Role of perfusion index in early detection of hypotension following spinal anesthesia for cesarean section

ABSTRACT

Background

The most common drawback of spinal anesthesia (SA) is hypotension, which has adverse effects on both mother and fetus; consequently, early detection and management of spinal hypotension have been considered a very important topic in obstetric anesthesia. Additionally, the capability to ultimately diagnose hypotension could permit initiation of adequate treatment. The standard method to estimate blood pressure during cesarean section is noninvasive blood pressure measurement. However, periods of hypotension could be missed within a reasonable time frame.

Methods

Perfusion index (PI) and blood pressure were measured in 100 pregnant women during elective cesarean section under SA.

Results

PI had a significant negative correlation with the change occurred in systolic blood pressure (SBP) (r = −.432, p < .0001); by using univariate linear regression analysis, the PI explains 20.2% of variability in SBP as PI significantly predicts the change occurred in SBP (F = 24.8, p < .0001), as each one unit increase in PI, accompanied by a significant decrease in SBP by 2.089 (mm/hg), as (b, t, p) (−2.089, −4.987, .0001), respectively. There was a significant difference in SBP and PI before and after giving oxytocin bolus [(z = −1.9, P = .05) and (z = −4.3, P < .0001), respectively]. By comparing PI before vs. after taking ephedrine bolus, there was a significant decrease in median of PI [median of PI before 10 (5.5–15) vs. median of PI after 7.5 (6–15.5) (z = −6.6, P < .0001)].

Discussion

After SA with sympathetic blockade, peripheral vascular tone declined and therefore PI increased.

Conclusion

PI could anticipate the incidence of hypotension during cesarean delivery with SA. Ephedrine effect could be evaluated rapidly by the alteration in the PI so that further need can be judged. Oxytocin has a significant impact on vascular tone with 5 international unit bolus, although it does not have a significant effect on blood pressure.

KEYWORDS:

• Anesthesia
• hypotension
• obstetric
• perfusion index
• pulse oximeter

Abbreviations

IV	=	intravenous
NIBP	=	noninvasive blood pressure
PI	=	perfusion index
SBP	=	systolic blood pressure
SA	=	spinal anesthesia

Acknowledgments

Thanks to all my family who supported me.

Consent

Trial registration number 0305448.

Disclosure statement

The authors report that there are no competing interests to declare.

The study protocol was approved by Alexandria University ethics committee. It was prospective observational study.

Additional information

Funding

Self fund.