Pulse contour analysis after normothermic cardiopulmonary bypass in cardiac surgery patients

INTRODUCTION: Monitoring of the cardiac output by continuous arterial pulse contour (CO(PiCCOpulse)) analysis is a clinically validated procedure proved to be an alternative to the pulmonary artery catheter thermodilution cardiac output (CO(PACtherm)) in cardiac surgical patients. There is ongoing debate, however, of whether the CO(PiCCOpulse )is accurate after profound hemodynamic changes. The aim of this study was therefore to compare the CO(PiCCOpulse )after cardiopulmonary bypass (CPB) with a simultaneous measurement of the CO(PACtherm). METHODS: After ethical approval and written informed consent, data of 45 patients were analyzed during this prospective study. During coronary artery bypass graft surgery, the aortic transpulmonary thermodilution cardiac output (CO(PiCCOtherm)) and the CO(PACtherm )were determined in all patients. Prior to surgery, the CO(PiCCOpulse )was calibrated by triple transpulmonary thermodilution measurement of the CO(PiCCOtherm). After termination of CPB, the CO(PiCCOpulse )was documented. Both CO(PACtherm )and CO(PiCCOtherm )were also simultaneously determined and documented. RESULTS: Regression analysis between CO(PACtherm )and CO(PiCCOtherm )prior to CPB showed a correlation coefficient of 0.95 (P < 0.001), and after CPB showed a correlation coefficient of 0.82 (P < 0.001). Bland-Altman analysis showed a mean bias and limits of agreement of 0.0 l/minute and -1.4 to +1.4 l/minute prior to CPB and of 0.3 l/minute and -1.9 to +2.5 l/minute after CPB, respectively. Regression analysis of CO(PiCCOpulse )versus CO(PiCCOtherm )and of CO(PiCCOpulse )versus CO(PACtherm )after CPB showed a correlation coefficient of 0.67 (P < 0.001) and 0.63 (P < 0.001), respectively. Bland-Altman analysis showed a mean bias and limits of agreement of -1.1 l/minute and -1.9 to +4.1 l/minute versus -1.4 l/minute and -4.8 to +2.0 l/minute, respectively. CONCLUSION: We observed an excellent correlation of CO(PiCCOtherm )and CO(PACtherm )measurement prior to CPB. Pulse contour analysis did not yield reliable results with acceptable accuracy and limits of agreement under difficult conditions after weaning from CPB in cardiac surgical patients. The pulse contour analysis thus should be re-calibrated as soon as possible, to prevent false therapeutic consequences

The impact of an hematocrit of 20% during normothermic cardiopulmonary bypass for elective low risk coronary artery bypass graft surgery on oxygen delivery and clinical outcome – a randomized controlled study [ISRCTN35655335]

INTRODUCTION: Cardiopulmonary bypass (CPB) induces hemodilutional anemia, which frequently requires the transfusion of blood products. The objective of this study was to evaluate oxygen delivery and consumption and clinical outcome in low risk patients who were allocated to an hematocrit (Hct) of 20% versus 25% during normothermic CPB for elective coronary artery bypass graft (CABG) surgery. METHODS: This study was a prospective, randomized and controlled trial. Patients were subjected to normothermic CPB (35 to 36°C) and were observed until discharge from the intensive care unit (ICU). Outcome measures were calculated whole body oxygen delivery, oxygen consumption and clinical outcome. A nonparametric multivariate analysis of variance for repeated measurements and small sample sizes was performed. RESULTS: In a total of 54 patients (25% Hct, n = 28; 20% Hct, n = 26), calculated oxygen delivery (p = 0.11), oxygen consumption (p = 0.06) and blood lactate (p = 0.60) were not significantly different between groups. Clinical outcomes were not different between groups. CONCLUSION: These data indicate that an Hct of 20% during normothermic CPB maintained calculated whole body oxygen delivery above a critical level after elective CABG surgery in low risk patients. The question of whether a transfusion trigger in excess of 20% Hct during normothermic CPB is still supported requires a larger prospective and randomized trial

COVID-19 in der geburtshilflichen Anästhesie

Background!#!In the current pandemic regarding the infection with the SARS-CoV-2-virus and COVID-19 as the disease, concerns about pregnant women, effects on childbirth and the health of the newborn remain high. Initially, due to the early manifestation of the disease in younger patients, high numbers of COVID-19 patients in women needing peripartum care were expected.!##!Objective!#!This article aims to provide a general overview over the beginning of the pandemic as well as the second wave of infections in Germany and Switzerland, regarding SARS-CoV‑2 positive pregnant women hospitalized for childbirth. We therefore launched a registry to gain timely information over the dynamic situation during the SARS-CoV‑2 pandemic in Germany.!##!Material and methods!#!As part of the COVID-19-related Obstetric Anesthesia Longitudinal Assessment (COALA) registry, centers reported weekly birth rates, numbers of suspected SARS-CoV‑2 cases, as well as the numbers of confirmed cases between 16 March and 3 May 2020. Data acquisition was continued from 18 October 2020 till 28 February 2021. The data were analyzed regarding distribution of SARS-CoV‑2 positive pregnant women hospitalized for childbirth between centers, calendar weeks and birth rates as well as maternal characteristics, course of disease and outcomes of SARS-CoV‑2 positive pregnant women.!##!Results!#!A total of 9 German centers reported 2270 deliveries over 7 weeks during the first wave of infections including 3 SARS-CoV‑2 positive cases and 9 suspected cases. During the second survey period, 6 centers from Germany and Switzerland reported 41 positive cases out of 4897 deliveries. One woman presented with a severe and ultimately fatal course of the disease, while another one needed prolonged ECMO treatment. Of the women 28 presented with asymptomatic infections and 6 neonates were admitted to a neonatal intensive care unit for further treatment. There was one case of neonatal SARS-CoV‑2 infection.!##!Conclusion!#!The number of pregnant women infected with SARS-CoV‑2 was at a very low level at the time of delivery, with only sporadic suspected or confirmed cases. Due to the lack of comprehensive testing in the first survey period, however, a certain number of asymptomatic cases are to be assumed. Of the cases 68% presented as asymptomatic or as mild courses of disease but the data showed that even in young healthy patients without the presence of typical risk factors, serious progression can occur. These outcomes should raise awareness for anesthesiologists, obstetricians, pediatricians and intensive care physicians to identify severe cases of COVID-19 in pregnant women during childbirth and to take the necessary precautions to ensure the best treatment of mother and neonate. The prospective acquisition of data allowed a timely assessment of the highly dynamic situation and gain knowledge regarding this vulnerable group of patients