RT Journal Article
SR Electronic
T1 Blood pressure and cardiac output during caesarean delivery under spinal anaesthesia: a prospective cohort study
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e046102
DO 10.1136/bmjopen-2020-046102
VO 11
IS 6
A1 Trond Melbye Michelsen
A1 Christian Tronstad
A1 Leiv Arne Rosseland
YR 2021
UL http://bmjopen.bmj.com/content/11/6/e046102.abstract
AB Objectives We have previously established a method to measure transfer of nutrients between mother, placenta and fetus in vivo. The method includes measurements of maternal and fetal blood flow by Doppler ultrasound prior to spinal anaesthesia. Spinal anaesthesia affects maternal blood pressure and cardiac output. We aimed to determine the effect of spinal anaesthesia in mothers undergoing an elective caesarean section on blood pressure, heart rate and cardiac output, and whether cardiac output levels were comparable before induction of spinal anaesthesia and before delivery.Design Prospective cohort study.Setting Tertiary hospital in Norway.Participants 76 healthy women with uneventful pregnancies undergoing an elective caesarean section.Interventions We induced spinal anaesthesia with a standard prevention of hypotension including intravenous fluid coloading and phenylephrine infusion.Primary and secondary outcome measures Primary outcome measure was maternal cardiac output, and secondary outcome measures were invasive systolic blood pressure and heart rate. We measured heart rate and blood pressure by continuous invasive monitoring with a cannula in the radial artery. Cardiac output was estimated based on continuous arterial waveform. We compared maternal parameters 30 s before induction of spinal anaesthesia to 30 s before delivery.Results Median age at delivery was 34.5 (range 21–43) years and 17 of 76 women were nulliparous. The most prevalent indications were previous caesarean section and maternal request. Among 76 included women, 71 had sufficient data for analysis of endpoints. Median cardiac output was 6.51 (IQR (5.56–7.54) L/min before spinal anaesthesia and 6.40 (5.83–7.56) L/min before delivery (p=0.40)). Median invasive systolic blood pressure increased from 128.5 (120.1–142.7) mm Hg to 134.1 (124.0–146.6) mm Hg (p=0.014), and mean heart rate decreased from 86.0 (SD 13.9) to 75.2 (14.2) (p<0.001).Conclusions Maternal cardiac output at the time of caesarean delivery is comparable to levels before induction of spinal anaesthesia.Trial registration number NCT00977769.Data are available in a public, open access repository. The project is completed, the dataset is anonymised and all data analysed in the present project are available open access (uploaded in Mendeley (Rosseland, Leiv Arne (2020), “Dataset C Section Hemodynamic”, Mendeley Data, v2 http://dx.doi.org/10.17632/f5cmz9npjw.2)).