Accuracy of Pulse Oximeter on Newborn Wrist and Ankle
Accuracy of Pulse Oximeter on Newborn Wrist and Ankle
Demographic data of our study population is presented in Table 1. In all, 150 infants with a mean birth weight of 2381±1020 g and gestational age of 34.3±4.3 weeks were enrolled in the study. Of these, 33 patients had a birth weight <1500 g. Median postnatal age at enrollment was 3.5 days (25th to 75th percentile 1 to 16 days). From the total population of 150 patients, those with measurements at baseline, 30 s and at 1 min were included. Thus, each included patient had three paired measurements from the wrist and ipsilateral palm or from the ankle and ipsilateral sole. Of the 150 neonates, 143 patients (429 pairs) had simultaneous SpO2 measurements at the right palm and right wrist; 145 (435 pairs) had SpO2 measured at the left palm and left wrist; 146 (438 pairs) had SpO2 measured at the right sole and right ankle; and 149 patients (447 pairs) had SpO2 measured from the left sole and left ankle. Table 2 shows the average SpO2, heart rate, perfusion index and the response time from these sites. The corresponding bias and precision and the correlation coefficients for paired SpO2 measurements are also shown in Table 2.
Figure 1a and b show the linear relationship between SpO2 measured at the right palm and the right wrist and SpO2 measured at the left palm and the left wrist respectively. The correlation coefficients (r) of SpO2 at the right palm versus the right wrist and the left palm versus the left wrist were adequate (r=0.95, P<0.001; r=0.97, P<0.001, respectively).
(Enlarge Image)
Figure 1.
(a) Relationship between SpO2 measured at the right palm and the right wrist. The correlation coefficient (r) of SpO2 at the right palm versus the right wrist was adequate (r=0.95, P<0.001). (b) Relationship between SpO2 measured at the left palm and the left wrist. The correlation coefficient (r) of SpO2 at the left palm versus the left wrist was adequate (r=0.97, P<0.001). (c) Relationship between SpO2 measured at the right sole and the right ankle. The correlation coefficient (r) of SpO2 at the right sole versus the right ankle was adequate (r=0.92, P<0.001). (d) Relationship between SpO2 measured at the left sole and the left ankle. The correlation coefficient (r) of SpO2 at the left sole versus the left ankle was adequate (r=0.91, P<0.001). The dot size varies by the amount of data points; larger dot size meaning more data points.
Figure 1c and dshow the linear relationship between SpO2 measured at the right sole and the right ankle and SpO2 measured at the left sole and the left ankle respectively. There was also a good correlation between SpO2 at the right sole versus the right ankle and the left sole versus the left ankle (r=0.92, P<0.001; r=0.91, P<0.001, respectively).
There was also a good agreement of paired SpO2 measurements from these sites. The Bland–Altman plots of the differences between SpO2 measured at the palms and the wrists are shown in Figure 2a and b. The mean difference (bias) and the SD of the differences (precision) for SpO2 at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%.
(Enlarge Image)
Figure 2.
(a) Bland–Altman analysis of the differences between SpO2 measured at the right palm and the right wrist (Figure 1a). The mean difference (bias) and the SD of the differences (precision) for SpO2 at the right palm and right wrist was 0.08±0.94%. (b) Bland–Altman analysis of the differences between SpO2 measured at the left palm and the left wrist (Figure 1b). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the left palm and the left wrist was 0.22±0.87%. The dot size varies by the amount of data points; larger dot size meaning more data points.
Similarly, the bias and precision for SpO2 measured at the right sole and the right ankle was −0.03±0.93% and for the left sole and left ankle −0.01±0.93%. The Bland–Altman plots of these differences between SpO2 measured at the soles and the ankles are presented in Figure 3a and b.
(Enlarge Image)
Figure 3.
(a) Bland-Altman analysis of the differences between SpO2 measured at the right sole and the right ankle (Figure 1c). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the right sole and right ankle was −0.03±0.93%. (b) Bland-Altman analysis of the differences between SpO2 measured at the left sole and the left ankle (Figure 1d). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the left sole and left ankle was −0.01±0.93%. The dot size varies by the amount of data points; larger dot size meaning more data points.
The time it took to obtain the initial SpO2 (response time) from the right palm versus the right wrist (8.8 and 8.9 s, P<0.05), and the soles versus the ankles (8.6 and 8.8 s (right side), P<0.01; 8.7 and 8.8 s (left side), P<0.05, respectively) were statistically different, although not clinically significant. There was no difference in the time to obtain the initial SpO2 from the left palm versus the left wrist (8.6 and 8.7 s, P=0.72; Table 2).
Results
Demographic data of our study population is presented in Table 1. In all, 150 infants with a mean birth weight of 2381±1020 g and gestational age of 34.3±4.3 weeks were enrolled in the study. Of these, 33 patients had a birth weight <1500 g. Median postnatal age at enrollment was 3.5 days (25th to 75th percentile 1 to 16 days). From the total population of 150 patients, those with measurements at baseline, 30 s and at 1 min were included. Thus, each included patient had three paired measurements from the wrist and ipsilateral palm or from the ankle and ipsilateral sole. Of the 150 neonates, 143 patients (429 pairs) had simultaneous SpO2 measurements at the right palm and right wrist; 145 (435 pairs) had SpO2 measured at the left palm and left wrist; 146 (438 pairs) had SpO2 measured at the right sole and right ankle; and 149 patients (447 pairs) had SpO2 measured from the left sole and left ankle. Table 2 shows the average SpO2, heart rate, perfusion index and the response time from these sites. The corresponding bias and precision and the correlation coefficients for paired SpO2 measurements are also shown in Table 2.
Figure 1a and b show the linear relationship between SpO2 measured at the right palm and the right wrist and SpO2 measured at the left palm and the left wrist respectively. The correlation coefficients (r) of SpO2 at the right palm versus the right wrist and the left palm versus the left wrist were adequate (r=0.95, P<0.001; r=0.97, P<0.001, respectively).
(Enlarge Image)
Figure 1.
(a) Relationship between SpO2 measured at the right palm and the right wrist. The correlation coefficient (r) of SpO2 at the right palm versus the right wrist was adequate (r=0.95, P<0.001). (b) Relationship between SpO2 measured at the left palm and the left wrist. The correlation coefficient (r) of SpO2 at the left palm versus the left wrist was adequate (r=0.97, P<0.001). (c) Relationship between SpO2 measured at the right sole and the right ankle. The correlation coefficient (r) of SpO2 at the right sole versus the right ankle was adequate (r=0.92, P<0.001). (d) Relationship between SpO2 measured at the left sole and the left ankle. The correlation coefficient (r) of SpO2 at the left sole versus the left ankle was adequate (r=0.91, P<0.001). The dot size varies by the amount of data points; larger dot size meaning more data points.
Figure 1c and dshow the linear relationship between SpO2 measured at the right sole and the right ankle and SpO2 measured at the left sole and the left ankle respectively. There was also a good correlation between SpO2 at the right sole versus the right ankle and the left sole versus the left ankle (r=0.92, P<0.001; r=0.91, P<0.001, respectively).
There was also a good agreement of paired SpO2 measurements from these sites. The Bland–Altman plots of the differences between SpO2 measured at the palms and the wrists are shown in Figure 2a and b. The mean difference (bias) and the SD of the differences (precision) for SpO2 at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%.
(Enlarge Image)
Figure 2.
(a) Bland–Altman analysis of the differences between SpO2 measured at the right palm and the right wrist (Figure 1a). The mean difference (bias) and the SD of the differences (precision) for SpO2 at the right palm and right wrist was 0.08±0.94%. (b) Bland–Altman analysis of the differences between SpO2 measured at the left palm and the left wrist (Figure 1b). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the left palm and the left wrist was 0.22±0.87%. The dot size varies by the amount of data points; larger dot size meaning more data points.
Similarly, the bias and precision for SpO2 measured at the right sole and the right ankle was −0.03±0.93% and for the left sole and left ankle −0.01±0.93%. The Bland–Altman plots of these differences between SpO2 measured at the soles and the ankles are presented in Figure 3a and b.
(Enlarge Image)
Figure 3.
(a) Bland-Altman analysis of the differences between SpO2 measured at the right sole and the right ankle (Figure 1c). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the right sole and right ankle was −0.03±0.93%. (b) Bland-Altman analysis of the differences between SpO2 measured at the left sole and the left ankle (Figure 1d). The mean difference (bias) and the s.d. of the differences (precision) for SpO2 at the left sole and left ankle was −0.01±0.93%. The dot size varies by the amount of data points; larger dot size meaning more data points.
The time it took to obtain the initial SpO2 (response time) from the right palm versus the right wrist (8.8 and 8.9 s, P<0.05), and the soles versus the ankles (8.6 and 8.8 s (right side), P<0.01; 8.7 and 8.8 s (left side), P<0.05, respectively) were statistically different, although not clinically significant. There was no difference in the time to obtain the initial SpO2 from the left palm versus the left wrist (8.6 and 8.7 s, P=0.72; Table 2).