Heart Rate Variability Predicts Severe Hypotension after Spinal Anesthesia for Elective Cesarean Delivery

Background Hypotension due to vasodilation during subarachnoid block (SAB) for elective cesarean delivery may be harmful. Heart rate variability (HRV), reflecting autonomic control, may identify patients at risk of hypotension. Methods Retrospectively, HRV was analyzed in 41 patients who were classified into one of three groups depending on the decrease in systolic blood pressure (SBP): mild (SBP > 100 mmHg), moderate (100 > SBP > 80 mmHg), or severe (SBP < 80 mmHg). Prospectively, HRV and hemodynamic data of 19 patients were studied. Relative low frequency (LF), relative high frequency (HF), and LF/HF ratio were analyzed. Results Retrospective analysis of HRV showed a significantly higher sympathetic and lower parasympathetic drive in the groups with moderate and severe compared with mild hypotension before SAB (median, 25th/75th percentiles): LF/HF: mild: 1.2 (0.9/1.8), moderate: 2.8 (1.8/4.6), P < 0.05 versus mild; severe: 2.7 (2.0/3.5), P < 0.05 versus mild. Results were confirmed by findings of LF and HF. Prospectively, patients were grouped according to LF/HF before SAB: low-LF/HF: 1.5 (1.1/2.0) versus high-LF/HF: 4.0 (2.8/4.7), P < 0.05; low-LF: 58 +/- 9% versus high-LF: 75 +/- 10%, P < 0.05; low-HF: 41 +/- 10% versus high-HF: 25 +/- 10%, P < 0.05. High-risk patients had a significantly lower SBP after SAB (76 +/- 21 vs. 111 +/- 12 mmHg; P < 0.05). Conclusions Retrospectively analyzed HRV of patients scheduled to undergo elective cesarean delivery during SAB showed significant differences depending on the severity of hypotension after SAB. Preliminary findings were prospectively confirmed. High LF/HF before SAB predicted severe hypotension. Preoperative HRV analysis may detect patients at risk of hypotension after SAB.

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Faculty Opinions recommendation of Heart rate variability-guided prophylactic treatment of severe hypotension after subarachnoid block for elective cesarean delivery.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.14249.471747 ◽

2006 ◽

Author(s):

Ruth Landau

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Cesarean Delivery ◽

Prophylactic Treatment ◽

Elective Cesarean Delivery ◽

Subarachnoid Block ◽

Severe Hypotension ◽

Elective Cesarean

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Pulse Transit Time Variability Predicts Severe Hypotension after Spinal Anesthesia for Elective Cesarean Delivery

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.2208 ◽

2013 ◽

Vol 753-755 ◽

pp. 2208-2213

Author(s):

Lei Sun ◽

Chao Huang ◽

Yan Shen ◽

Xiu Quan Fu ◽

Yi Hu ◽

...

Keyword(s):

Spinal Anesthesia ◽

Cesarean Delivery ◽

Transit Time ◽

Physiological Mechanism ◽

Pulse Transit Time ◽

Preoperative Assessment ◽

Time Variability ◽

Elective Cesarean Delivery ◽

Severe Hypotension ◽

Elective Cesarean

Hypotension after spinal anesthesia for elective cesarean delivery may be harmful. This article first proposed pulse transit time variability (PTTV) analysis could be applied in the preoperative assessment of its risk. 42 patients were classified into groups of Mild, Moderate and Severe. Frequency domain analysis was performed on the day before surgery using autoregressive model. We divided the frequency band according to the troughs and extracted relevant parameters of power spectrum, while differences between groups were evaluated by t-test. The results indicating significant differences are presented in PR5, PR1/PR5, PR3/PR5 and PR4/PR5, with their discriminant accuracy on the 42 patients reaching 80.77% in low-BP group and 75% in norm-BP group. We conclude PTTV analysis can help predict the risk of hypotension on the day before surgery and the physiological mechanism is mainly due to parasympathetic regulation.

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Prophylactic Angiotensin II Infusion during Spinal Anesthesia for Elective Cesarean Delivery

Anesthesiology ◽

10.1097/00000542-199806000-00009 ◽

1998 ◽

Vol 88 (6) ◽

pp. 1475-1479 ◽

Cited By ~ 30

Author(s):

Robert D. Vincent ◽

Carol F. Werhan ◽

Patricia F. Norman ◽

Grace H. Shih ◽

David H. Chestnut ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Angiotensin Ii ◽

Systolic Blood Pressure ◽

Spinal Anesthesia ◽

Cesarean Delivery ◽

Elective Cesarean Section ◽

Elective Cesarean Delivery ◽

Maternal Heart Rate ◽

Elective Cesarean

Background Angiotensin II may prove useful in treating regional anesthesia-induced hypotension in obstetric patients, because it causes less uterine vasoconstriction than do other vasoconstrictor drugs (such as phenylephrine). This study compared (1) maternal blood pressure and heart rate and (2) fetal status at delivery in parturients given either prophylactic angiotensin II or ephedrine infusion during spinal anesthesia for elective cesarean delivery. Methods Fifty-four women were randomized to receive either angiotensin II or ephedrine infusion intravenously during spinal anesthesia for elective cesarean section delivery. Simultaneous with subarachnoid injection, infusion of angiotensin II (2.5 microg/ml) or ephedrine (5 mg/ml) was initiated at 10 ng x kg(-1) x min(-1) and 50 microg x kg(-1) x min(-1), respectively. The rate of each infusion was adjusted to maintain maternal systolic blood pressure at 90-100% of baseline. Results Cumulative vasopressor doses (mean+/-SD) through 10, 20, and 30 min were 150+/-100, 310+/-180, and 500+/-320 ng/kg in the angiotensin group and 480+/-210, 660+/-390, and 790+/-640 microg/kg in the ephedrine group. Maternal heart rate was significantly higher (P < 0.001) during vasopressor infusion in the ephedrine group than in the angiotensin group. Umbilical arterial and venous blood pH and base excess were all significantly higher (P < 0.05) in the angiotensin group than in the ephedrine group. Conclusions Angiotensin II infusion maintained maternal systolic blood pressure during spinal anesthesia without increasing maternal heart rate or causing fetal acidosis.

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Crystalloid Coload vs Colloid Coload following Spinal Anesthesia for Elective Cesarean Delivery: The Effects on Maternal Central Venous Pressure

The Journal of Medical Sciences ◽

10.5005/jp-journals-10045-0066 ◽

2017 ◽

Vol 3 (4) ◽

pp. 95-101

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Central Venous Pressure ◽

Spinal Anesthesia ◽

Cesarean Delivery ◽

Venous Pressure ◽

Elective Cesarean Delivery ◽

Central Venous ◽

Arterial Blood ◽

Elective Cesarean

ABSTRACT Introduction Spinal anesthesia is widely used in the management of uncomplicated cesarean section. Maternal hypotension is the commonest serious problem which decreases uterine blood flow causing fetal hypoxia, acidosis, and neonatal depression. Fluid administration before start of the surgery (preloading) with crystalloid is found to be ineffective due to rapid redistribution of fluids in various tissue spaces. A “coload” given at the time of spinal anesthesia may be more effective. Most studies have concentrated on noninvasive systolic blood pressure (SBP) measurements to evaluate the effect of such regimens. We used central venous pressure (CVP) measurement technique in parturients receiving rapid administration of crystalloid or colloid solution at the time of initiation of anesthesia (coload). We hypothesized that a colloid coload compared with a crystalloid coload would produce a larger sustained increase in volume and therefore reduce vasopressor requirements. Materials and methods We recruited healthy term women scheduled for elective cesarean delivery under spinal anesthesia for this randomized study. Baseline heart rate, baseline mean arterial blood pressure (MAP), and CVP were recorded. At the time of spinal injection, subjects were allocated to receive a rapid 1 L coload of either polymerized gelatin 3.5% (Haemaccel) or Hartmann (crystalloid) solution. The primary outcome CVP was compared between groups, as were secondary outcomes: phenylephrine dose and maternal hemodynamics data. Results Maternal demographics, surgical times, and American Society of Anesthesiologists (ASA) were similar between groups. Baseline parameters were similar in all the three groups. Heart rate increased from the baseline in all the three groups; however, mean heart rate was highest in crystalloid group. Mean arterial blood pressure decreased in all the three groups from baseline; however, highest fall was recorded in crystalloid group. The incidence of hypotension was 66.66% in crystalloid group as compared with 36.66% in colloid group. Crystalloid group patients received 6.33 ± 4.54 mg of ephedrine as compared with 2.40 ± 2.82 mg in colloid group. Thus, the incidence of hypotension and ephedrine consumption was significantly higher in crystalloid group as compared with colloid group. We found statistically significant differences in the mean preoperative CVP reading (p < 0.05) between the two groups, the mean CVP reading in crystalloid group being slightly lower. With preloading, similar CVP readings were obtained in both groups. The fall in CVP during subarachnoid blockade was also not significant. The CVP began to fall with the establishment of the block until the delivery of the baby after which it was found to rise. The predelivery CVP was significantly lower than preoperative CVP in both groups—the fall being significantly more in crystalloid group. Conclusion In our study, the results showed statistically significant decrease in volume requirement, when colloid coload is used than crystalloid coload using CVP monitor as a guide. Colloid coloading is effective and superior to crystalloid coloading for prevention of maternal hypotension in cesarean section. How to cite this article Sivanna U. Crystalloid Coload vs Colloid Coload following Spinal Anesthesia for Elective Cesarean Delivery: The Effects on Maternal Central Venous Pressure. J Med Sci 2017;3(4):95-101.

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