Table 1. Characteristics of the selected randomized controlled trials.
| Study | Inclusion criteria | No. of patients (% male) | Age, years, mean ± SD | Baseline oxygenation | Sedative or anesthetic agents; duration of bronchoscopy (min) | Interventions |
|---|---|---|---|---|---|---|
| Ben-Menachem [13] | Age ≥ 18 years; lung transplant recipients; undergoing TBLB; able to provide informed consent; English speaking | H: 37 (40.5) | H: 54.9 ± 11.7 | H: 98 (97–99)†,a | Local Topicalized anesthesia with nebulized 2% lidocaine and midazolam (1 to 3 mg) sedation with midazolam, propofol (321 mg in intervention group and 337 mg in control group) and alfentanil (586 mcg in intervention group and 691 mcg in control group) to keep ASA score II–III; H: 33 ± 10, C: 34 ± 8 | H: FiO2: 100%, flow rate: 30–50 LPM through the nasal cannula |
| C: 39 (25.6) | C: 55.8 ± 11.9 | C: 98 (97–99)†,a | C: Flow rate: 4–10 LPM through standard oxygen tubing | |||
| Douglas [14] | Age ≥ 18 years; able to provide informed consent; sedation planned; English speaking | H: 30 (63) | H: 62.8 ± 14.1 | H: 96 (95–99)†,a | Topical 2% lignocaine to patient’s nasopharynx and oropharynx Sedation with midazolam, opioids or propofol to keep MOAA/S = 4; I: 24 (26–28)†, C: 21 (17–32)† | H: FiO2: 100%, flow rate: 30–50 LPM (up to 70 LPM if necessary) through the nasal cannula |
| C: 30 (63) | C: 63.4 ± 14.3 | C: 96 (94–98)†,a | C: Flow rate: 10 LPM (up to 15 LPM if necessary) through the bite block | |||
| Irfan [15] | Age ≥ 18 years; SpO2 ≥ 90%; able to breathe spontaneously throughout the procedure | H: 20 (60) | H: 61.9 ± 12 | H: 98.4 ± 2.7a | Local anesthesia sedation with midazolam (5.6 mg in intervention group and 5.5 mg in control group) and alfentanil (300 mcg in intervention group and 287 mcg in control group) varied by assessing purposeful response to verbal and/or tactile stimuli while preserving spontaneous respiratory efforts; NI | H: FiO2: 36%, flow rate: 30 LPM through the nasal cannula |
| C: 20 (60) | C: 64.5 ± 14 | C: 96.9 ± 1.9a | C: Nasal prong to maintain SpO2 ≥ 94% | |||
| Longhini [16] | Age ≥ 18 years; outpatients undergoing flexible bronchoscopy for bronchoalveolar lavage | H: 18 (83) | H: 61.9 ± NI | H: 10.8 (8.7–12.0)†,b | Topical Aanesthetic spray containing 10% lidocaine over tongue and nasopharynx; gargles with 10 mL of 2% lidocaine hydrochloride solution guaranteed further anesthesia of the oropharynx; H: 11 min 30 s ± NI, C: 12 min 50 s ± NI | H: FiO2 set to reach SpO2 ≥ 95%, flow rate: 60 LPM through the nasal cannula |
| C: 18 (67) | C: 64.5 ± NI | C: 11.1 (10.5–12.1)†,b | C: Nasal cannula to keep SpO2 ≥ 94% | |||
| Lucangelo [17] | Age ≥ 18 years; BMI ranging from 21 to 30 | H60: 15 (47) | H60: 64 (63–70)† | H60: 350.9 (304.3–363.8)†,c | Anesthesia by nNebulized 2% lidocaine 2% through the mouth and nostrils to guarantee fully developed local anesthesia; 4mg midazolam in each group delivered as demanded by each patient, reaching a maximum dose of 0.1 mg/kg BW; H60: 15 (9–21)†, H40: 15 (12–16)†, C: 14 (10–16)† | H60: FiO2: 50%, flow rate: 60 LPM through the nasal cannula |
| H40: 15 (53) | H40: 70 (61–76)† | H40: 342.8 (295.7–371.9) †,c | H40: FiO2: 50%, flow rate: 40 LPM through the nasal cannula | |||
| C: 15 (60) | C: 68 (62–78)† | C: 322.4 (295.6–374.3)†,c | C: FiO2: 50%, flow rate: 40 LPM through the venturi mask |
†Data reported as median (IQR); aData reported as SpO2; bData reported as PaO2 in kPa; cData reported as PaO2/FiO2 ratio.
Abbreviations: BMI, body mass index; C, conventional oxygen therapy; H, high-flow nasal cannula; H60, high-flow nasal cannula with flow of 60 LPM; H40, high-flow nasal cannula with flow of 40 LPM; LPM, liters per minute; MOAA/S, Modified Observer’s Assessment of Alertness/Sedation Scale; NI, no information; TBLB, transbronchial lung biopsy.