TABLE 4.

Shunt and alveolar dead space in acute COVID-19 patients (including the subgroup of 17 patients studied later in recovery), recovered patients and healthy subjects.

	Acute (n=30)	Acute# (n=17)	Recovered (n=17)	Healthy (n=13)
Shunt (%)	10.4±5.4 (0–22.0)	11.7±5.1 (4.1–22.0)	2.4±1.9** (0–6.1)	1.2±1.1 (0–4.1)
Alveolar dead space (%)	14.9±9.6 (0–32.3)	14.4±9.7 (0–29.7)	8.6±5.5* (0–22.4)	4.7±4.3 (0–11.8)

Data are presented as mean±sd (range). ^#: subgroup studied in recovery. *: p<0.05; **: p<0.0001 (compared with acute subgroup).