Table 2.
Comparing baseline characteristics and outcomes of patients initiated on HFNC post extubation (n = 46)
| HFNC success (n = 30) | HFNC failure (n = 16) | p value | |
|---|---|---|---|
| Age, years | 64 (53–71) | 61 (52–72) | 0.982 |
| Male gender | 17 (56.7) | 7 (43.8) | 0.978 |
| Charlson comorbidity index | 5 (3–6) | 4 (3–6) | 0.557 |
| Moderate to severe CKD | 4 (13.3) | 2 (12.5) | 1.000 |
| Congestive heart failure | 1 (3.3) | 2 (12.5) | 0.274 |
| Chronic respiratory disease | 3 (21.4) | 1 (8.3) | 0.598 |
| Immunocompromised host | 11 (36.7) | 12 (75.0) | 0.029 |
| Solid organ cancer with chemotherapy | 4 (36.4) | 1 (8.3) | 0.155 |
| Hematological transplant or malignancy | 6 (54.5) | 4 (33.3) | 0.414 |
| Chronic immunosuppressive therapy | 1 (9.1) | 6 (50.0) | 0.069 |
| HIV/AIDS | 0 (0.0) | 1 (8.3) | 1.000 |
| APACHE II* | 15 (13–19) | 16 (11–21) | 0.899 |
| SOFA* | 5 (3–9) | 4 (3-7) | 0.368 |
| Primary etiology for respiratory failure | |||
| Pneumonia | 25 (83.3) | 14 (87.5) | 1.000 |
| Interstitial lung disease/drug induced pneumonitis | 3 (10.0) | 0 (0.0) | 0.542 |
| Cancer/Lymphangitis carcinomatosis | 0 (0.0) | 2 (12.5) | 0.116 |
| Others | 2 (6.7) | 0 (0.0) | 0.536 |
| Duration of mechanical ventilation before extubation, h | 94 (53–197) | 171 (92–194) | 0.137 |
| Vasopressor support at time of HFNC initiation | 0 (0.0) | 0 (0.0) | NA |
| Number of quadrants affected on CXR | 3 (3–4) | 4 (3–4) | 0.327 |
| Arterial blood gas analysis pre-HFNC initiation | |||
| pH | 7.46 (7.43–7.48) | 7.45 (7.41–7.48) | 0.406 |
| PaO2/FIO2 ratio | 165 153–190) | 157 (129–180) | 0.122 |
| PaCO2, mmHg | 41 (36–44) | 41 (38–45) | 0.773 |
| Serum bicarbonate, μmol/L | 27 (24–30) | 27 (24–31) | 0.936 |
| Duration of HFNC, h | 29.3 (22.6–49.8) | 46.0 (9.6–86.6) | 0.827 |
| Max FIO2 on HFNC | 50 (50–60) | 80 (60–100) | < 0.001 |
| Max flow on HFNC, L/min | 50 (40–50) | 60 (50–60) | 0.021 |
| Hospital mortality | 6 (20.0) | 10 (62.5) | 0.004 |
| ICU mortality | 4 (13.3) | 8 (50.0) | 0.013 |
Values are expressed in number (percentage) and median (interquartile range). HFNC high flow nasal cannula, CKD chronic kidney disease, HIV human immunodeficiency, AIDS acquired immunodeficiency syndrome, APACHE acute physiologic assessment and chronic health evaluation, SOFA sequential organ failure assessment score, CXR chest x-ray, ICU intensive care unit. Etiology for ‘Others’ include diffuse alveolar haemorrhage, pulmonary embolism and cardiogenic pulmonary edema.
*APACHE II and SOFA scores were recorded based on the highest scores in the 24 h preceding HFNC initiation