High Flow Oxygen

To understand the prevalence of humidified high-flow nasal oxygen (HHFNOx) use at the authors’ institution, and to investigate characteristics related to HHFNOx initiation, discontinuation, and consistency with patient goals of care

In this retrospective study, the characteristics of HHFNOx—Optiflow™—use, including malignancy diagnosis, underlying cardiopulmonary disease, reason for HHFNOx initiation (hypoxia/dyspnea), duration of HHFNOx therapy, reported HHFNOx impact, reason for discontinuation (stable, declined, or expired), and patient outcome were analyzed (discharge/code status). Patients who used the HHFNOx device—Optiflow™—since 2008 were identified via the institution’s database search. Of the 353 patients identified, 183 were randomly selected for analysis. Objective (documented patient comfort and SaO2 on the device, and “step up” and “step down” grading to other oxygen support devices) and subjective (recorded patient and clinician impressions of tolerability) outcomes, oxygen saturation (SaO2), and oxygen interventions pre and post HHFNOx were examined.

• N = 183   
• MEDIAN AGE = 67 years
• AGE RANGE = 20–95 years
• MALES: Not specified, FEMALES: Not specified
• CURRENT TREATMENT: Not applicable
• KEY DISEASE CHARACTERISTICS: The population includes the following malignancies: hematologic (29%), lung (17%), gastrointestinal (15%), sarcoma (6%), head/neck/CNS tumors (5%), breast (4%), and other tumors (24%)
• OTHER KEY SAMPLE CHARACTERISTICS: HHFNOx was used in the intensive care unit (ICU) in 72% of cases and otherwise in the hospital ward alone or in the post-ICU stay.

• SITE: Single site   
• SETTING TYPE: Inpatient    
• LOCATION: Memorial Sloan Kettering Cancer Center in New York, NY

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

• Retrospective

• Oxygen saturation (SaO2) percentile range subsets (e.g., 60s, 70s, and so forth)
• Recorded patient and clinician impressions of tolerability to HHFNOx
• Documented SaO2 
• “Step up” and “step down” grading to other oxygen support devices
• Documented reasons for initiation or discontinuation of HHFNOx
• Documented outcome (discharge, vitals, code status)

• Forty-one percent improved while on HHFNOx, 44% remained stable, and 15% declined.
• Subjective reports by the patients were well-documented as well as tolerated with seldom complaints.
• The majority (66%) of patients appeared to benefit indirectly from HHFNOx as it acted as a “step up” or “step down” device between more intensive or invasive forms of ventilation and lower oxygenation.
• Recorded pre-and post-HHFNOx saturations were maintained within the normal range of 90%–100% SaO2.
• At time of data abstraction, 44% of patients were alive, 33% died at the institution, and 22% died outside the institution. 
• Median time of HHFNOx was three days (range = 1–27 days).
• The majority of patients with DNR status pre (12%) or post (43%) HHFNOx died at the institution (78%).
• Full-code status patients (82%) were discharged either to home (82%) or to an outside facility (11%).

HHFNOx was effective in the stabilization or improvement of oxygen saturation in the majority of treated patients. Though HHFNOx devices are expensive, they are a more cost-effective oxygen delivery alternative because they may help prevent escalation to more invasive oxygenation (e.g., mechanical ventilation).

• Risk of bias (no control group)
• Risk of bias (no random assignment)
• Risk of bias (sample characteristics)
• Key sample group differences that could influence results
• The sample included patients with differing goals of care (e.g., curative versus palliative) which would have affected interpretation of effectiveness of the intervention. Distinction between treatment intents are, therefore, not clearly defined because of the limitation of the retrospective design of the study. No data recorded on oxygen support devices after discharge limits the understanding of the role of HHFNOx in discharge planning. Reporting and scoring of dyspnea were not available and, therefore, limits the ability to compare with other studies examining dyspnea and other symptoms. No measurement or report of symptoms of dyspnea exist.

HHFNOx seems well tolerated by various malignancies and clinical trajectories and generally safe. The study claims to be the only clinical description of HHFNOx device used exclusively in the cancer population. Users were able to benefit from high flow of oxygen delivery while still being able to eat and drink (as opposed to oxygen delivery via face mask or face tent).

To examine changes in dyspnea through a randomized trial of high-flow oxygen (HFO) and bilevel positive airway pressure (BiPAP) in patients with cancer

Patients were randomized using a computer-generated randomization scheme in a 1:1 ratio to receive either two hours of HFO followed by a washout period and then two hours of BiPAP or two hours of BiPAP followed by a washout period followed by two hours of HFO. Data on dyspnea were collected every 10 minutes after the first intervention for as much as one hour. Patients participated in the second intervention if their dyspnea level was ≥ baseline dyspnea level minus one or  ≥ 3/10 after one hour.

• N = 30
• AVERAGE AGE = 61 years (range = 29–79 years)
• MALES: 47% (n = 14), FEMALES: 53% (n = 16)
• KEY DISEASE CHARACTERISTICS: Lung 43% (n = 13), head and neck 3% (n = 1), genitourinary 3% (n = 1), gastrointestinal 10% (n = 3), breast 17% (n = 5), other 23% (n = 7); cancer stage metastatic 87% (n = 26) and local 13% (n = 4); causes of dyspnea were pulmonary parenchymal lesions 70% (n = 21), pleural effusions 50% (n = 15), lymphangitic carcinomatosis 7% (n = 2), and other noncancer causes; not already on home supplemental oxygen 70% (n = 21); majority of participants (93%) on supplemental oxygen at the time of enrollment with a median of 3 L per minute and an average oxygen saturation of 95% (SD = 4%). 
• OTHER KEY SAMPLE CHARACTERISTICS: Inclusion criteria: average intensity of dyspnea at rest over the past week ≥ 3/10 on a numeric rating scale despite the use of supplemental oxygen, life expectancy of more than one week, and English-speaking; exclusion criteria: hemodynamic instability, acute respiratory distress with impending intubation, delirium (Memorial Delirium Assessment Scale > 13/30), Glasgow Coma Scale < 8/15, contraindications to BiPAP, or noncancer-related dyspnea with supplemental home oxygen before hospitalization

• SITE: Single site  
• SETTING TYPE: Inpatient  
• LOCATION: MD Anderson Cancer Center

• PHASE OF CARE: End-of-life care
• APPLICATIONS: Palliative care

Randomized, open-label study with a parallel design and an optional second intervention

• Numeric Rating Scale (NRS), a measurement of dyspnea on a 0–10 scale
• Modified Borg Scale (MBS), an assessment scale for dyspnea
• Global symptom evaluation
• Memorial Delirium Assessment Scale (MDAS)
• Glasgow Coma Scale (GCS)

HFO and BiPAP were found to alleviate dyspnea and improve physiologic parameters. The results of this study justify larger randomized, controlled studies to validate these findings. The authors of this study proposed that HFO and BiPAP be examined separately.

• Small sample (< 100)
• Risk of bias (no control group)
• Risk of bias (no blinding)
• Other limitations/explanation: Multiple statistical comparisons were conducted. Baseline arterial blood gas and a measurement of oxygen saturation while on room air were not conducted.

Dyspnea is one of the most common symptoms for patients with cancer. This study shows that HFO and BiPAP may alleviate dyspnea. These devices are safe for patients to use. Larger randomized, controlled clinical trials are needed to confirm the findings of this study.

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.