillset in educational curriculums is challenging authority. This narrative synthesis aims to explore the literature on challenging authority in the OR environment. A systematic search of Medline, EBM reviews and PsycINFO was conducted using terms related to challenging authority, speaking up, communication, patient safety, gradients and hierarchy. The initial search identified 4822 publications, out of which 31 studies were included. The data synthesis of the included studies was grouped into three distinct categories following a meta-aggregative approach: discussion and review articles, observational or qualitative studies, and studies identifying the role of specific barriers or investigating the effect of educational interventions. Themes emerging from expert beliefs, what reality tells us and what we test are consistent. Hierarchy, organisational culture and education are the most frequently observed and tested themes. Simulation research has been successful in eliciting and confirming the role of specific barriers to speaking up. Barriers and enablers are largely modifiable within institutions however, education regarding the importance of speaking up will need to accompany these modifications for any significant changes to occur.

Determination of the optimal programmed intermittent epidural bolus volume of bupivacaine 0.0625% with fentanyl 2 µg.ml-1 at a fixed interval of forty minutes: a biased coin up-and-down sequential allocation trial.

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.

Gastric ultrasound in the third trimester of pregnancy: a randomised controlled trial to develop a predictive model of volume assessment.

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.

Ultrasound assessment of gastric volume in severely obese individuals: a validation study.

BACKGROUND: Point-of-care gastric ultrasound is an emerging tool to assess gastric content and volume at the bedside. The examination includes both a qualitative and a quantitative component. The aim of this study was to evaluate the performance of an existing model for predicting gastric volume in severely obese subjects (BMI >35 kg m-2). METHODS: This observer-blinded experimental study compared the gastric volume predicted based on a sonographically measured cross-sectional area of the gastric antrum with the gastric volume measured by suctioning under gastroscopic guidance in a cohort of severely obese subjects. Volumes between 0 and 400 ml, in 100 ml increments, were studied. Allocation was randomized, and all study observations were blinded to group allocation. The correlation and the level of agreement between predicted and observed volumes were studied. RESULTS: Data from 38 subjects suggested that the gastric volume predicted by sonographic assessment correlated strongly with that measured by gastric suctioning (concordance correlation coefficient of 0.82 and Pearson's correlation coefficient of 0.86). In addition, Bland-Altman analysis suggested a high level of agreement between the calculated and suctioned volumes, with a mean difference of 35 ml, and 95% limits of agreement similar (within 30%) to those observed in the non-obese population. CONCLUSIONS: Our results suggest that the existing mathematical model to determine gastric fluid volume based on sonographic assessment performs well in severely obese individuals.

Influence of Feeding Enzymatically Hydrolyzed Yeast Cell Wall on Growth Performance and Digestive Function of Feedlot Cattle during Periods of Elevated Ambient Temperature.

In experiment 1, eighty crossbred steers (239±15 kg) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h temperature humidity index averaged 80, EHY increased dry matter intake (DMI) (linear effect, p<0.01) and average daily gain (ADG) (linear effect, p = 0.01). There were no treatment effects (p>0.10) on carcass characteristics. In experiment 2, four Holstein steers (292±5 kg) with cannulas in the rumen and proximal duodenum were used in a 4×4 Latin Square design experiment to evaluate treatments effects on characteristics of ruminal and total tract digestion in steers. There were no treatment effects (p>0.10) on ruminal pH, total volatile fatty acid, molar proportions of acetate, butyrate, or estimated methane production. Supplemental EHY decreased ruminal molar proportion of acetate (p = 0.08), increased molar proportion of propionate (p = 0.09), and decreased acetate:propionate molar ratio (p = 0.07) and estimated ruminal methane production (p = 0.09). It is concluded that supplemental EHY may enhance DMI and ADG of feedlot steers during periods of high ambient temperature. Supplemental EHY may also enhance ruminal fiber digestion and decrease ruminal acetate:propionate molar ratios in feedlot steers fed steam-flaked corn-based finishing diets.

Antioxidant activity in plasma and rumen papillae development in lambs fed fermented apple pomace.

The effect of fermented apple pomace (FAP) on animal health, antioxidant activity (AA), hematic biometry (HBm) and the development of ruminal epithelium were investigated in a study with 24 finishing lambs (BW = 25.4 ± 3.3 Kg). Lambs were grouped by sex (12 male and 12 female) and fed (n = 6 per group of treatment) a basal fattening diet (Control diet, T1) or the basal diet supplemented to include 10.91% of fermented apple pomace (FAP diet, T2). The animals were kept 56 d in individual metabolic cages, with ad libitum access to water and feed. Two blood samples were collected from each animal on d 0, 28, and 56 to determine AA in plasma and hematic biometry (HBm). Four samples of ruminal tissue were taken postmortem to evaluate the development of ruminal epithelium based on the length (LP) and width (WP) of papillae. AA and HBm data were analyzed with a mixed model (fixed effects: diet, sampling, sex, and their interaction; using the experimental unit nested in the effect of the diet as the random effect). LP and WP were analyzed with a hierarchical model, as simple and nested effects in the sampling site, where the fixed effects were the diet and the sex of the animal and their interaction. There was an effect of diet on AA, which was higher (P < 0.06) in T2 vs. T1 at 56 d (24.34 vs. 21.79 mM Fe2). Leukocytes increased (P < 0.05) from 7.52*10(3) ± 1.29*10/(3)µL to 9.14*10(3) ± 1.24*10(3)/µL in all the animals in the experiment, with a marked increased (P < 0.05) at 28 d after beginning of the feeding period, with values within the normal range for this species and without effect of the diet (P > 0.05) for the other indicators of HBm. Males' LP was higher in T2 than in T1 (P < 0.05). It was concluded that the use of FAP in the diets of finishing sheep reaped benefits on animal health and the development of rumen epithelium by improving antioxidant activity in plasma and stimulating the growth of papillae.

Effect of repeated suboptimal chlorate treatment on ruminal and fecal bacterial diversity.

The minimal effective dose of sodium chlorate as an intervention to reduce the carriage of pathogenic bacteria in food-producing animals has not been clearly established. The effect of low-level oral chlorate administration to ewes was assessed by comparing the diversity of prominent bacterial populations in their gastrointestinal tract. Twelve lactating crossed Pelibuey and Blackbelly-Dorper ewes (average body weight, 65 kg) were randomly assigned (four per treatment) to receive a control treatment (TC; consisting of 3 g of NaCl per animal per day) or one of two chlorate treatments (T3 or T9; consisting of 1.8 or 5.4 g of NaClO3 per animal per day, respectively). Treatments were administered twice daily via oral gavage for 5 days. Ruminal and fecal samples were collected daily, starting 3 days before and ending 6 days after treatment, and were subjected to denaturing gradient gel electrophoresis of the 16S rRNA gene sequence amplified from total population DNA. For ruminal microbes, percent similarity coefficients (SCs) between groups varied from 23.0 to 67.5% and from 39.4 to 43.3% during pretreatment and treatment periods, respectively. During the treatment period, SCs within groups ranged from 39.4 to 90.3%, 43.3 to 86.7%, and 67.5 to 92.4% for TC, T3, and T9, respectively. For fecal microbes, SCs between groups varied from 38.0 to 85.2% and 38.0 to 94.2% during pretreatment and treatment periods, respectively. SCs for fecal populations during treatment were most varied for TC (38.0 to 67.9%), intermediate for T9 (75.6 to 92.0%), and least varied for T3 (80.6 to 90.6%). Heterogeneity within and between groups provided no evidence of an effect of chlorate treatment on ruminal or fecal microbial populations.

Interrater reliability of qualitative ultrasound assessment of gastric content in the third trimester of pregnancy.

BACKGROUND: Pulmonary aspiration of gastric contents in pregnant women undergoing general anaesthesia is one of the most feared complications in obstetric anaesthesia. Bedside gastric ultrasonography is a feasible imaging tool to assess the gastric content. The purpose of this study was to investigate the reliability of qualitative bedside assessment of the gastric content performed by anaesthesiologists on third trimester pregnant women. METHODS: Pregnant women (≥32 weeks gestational age) were randomized to undergo ultrasound (US) assessments of their stomach in a fasting state (>8 h), or after ingestion of clear fluids only, or solid food. Three anaesthesiologists trained in gastric ultrasonography performed the assessments using a low-frequency curved-array US transducer (5-2 MHz). Primary outcome of the study was the consistency of raters in diagnosing the correct status of the gastric content, which was used to determine the interrater reliability among the three anaesthesiologists. Secondary outcomes were overall proportion of correct and incorrect diagnoses and the specific proportions of correct diagnosis across the three gastric content groups. RESULTS: We analysed 32 pregnant women. The interrater reliability displayed a kappa statistic of 0.74 (bias corrected 95% CI: 0.68-0.84). The overall proportion of correct diagnosis was 87.5% (84 of 96). The odds of correct diagnosis for 'solid contents' were 16.7 times the odds for 'empty', and 14.3 times for 'clear fluid'. CONCLUSIONS: Our results show the consistency of the qualitative US assessment of gastric contents of pregnant women in the third trimester by anaesthesiologists. A kappa of 0.74 suggests substantial agreement in terms of interrater reliability for this diagnostic measurement. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01564030.

Standardised training program in spinal ultrasound for epidural insertion: protocol driven versus non-protocol driven teaching approach.

Spinal ultrasonography provides guidance for epidural insertion in obstetric patients. The primary objective of the study was to develop a training program in spinal ultrasound for anaesthetists and to determine its effect on the skill acquisition of anaesthetists with no prior spinal ultrasound experience. Eighteen anaesthetists underwent two structured workshops (one week apart), each followed by a practice session and videorecorded assessments. Participants were randomised to a protocol-driven or non-protocol driven spinal ultrasound teaching program. Two experts rated each individual's performance using a global rating scale (GRS), checklist and image quality scale. The primary outcome was the mean difference in GRS score between the two workshops, analysed using linear mixed models. Intraclass correlation coefficients were calculated to assess agreement between assessors' ratings. A total of 108 ultrasound scans were performed on five pregnant volunteers during the assessment periods. After adjusting for confounders, GRS scores increased on all three rating scales at the second workshop, this increase being 6.01 points (95% confidence interval 4.56 to 7.46, P<0.001) from a mean score of 28.4 (95% confidence interval 24.8 to 32.0). There was no significant difference in the scores between the two teaching groups (difference in GRS scores=1.36 points, 95% confidence interval -0.77 to 3.50, P=0.211). Intraclass correlation coefficients showed substantial assessor agreement for all three assessment methods (range 0.59 to 0.89). The results demonstrate that programmed spinal ultrasound training sessions involving practice with guidance and feedback from an expert, whether protocol-based or non-protocol based, lead to improved performance.

Challenging authority during a life-threatening crisis: the effect of operating theatre hierarchy.

BACKGROUND: Effective operating theatre (OT) communication is important for team function and patient safety. Status asymmetry between team members may contribute to communication breakdown and threaten patient safety. We investigated how hierarchy in the OT team influences an anaesthesia trainee's ability to challenge an unethical decision by a consultant anaesthetist in a simulated crisis scenario. METHODS: We prospectively randomized 49 postgraduate year (PGY) 2-5 anaesthesia trainees at two academic hospitals to participate in a videotaped simulated crisis scenario with a simulated OT team practicing either a hierarchical team structure (Group H) or a non-hierarchical team structure (Group NH). The scenario allowed trainees several opportunities to challenge their consultant anaesthetist when administering blood to a Jehovah's Witness. Three independent, blinded raters scored the performances using a modified advocacy-inquiry score (AIS). The primary outcome was the comparison of the best-response AIS between Groups H vs NH. Secondary outcomes included the comparison of best AIS by PGY and the percentage in each group that checked and administered blood. RESULTS: The AIS did not differ between the groups (P=0.832) but significantly improved from PGY2 to PGY5 (P=0.026). The rates of checking blood (92% vs 76%, P=0.082) and administering blood (62% vs 57%, P=0.721) were high in both groups but not significantly different between the groups. CONCLUSIONS: This study did not show a significant effect of OT team hierarchical structure on trainee's ability to challenge authority; however, the results are concerning. The challenges were suboptimal in quality and there was an alarming high rate of blood checking and administration in both groups. This may reflect lack of training in appropriately and effectively challenging authority within the formal curriculum with implications for patient safety.

Efficacy of low-dose bupivacaine in spinal anaesthesia for Caesarean delivery: systematic review and meta-analysis.

Spinal anaesthesia is the preferred anaesthetic technique for elective Caesarean deliveries. Hypotension is the most common side-effect and has both maternal and neonatal consequences. Different strategies have been attempted to prevent spinal-induced hypotension, including the use of low-dose bupivacaine. We conducted a systematic search for randomized controlled trials comparing the efficacy of spinal bupivacaine in low dose (LD ≤8 mg) with conventional dose (CD >8 mg) for elective Caesarean delivery. Thirty-five trials were identified for eligibility assessment, 15 were selected for data extraction, and 12 were finally included in the meta-analysis. We investigated sources of heterogeneity, subgroup analysis, and meta-regression for confounding variables (baricity, intrathecal opioids, lateral vs sitting position, uterine exteriorization, and study population). Sensitivity analysis was performed to test the robustness of the results. In the LD group, the need for analgesic supplementation during surgery was significantly higher [risk ratio (RR)=3.76, 95% confidence interval (95% CI)=2.38-5.92] and the number needed to treat for an additional harmful outcome (NNTH) was 4 (95% CI=2-7). Furthermore, the LD group exhibited a lower risk of hypotension (RR=0.78, 95% CI=0.65-0.93) and nausea/vomiting (RR=0.71, 95% CI=0.55-0.93). Conversion to general anaesthesia occurred only in the LD group (two events). Neonatal outcomes (Apgar score, acid-base status) and clinical quality variables (patient satisfaction, surgical conditions) showed non-significant differences between LD and CD. This meta-analysis demonstrates that low-dose bupivacaine in spinal anaesthesia compromises anaesthetic efficacy (risk of analgesic supplementation: high grade of evidence), despite the benefit of lower maternal side-effects (hypotension, nausea/vomiting: moderate grade of evidence).