Perfusion index as a predictor of hypotension after induction of general anesthesia in elderly patients – a prospective observational study

Figures & data

Table 1. Demographic data.

	All patients (no. 30)	H group (no. 16)	Hout group (no. 14)	P value
Age (years)	70.62 ± 6.42 (95%CI: 68.33 to 72.91)	70.13 ± 7.00 (95%CI: 66.70 to 73.55)	70.5 ± 5.88 (95%CI: 67.42 to 73.58)	*0.95
				** 0.64	*** 0.58
ASA (I/II)	7/23	3/13	4/10	*0.67
				** 0.73	*** 0.92
Sex (M/F)	19/11	10/6	9/5	*0.73
				** 0.72	** 0.33
SBP (mmHg)	161.15 ± 13.82 (95%CI: 156.22 to 166.08)	154.06 ± 18.16 (95%CI: 145.17 to 162.95)	157.86 ± 14.90 (95%CI: 150.05 to 165.65)	*0.44
				** 0.53	*** 0.14
DBP (mmHg)	85.54 ± 7.19 (95%CI: 82.95 to 88.11)	85.63 ± 9.49 (95%CI: 81.97 to 90.27)	86.79 ± 7.64 (95%CI: 82.79 to 90.79)	*0.73
				** 0.98	*** 0.70
MAP (mmHg)	109.85 ± 8.28 (95%CI: 106.87 to 112.81)	104.13 ± 10.04 (95%CI: 99.22 to 109.04)	113.79 ± 9.02 (95%CI: 109.03 to 118.53)	*0.05
				** 0.25	*** 0.29
HR (beat/min)	76.15 ± 10.71 (95%CI: 72.33 to 79.97)	83.63 ± 14.48 (95%CI: 76.54 to 90.72)	77.5 ± 11.96 (95%CI: 71.24 to 82.76)	*0.10
				** 0.92	*** 0.23
PI	2.07 ± 2.78 (95%CI: 1.07 to 3.07)	0.78 ± 0.40 (95%CI: 0.59 to 0.97)	2.62 ± 2.38 (95%CI: 1.38 to 3.86)	*0.02
				** 0.06	*** 0.11

Data are presented as means ± standard deviation. 95% CI, 95% confidence interval, numbers; M, males; F, females; ASA, the American Society of Anesthesiology; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; HR, heart rate; PI, perfusion index. *P value for H and Hout, ** P value for all patients and H, ***P value for all patients and Hout.

Figure 1. The AUC analysis for the ability of baseline PI to predict early postinduction hypotension.

Table 2. The AUC analysis for the ability of baseline PI to predict early and late postinduction hypotension.

	AUC	Sensitivity	Specificity	PPV	NPV	Cutoff value
Early hypotension (no. 16)	0.97	88	93	93	87	≤1.3
Late hypotension (no. 11)	0.66	91	58	56	92	>0.91

AUC, area under receiver operating characteristic curve; CI, confidence interval; NPV, negative predictive value; PI, perfusion index; PPV, positive predictive value.

Figure 2. Trends of mean SBP and PI in patients with early hypotension (H) and patients without (Hout).

Table 3. Trends of heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and perfusion index in patients with early hypotension (H) and patients without early hypotension (Hout).

		F	P value
HR (beat/min)	First 3 min	4.11	0.11
	Overall 15 min	12.74	0.001
SBP (mmHg)	First 3 min	31.52	0.005
	Overall 15 min	6.51	0.016
DBP (mmHg)	First 3 min	4.79	0.094
	Overall 15 min	0.17	0.682
MAP (mmHg)	First 3 min	1.30	0.033
	Overall 15 min	4.18	0.050
PI	First 3 min	5.86	0.002
	Overall 15 min	48.21	<0.0001

Note: P < 0.05 is significant. F = variation between sample means/variation within the samples.