Table 1 Characteristics of the included studies
| Study (author, year) | Study groups | Study design | Inclusion criteria | Settings of experimental group and control group intervention | Follow-up period |
|---|---|---|---|---|---|
| Yu, 2017 | HFNC 56, SO 54 | Multicenter, prospective, randomize, interventional trial | Patients who underwent thoracoscopic lobectomy because of lung tumor and were at intermediate to high risk for PPC as determined by an ARISCAT score ≥ 26. Patients were immunocompetent, not pregnant, between 18 and 80 years old |
HFNC: received at a flow rate if 35 to 60 L/min and FiO2 was titrated from 45 to 100% to maintain a SpO2 of 95% or more SO: received oxygen via nasal prongs or facemasks with FiO2 titrated between 45 and 100% to maintain SpO2 of 95% or more | 72 h following extubation |
| Futier, 2016 | HFNC 108, SO 112 | Multicenter, randomized controlled trial | Adult patients scheduled for planned or unplanned abdominal, or abdominal and thoracic surgery with and anticipated duration of 2 h or more and an ARISCAT score ≥ 26 |
HFNC: flow rate of 50 to 60 L/min to maintain an SpO2 of 95% or more SO: O2 delivered continuously using nasal prongs or facemasks to maintain an SpO2 of 95% or more | 7 days post-op |
| Gupta, 2016 | HFNC 10, NIV 10 | Pilot study, single-center, randomized controlled trial | Postoperative hypoxemia in post-liver transplant patients |
HFNC: initiated at a flow rate of 60 L/min and titrated according to ABG NIV: set EPAP of 5 cm and IPAP at 10 cm and titrated according to ABG | 48 h post-op. |
| Jaber, 2016 | SO 145, NIV 148 | Multicenter, randomized, parallel-group clinical trial | Patients older than 19 who had undergone laparoscopic or non-laparoscopic elective or nonelective abdominal surgery under general anesthesia that were diagnosed with ARF within 7 days of surgical procedure defined as persistence of more than 30 min of hypoxemia |
SO: supplemental O2 at a rate of up to 15 L/min to maintain SpO2 of at least 94% NIV: facemask connected to an ICU or NIV dedicated ventilator titrating PEEP and FiO2 to maintain an SpO2 of at least 94% | 90 days post-op. |
| Stephan, 2015 | HFNC 414, NIV 416 | Multicenter, randomized, noninferiority trial | Patients who had undergone cardiothoracic surgery who developed ARF (failure of SBT or successful SBT but failed extubation) or were deemed at risk for respiratory failure post-extubation due to preexisting risk factors |
HFNC: initial rate of 50 L/min with initial FiO2 50% adjusted to maintain SpO2 92% or more BiPAP: full facemask connected to ventilator with adjustments made to PEEP and FiO2 to maintain SpO2 of 92% or more | 3 days |
| Zhu, 2013 | NIV 48, SO 47 | Single-center, prospective, randomized control study | Patients who after cardiac surgery developed ARF after initial extubation who were hemodynamically stable with no evidence of bleeding |
NPPV: BiPAP via facemask. FiO2 adjusted to maintain SpO2 of around 92% SO: standard medical care and oxygen therapy as needed | Length of hospital stay |
| Squadrone, 2005 | NIV 105, SO 104 | Multicenter, randomized, controlled, unblinded study | Post-op elective abdominal surgery under GA if surgery required laparotomy and time of viscera exposure longer than 90 min. Patients were extubated after surgery, and if they developed a PaO2/FiO2 of 300 less, they were included in study. |
CPAP: treated with FiO2 of 0.5 plus CPAP of 7.5. After 6 h, patients underwent 1-h screening test breathing O2 through a venture mask at an FiO2 of 0.3. Patients returned to assigned treatment if PaO2/FiO2 ratio was 300 or less, and treatment was interrupted if the ratio was higher than 300 SO: 8 to 10 L/min oxygen. | Length of hospital stay |
| Auriant, 2001 | NIV 24, SO 24 | Prospective, randomized controlled trial | Patients with AHRI following lung resection if they met at least three of the following criteria: dyspnea at rest, active contraction of accessory respiratory muscles, PaO2/FiO2 less than 200, chest radiographic abnormalities |
NPPV: cushion bridge nasal mask with BiPAP. PS was increased to achieve exhaled TV of 8–10 mL/kg and RR of less than 25 breaths/min. FiO2 was adjusted to obtain SpO2 above 90% SO: O2 supplementation to achieve SaO2 above 90% | 120 days |
| Antonelli, 2000 | NIV 20, SO 20 | Single center, prospective, randomized study | Recipients of solid organ transplants with acute hypoxemic respiratory failure. Criteria included acute respiratory distress, respiratory rate greater than 35/min, ratio of PaO2/FiO2 of less than 200, active contraction of accessory muscles or paradoxical abdominal motion |
NIV: ventilator connected to full-face mask with titration of PS to obtain exhaled TV of 8 to 10 mL/kg, RR less than 25/min. PEEP increased gradually and up to 10 cm H2O until FiO2 requirement was 0.6 or less. Settings were adjusted based on continuous oximetry and measurements of ABG. Standard oxygen: Venturi mask started with FiO2 of 40% and titrated to achieve a level of SpO2 90% | NA |