Noninvasive Mechanical Ventilation in Patients with Viral Pneumonia-Associated Acute Respiratory Distress Syndrome: An Observational Retrospective Study

Table 2

Laboratory indexes, clinical symptoms, and physical examination of 45 patients with influenza A-associated acute respiratory distress syndrome.

	NIV success (n = 24)	NIV failure (n = 21)	value
Symptom
Cough	24 (100%)	21 (100%)	—
Expectoration	24 (100%)	21 (100%)	—
Hemoptysis	7 (29.1%)	11 (52.3%)	0.138^a
Fever	24 (100%)	20 (95.2%)	0.467^a
Dyspnea	21 (87.5%)	21 (100%)	0.236^a
Body aches	8 (33.3%)	4 (19.0%)	0.329^a
Headache	2 (8.3%)	4 (19.0%)	0.396^a
Melena	1 (4.1%)	1 (4.1%)	1.000^a
Vomit	1 (4.1%)	0 (0.0%)	1.000^a
Anorexia	1 (4.1%)	2 (9.5%)	0.592^a
Clinical features
Days with fever before admission	5.6 ± 2.3	5.3 ± 1.8	0.655^b
Days with dyspnea before admission	4.5 ± 2.4	4.1 ± 1.7	0.629^b
The mean time from symptom onset to presentation (days)	6.0 ± 2.3	5.3 ± 1.8	0.336^b
Aximum body temperature (°C)	39.1 ± 0.8	39.0 ± 0.8	0.514^b
The duration of fever in hospital (days)	2 (0–5)	5 (2–9)	0.007^c
Vital signs
Heart rate in admission (cycles/min)	99 ± 12	111 ± 14	0.006^b
Systolic pressure (mmHg)	125 ± 18	130 ± 20	0.445^b
Diastolic pressure (mmHg)	76 ± 12	78 ± 17	0.633^b
OI (mmHg)	164.0 ± 71.4	85.9 ± 33.1	<0.001^b
Laboratory index
W.B.C count (10^9/L)	5.0 ± 2.1	6.1 ± 4.6	0.335^b
Lymphocyte count (10^9/L)	0.6 ± 0.4	0.5 ± 0.2	0.276^b
Platelet count (10^9/L)	148.0 ± 46.9	154.6 ± 62.0	0.686^b
C-reactive protein (mg/L)	131.9 ± 68.7	162.6 ± 74	0.157^b
Procalcitonin (ng/mL)	1.5 ± 2.4	3.5 ± 5.8	0.134^b
APTT	34.9 ± 5.3	36.9 ± 10.1	0.399^b
Fibrinogen (g/L)	3.4 ± 0.9	3.4 ± 1.0	0.987^b
ALT (U/L)	40.5 (33.2–86.0)	60.0 (38.0–96.1)	0.311^c
AST (U/L)	57.5 (48.9–98.0)	103.0 (59.0–194.0)	0.090^c
ALP (U/L)	77.5 (61.2–106.5)	93.0 (80.5–137.8)	0.072^c
BUN (mmol/L)	5.2 (3.9–6.8)	7.0 (5.1–14.2)	0.032^c
Cr (μmol/L)	85.2 (68.1–96.9)	87.4 (68.0–146.1)	0.363^c
LDH (U/L)	447.0 (383.2–680.5)	826.0 (629.5–1446.0)	<0.001^c
CK (U/L)	149.0 (108.5–813.5)	187.0 (58.5–1138.0)	0.593^c
CK-MB (U/L)	13.8 (8.0–20.4)	15.0 (10.5–35.3)	0.187^c
Ventilator parameters
Vte (ml/kg)	7.2 ± 1.5	7.8 ± 2.3	0.380^b
The median length of ICU stay (days)	10.0 (6.2–14.0)	24.5 (13.5–40.0)	<0.001^c

Note. OI = oxygenation index; APTT =  activated partial thromboplastin time; ALT =  alanine aminotransferase; AST =  aspartate aminotransferase; ALP = alkaline phosphatase; BUN = blood urea nitrogen; Cr = creatinine; LDH = lactate dehydrogenase; CK = creatine kinase; CK-MB = creatine kinase isoenzyme; Vte = expired tidal volume (calculated every 2 h and the average value was used for analysis). ^aCalculated using the chi-square test; ^bcalculated using student's t test; ^ccalculated using the Wilcoxon rank sum test.