Oxygen reserve index for non-invasive early hypoxemia detection during endotracheal intubation in intensive care: the prospective observational NESOI study

Annals of Intensive Care

Table 2 Comparison of peripheral oxygen saturation (SpO₂) and oxygen reserve index (ORI) in patients with and without SpO₂ < 97% during endotracheal intubation (ETI)

	Total n = 51	SpO₂ ≥ 97% n = 31	SpO₂ < 97% n = 20	P value
SpO₂ at the start of preoxygenation, median [IQR]	97.00 [95.00–99.00]	98.00 [95.00–100.00]	97.00 [95.00–97.00]	0.0951
SpO₂ at the end of preoxygenation, median [IQR]	100.00 [99.00–100.00]	100.00 [99.00–100.00]	100.00 [99.00–100.00]	0.5931
SpO₂ at ETI, median [IQR]	99.00 [95.00–100.00]	100.00 [99.00–100.00]	93.00 [85.50–97.00]	< 0.0001
ORI at the start of preoxygenation, median [IQR]	0.04 [0.01–0.13]	0.05 [0.02–0.20]	0.04 [0.01–0.12]	0.2891
ORI at the end of preoxygenation, median [IQR]	0.62 [0.26–0.83]	0.71 [0.54–0.94]	0.39 [0.15–0.65]	0.0082
Change in ORI from start to end of preoxygenation, median [IQR]	0.46 [0.15–0.64]	0.52 [0.23–0.82]	0.17 [0.10–0.50]	0.0191
Highest ORI during preoxygenation, median [IQR]	0.67 [0.31–0.94]	0.77 [0.59–1.00]	0.49 [0.22–0.77]	0.0212
Changes in SpO₂ from start to end of preoxygenation, median [IQR]	3.00 [1.00–4.00]	2.00 [0.00–4.00]	3.00 [2.00–5.00]	0.1181

SpO₂ oxygen saturation by pulse oximeter; IQR interquartile range; ETI endotracheal intubation; ORI oxygen reserve index