Noninvasive ventilation (NIV) and high-flow oxygen therapy (HFOT) are superior to conventional oxygen therapy (COT) for oxygen supplementation during bronchoscopy procedures among patients with chronic obstructive pulmonary disease (COPD), according to study findings published in BMJ Open Respiratory Research.
NIV has been found to be superior to COT as respiratory support during bronchoscopy in patients with COPD, who are at high risk for hypoxia; however, it has been unclear how HFOT compared as a potential option for such patients. Researchers therefore conducted a triple-arm study assessing the use of NIV, HFOT, and COT in patients with COPD undergoing flexible bronchoscopy as an outpatient procedure. The researchers compared the incidence of hypoxia, defined as saturation of peripheral oxygen (SpO2) less than 94% lasting for 10 seconds or more (measured noninvasively by continuous SpO2 monitoring via pulse oximetry) in the 3 arms.
Eligible participants were aged 40 to 75 years with COPD and undergoing bronchoscopy. These patients were randomly assigned 1:1:1 to COT, NIV, or HFOT. Blood samples for arterial blood gases were obtained from the radial artery at baseline and after the bronchoscopy was completed. Patients’ blood pressure, heart rate, respiratory rate, and oxygen saturation by SpO2 were recorded and monitored throughout.
A total of 90 patients with COPD were randomly assigned to the 3 arms. Participants had a mean (SD) age of 61.71 (7.5) years (range, 40-74 years), and 84% were male. Of the cohort, 51 patients had moderate COPD, 34 had severe COPD, and 5 had very severe COPD. Their mean body mass index was 20.81 (3.1) kg/m2 and 90% of participants had a history of smoking, including 57 participants who currently smoked.
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HFOT may be recommended to prevent hypoxia without compromising on the patient’s comfort or the operator’s ease.
In comparing the lowest mean recorded SpO2 values among the 3 groups, the lowest value was found in the COT group (COT: 87.03 [5.7%] vs HFOT: 95.57 [5.0%] vs NIV: 97.40 [1.6%]; P <.001).
The 3 groups had comparable average heart rates during bronchoscopy, with an average respiratory rate during bronchoscopy of 18.53 (3.4) per minute (COT: 20.23 [3.1]; HFOT: 18.57 [4.1]; NIV: 16.8 [1.9]; P <.01).
In the NIV group, postbronchoscopy saturation of peripheral oxygen (PaO2) was numerically the highest (COT: 69.30 [11.9] mm Hg; HFOT: 69.03 [13.6] mm Hg; NIV: 84.27 [21.2] mm Hg; P <.01).
The operator’s ease of doing the procedure was lower in the NIV group compared with that in the HFOT and COT groups (COT: 0.00 [interquartile range {IQR}, 0.0-0.0]; HFOT: 0.00 [IQR, 0.0-0.0; NIV: 17.5 [IQR, 15.0-20.0]; P <.01).
Mild nose pain occurred with an increased frequency among patients in the NIV group (COT: 4; HFOT: 2; NIV: 14; P <.01).
Study limitations include the single-center design and repeated interruption of routine bronchoscopy services due to the COVID-19 pandemic. Also, an in-house modified NIV mask was used to perform the procedure and maintain the air seal, but it was not standardized or externally validated.
“HFOT may be recommended to prevent hypoxia without compromising on the patient’s comfort or the operator’s ease,” stated the study authors.
