Nasal High Flow Use in COPD Patients with Hypercapnic Respiratory Failure: Treatment Algorithm & Review of the Literature.

Nasal high flow (NHF) therapy has recently gained attention as a new respiratory support system and is increasingly being utilized in every day clinical practice. Recent studies suggest that it may also be effective in patients with hypercapnia and suggest NHF as a possible alternative for patients who cannot tolerate standard noninvasive ventilation. The present review discusses the mechanisms of action that make NHF potentially suitable for chronic obstructive pulmonary disease (COPD) patients and evaluates the current evidence of NHF use for treatment of stable hypercapnic COPD patients as well as acute hypercapnic exacerbation of COPD. An algorithm is also proposed for the clinical application of NHF in patients with acute hypercapnic exacerbation of COPD, based on current literature.

Community Knowledge and Awareness of Stroke in New Zealand.

INTRODUCTION: Community knowledge and stroke awareness is crucial for primary prevention of stroke and timely access to stroke treatments including acute reperfusion therapies. We conducted a national telephone survey to quantify the level of community stroke awareness. METHODS: A random sample of 400 adults in New Zealand (NZ), stratified by the 4 main ethnic groups, was surveyed. Eligible participants answered stroke awareness questions using both unprompted (open-ended) and prompted questions (using a list). Proportional odds logistic regression models were used to identify factors associated with stroke awareness. RESULTS: Only 1.5% of participants named stroke as a major cause of death. The stroke signs and symptoms most frequently identified from a list were sudden speech difficulty (94%) and sudden 1-sided weakness (92%). Without prompting, 78% of participants correctly identified at least 1 risk factor, 62% identified at least 2, and 35% identified 3 or more. When prompted with the list, scores increased 10-fold compared with unprompted responses. Ethnic disparities were observed, with Pacific peoples having the lowest level of awareness among the 4 ethnic groups. Higher education level, higher income, and personal experience of stroke were predictive of greater awareness (P ≤ .05). CONCLUSIONS: Stroke was not recognized as a major cause of death. Although identification of stroke risk factors was high with prompting, awareness was low without prompting, particularly among those with lower education and income. Nationwide, culturally tailored public awareness campaigns are necessary to improve knowledge of stroke risk factors, recognition of stroke in the community and appropriate actions to take in cases of suspected stroke.

Predictive value of the New Zealand Early Warning Score for early mortality in low-acuity patients discharged at scene by paramedics: an observational study.

OBJECTIVES: The utility of New Zealand Early Warning Score (NZEWS) for prediction of adversity in low-acuity patients discharged at scene by paramedics has not been investigated. The objective of this study was to evaluate the association between the NZEWS risk-assessment tool and adverse outcomes of early mortality or ambulance reattendance within 48 hours in low-acuity, prehospital patients not transported by ambulance. DESIGN: A retrospective cohort study. SETTING: Prehospital emergency medical service provided by St John New Zealand over a 2-year period (1 July 2016 through 30 June 2018). PARTICIPANTS: 83 171 low-acuity, adult patients who were attended by an ambulance and discharged at scene. Of these, 41 406 had sufficient recorded data to calculate an NZEWS. PRIMARY AND SECONDARY OUTCOMES AND MEASURES: Binary logistic regression modelling was used to investigate the association between the NZEWS and adverse outcomes of reattendance within 48 hours, mortality within 2 days, mortality within 7 days and mortality within 30 days. RESULTS: An NZEWS greater than 0 was significantly associated with all adverse outcomes studied (p<0.01), compared with the reference group (NZEWS=0). There was a startling correlation between 2-day, 7-day and 30-day mortality and higher early warning scores; the odds of 2-day mortality in patients with an early warning score>10 was 70 times that of those scoring 0 (adjusted OR 70.64, 95% CI: 30.73 to 162.36). The best predictability for adverse outcome was observed for 2-day and 7-day mortality, with moderate area under the receiver operating characteristic curve scores of 0.78 (95% CI: 0.73 to 0.82) and 0.74 (95% CI: 0.71 to 0.77), respectively. CONCLUSIONS: Adverse outcomes in low-acuity non-transported patients show a significant association with risk prediction by the NZEWS. There was a very high association between large early warning scores and 2-day mortality in this patient group. These findings suggest that NZEWS has significant utility for decision support and improving safety when determining the appropriateness of discharging low-acuity patients at the scene.

A prospective five-year cohort study of undiagnosed sleep apnea in patients undergoing coronary artery bypass graft surgery.

BACKGROUND: We aimed to study prospectively the nature and effect of sleep apnea-hypopnea syndrome (SAHS) in patients undergoing coronary artery bypass graft (CABG) surgery over five years of follow-up. METHODS: Patients undergoing CABG surgery (N.=145) were assessed longitudinally (baseline, 1 year, and 5 years post-surgery) using the 'STOP-BANG' screen of sleep apnea risk. Additionally, all patients had a preoperative multiple-channel sleep-study, providing acceptable data for an obstructive and central apnea, and desaturation index in 97 patients. RESULTS: Preoperatively, over half (63%) of patients obtained an apnea-hypopnea index score (combining apnea types) in the moderate-severe range for SAHS, and STOP-BANG threshold score (>3/8) was reached by most (95%) patients. Despite some improvement in 'STOP symptoms' at 1-year follow-up, most patients (98%) remained at risk of SAHS at 5 years post-surgery. There was an underlying and chronic relationship between STOP-BANG score and cardiac symptoms at both baseline and 5-year follow-up. Additionally, SAHS variables were associated with greater incidence of acute postoperative events, and generally with increased length of stay on the intensive care unit. CONCLUSIONS: We confirm that SAHS is common in CABG-surgery patients, presenting additional clinical challenges and cost implications. The underlying pathophysiology is complex, including upper airway obstruction and cardiorespiratory changes of heart failure. In patients presenting for CABG-surgery, we show chronic susceptibility to SAHS, likely associated with traditional risk factors e.g. obesity but perhaps also with gradual decline in heart function itself. Superimposed on this, there is potential for exacerbated risk of morbidity at the time of CABG surgery itself.

Nasal high-flow oxygen versus noninvasive ventilation in acute exacerbation of COPD: protocol for a randomised noninferiority clinical trial.

BACKGROUND: Noninvasive ventilation (NIV) is considered as the first-line treatment for acute exacerbation of COPD (AECOPD) complicated by respiratory acidosis. Recent studies demonstrate a role of nasal high-flow oxygen (NHF) in AECOPD as an alternative treatment in patients intolerant to NIV or with contraindications to it. AIM: The study aimed to evaluate whether NHF respiratory support is noninferior compared to NIV in respect to treatment failure, defined as need for intubation or change to alternative treatment group, in patients with AECOPD and mild-to-moderate acute or acute-on-chronic hypercapnic respiratory failure. METHODS: We designed a multicentre, prospective, randomised trial on patients with AECOPD, who have pH<7.35 but >7.25 and P aCO2  >45 mmHg, in whom NIV is indicated as a first-line treatment. According to power analysis, 498 participants will be required for establishing noninferiority of NHF compared to NIV. Patients will be randomly assigned to receive NIV or NHF. Treatment will be adjusted to maintain S pO2 between 88%-92% for both groups. Arterial blood gases, respiratory variables, comfort, dyspnoea score and any pulmonary or extrapulmonary complications will be assessed at baseline, before treatment initiation, and at 1, 2, 4, 6, 12, 24, 48 h, then once daily from day 3 to patient discharge, intubation or death. CONCLUSION: Given the increasing number of studies demonstrating the physiological effects of NHF in COPD patients, we hypothesise that NHF respiratory support will be noninferior to NIV in patients with AECOPD and mild-to-moderate acute or acute on chronic hypercapnic respiratory failure.

Nasal High Flow Versus Conventional Oxygen Therapy for Postoperative Cardiothoracic Surgery Patients.

BACKGROUND: Reintubation and complications in postoperative cardiothoracic patients remain high despite medical advancements. A 2-year retrospective, observational study was conducted in postextubated cardiothoracic patients to assess the effectiveness of the current standard-conventional oxygen therapy (COT) compared with a nasal high flow (NHF) therapy. OBJECTIVES: The objective of this study was to understand whether NHF therapy would reduce the need for reintubation and improve clinical outcomes after surgery. METHOD: All consecutive postoperative patients who had same-day elective cardiothoracic surgery in a tertiary hospital were included. The 2013 data were from patients' charts who received COT, and the 2014 data were from patients' charts after the implementation of NHF therapy post extubation as a standard of care. RESULTS: A total of 400 patient charts were analyzed: 221 and 179 patients in the COT and NHF, respectively. No significant difference was seen in the frequency of reintubation (P = .48). Despite both cohorts having the same length of stay (P = .10), patients treated with NHF required less time on supplemental oxygen (P = .001). Day 1 postoperative chest x-ray results did not show any significant differences between groups, whereas day 2 x-rays showed worsening results in the COT cohort (P < .001). Furthermore, the incidence of ventilator-associated pneumonia (VAP) post extubation was significantly higher in the COT cohort, with zero VAP episodes reported in the NHF cohort (P = .02). DISCUSSION: Although this study was not able to demonstrate the reduction in reintubation between groups, the use of NHF compared with COT seems to reduce the time spent on oxygen therapy and decrease the rate of VAP. Further evidence including randomized controlled trials is required to determine the impact of NHF on reintubation and complications in postoperative cardiothoracic surgery.