Noninvasive ventilation in acute cardiogenic pulmonary edema. Curr Opin Crit Care. 2008;14:531-535. [PMID: 18787445 DOI: 10.1097/mcc.0b013e32830c4862]

Helmet continuous positive airway pressure vs. high flow nasal cannula oxygen in acute cardiogenic pulmonary oedema: a randomized controlled trial

AIMS 

Non-invasive ventilation represents an established treatment for acute cardiogenic pulmonary oedema (ACPO) although no data regarding the best ventilatory strategy are available. We aimed to compare the effectiveness of helmet CPAP (hCPAP) and high flow nasal cannula (HFNC) in the early treatment of ACPO.

METHODS AND RESULTS 

Single-centre randomized controlled trial of patients admitted to the emergency department due to ACPO with hypoxemia and dyspnoea on face mask oxygen therapy. Patients were randomly assigned with a 1:1 ratio to receive hCPAP or HFNC and FiO2 set to achieve an arterial oxygen saturation >94%. The primary outcome was a reduction in respiratory rate; secondary outcomes included changes in heart rate, PaO2/FiO2 ratio, Heart rate, Acidosis, Consciousness, Oxygenation, and Respiratory rate (HACOR) score, Dyspnoea Scale, and intubation rate. Data were collected before hCPAP/HFNC placement and after 1 h of treatment. Amongst 188 patients randomized, hCPAP was more effective than HFNC in reducing respiratory rate [-12 (95% CI; 11-13) vs. -9 (95% CI; 8-10), P < 0.001] and was associated with greater heart rate reduction [-20 (95% CI; 17-23) vs. -15 (95% CI; 12-18), P = 0.042], P/F ratio improvement [+149 (95% CI; 135-163) vs. +120 (95% CI; 107-132), P = 0.003] as well as in HACOR scores [6 (0-12) vs. 4 (2-9), P < 0.001] and Dyspnoea Scale [4 (1-7) vs. 3.5 (1-6), P = 0.003]. No differences in intubation rate were noted (P = 0.321).

CONCLUSION 

Amongst patients with ACPO, hCPAP resulted in a greater short-term improvement in respiratory and hemodynamic parameters as compared with HFNC.

TRIAL REGISTRATION 

Clinical trial submission: NMRR-17-1839-36966 (IIR). Registry name: Medical Research and Ethics Committee of Malaysia Ministry of Health. Clinicaltrials.gov identifier: NCT04005092. URL registry: https://clinicaltrials.gov/ct2/show/NCT04005092.

Noninvasive Mechanical Ventilation in Acute Ventilatory Failure: Rationale and Current Applications

Noninvasive ventilation plays a pivotal role in acute ventilator failure and has been shown, in certain disease processes such as acute exacerbation of chronic obstructive pulmonary disease, to prevent and shorten the duration of invasive mechanical ventilation, reducing the risks and complications associated with it. The application of noninvasive ventilation is relatively simple and well tolerated by patients and in the right setting can change the course of their illness.

Blunt thoracic trauma: recent advances and outstanding questions

PURPOSE OF REVIEW

The treatment of blunt thoracic injuries is complex and evolving. The aim of this review is to focus on what is new with ventilation for blunt chest trauma as well as an update on the current management strategies for blunt aortic injury and rib fractures.

RECENT FINDINGS

Early use of noninvasive ventilation appears to be well tolerated in select hemodynamically stable blunt trauma patients. For those patients requiring intubation, airway pressure release ventilation is an excellent mode to decrease the risk of posttraumatic acute lung injury. Endovascular repair of blunt thoracic aortic injuries provides benefit over open repair and, if possible, delayed repair confers a mortality advantage. Despite its increasing use, there continue to be conflicting results about the role of surgical rib fixation for the treatment of flail chest.

SUMMARY

Blunt thoracic injuries are commonly treated in the ICU and a solid knowledge of mechanical ventilation strategies (both noninvasive and invasive) is essential. Blunt thoracic aortic injuries require early diagnosis and aggressive blood pressure management. Not all such injuries need operative repair but those that do benefit from an endovascular approach. The management of flail chest includes early aggressive multimodal analgesia, adequate oxygen, and ventilatory support. Surgical rib fixation should be considered in select patients.

Intra-aortic balloon pump combined with mechanical ventilation for treating patients aged > 60 years in cardiogenic shock: Retrospective analysis

Objective

To examine if mechanical ventilation with positive end-expiratory pressure (PEEP) combined with intra-aortic balloon pump (IABP) provided a better outcome than IABP alone for the treatment of cardiogenic shock after acute myocardial infarction in patients aged > 60 years.

Methods

This was a retrospective analysis of data from patients in cardiogenic shock, refractory to pharmacological therapy and treated at a geriatric coronary care unit.

Results

Sixty-two patients were eligible for study inclusion: 33 received IABP alone; 29 received IABP combined with mechanical ventilation. Patients in the IABP + mechanical ventilation group had lower mean arterial blood pressure (BP), systolic BP and partial pressure of oxygen compared with the IABP group, indicating worse cardiac and pulmonary function. In addition, higher rates of pulmonary infection and renal insufficiency were observed in the IABP + mechanical ventilation group than in the IABP group. A statistically significant improvement of left ventricular function before and after treatment was observed in the IABP + mechanical ventilation group, but not in the IABP group. Pulmonary infection and renal insufficiency were risk factors for all-cause in-hospital mortality; successful revascularization was a negative risk factor. There was no between-group difference in survival.

Conclusion

Mechanical ventilation with an appropriate level of PEEP appears to enhance the beneficial effects of IABP on left ventricular function for patients in cardiogenic shock.

Positive airway pressure therapy for heart failure

Heart failure (HF) is a life-threatening disease and is a growing public health concern. Despite recent advances in pharmacological management for HF, the morbidity and mortality from HF remain high. Therefore, non-pharmacological approaches for HF are being developed. However, most non-pharmacological approaches are invasive, have limited indication and are considered only for advanced HF. Accordingly, the development of less invasive, non-pharmacological approaches that improve outcomes for patients with HF is important. One such approach may include positive airway pressure (PAP) therapy. In this review, the role of PAP therapy applied through mask interfaces in the wide spectrum of HF care is discussed.

State of the evidence: mechanical ventilation with PEEP in patients with cardiogenic shock

The need to provide invasive mechanical ventilatory support to patients with myocardial infarction and acute left heart failure is common. Despite the large number of patients requiring mechanical ventilation in this setting, there are remarkably few data addressing the ideal mode of respiratory support in such patients. Although there is near universal acceptance regarding the use of non-invasive positive pressure ventilation in patients with acute pulmonary oedema, there is more concern with invasive positive pressure ventilation owing to its more significant haemodynamic impact. Positive end-expiratory pressure (PEEP) is almost universally applied in mechanically ventilated patients due to benefits in gas exchange, recruitment of alveolar units, counterbalance of hydrostatic forces leading to pulmonary oedema and maintenance of airway patency. The limited available clinical data suggest that a moderate level of PEEP is safe to use in severe left ventricular (LV) dysfunction and cardiogenic shock, and may provide haemodynamic benefits as well in LV failure which exhibits afterload-sensitive physiology.

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.

Prevalence, characteristics, and outcomes of patients presenting with cardiogenic unilateral pulmonary edema

BACKGROUND

Cardiogenic unilateral pulmonary edema (UPE) is a rare entity, frequently leading to initial misdiagnosis. We sought to assess the prevalence of UPE and to determine its impact on prognosis compared with bilateral pulmonary edema.

METHODS AND RESULTS

We studied the characteristics and outcomes of patients admitted to our institution for cardiogenic pulmonary edema during an 8-year period. The study population included 869 consecutive patients. The prevalence of UPE was 2.1%: 16 right-sided UPE (89%) and 2 left-sided UPE (11%). In patients with UPE, blood pressure was significantly lower (P≤0.01), whereas noninvasive or invasive ventilation and catecholamines were used more frequently (P=0.0004 and P<0.0001, respectively). The prevalence of severe mitral regurgitation in patients with bilateral pulmonary edema and UPE was 6% and 100%, respectively (P<0.0001). In patients with UPE, use of antibiotic therapy and delay in treatment were significantly higher (P<0.0001 and P=0.003, respectively). In-hospital mortality was 9%: 39% for UPE versus 8% for bilateral pulmonary edema (odds ratio, 6.9; 95% confidence interval, 2.6 to 18; P<0.001). In multivariate analysis, unilateral location of pulmonary edema was independently related to death whatever the model used (adjusted odds ratio, 6.5; 95% confidence interval, 1.3 to 32; P=0.021 for model A; and adjusted odds ratio, 6.8; 95% confidence interval, 1.1 to 41; P=0.037 for model B).

CONCLUSIONS

Unilateral pulmonary edema represented 2.1% of cardiogenic pulmonary edema in our study, usually appeared as an opacity involving the right lung, and was always associated with severe mitral regurgitation. Unilateral pulmonary edema is related to an independent increased risk of mortality and should be promptly recognized to avoid delays in treatment.

Continuous positive airway pressure vs. pressure support ventilation in acute cardiogenic pulmonary edema: a randomized trial

BACKGROUND

Both non-invasive continuous positive airway pressure (nCPAP) and non-invasive pressure support ventilation (nPSV) have been shown to be effective treatment for acute cardiogenic pulmonary edema (ACPE). In patients with severe ACPE who are treated with standard medical treatment, the baseline intubation rate is approximately 24%.

STUDY OBJECTIVE

This study was conducted to compare the endotracheal intubation (ETI) rate using two techniques, nCPAP vs. nPSV. In addition, mortality rate, improvement in gas exchange, duration of ventilation, and hospital length of stay were also assessed.

METHODS

This prospective, multi-center, randomized study enrolled 80 patients with ACPE who were randomized to receive nCPAP or nPSV (40 patients in each group) via an oronasal mask. Inclusion criteria were severe dyspnea, respiratory rate > 30 breaths/min, use of respiratory accessory muscles, or PaO(2)/FiO(2) < 200.

RESULTS

ETI was required in 0 (0%) and in 3 (7.5%) patients in the nCPAP group and in the nPSV group, respectively (p = 0.241). No significant difference was observed in in-hospital mortality: 2 (5%) vs. 7 (17.5%) in nCPAP and nPSV groups, respectively (p = 0.154). No difference in hospital length of stay was observed between the two groups, nor was there a difference observed in duration of ventilation, despite a trend for reduced time with nPSV vs. nCPAP (5.91 ± 4.01 vs. 8.46 ± 7.14 h, respectively, p = 0.052). Both nCPAP and nPSV were effective in improving gas exchange, including in the subgroup of hypercapnic patients.

CONCLUSIONS

Both methods are effective treatment for patients with ACPE. Non-invasive CPAP should be considered as the first line of treatment because it is easier to use and less expensive than non-invasive PSV.