[The Myth about the Laryngeal Mask]. / Der Mythos um die Larynxmaske.

Peak pressures ≥ 20 mbar are not a contraindication for laryngeal masks. The oropharyngeal leak pressure of a laryngeal mask does not correspond to the pressure at which oesophagogastric air leakage occurs. Setting a peak pressure limit of 20 cm H2O on the respirator can lead to critical situations because the tidal volume may then remain too low. A good alternative is to use a pressure alarm limit. The use of laryngeal masks does not preclude the use of PEEP and/or relaxation.

Implementation of the Kidney Disease Improving Global Outcomes guidelines for the prevention of acute kidney injury after cardiac surgery: An international cohort survey.

BACKGROUND: Increasing evidence from randomised controlled trials supports the implementation of a six-measure care bundle proposed by the Kidney Disease Improving Global Outcomes (KDIGO) guidelines in patients at high risk for acute kidney injury (AKI) to reduce its incidence after cardiac surgery. OBJECTIVE: To assess compliance with the KDIGO bundle in clinical practice. DESIGN: Prospective observational multinational study. SETTING: Six international tertiary care centres, from February 2021 to November 2021. PATIENTS: Five hundred and thirty-seven consecutive patients undergoing cardiac surgery during a 1-month observational period. INTERVENTIONS: All patients were assessed for the postoperative implementation of the following measures: avoidance of nephrotoxic medication and radiocontrast agents whenever possible, strict glycaemic control, close monitoring of renal function, optimisation of haemodynamic and volume status and functional monitoring of haemodynamic status. MAIN OUTCOME MEASURES: The primary endpoint was the proportion of patients receiving fully compliant care. Secondary outcomes were occurrence of AKI and major adverse kidney event rate at day 30. RESULTS: The full care bundle was applied to 0.4% of patients. There was avoidance of nephrotoxic drugs in 15.6%, radiocontrast agents in 95.3% and hyperglycaemia in 39.6%. Close monitoring of urine output and serum creatinine was achieved in 6.3%, 57.4% underwent optimisation of volume and haemodynamic status, and 43.9% received functional haemodynamic monitoring. 27.2% developed AKI within 72 h after surgery. The average number of implemented measures was 2.6 ±â€Š1.0 and did not differ between AKI or non-AKI patients ( P  = 0.854). CONCLUSION: Adherence with the KDIGO bundle was very low in cardiac surgery patients. Initiatives to improve guideline compliance might provide a strategy to mitigate the burden of AKI. TRIAL REGISTRATION: www.drks.de DRKS00024204.

Coagulation management and transfusion in massive postpartum hemorrhage.

PURPOSE OF REVIEW: Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality. RECENT FINDINGS: Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology. SUMMARY: Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

[Postpartum Hemorrhage]. / Postpartale Hämorrhagie.

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

The Association Between Angiotensin II and Renin Kinetics in Patients After Cardiac Surgery.

BACKGROUND: Hyperreninemia after cardiac surgery is associated with cardiovascular instability. Angiotensin II (AT-II) could potentially attenuate hyperreninemia while maintaining target blood pressure. This study assesses the association between AT-II usage and renin levels in cardiac surgery patients with postoperative hyperreninemia and vasoplegia. METHODS: Between September 2020 and March 2021, we retrospectively identified 40 cardiac surgery patients with high Δ-renin levels (4 hours after cardiopulmonary bypass [CPB] minus preoperative levels) (defined as higher than 3.7 µU/mL) and vasopressor use who received a vasopressor therapy with either AT-II or continued norepinephrine alone. The primary outcome was the renin plasma level at 12 hours after surgery, adjusted by the renin plasma level at 4 hours after surgery. RESULTS: Overall, the median renin plasma concentration increased from a baseline with median of 44.3 µU/mL (Q1-Q3, 14.6-155.5) to 188.6 µU/mL (Q1-Q3, 29.8-379.0) 4 hours after CPB. High Δ-renin (difference between postoperation and preoperation) patients (higher than 3.7 µU/mL) were then treated with norepinephrine alone (median dose of 3.25 mg [Q1-Q3, 1.00-4.75]) or with additional AT-II (norepinephrine dose: 1.33 mg [Q1-Q3, 0.78-2.04]; AT-II dose: 0.34 mg [Q1-Q3, 0.29-0.78]). At 12 hours after surgery, AT-II patients had lower renin levels than standard of care patients (71.7 µU/mL [Q1-Q3, 21.9-211.4] vs 130.6 µU/mL [Q1-Q3, 62.9-317.0]; P = .034 adjusting for the renin plasma level at 4 hours after surgery). CONCLUSIONS: In cardiac surgery patients with hypotonia and postoperative high Δ-renin levels, AT-II was associated with reduced renin plasma levels for at 12 hours and significantly decreased norepinephrine use, while norepinephrine alone was associated with increased renin levels. Further studies of AT-II in cardiac surgery appear justified.

Kinetic Changes of Plasma Renin Concentrations Predict Acute Kidney Injury in Cardiac Surgery Patients.

Rationale: The renin-angiotensin-aldosterone system is a major pathway in regulating blood pressure, glomerular filtration, and fluid homeostasis. During inflammatory diseases, generation of angiotensin II might be disturbed, leading to increased renin concentrations. Cardiac surgery and the use of cardiopulmonary bypass both induce inflammatory response and cardiovascular instability, which can contribute to acute kidney injury (AKI).Objectives: To investigate whether renin concentrations are associated with hypotension and AKI.Methods: This is a single-center, prospective, observational study among patients undergoing cardiac surgery.Measurements and Main Results: The primary endpoint was the occurrence of AKI within 72 hours after cardiac surgery. A total of 197 patients were available for the primary analysis. The median renin serum concentration was 40.2 µU/ml (quartile 1 [Q1]-Q3, 9.3-144.4) at baseline and 51.3 µU/ml (Q1-Q3, 19.1-167.0) 4 hours after cardiac surgery, whereas the difference between postoperation and preoperation concentrations (Δ-renin) was 3.7 µU/ml (Q1-Q3, -22.7 to 50.9). Patients with an elevated Δ-renin developed an AKI significantly more often (43% vs. 12.2%; P < 0.001). High Δ-renin after cardiac surgery was associated with a significantly lower mean arterial pressure, longer time on vasopressors, and longer length of ICU and hospital stay. The area under the curve (AUC) of Δ-renin for the prediction of AKI (AUC, 0.817; 95% confidence interval, 0.747-0.887) was significantly greater compared with the AUC of the postoperative renin concentrations (AUC, 0.702; 95% CI, 0.610-0.793; P = 0.007).Conclusions: Elevated renin concentrations were associated with cardiovascular instability and increased AKI after cardiac surgery. Elevated renin concentrations could be used to identify high-risk patients for cardiovascular instability and AKI who would benefit from timely intervention that could improve their outcomes.

Supine hypotensive syndrome of pregnancy: A review of current knowledge.

Since the first description of supine hypotensive syndrome in the 1950s, its potentially detrimental effects on otherwise healthy women during late pregnancy have become a persistent challenge in obstetric practice. Establishing a 15° left lateral tilt during labour and caesarean section is a fundamental principle of obstetric care, universally adopted and upheld by current guidelines and recommendations. Reassessment of the original landmark studies in the light of current physiological and anatomical knowledge questions adherence to this standard in clinical practice. The modern practice of providing vasopressor support during caesarean delivery under neuraxial anaesthesia appears to negate any potential negative effects of a maternal full supine position. Recent MRI studies provide evidence as to the cause of supine hypotension and the physiological effects of different maternal positions at term. This review highlights current data on the acute supine hypotensive syndrome in contrast to traditional knowledge and established practice.

Effect of Intraoperative Handovers of Anesthesia Care on Mortality, Readmission, or Postoperative Complications Among Adults: The HandiCAP Randomized Clinical Trial.

Importance: Intraoperative handovers of anesthesia care are common. Handovers might improve care by reducing physician fatigue, but there is also an inherent risk of losing critical information. Large observational analyses report associations between handover of anesthesia care and adverse events, including higher mortality. Objective: To determine the effect of handovers of anesthesia care on postoperative morbidity and mortality. Design, Setting, and Participants: This was a parallel-group, randomized clinical trial conducted in 12 German centers with patients enrolled between June 2019 and June 2021 (final follow-up, July 31, 2021). Eligible participants had an American Society of Anesthesiologists physical status 3 or 4 and were scheduled for major inpatient surgery expected to last at least 2 hours. Interventions: A total of 1817 participants were randomized to receive either a complete handover to receive anesthesia care by another clinician (n = 908) or no handover of anesthesia care (n = 909). None of the participating institutions used a standardized handover protocol. Main Outcomes and Measures: The primary outcome was a 30-day composite of all-cause mortality, hospital readmission, or serious postoperative complications. There were 19 secondary outcomes, including the components of the primary composite, along with intensive care unit and hospital lengths of stay. Results: Among 1817 randomized patients, 1772 (98%; mean age, 66 [SD, 12] years; 997 men [56%]; and 1717 [97%] with an American Society of Anesthesiologists physical status of 3) completed the trial. The median total duration of anesthesia was 267 minutes (IQR, 206-351 minutes), and the median time from start of anesthesia to first handover was 144 minutes in the handover group (IQR, 105-213 minutes). The composite primary outcome occurred in 268 of 891 patients (30%) in the handover group and in 284 of 881 (33%) in the no handover group (absolute risk difference [RD], -2.5%; 95% CI, -6.8% to 1.9%; odds ratio [OR], 0.89; 95% CI, 0.72 to 1.10; P = .27). Nineteen of 889 patients (2.1%) in the handover group and 30 of 873 (3.4%) in the no handover group experienced all-cause 30-day mortality (absolute RD, -1.3%; 95% CI, -2.8% to 0.2%; OR, 0.61; 95% CI, 0.34 to 1.10; P = .11); 115 of 888 (13%) vs 136 of 872 (16%) were readmitted to the hospital (absolute RD, -2.7%; 95% CI, -5.9% to 0.6%; OR, 0.80; 95% CI, 0.61 to 1.05; P = .12); and 195 of 890 (22%) vs 189 of 874 (22%) experienced serious postoperative complications (absolute RD, 0.3%; 95% CI, -3.6% to 4.1%; odds ratio, 1.02; 95% CI, 0.81 to 1.28; P = .91). None of the 19 prespecified secondary end points differed significantly. Conclusions and Relevance: Among adults undergoing extended surgical procedures, there was no significant difference between the patients randomized to receive handover of anesthesia care from one clinician to another, compared with the no handover group, in the composite primary outcome of mortality, readmission, or serious postoperative complications within 30 days. Trial Registration: ClinicalTrials.gov Identifier: NCT04016454.

Prevention of Cardiac Surgery-Associated Acute Kidney Injury by Implementing the KDIGO Guidelines in High-Risk Patients Identified by Biomarkers: The PrevAKI-Multicenter Randomized Controlled Trial.

BACKGROUND: Prospective, single-center trials have shown that the implementation of the Kidney Disease: Improving Global Outcomes (KDIGO) recommendations in high-risk patients significantly reduced the development of acute kidney injury (AKI) after surgery. We sought to evaluate the feasibility of implementing a bundle of supportive measures based on the KDIGO guideline in high-risk patients undergoing cardiac surgery in a multicenter setting in preparation for a large definitive trial. METHODS: In this multicenter, multinational, randomized controlled trial, we examined the adherence to the KDIGO bundle consisting of optimization of volume status and hemodynamics, functional hemodynamic monitoring, avoidance of nephrotoxic drugs, and prevention of hyperglycemia in high-risk patients identified by the urinary biomarkers tissue inhibitor of metalloproteinases-2 [TIMP-2] and insulin growth factor-binding protein 7 [IGFBP7] after cardiac surgery. The primary end point was the adherence to the bundle protocol and was evaluated by the percentage of compliant patients with a 95% confidence interval (CI) according to Clopper-Pearson. Secondary end points included the development and severity of AKI. RESULTS: In total, 278 patients were included in the final analysis. In the intervention group, 65.4% of patients received the complete bundle as compared to 4.2% in the control group (absolute risk reduction [ARR] 61.2 [95% CI, 52.6-69.9]; P < .001). AKI rates were statistically not different in both groups (46.3% intervention versus 41.5% control group; ARR -4.8% [95% CI, -16.4 to 6.9]; P = .423). However, the occurrence of moderate and severe AKI was significantly lower in the intervention group as compared to the control group (14.0% vs 23.9%; ARR 10.0% [95% CI, 0.9-19.1]; P = .034). There were no significant effects on other specified secondary outcomes. CONCLUSIONS: Implementation of a KDIGO-derived treatment bundle is feasible in a multinational setting. Furthermore, moderate to severe AKI was significantly reduced in the intervention group.

[Safer anesthesia and duty hour limits: are handovers of personnel allowed?] / Sichere Anästhesie und Arbeitszeitgesetz: Wechsel von Personal erlaubt?

Restrictions of duty hours in medicine are an ambivalent matter with respect to patient safety. Continuity of treatment carries the risk of medical errors from declining performance capability and must be balanced against the risk of communication failure and information loss due to personnel changes. Complete intraoperative changes of anesthetists are frequently carried out in the clinical routine but possibly have the potential to negatively influence the postoperative morbidity and mortality. The relevance of anesthesiological care for the perioperative outcome also seems to vary depending on the specialist discipline involved. While standardized handover protocols seem to be only of limited effectiveness for the improvement of transfer of information, they are nevertheless a reasonable approach for optimization of interprofessional communication and reduction of treatment errors.

[Myths and Legends: Electrocardiographic Position Control of Central Venous Catheters - Where Does the P Come from?] / Mythen und Legenden: EKG-Lagekontrolle zentraler Katheter ­ woher kommt das P?

Misplacement of central venous accesses can be associated with deleterious iatrogenic complications. Electrocardiography is often used to guide the placement of central venous catheters and to confirm the correct position of the catheter tip. A characteristically peaked p-wave is traditionally considered to indicate the entrance of the catheter tip into the right atrium. However, recent data show that intraarterial and even extravascular localisation might result in an increased amplitude. The peaked p-wave most likely detects the pericardial reflection rather than a right atrial catheter position, hence real-time ultrasound is to be recommended as a superior technique to confirm a correct catheter position.

Nasolaryngeal Distances in the Adult Population and an Evaluation of Commercially Available Nasotracheal Tubes.

BACKGROUND: Preformed nasal endotracheal tubes (NETs) come with a predefined insertion depth due to their curved design. While size indication refers to internal diameter, there is a considerable variability in the corresponding lengths and proportions of same-sized tubes of different manufacturers which is probably based on the lack of data of nasolaryngeal distances (NLDs) in the adult population. Choosing the best-fitting NET is therefore difficult and carries the risk of endobronchial intubation or, on the contrary, cuff inflation at the vocal cord level. The aim of this study was to develop a prediction model for NLD and a selection guide to choose the appropriate NET based on a radiographic description of NLD in comparison to the measurements of available NETs of several manufacturers. METHODS: After institutional ethics board review, 388 computed tomography (CT) scan images of head, neck, and upper thorax in a heterogeneous adult cohort were included. Mean distances from the nares to the lower border of the thyroid cartilage were measured. NETs from different manufacturers were measured and compared to the NLD derived from the radiographic analysis. The patients' sex, body height, and weight were considered as possible covariates in quantile regression models for predicting the NLD. RESULTS: Data from 200 patients were analyzed. NLD was associated with sex, body height, and weight. A simple quantile regression model using the body height as the only covariate sufficed to achieve accurate predictions of NLD. Validation on independent test data showed that 92.8% of the NLD predictions were closer than ±20 mm to the observed NLD values. Measurements of equal-sized NETs varied considerably in outer diameter, proportion, the nasopharyngeal part, and guide marks. Length differences of the bend-to-cuff distance, containing the anatomically NLD, ranged between 218 and 270 mm at same sizes. CONCLUSIONS: A reliable prediction of NLD can be obtained simply by body height, using the formula (Equation is included in full-text article.). As manufacturers' tube lengths vary substantially, additional information about the bend-to-cuff distance as corresponding tube section would allow for more accurate tube selection.

Hypotension after spinal anesthesia for cesarean section: how to approach the iatrogenic sympathectomy.

PURPOSE OF REVIEW: Hypotension during cesarean section remains a frequent complication of spinal anesthesia and is associated with adverse maternal and fetal events. RECENT FINDINGS: Despite ongoing research, no single measure for sufficient treatment of spinal-induced hypotension was identified so far. Current literature discusses the efficacy of low-dose spinal anesthesia, timing and solutions for adequate fluid therapy and various vasopressor regimens. Present guidelines favor the use of phenylephrine over ephedrine because of decreased umbilical cord pH values, while norepinephrine is discussed as a probable superior alternative with regard to maternal bradycardia, although supporting data is limited. Alternative pharmacological approaches, such as 5HT3-receptor antagonists and physical methods may be taken into consideration to further improve hemodynamic stability. SUMMARY: Current evidence favors a combined approach of low-dose spinal anesthesia, adequate fluid therapy and vasopressor support to address maternal spinal-induced hypotension. As none of the available vasopressors is associated with relevantly impaired maternal and fetal outcomes, none of them should be abandoned from obstetric practice. Rapid crystalloid co-loading is of equivalent efficacy as compared with colloids and should be preferred because of a more favorable risk profile.

[Update: Renal Replacement Therapy]. / Organersatzverfahren: Update Nierenersatztherapie.

Renal replacement therapy (RRT) remains the cornerstone of treatment for severe acute kidney injury. However, despite its spreading use along with rising incidences of acute kidney injury, evidence of most recommendations is limited so far. Early initiation of RRT seems to reduce mortality but is associated with higher incidence of adverse events. Continuous RRT is advantageous in terms of hemodynamic control and decreased incidence of chronic dialysis dependency but without affecting mortality. Regional citrate anticoagulation should be preferred with regard to longer filter circuit life span. Intensified RRT with a prescribed dose ≥ 35 mL/kg/h has no benefit with regard to mortality but is associated with higher occurrence of complications. Urine output has the best prognostic value for cessation of RRT. Biomarkers of renal impairment and recovery are needed for better guidance of therapy.

High-fidelity is not superior to low-fidelity simulation but leads to overconfidence in medical students.

BACKGROUND: Simulation has become integral to the training of both undergraduate medical students and medical professionals. Due to the increasing degree of realism and range of features, the latest mannequins are referred to as high-fidelity simulators. Whether increased realism leads to a general improvement in trainees' outcomes is currently controversial and there are few data on the effects of these simulators on participants' personal confidence and self-assessment. METHODS: One-hundred-and-thirty-five fourth-year medical students were randomly allocated to participate in either a high- or a low-fidelity simulated Advanced Life Support training session. Theoretical knowledge and self-assessment pre- and post-tests were completed. Students' performance in simulated scenarios was recorded and rated by experts. RESULTS: Participants in both groups showed a significant improvement in theoretical knowledge in the post-test as compared to the pre-test, without significant intergroup differences. Performance, as assessed by video analysis, was comparable between groups, but, unexpectedly, the low-fidelity group had significantly better results in several sub-items. Irrespective of the findings, participants of the high-fidelity group considered themselves to be advantaged, solely based on their group allocation, compared with those in the low-fidelity group, at both pre- and post-self-assessments. Self-rated confidence regarding their individual performance was also significantly overrated. CONCLUSION: The use of high-fidelity simulation led to equal or even worse performance and growth in knowledge as compared to low-fidelity simulation, while also inducing undesirable effects such as overconfidence. Hence, in this study, it was not beneficial compared to low-fidelity, but rather proved to be an adverse learning tool.

Epidural test dose in obstetric patients: should we still use it?

PURPOSE OF REVIEW: As the application of a test dose after epidural catheter insertion in obstetrics has recurrently been associated with serious adverse events affecting both maternal and foetal outcomes, the question whether to test or not remains a controversial issue. RECENT FINDINGS: Present guidelines do not provide clear recommendations in this regard and several recent surveys indicate a heterogeneity in clinical routine. SUMMARY: Physiological alterations during pregnancy and labour restrict the use and also the validity of traditional test agents. Epinephrine is not appropriate to detect a vascular insertion in labour and the application of a local anaesthetic test dose may lead to dose-dependent fatal consequences should the catheter be intrathecal, due to an increased sensitivity in parturients. Given the current practice of opioid-amended-low-concentration epidurals, the waiving of a test dose results at worst in a failed epidural, a stark contrast to the potentially severe to fatal complications of a 'traditional' test dose. Hence, an originally preventive measure providing potentially more harm than the consequences of the situation aimed to prevent, should not be recommended. A simple fractionated administration of the initial analgesic dose seems reasonable though.

Availability of cookies during an academic course session affects evaluation of teaching.

OBJECTIVES: Results from end-of-course student evaluations of teaching (SETs) are taken seriously by faculties and form part of a decision base for the recruitment of academic staff, the distribution of funds and changes to curricula. However, there is some doubt as to whether these evaluation instruments accurately measure the quality of course content, teaching and knowledge transfer. We investigated whether the provision of chocolate cookies as a content-unrelated intervention influences SET results. METHODS: We performed a randomised controlled trial in the setting of a curricular emergency medicine course. Participants were 118 third-year medical students. Participants were randomly allocated into 20 groups, 10 of which had free access to 500 g of chocolate cookies during an emergency medicine course session (cookie group) and 10 of which did not (control group). All groups were taught by the same teachers. Educational content and course material were the same for both groups. After the course, all students were asked to complete a 38-question evaluation form. RESULTS: A total of 112 students completed the evaluation form. The cookie group evaluated teachers significantly better than the control group (113.4 ± 4.9 versus 109.2 ± 7.3; p = 0.001, effect size 0.68). Course material was considered better (10.1 ± 2.3 versus 8.4 ± 2.8; p = 0.001, effect size 0.66) and summation scores evaluating the course overall were significantly higher (224.5 ± 12.5 versus 217.2 ± 16.1; p = 0.008, effect size 0.51) in the cookie group. CONCLUSIONS: The provision of chocolate cookies had a significant effect on course evaluation. These findings question the validity of SETs and their use in making widespread decisions within a faculty.