Treatment of presumed acute cardiogenic pulmonary oedema in an ambulance system by nurses using Boussignac continuous positive airway pressure

Is disposable continuous positive airway pressure system effective for the management of acute hypercapnic respiratory failure?

AIM

This study aimed to investigate the effectiveness of disposable continuous positive airway pressure (DCPAP) system in decreasing the partial pressure of carbon dioxide (PaCO2) levels in patients with acute hypercapnic respiratory failure (AHRF).

MATERIAL AND METHODS

This retrospective observational study included patients treated in the emergency department (ED) with respiratory distress and PaCO2 > 45 mmHg. Patients were divided into two groups (DCPAP and non-DCPAP), depending on the treatment received to treat AHRF. The difference between the baseline PaCO2 levels in the first blood gas obtained from patients at the time of admission and the follow-up blood gas after treatment. Then, the calculated PaCO2 decrease was divided by the time elapsed to obtain the rate of decrease in PaCO2 levels in mmHg/min. The statistical analyses were performed using SPSS version 18.0 software. A p value of < 0.05 was considered statistically significant.

RESULTS

A total of 61 patients were included in the study, 31 patients in the DCPAP group and 30 patients in the non-DCPAP group. The mean age of the patients was 74.03 ± 10.04, and the male/female was 23/38. The study demonstrated a statistically significant difference between the DCPAP and non-DCPAP groups in terms of PaCO2 decreasing rate, and it was found to be twice higher in the DCPAP group (0.11 ± 0.07 mmHg/min) than in the non-DCPAP group (0.05 ± 0.06 mmHg/min).

CONCLUSION

The study demonstrated that the treatment of AHRF patients with a DCPAP provides a faster decrease in PaCO2 levels in hypercapnic patients compared to standard medical therapy alone.

Non-Invasive Ventilation in the Prehospital Emergency Setting: A Systematic Review and Meta-Analysis

INTRODUCTION

Noninvasive ventilation is a well-established treatment for acute respiratory failure, being increasingly applied in the prehospital setting. This systematic review and meta-analysis aims to investigate whether early prehospital initiation of noninvasive ventilation reduces mortality compared to standard oxygen therapy.

METHODS

We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to February 7^th, 2022, for studies comparing prehospital noninvasive ventilation performed by emergency medical services versus standard oxygen therapy in patients with acute respiratory failure. The primary outcome was mortality at the longest follow-up available.

RESULTS

We included ten randomized studies and two quasi-randomized studies for a total of 1485 patients. Prehospital treatment with noninvasive ventilation compared with standard oxygen therapy did not significantly reduce mortality at the longest follow-up available (107/810 [13%] vs 114/772 [15%]; RR = 0.89; 95% CI, 0.70-1.13; P = 0.34; I²=24%). The endotracheal intubation rate was reduced when receiving prehospital noninvasive ventilation (38/776 [4.9%] vs 81/743 [11%]; RR = 0.44; 95% CI, 0.31-0.63; P < 0.001; I²=0%; number needed to treat 17). The intensive care admission rate (114/532 [21%] vs 129/507 [25%]; RR = 0.85; 95% CI, 0.69-1.04; P = 0.11; I²=0%) and length of hospital stay (mean difference=-1.29 days; 95% CI, -3.35-0.77; P = 0.21; I²=82%) were similar between groups.

CONCLUSIONS

Adults with acute respiratory failure treated in the prehospital setting with noninvasive ventilation had a lower risk of intubation than those managed with standard oxygen therapy, with similar risk of death, intensive care admission, and length of hospital stay.

REVIEW REGISTRATION

PROSPERO CRD42021284947.

Implementation of extended possibility for CPAP in general wards: A quality inter-professional intervention project

INTRODUCTION AND OBJECTIVES

In a Danish Hospital, 70% of all activations of the rapid response team (RRT) in 2016 were related to adult patients with respiratory insufficiency. The most frequent RRT intervention was continuous positive airway pressure (CPAP). However, there was no systematic follow-up and patients could not receive CPAP outside of daytime hours. The aim of the study was to implement and evaluate a CPAP intervention to improve healthcare.

PATIENTS AND METHODS

A quality inter-professional intervention project was conducted. The interventions consisted of: theoretical and practical education in respiratory insufficiency (including use of CPAP) of nurses and physicians from the general wards, physiotherapists and staff from the RRT; development of an instruction leaflet and video; an update of the existing guidelines. The interventions entailed patients being able to receive CPAP a minimum of 3 times for 5-10min within a 24-h period. All RRT activations were registered and compared in a before-after evaluation of the intervention. Additionally, all staff groups received an electronic questionnaire after implementation.

RESULTS

After implementation, respiratory insufficiency was still the highest primary course for RRT activation. The use of CPAP increased, and the number of patients needing a transfer to the intensive care unit decreased. The response rate for the questionnaire was 44% (203 out of 465), and staff experienced new competences, improved inter-professional cooperation and improved healthcare. However, a substantial number of staff did not feel sufficiently trained or that the intervention was well-implemented.

CONCLUSION

The intervention entailed new competences for the staff, as well as improved system performance, inter-professional cooperation and healthcare. However, there is a need for continuous focus on the intervention.

Pre-hospital non-invasive ventilation for acute respiratory failure: a systematic review and cost-effectiveness evaluation

BACKGROUND

Non-invasive ventilation (NIV), in the form of continuous positive airway pressure (CPAP) or bilevel inspiratory positive airway pressure (BiPAP), is used in hospital to treat patients with acute respiratory failure. Pre-hospital NIV may be more effective than in-hospital NIV but requires additional ambulance service resources.

OBJECTIVES

We aimed to determine the clinical effectiveness and cost-effectiveness of pre-hospital NIV compared with usual care for adults presenting to the emergency services with acute respiratory failure and to identify priorities for future research.

DATA SOURCES

Fourteen electronic databases and research registers (including MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, and Cumulative Index to Nursing and Allied Health Literature) were searched from inception to August 2013, supplemented by hand-searching reference lists and contacting experts in the field.

REVIEW METHODS

We included all randomised or quasi-randomised controlled trials of pre-hospital NIV in patients with acute respiratory failure. Methodological quality was assessed according to established criteria. An aggregate data network meta-analysis (NMA) of mortality and intubation was used to jointly estimate intervention effects relative to usual care. A NMA, using individual patient-level data (IPD) and aggregate data where IPD were not available, was carried out to assess whether or not covariates were treatment effect modifiers. A de novo economic model was developed to explore the costs and health outcomes when pre-hospital NIV (specifically CPAP provided by paramedics) and standard care (in-hospital NIV) were applied to a hypothetical cohort of patients with acute respiratory failure.

RESULTS

The literature searches identified 2284 citations. Of the 10 studies that met the inclusion criteria, eight were randomised controlled trials and two were quasi-randomised trials (six CPAP; four BiPAP; sample sizes 23-207 participants). IPD were available from seven trials (650 patients). The aggregate data NMA suggested that CPAP was the most effective treatment in terms of mortality (probability = 0.989) and intubation rate (probability = 0.639), and reduced both mortality [odds ratio (OR) 0.41, 95% credible interval (CrI) 0.20 to 0.77] and intubation rate (OR 0.32, 95% CrI 0.17 to 0.62) compared with standard care. The effect of BiPAP on mortality (OR 1.94, 95% CrI 0.65 to 6.14) and intubation rate (OR 0.40, 95% CrI 0.14 to 1.16) compared with standard care was uncertain. The combined IPD and aggregate data NMA suggested that sex was a statistically significant treatment effect modifier for mortality. The economic analysis showed that pre-hospital CPAP was more effective and more expensive than standard care, with an incremental cost-effectiveness ratio of £20,514 per quality-adjusted life-year (QALY) and a 49.5% probability of being cost-effective at the £20,000-per-QALY threshold. Variation in the incidence of eligible patients had a marked impact on cost-effectiveness and the expected value of sample information for a future randomised trial.

LIMITATIONS

The meta-analysis lacked power to detect potentially important differences in outcome (particularly for BiPAP), the intervention was not always compared with the best alternative care (in-hospital NIV) in the primary studies and findings may not be generalisable.

CONCLUSIONS

Pre-hospital CPAP can reduce mortality and intubation rates, but cost-effectiveness is uncertain and the value of further randomised evaluation depends on the incidence of suitable patients. A feasibility study is required to determine if a large pragmatic trial of clinical effectiveness and cost-effectiveness is appropriate.

STUDY REGISTRATION

The study is registered as PROSPERO CRD42012002933.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Paramedic identification of acute pulmonary edema in a metropolitan ambulance service

INTRODUCTION

Acute pulmonary edema (APE) is a common cause of acute dyspnea. In the prehospital setting, it is often difficult to differentiate APE from other causes of shortness of breath (SOB). Radiography and echocardiography aid in the identification of APE but are often not available. There is little information on how accurately ambulance paramedics identify patients with APE. Objectives. This study aimed to 1) describe the prehospital clinical presentation and management of patients with a clinical diagnosis of APE and 2) compare the accuracy of coding of APE by paramedics against the emergency department (ED) medical discharge diagnosis.

METHODS

This study included a retrospective cohort of all patients who had episodes identified as APE by ambulance paramedics and were transported to a metropolitan hospital ED in 2011. Two databases were used: an ambulance database and the Emergency Department Information System. The ED medical discharge diagnosis (using International Statistical Classification of Diseases and Related Problems, 10th Revision, Australian Modification [ICD-10-AM] codes) was used as the comparator with paramedic-assigned problem codes for APE. The outcomes for the study were the positive predictive value, i.e., the proportion of patients identified as having APE in the ambulance database who also had an ED discharge diagnosis of APE, and the sensitivity of paramedic identification of APE, i.e., the proportion of patients with an ED discharge diagnosis of APE that were correctly identified as APE by the ambulance paramedics.

RESULTS

Four hundred ninety-five patients were transported to an ED with APE identified by the paramedics as the primary problem code. Shortness of breath, crepitations, high systolic blood pressure, and chest pain were the most common presenting signs and symptoms. Pink frothy sputum was rare (3% of patient episodes of APE). One hundred eighty-six patients received an ED discharge diagnosis of APE, i.e., a positive predictive value of 41%. Of 631 ED presentations with APE, paramedics identified 186, i.e., a sensitivity of 29%.

CONCLUSION

Acute pulmonary edema is difficult to identify in the prehospital setting because of the variability in the signs and symptoms associated with this condition. Improved identification of APE is essential in the initiation of appropriate and timely care. Ambulance paramedics need to be aware of such variability when considering patients who may be suffering from APE. Key words: pulmonary edema; acute pulmonary edema; emergency medical services; ambulance; paramedics.

Prehospital continuous positive airway pressure for acute respiratory failure: a systematic review and meta-analysis

INTRODUCTION

Acute respiratory failure (ARF) is a common problem encountered by emergency medical services and is associated with significant morbidity, mortality, and health care costs. Continuous positive airway pressure (CPAP) is an integral part of the hospital treatment of acute ARF, predominantly because of congestive heart failure. Intuitively, better patient outcomes may be achieved when CPAP is applied early in the prehospital setting, but there are few outcome studies to validate its use in this setting.

OBJECTIVE

This systematic review and meta-analysis aimed to examine the effectiveness of CPAP in the prehospital setting for patients with ARF.

METHODS

A literature review of bibliographic databases and secondary sources was conducted and potential papers were assessed by two independent reviewers. Included studies were those that compared CPAP therapy (and usual care) with no CPAP for ARF in the prehospital setting. Studies of other methods of noninvasive ventilation were not included. Methodologic quality was assessed using guidelines from the Cochrane Collaboration. Outcomes included the number of intubations, mortality, physiologic parameters, and dyspnea score. Forrest plots were constructed to estimate the pooled effect of CPAP on outcomes.

RESULTS

Five studies (1,002 patients) met the selection criteria--three randomized controlled trials (RCTs), a nonrandomized comparative study, and a retrospective comparative study using chart review. Forty-seven percent of the patients were allocated to the CPAP group. Baseline characteristics were similar between groups. The pooled estimates demonstrated significantly fewer intubations (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.19-0.51) and lower mortality (OR 0.41; 95% CI 0.19-0.87) in the CPAP group.

CONCLUSION

The studies included in this review showed a reduction in the number of intubations and mortality in patients with ARF who received CPAP in the prehospital setting. The results may not be applicable to other health care contexts because of the inherent differences in the organization and staffing of the EMS systems. Information from large RCTs on the efficacy of CPAP initiated early in the prehospital setting is critical to establishing the evidence base underpinning this therapy before ambulance services incorporate CPAP as routine clinical practice.

When Pressure is Positive: A Literature Review of the Prehospital Use of Continuous Positive Airway Pressure

Background

Heart failure poses a significant burden of disease, resulting in 2,658 Australian deaths in 2008, and listed as an associated cause of death in a further 14,466 cases. Common in the hospital setting, continuous positive airway pressure (CPAP) therapy is a non-invasive ventilation technique used to prevent airway collapse and manage acute pulmonary edema (APO). In the hospital setting, CPAP has been known to decrease the need for endotracheal intubation in patients with APO. Therefore the objective of this literature review was to identify the effectiveness of CPAP therapy in the prehospital environment.

Methods

A review of selected electronic medical databases (Cochrane, Medline, EMBASE, and CINAHL) was conducted from their commencement date through the end of May 2012. Inclusion criterion was any study type reporting the use of CPAP therapy in the prehospital environment, specifically in the treatment of heart failure and acute pulmonary edema. References of relevant articles were also reviewed.

Results

The literature search located 1,253 articles, 12 of which met the inclusion criteria. The majority of studies found that the use of CPAP therapy in the prehospital environment is associated with reduced short-term mortality as well as reduced rates of endotracheal intubation. Continuous positive airway pressure therapy was also shown to improve patient vital signs during prehospital transport and reduce myocardial damage.

Discussion

The studies conducted of prehospital use of CPAP to manage APO have all demonstrated improvement in patient outcomes in the short term.

Conclusion

Available evidence suggests that the use of CPAP therapy in the prehospital environment may be beneficial to patients with acute pulmonary edema as it can potentially decrease the need for endotracheal intubation, improve vital signs during transport to hospital, and improve short-term mortality.

WilliamsB, BoyleM, RobertsonN, GiddingsC. When pressure is positive: a literature review of the prehospital use of continuous positive airway pressure. Prehosp Disaster Med.2013;28(1):1-10.