Heart rate variability as a predictor of hypotension after spinal anesthesia in hypertensive patients

Abstract

BackgroundHypotension is a common phenomenon after spinal anesthesia in hypertensive patients. We investigated whether heart rate variability could predict the occurrence of hypotension after spinal anesthesia in hypertensive patients.MethodsForty-one patients undergoing spinal anesthesia were included. Heart rate variability was measured at five different time points such as before fluid loading (baseline), after fluid loading as well as 5 min, 15 min and 30 min after spinal anesthesia. Fluid loading was performed using 5 ml/kg of a crystalloid solution. Baseline total power and low to high frequency ratio (LF/HF) in predicting hypotension after spinal anesthesia were analyzed by calculating the area under the receiver operating characteristic curves (AUC).ResultsModerate hypotension, defined as a decrease of mean arterial pressure to below 20-30% of the baseline, occurred in 13 patients and severe hypotension, defined as a decrease of mean arterial pressure greater than 30% below the baseline, occurred in 7 patients. LF/HF ratiosand total powers did not significantly change after spinal anesthesia. AUCs of LF/HF ratio for predicting moderate hypotension was 0.685 (P = 0.074), severe hypotension was 0.579 (P = 0.560) and moderate or severe hypotension was 0.652 (P = 0.101), respectively. AUCs of total power for predicting moderate hypotension was 0.571 (P = 0.490), severe hypotension was 0.672 (P = 0.351) and moderate or severe hypotension was 0.509 (P = 0.924), respectively.ConclusionsHeart rate variability is not a reliable predictor of hypotension after spinal block in hypertensive patients whose sympathetic activity is already depressed.

Estimating the influence of spinal block and ataractanalgesia on the coupling between the rhythms of autonomic control of heart rate and vascular tone during gynecological operations

“…In contrast to the previous studies [7][8][9][10][11][12] focused on the detection of influence of different anesthetic drugs on autonomic control of heart rate and arterial pressure, the present study was aimed at estimating the strength and direction of coupling between the autonomic control of heart rate and vascular tone for the patients under the spinal block and the ataractanalgesia. In [8][9][10] it was demonstrated that propofol suppresses the activity of sympathetic control of heart rate.…”

“…Earlier it was demonstrated in [7][8][9][10][11][12] that different anesthetic drugs have different impacts on sympathetic and parasympathetic control of heart rate and arterial pressure. During the choice of a therapy it is important to take into account the patient's circulation conditions.…”

Perbandingan Efektivitas Anestesi Spinal Menggunakan Bupivakain Hiperbarik dengan Bupivakain Isobarik pada Pasien yang Menjalani Prosedur Operasi Abdomen Bagian Bawah di RSUP Dr. Kariadi

“…Terjadi dilatasi pada vena dan venule perifer dengan pengumpulan darah akan menurunkan curah balik ke jantung sehingga akan menyebabkan penurunan curah jantung dan tekanan darah. 18,19 Semakin banyak daerah yang mengalami denervasi simpatis seperti pada bupivakain hiperbarik maka akan semakin banyak arteri dan vena yang mengalami dilatasi sehingga memperbesar persentase penurunan tekanan darah yang lebih tinggi dibandingkan dengan bupivakain isobarik. 20,21 Hal ini memperlihatkan perbedaan luas area yang terkena blokade pada kedua kelompok akan memberi efek pada tekanan darah yang secara teori dijelaskan bahwa semakin luas daerah blokade maka akan terjadi penurunan resistensi pembuluh darah sistemik sehingga penumpukan darah pada vena semakin besar, pada akhirnya akan menurunkan aliran darah yang kembali ke jantung.…”

Hipotensión bajo anestesia regional subaracnoidea en población no obstétrica

“…A través de un método no invasivo que mide y analiza la variabilidad de la frecuencia cardíaca 12 ; varios estudios han demostrado el valor predictivo de este en maternas programadas para cesárea 13,14 ; sin embargo, queda determinar su aplicabilidad en población no obstétrica 7 . El análisis se realiza bajo los estándares del Task Force 15 , consiste en un registro de 5 minutos de ondas R rápidas en electrocardiograma a una frecuencia de 1024 Hz; se calcula un espectro de densidades para frecuencias bajas y para frecuencias altas, LF y HF por sus siglas en inglés, respectivamente 7,16 . Se ha propuesto que la relación LF/HF refleja el balance de la regulación del sistema nervioso autónomo es decir, la relación entre los componentes simpático y parasimpático 13 , siendo LF la actividad vasomotora (como índice indirecto de actividad simpática) y HF la actividad vagal [17][18][19][20] .…”