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In 2019 the annual conference of the scientific working group on obstetric anesthesiology of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) took place in the usual manner. Emergency situations, such as the challenge of a preclinical birth or the recognition and treatment of an amniotic fluid embolism were discussed. In addition, topics on the correct treatment of a female patient with a known addictive disorder were of great interest as well as the discussion on the question when a transfusion should be performed in postpartum anemia and which risks accompany the increasing prevalence of obesity, especially during pregnancy. A further hot topic was the deliberation on the prevalence and differential diagnostic clarification of neurological complications after epidural anesthesia. In connection with the topic of birth, exciting and practice relevant topics for all anesthetists confronted with this field were presented and discussed. The essential aspects are summarized in this article.

Background: Arterial hypotension is a frequent complication following spinal anesthesia for cesarean sections. A fast treatment is necessary to maintain the well-being of the mother and to avoid deficiencies in the intrauterine supply to the child., Objective: The aim of this analysis was to evaluate the effects of the most frequently used vasoactive substances for treatment of hypotension in patients undergoing cesarean sections in Germany, i.e. ephedrine (E), phenylephrine (P) and Akrinor (A, cafedrine/theodrenaline), a 20:1 combination of cafedrine and theodrenaline., Methods: A retrospective single center analysis of 772 patients (16-50 years old) with arterial hypotension following spinal anesthesia for cesarean section and requiring treatment with vasoactive substances (July 2012-April 2017) was carried out. In the three observation periods the respective current clinical standard treatment of E, P or A was applied. The primary end-points were changes in maternal hemodynamics, pH and base excess (BE) in the child and the resulting blood pressure values. The statistical analysis plan of the study was registered in the German registry for clinical trials (DRKS-ID: DRKS00012520)., Results: The initial blood pressure before the intervention was comparable in all three groups, with no clinically relevant differences between the individual groups. In the course of anesthesia the largest blood pressure decrease as well as the largest resulting increase after the intervention were found in group A. In group P there was an increased need for an alternative catecholamine in comparison to the other two groups (P : 13 patients, 3.7%, E: 5 patients, 3.3% and A: 0 patients (0%), p  0.007). Differences were detected in the BE of the child (mean E: -1.36, P : -2.03, A: -2.57, p  0.0001) and the incidence of bradycardia requiring drug intervention (E: 0.7%, P : 5.4%, A: 1.9%, p = 0.007). No significant differences were found for the arterial pH of the child and APGAR scores., Conclusion: The differences of the individual vasoactive substances seemed to be much smaller than one would expect based on the results of randomized clinical trials. The incidence and extent of bradycardia and neonatal acidosis were much lower than previously reported. The determined differences seemed to have no major clinical relevance. Although the A group required less bolus administrations and seemed to be the most potent substance, the results imply that the assessment of the effects of vasoactive substances should not be carried out without consideration of the accompanying measures.

Background: Up to now hydroxyethyl starch preparations have frequently been used to compensate for volume deficits accompanying blood withdrawal during acute normovolemic hemodilution. This approach was questioned with respect to the current limitations for use of hydroxyethyl starch solutions imposed by the European Medicines Agency. Because crystalloids distribute evenly across the whole extracellular compartment, 80 % of the infused solution will be "lost" to the interstitial space. Thus, a physiological adjustment of blood loss caused by hemodilution with crystalloids alone (1:5 ratio) seems hardly feasible and according to current data perhaps not even desirable. A 3:1 ratio (crystalloids versus blood loss) as applied in the current study can be regarded as a practical compromise between physiological needs and recommendations according to the literature (1.4:1) but will lead to moderate hypovolemia the hemodynamic consequences of which are not well described., Aim: The current study investigates the hemodynamic impact of a hemodilution with crystalloids under the precondition of a 3:1 substitution ratio compared to withdrawn blood., Methods: In the context of acute perioperative hemodilution 10 otherwise healthy women graded I and II on the American Society of Anesthesiologists (ASA) classification scheduled for open gynecological cancer surgery underwent an average blood withdrawal of 1097 ± 285 ml which was substituted by an average of 3430 ± 806 ml of Ringer's lactate. The resulting deficit in blood volume was exactly quantified by a double tracer technique. Hemodynamic changes were evaluated by a combination of thermodilution and pulse contour analysis (PiCCO system®). Subsequently, the remaining volume deficit was compensated by 245 ± 64 ml of a 20 % albumin solution and hemodynamic parameters were again evaluated., Results: When infusing Ringer's lactate in a 3:1 ratio compared to the actual blood loss, the blood volume decreased by 12 %. The volume effect of Ringer's lactate proved to be 17 %. While mean arterial pressure and heart rate remained constant, key hemodynamic parameters changed relevantly during the time course. A significant rise in cardiac output and myocardial contractility could be observed which was accompanied by a decrease in systemic vascular resistance. In contrast, cardiac preload and the parameters representing pulmonary vascular permeability remained unaltered. The infusion of 245 ± 64 ml of a 20 % albumin solution nearly completely restituted blood volume and led to an insignificant rise in systemic vascular resistance but did not normalize cardiac output or myocardial contractility., Conclusion: In the study population, the loss of intravascular fluid during perioperative haemodilution could be compensated by an increase in cardiac performance. However, whether patients with a reduced cardiac capacity (i.e. older patients) are capable to improve their cardiac output sufficiently in order to compensate hypovolemia accompanying perioperative haemodilution with crystalloids remains questionable.