Peters, S.G., Holets, S.R., & Gay, P.C. (2013). High-flow nasal cannula therapy in do-not-intubate patients with hypoxemic respiratory distress. Respiratory Care, 58, 597–600.

To document the characteristics of do-not-intubate (DNI) patients on high-flow nasal cannula (HFNC)—Optiflow™—including underlying disease, HFNC FiO2/flows, breathing frequency, oxygen saturation (pre and post HFNC), escalation to noninvasive ventilation (NIV), and hospital mortality for participants

Based on chart review, HFNC therapy was usually started at previous FiO2 and at a flow of 35 L per minute, with flow titrated as tolerated to 45–50 L per minute. FiO2 was ultimately titrated to maintain SaO2 greater than 90%, or according to specific clinical orders. Average changes in oxygen saturation and breathing frequency before and after HFNC were compared. Arterial blood gases were available for all participants at baseline but with variable availability after HFNC. Data were analyzed using closest values prior to HFNC and about one hour after starting HFNC (participants served as their own control).

• N = 50   
• MEAN AGE = 73 years
• AGE RANGE = 27–96 years
• MALES: 50%, FEMALES: 50% 
• CURRENT TREATMENT: Not applicable
• KEY DISEASE CHARACTERISTICS: Participant diagnoses include pulmonary fibrosis (PF) (n = 15), pneumonia (n = 15), chronic obstructive pulmonary disease (COPD) (n = 12), cancer (n = 7), hematologic malignancy (n = 7), congestive heart failure (CHF) (n = 3), pulmonary embolism (n = 2), sepsis (n = 2), alveolar hemorrhage (n = 1), and myocardial infarction (n = 1).
• OTHER KEY SAMPLE CHARACTERISTICS: Subjects were included if they had do-not-resusitate (DNR)/DNI status, clinical evidence of respiratory distress (e.g., dyspnea, tachypnea), hypoxemia, and mild or compensated hypercapnia (PaCO2 less than or equal to 65; pH greater than 7.28). Participants were excluded if they were on comfort care or if no indication for progress to NIV was evident.

• SITE: Single site   
• SETTING TYPE: Inpatient    
• LOCATION: Medical or medical-surgical intensive care unit (ICU) of two hospitals of the Mayo Clinic in Rochester, MN

• PHASE OF CARE: Multiple phases of care
• APPLICATIONS: Palliative care 

• Retrospective study

• PaO2
• SaO2
• PaCO2
• pH
• FiO2
• Breaths per minute

• Hospital mortality for participants was 60% (30 out of 50) ranging from 33.3% in COPD and CHF patients to 73.3% in patients with PF.
• Breathing frequency decreased from 30.6 to 24.7 breaths per minute on HFNC (p < 0.001).
• Mean oxygen saturation improved from 89.1% to 94.7% (p <  0.001).
• Nine out of 50 (18%) participants escalated to NIV, and 41 of 50 participants (82%) were maintained on HFNC until improvement or withdrawal of support. Of the nine patients who escalated to NIV, six (67%) died versus death in 24 of 41 (58%) who did not receive NIV (p = 0.72). Of the nine participants who escalated to NIV, the six had PF, two had COPD, and one had sepsis.
• Median duration of use of HFNC was 30 hours (mean = 41.9 hours, range = 2–144 hours).
• HFNC was well-tolerated with no documented nasal bleeding or facial skin breakdown.

HFNC reduced hypoxemic respiratory failure in patients with DNI, as well as the need for NIV. HFNC is, therefore, an effective, tolerable, and safe alternative to noninvasive intubation for patients with DNI with hypoxemic respiratory failure.

• Small sample (< 100)
• Risk of bias (no random assignment)
• Retrospective analysis of data was from a single institution. The mixture of diagnoses allowed for only small samples for generalization. Participants with severe acidosis and hypercapnia were excluded. The timing of baseline arterial blood gases varied prior to ICU admission or transfer and was relative to HFNC initiation. Participants all were managed in the ICU, so no comparison of management on the ward was available. Sample was notably very ill as evidenced by overall hospital mortality and may, therefore, have some influence on the generizability of the data.

HFNC has the ability to generate a low level of positive airway pressure with the mouth closed and sufficiently provides oxygenation for patients with hypoxemic respiratory failure.