[Obstetric Anesthesia During the SARS-CoV-2 Pandemic - a Brief Overview of Published Recommendations for Action by National and International Specialist Societies and Committees]

The most common human corona viruses cause common colds. But three of these viruses cause more serious, acute diseases; Middle East Respiratory Syndrome (MERS by MERS-CoV), Severe Acute Respiratory Syndrome (SARS) by SARS-CoV and COVID-19 by SARS-CoV-2. The current outbreak was classified by the WHO as a "global public health emergency". Despite all efforts to reduce the surgical lists and to cancel or postpone non-time-critical surgical interventions, some surgical and anesthetic interventions outside of intensive care medicine are still necessary and must be performed. This is particularly true for obstetric interventions and neuraxial labor analgesia. Workload in the delivery room is presumably not going to decrease and planned cesarean sections cannot be postponed. In the meantime, the clinical course and outcome of some COVID-19 patients with an existing pregnancy or peripartum courses have been reported. There are already numerous recommendations from national and international bodies regarding the care of such patients. Some of these recommendations will be summarized in this manuscript. The selection of aspects should by no means be seen as a form of prioritization. The general treatment principles in dealing with COVID-19 patients and the recommendations for action in intensive care therapy also apply to pregnant and postpartum patients. In this respect, there are naturally considerable redundancies and only a few aspects apply strictly or exclusively to the cohort of obstetric patients. In summary, at present it must be stated that the general care recommendations that also apply to non-COVID-19 patients are initially valid with regard to obstetric anesthesia. Nevertheless, the special requirements on the part of hygiene and infection protection result in special circumstances that should be taken into account when caring for pregnant patients from an anesthetic point of view. These relate to both medical aspects, but also to a particular extent logistics issues with regard to spatial separation, staffing and material resources.

Cardiac Structure and Function in Morbidly Obese Parturients: An Echocardiographic Study

BACKGROUND

The increasing prevalence of obesity worldwide is a major threat to global health. Cardiac structural and functional changes are well documented for obesity as well as for pregnancy, but there is limited literature on morbidly obese parturients. We hypothesized that there are both cardiac structural and functional differences between morbidly obese pregnant women and pregnant women of normal body mass index (BMI).

METHODS

This prospective cross-sectional study was performed in 2 referral maternity units in Cape Town, South Africa, over a 3-month period. Forty morbidly obese pregnant women of BMI ≥40 kg·m (group O) were compared to 45 pregnant women of BMI ≤30 kg·m (group N). Cardiac structure and function were assessed by transthoracic echocardiography, according to the recommendations of the British Society of Echocardiography. The 2-sample t-test with unequal variances was used for the comparison of the mean values between the groups.

RESULTS

Acceptable echocardiographic images were obtained in all obese women. Statistical significance was defined as P < .0225 after applying the Benjamini-Hochberg correction for multiple testing. Mean (standard deviation) mean arterial pressure was higher in group O (91 [8.42] vs 84 [9.49] mm Hg, P < .001). There were no between-group differences in heart rate, stroke volume, or cardiac index (84 [12] vs 79 [13] beats·minute, P = .103; 64.4 [9.7] vs 59.5 [13.5] mL, P = .069; 2551 [474] vs 2729 [623] mL·minute·m, P = .156, for groups O and N, respectively). Stroke volume index was lower, and left ventricular mass was higher in group O (30.14 [4.51] vs 34.25 [7.00] mL·m, P = .003; 152 [24] vs 115 [29] g, P < .001). S' septal was lower in group O (8.43 [1.20] vs 9.25 [1.64] cm·second, P = .012). Considering diastolic function, isovolumetric relaxation time was significantly prolonged in group O (73 [15] vs 61 [15] milliseconds, P < .001). The septal tissue Doppler index E' septal was lower in group O (9.08 [1.69] vs 11.28 [3.18], P < .001). There were no between-group differences in E' average (10.7 [2.3] vs 12.0 [2.7], P = .018, O versus N) or E/E' average (7.85 [1.77] vs 7.27 [1.68], P = .137, O versus N). Right ventricular E'/A' was lower in group O (1.07 [0.47] vs 1.29 [0.32], P = .016).

CONCLUSIONS

Cardiac index did not differ between obese pregnant women and those with normal BMI. Their increased left ventricular mass and lower stroke volume index could indicate a limited adaptive reserve. Obese women had minor decreases in septal left ventricular tissue Doppler velocity, but the E/E' average values did not suggest clinically significant diastolic dysfunction.

A systematic review of phenylephrine vs. noradrenaline for the management of hypotension associated with neuraxial anaesthesia in women undergoing caesarean section

Phenylephrine is recommended for the management of hypotension after spinal anaesthesia in women undergoing caesarean section. Noradrenaline, an adrenergic agonist with weak β-adrenergic activity, has been reported to have a more favourable haemodynamic profile than phenylephrine. However, there are concerns that noradrenaline may be associated with a higher risk of fetal acidosis, defined as an umbilical artery pH < 7.20. We performed a systematic review of trials comparing noradrenaline with phenylephrine, concentrating on primary outcomes of fetal acidosis and maternal hypotension. We identified 13 randomised controlled trials including 2002 patients. Heterogeneity among the studies was high, and there were too few data to calculate a pooled effect estimate. Fetal acidosis was assessed in four studies that had a low risk of bias and a low risk of confounding, that is, studies which used a prophylactic vasopressor and where women received the allocated vasopressor only. There were no significant differences between these studies. No significant differences were observed for hypotension. Two trials found a significantly lower incidence of bradycardia when using noradrenaline. Cardiac output was significantly higher after noradrenaline in two of three studies. For other secondary outcomes including nausea, vomiting and Apgar scores at 1 and 5 min, no studies found significant differences. The evidence so far is too limited to support an advantage of noradrenaline over phenylephrine. Concerns of a deleterious effect of noradrenaline on fetal blood gas status cannot currently be assuaged by the available data from randomised controlled studies.

Patient blood management (PBM) in pregnancy and childbirth: literature review and expert opinion

PURPOSE

Patient blood management [PBM] has been acknowledged and successfully introduced in a wide range of medical specialities, where blood transfusions are an important issue, including anaesthesiology, orthopaedic surgery, cardiac surgery, or traumatology. Although pregnancy and obstetrics have been recognized as a major field of potential haemorrhage and necessity of blood transfusions, there is still little awareness among obstetricians regarding the importance of PBM in this area. This review, therefore, summarizes the importance of PBM in obstetrics and the current evidence on this topic.

METHOD

We review the current literature and summarize the current evidence of PBM in pregnant women and postpartum with a focus on postpartum haemorrhage (PPH) using PubMed as literature source. The literature was reviewed and analysed and conclusions were made by the Swiss PBM in obstetrics working group of experts in a consensus meeting.

RESULTS

PBM comprises a series of measures to maintain an adequate haemoglobin level, improve haemostasis and reduce bleeding, aiming to improve patient outcomes. Despite the fact that the WHO has recommended PBM early 2010, the majority of hospitals are in need of guidelines to apply PBM in daily practice. PBM demonstrated a reduction in morbidity, mortality, and costs for patients undergoing surgery or medical interventions with a high bleeding potential. All pregnant women have a significant risk for PPH. Risk factors do exist; however, 60% of women who experience PPH do not have a pre-existing risk factor. Patient blood management in obstetrics must, therefore, not only be focused on women with identified risk factor for PPH, but on all pregnant women. Due to the risk of PPH, which is inherent to every pregnancy, PBM is of particular importance in obstetrics. Although so far, there is no clear guideline how to implement PBM in obstetrics, there are some simple, effective measures to reduce anaemia and the necessity of transfusions in women giving birth and thereby improving clinical outcome and avoiding complications.

CONCLUSION

PBM in obstetrics is based on three main pillars: diagnostic and/or therapeutic interventions during pregnancy, during delivery and in the postpartum phase. These three main pillars should be kept in mind by all professionals taking care of pregnant women, including obstetricians, general practitioners, midwifes, and anaesthesiologists, to improve pregnancy outcome and optimize resources.

Einleitung von nicht nüchternen Patienten am Beispiel von Schwangeren und Kindern

Die klassische Technik der Rapid Sequence Induction (RSI) ist eine fundamentale Form der Anästhesieeinleitung bei nicht nüchternen Patienten zur Verhinderung der Aspiration von Mageninhalt. Schwangere und Kinder sind aufgrund ihrer Hypoxiegefährdung eine besondere Herausforderung; das klassische RSI-Konzept „Induktion – Apnoe – (Krikoiddruck –) Intubation“ muss bei ihnen zugunsten einer kontrollierten Technik mit Erhalt der Oxygenierung modifiziert werden.

Maligne Hyperthermie: Diagnostik konkret

Sowohl in der präoperativen Visite als auch bei intraoperativ verdächtigen Zwischenfällen kann sich die Frage nach einer Abklärung auf maligne Hyperthermie ergeben. Heute stehen mit molekulargenetischen Methoden und mit der Muskelbiopsie und Kontrakturtest 2 grundsätzliche verschiedene Testmethoden zur Verfügung. Beide diagnostischen Methoden haben Vor- und Nachteile – und ergänzen sich.

Generalisability of randomised trials of the programmed intermittent epidural bolus technique for maintenance of labour analgesia: a prospective single centre cohort study

BACKGROUND

Several randomised controlled trials show that maintenance of labour epidural analgesia with programmed intermittent epidural bolus reduces the maternal motor block compared with maintenance with a continuous infusion. However, these trials were usually restricted to healthy nulliparous parturients. To assess the generalisability of these randomised controlled trials to 'real-world' conditions, we compared maternal motor function (modified Bromage score) over time between healthy nulliparous and parous women using routinely collected quality-control data.

METHODS

After ethical approval, all parturients receiving programmed intermittent epidural bolus labour analgesia between June 2013 and October 2014 were included in this prospective cohort study. Bupivacaine 0.1% with fentanyl 2 μg ml^-1 was used allowing for patient-controlled bolus every 20 min. The maternal motor function (primary outcome) was regularly assessed from insertion of the epidural catheter until delivery.

RESULTS

Of the 839 parturients included, 553 (66%) were nulliparous and 286 (34%) were parous. The parous women had a shorter median duration of epidural analgesia (3 h 59 min vs 5 h 45 min) and a higher incidence of spontaneous delivery (66% vs 37%). The probability of being in a certain Bromage category at birth was similar in nulliparous and parous women in a general additive model adjusting for duration of epidural analgesia, number of rescue top-ups, and number of catheter manipulations (cumulative odds ratio: 1.18; 95% confidence interval: 0.98-1.41). Parous women required a higher time-weighted number and volume of rescue top-ups.

CONCLUSIONS

The results of the randomised controlled trials on a reduced motor block with programmed intermittent epidural bolus seem generalisable to parturients typically not included in these trials.

Adherence to the WHO surgical safety checklist: an observational study in a Swiss academic center

Background

The World Health Organization (WHO) Surgical Safety Checklist is used globally to ensure patient safety during surgery. Two years after its implementation in the University Hospital Basel's operating rooms, adherence to the protocol was evaluated.

Methods

This mixed method observational study took place in the surgical department of the University Hospital of Basel, Switzerland from April to August 2017. Data collection was via individual structured interviews with selected OR team members regarding checklist adherence and on-site non-participant observations of Team Time Out and Team Sign Out sequences in the OR. Data were subjected to thematic analysis and descriptive statistics compiled.

Results

Comprehensive local expert interviews indicated that individual, procedural and contextual variables influenced the application of the checklist. Facilitating factors included well-informed specialists who advocated the use of the Checklist, as well as teams focused on the checklist's intended process and on its content. In contrast, factors such as staff insecurity, a generally negative attitude towards the checklist, a lack of teamwork, and hesitance to complete the checklist, hindered its implementation.The checklist's application was evaluated in 104 on-site observations comprising of 72 Team Time Out (TTO) and 32 Team Sign Out (TSO) sections. Adherence to the protocol ranged between 96 and 100% in TTO and 22% in TSO respectively. Lack of implementation of the TSO was mainly due to the absence of one of the key OR team members, who were busy with other tasks or no longer present in the operating room.

Conclusion

The study illustrates factors, which foster and hinder consistent application of the WHO surgical safety checklist namely individual, procedural and contextual. It also demonstrates that the TTO was consistently and correctly applied, while the unavailability of key OR team members at sign-out time was the most common reason for omission or incomplete use of the TSO.

Efficacy and safety of carbetocin given as an intravenous bolus compared with short infusion for Caesarean section - double-blind, double-dummy, randomized controlled non-inferiority trial

Background

Carbetocin is a synthetic oxytocin-analogue, which should be administered as bolus according to manufacturer's recommendations. A higher speed of oxytocin administration leads to increased cardiovascular side-effects. It is unclear whether carbetocin administration as short infusion has the same efficacy on uterine tone compared with bolus administration and whether haemodynamic parameters differ.

Methods

In this randomized, double-blind, non-inferiority trial, women undergoing planned or unplanned Caesarean section (CS) under regional anaesthesia received a bolus and a short infusion, only one of which contained carbetocin 100 mcg (double dummy). Obstetricians quantified uterine tone two, three, five and 10 min after cord-clamping by manual palpation using a linear analogue scale from 0 to 100. We evaluated whether the lower limit of the 95% CI of the difference in maximum uterine tone within the first five min after cord-clamping did not include the pre-specified non-inferiority limit of -10.

Results

Between December 2014 and November 2015, 69 patients were randomized to receive carbetocin as bolus and 71 to receive it as short infusion. Maximal uterine tone was 89 in the bolus and 88 in the short infusion group (mean difference -1.3, 95% CI -5.7 to 3.1). Bp, calculated blood loss, use of additional uterotonics, and side-effects were comparable.

Conclusions

Administration of carbetocin as short infusion does not compromise uterine tone and has similar cardiovascular side-effects as a slow i.v. bolus. In accordance with current recommendations for oxytocin, carbetocin can safely be administered as short -infusion during planned or unplanned CS.

Clinical trial registration

ClinicalTrials.gov NCT02221531 and www.kofam.ch SNCTP000001197.

[Update in Obstetric Anesthesia - Tried and Trusted Methods, Controversies and New Perspectives]

Since 1975, a plethora of lectures within the context of annual meetings relevant for the clinical care has been summarized in "what's new in obstetric anesthesia" by the society for Obstetric anesthesia and Perinatology which can be recommended to everyone interested in anaesthesiology in the delivery room. After the death of Gerard W. Ostheimer, Professor of Anaesthesiology at Brigham and Women's Hospital in Boston, Massachusetts, it became renamed the Gerard W. Ostheimer "what's new in obstetric anesthesia" lecture to honor his contributions to regional anesthesia and obstetric anaesthesia. Each year the event held by selected professional representatives and their imprint in leading anesthesia journals give insight into a critical appraisal of recent literature and the possible consequences for - but not only - the anaesthetic delivery room practice.A similar event has been established in Germany for more than 16 years (first event on April 1, 2000, most recently held on February 27, 2016, in Munich): the obstetrical anesthesia symposium of the academic working group "regional anesthesia and obstetrical anesthesia" [1], [2]."Evergreens" or "hot topics" with regard to anaesthesiological delivery room practice are presented and discussed regularly. The lectures often reveal the subtle change of the issues being debated much earlier than traditional textbook chapters do. This manuscript summarizes important findings from the last symposium held in 2016. Part I focuses on relevant causes for maternal morbidity and mortality as well as preventive measures, pregnancy in obese patients and sepsis in obstetric anaesthesia. Part II addresses established standards and new perspectives in the direct obstetric setting regarding epidural analgesia, post-dural puncture headache, anaesthesia and analgesia during and after caesarean section, haemodynamic monitoring during cesarean section and postpartum haemorrhage.

[Update in Obstetric Anesthesia: Tried and Trusted Methods, Controversies and New Perspectives - Part 1]

Since 1975, a plethora of lectures within the context of annual meetings relevant for the clinical care has been summarized in "what's new in obstetric anesthesia" by the Society for Obstetric Anesthesia and Perinatology which can be recommended to everyone interested in anaesthesiology in the delivery room. After the death of Gerard W. Ostheimer, Professor of Anaesthesiology at Brigham and Women's Hospital in Boston, Massachusetts, it became renamed the Gerard W. Ostheimer "what's new in obstetric anesthesia" lecture to honor his contributions to regional anesthesia and obstetric anaesthesia. Each year the event held by selected professional representatives and their imprint in leading anesthesia journals give insight into a critical appraisal of recent literature and the possible consequences for - but not only - the anaesthetic delivery room practice.A similar event has been established in Germany for more than 16 years: the obstetrical anesthesia symposium of the academic working group "regional anesthesia and obstetrical anesthesia" 1, 2."Evergreens" or "hot topics" with regard to anaesthesiological delivery room practice are presented and discussed regularly. The lectures often reveal the subtle change of the issues being debated much earlier than traditional textbook chapters do. This manuscript summarizes important findings from the last symposium held in 2016. Part I focuses on relevant causes for maternal morbidity and mortality as well as preventive measures, pregnancy in obese patients and sepsis in obstetric anaesthesia. Part II addresses established standards and new perspectives in the direct obstetric setting regarding epidural analgesia, post-dural puncture headache, anaesthesia and analgesia during and after caesarean section, haemodynamic monitoring during cesarean section and postpartum haemorrhage.

Geburtshilfe: hypertensive Erkrankungen in der Schwangerschaft

Hypertensive disorders of pregnancy are one of the most common complications in pregnancy. They are associated with a high maternal, fetal and neonatal morbidity and mortality. 99 % of all maternal deaths occur in developing countries, but we should not forget that even in highly developed countries mothers still die from the complications of hypertensive disorders of pregnancy. This term encompasses chronic hypertension as well as pregnancy specific disorders such as gestational hypertension and preeclampsia. The physiological changes of pregnancy can make the differentiation between benign symptoms of pregnancy and life threatening conditions challenging. In order to provide optimal care for these women, an interdisciplinary approach between all members of the obstetric care team is crucial. The current review article discusses new advances in the diagnosis and treatment of hypertensive disorders of pregnancy.

Resequencing array for gene variant detection in malignant hyperthermia and butyrylcholinestherase deficiency

Malignant hyperthermia (MH) and butyrylcholinestherase (BCHE) deficiency are two relevant pharmacogenetic disorders in anesthetic practice linked with sequence variants, the former in the RyR1 and CACNA1S genes, the latter in the BCHE gene. Genotyping for known pathogenic variants in these genes is useful to help identify susceptible individuals, and others may exist but remain unknown, because full-length sequence of these genes is, in general, not investigated. To facilitate this task, we developed a resequencing DNA array, the perioperative patient safety (POPS) array, to be able to screen the entire coding sequences of the RyR1, CACNA1S and BCHE genes. MH-susceptible individuals (n = 121) identified with the in vitro contracture test, the standard diagnostic tool for MH susceptibility, were genotyped with the arrays. Compared with capillary sequencing, call rates with the arrays could achieve 100% at maximal sensitivity, although to reduce false positive rates, sensitivity was adjusted to 0.85, 0.87 and 0.66 for RyR1, CACNA1S and BCHE respectively, with overall base call specificity exceeding 99%. Detection of 29 predetermined RyR1 variants in 44 individuals was successful in 97% of the cases, among them all 16 variants of established diagnostic value. In a trial application of the arrays, 21 MH-susceptible subjects with no known RyR1 or CACNA1S variants were screened, resulting in the discovery of new variants, all confirmed by capillary sequencing. In conclusion, arrays offer an efficient high-throughput alternative for diagnostic genotyping of candidate genes affecting MH susceptibility, BCHE deficiency and other neuromuscular disorders, simultaneously enabling a comprehensive search for rare variants in these genes.