Review article: Lack of effect of opiates in the treatment of acute cardiogenic pulmonary oedema

Signal of harm in morphine use in adults with acute pulmonary oedema: A rapid systematic review

BACKGROUND

Heart failure affects nearly 65 million people globally, resulting in recurrent hospital admissions and substantial healthcare expenditure. The use of morphine in the management of acute pulmonary oedema remains controversial, with conflicting guidance and significant variation in practice. Synthesised evidence is needed to inform standard treatment guidelines and clinical practice.

OBJECTIVE

To determine whether morphine should be used in the treatment of acute pulmonary oedema (APE) in adults.

METHODS

A rapid review of systematic reviews of randomised controlled trials or observational studies, and then randomised controlled trials, was conducted searching three electronic databases (PubMed, Embase, Cochrane Library) and one clinical trial registry on 12 February 2022. We used a prespecified protocol following Cochrane rapid review methods and aligned to the National Standard Treatment Guidelines and Essential Medicines List methodology. We first considered relevant high-quality systematic reviews of randomised controlled trials or observational studies, then (if required) randomised controlled trials to inform time-sensitive or urgent evidence requests, clinical practice, policy, or standard treatment guidelines.

RESULTS

We identified four systematic reviews of observational studies. The two most relevant, up-to-date, and highest-quality reviews were used to inform evidence for critical outcomes. Morphine may increase in-hospital mortality (odds ratio (OR) 1.78; 95% confidence interval (CI) 1.01 - 3.13; low certainty of evidence; six observational studies, n=151 735 participants), resulting in 15 more per 1 000 hospital deaths, ranging from 0 to 40 more hospital deaths. Morphine may result in a large increase in invasive mechanical ventilation (OR 2.72; 95% CI 1.09 - 6.80; low certainty of evidence; four observational studies, n=167 847 participants), resulting in 45 more per 1 000 ventilations, ranging from 2 more to 136 more. Adverse events and hospital length of stay were not measured across reviews or trials.

CONCLUSION

Based on the most recent, relevant and best-available quality evidence, morphine use in adults with APE may increase in-hospital and all-cause mortality and may result in a large increase in the need for invasive mechanical ventilation compared to not using morphine. Recommending against the use of morphine in pulmonary oedema may improve patient outcomes. Disinvesting in morphine for this indication may result in cost savings, noting the possible accrued benefits of fewer patients requiring invasive ventilation and management of morphine-related side-effects.

The safety of morphine in patients with acute heart failure: A systematic review and meta-analysis

While morphine has long been widely used in treating acute heart failure (AHF) due to its vasodilatory properties and anticipated anxiolysis, it remains unclear whether the application of morphine to those patients is reasonable. We aim to conduct a systematic review and meta-analysis to assess the safety of morphine in patients with AHF. We searched PubMed, Cochrane Library, and Embase electronic databases from inception through March 2020. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the outcomes. Seven studies with 172, 226 patients were included. The results showed that morphine usage was not associated with increased in-hospital mortality (OR: 1.94; 95% CI 0.93 to 4.03; p = 0.08). However, the use of morphine significantly increased the risk of invasive ventilation (OR: 2.72; 95% CI 1.09 to 6.80; p = 0.03). Furthermore, the subgroup analysis indicated that the application of morphine was not associated with increased 7-day all-cause mortality in patients with AHF (OR: 1.69; 95% CI 0.80 to 3.22; p = 0.11) but significantly increased the risk of 30-day all-cause mortality (OR: 1.59; 95% CI 1.16 to 2.17; p = 0.004). Based on current evidence, our results suggested that although morphine therapy did not significantly increase the risk of short-term death (in the hospital or within 7 days) in patients with AHF, the risk of long-term death and invasive ventilation were significantly increased. This result needs to be further confirmed by an ongoing randomized control trial.

Morphine Use in the ED and Outcomes of Patients With Acute Heart Failure: A Propensity Score-Matching Analysis Based on the EAHFE Registry

OBJECTIVE

The objective was to determine the relationship between short-term mortality and intravenous morphine use in ED patients who received a diagnosis of acute heart failure (AHF).

METHODS

Consecutive patients with AHF presenting to 34 Spanish EDs from 2011 to 2014 were eligible for inclusion. The subjects were divided into those with (M) or without IV morphine treatment (WOM) groups during ED stay. The primary outcome was 30-day all-cause mortality, and secondary outcomes were mortality at different intermediate time points, in-hospital mortality, and length of hospital stay. We generated a propensity score to match the M and WOM groups that were 1:1 according to 46 different epidemiological, baseline, clinical, and therapeutic factors. We investigated independent risk factors for 30-day mortality in patients receiving morphine.

RESULTS

We included 6,516 patients (mean age, 81 [SD, 10] years; 56% women): 416 (6.4%) in the M and 6,100 (93.6%) in the WOM group. Overall, 635 (9.7%; M, 26.7%; WOM, 8.6%) died by day 30. After propensity score matching, 275 paired patients constituted each group. Patients receiving morphine had a higher 30-day mortality (55 [20.0%] vs 35 [12.7%] deaths; hazard ratio, 1.66; 95% CI, 1.09-2.54; P = .017). In patients receiving morphine, death was directly related to glycemia (P = .013) and inversely related to the baseline Barthel index and systolic BP (P = .021) at ED arrival (P = .021). Mortality was increased at every intermediate time point, although the greatest risk was at the shortest time (at 3 days: 22 [8.0%] vs 7 [2.5%] deaths; OR, 3.33; 95% CI, 1.40-7.93; P = .014). In-hospital mortality did not increase (39 [14.2%] vs 26 [9.1%] deaths; OR, 1.65; 95% CI, 0.97-2.82; P = .083) and LOS did not differ between groups (median [interquartile range] in M, 8 [7]; WOM, 8 [6]; P = .79).

CONCLUSIONS

This propensity score-matched analysis suggests that the use of IV morphine in AHF could be associated with increased 30-day mortality.

Morphine blocks the Mesobuthus tamulus venom-induced augmentation of phenyldiguanide reflex and pulmonary edema in anesthetized rats

Objective:

Pulmonary edema, a manifestation of scorpion envenomation syndrome, is attributed to cardiogenic or noncardiogenic factors. Morphine is a drug used for cardiogenic pulmonary edema and its effect on Mesobuthus tamulus (MBT) venom-induced changes is not known. Therefore, we hypothesized that morphine blocks the MBT venom-induced augmentation of phenyldiguanide (PDG) reflex and pulmonary edema.

Materials and Methods:

Experiments were performed on anesthetized adult female rats. Trachea and jugular vein were cannulated, and the electrocardiographic potentials were recorded by connecting needle electrodes in limb lead II configuration. PDG (10 ΅g/kg, IV, bolus injection) responses were elicited by bolus injection initially, after saline/morphine (1 mg/kg) and after injecting MBT venom (100 μg/kg). The time-response area of the PDG-induced bradycardiac response after treatment was calculated as % of the initial PDG response area. At the end of experiments, lungs were excised for determination of pulmonary water content.

Results:

PDG produced bradycardiac response that lasted for >60 s. MBT venom augmented the PDG reflex response by 2.5 times. In morphine pretreated group, augmentation of bradycardiac response induced by MBT venom was absent. MBT venom increased the pulmonary water content, and the increase was absent in morphine pretreated animals.

Conclusion:

The results reveal that morphine prevents the MBT venom-induced augmentation of PDG reflex response and pulmonary edema. Thus, morphine can be useful in scorpion envenomation syndrome associated with pulmonary edema.

Sympathetic crashing acute pulmonary edema

Sympathetic crashing acute pulmonary edema (SCAPE) is the extreme end of the spectrum of acute pulmonary edema. It is important to understand this disease as it is relatively common in the emergency department (ED) and has better outcomes when managed appropriately. The patients have an abrupt redistribution of fluid in the lungs, and when treated promptly and effectively, these patients will rapidly recover. Noninvasive ventilation and intravenous nitrates are the mainstay of treatment which should be started within minutes of the patient's arrival to the ED. Use of morphine and intravenous loop diuretics, although popular, has poor scientific evidence.

Congestive Heart Failure

Patients with acute decompensated heart failure are usually critically ill and require immediate treatment. However, most are not volume overloaded. Emergency department (ED) management is based on rapid initiation of noninvasive positive-pressure ventilation and aggressive titration of nitrates. Afterload reduction with an angiotensin-converting enzyme inhibitor can be considered. A diuretic should not be administered before optimal preload and afterload reduction has been achieved. Short-term inotropic therapy can be considered in select patients with cardiogenic shock and acute decompensated heart failure (ADHF) who fail to respond to standard therapy.

Acute lung failure

Lung failure is the most common organ failure seen in the intensive care unit. The pathogenesis of acute respiratory failure (ARF) can be classified as (1) neuromuscular in origin, (2) secondary to acute and chronic obstructive airway diseases, (3) alveolar processes such as cardiogenic and noncardiogenic pulmonary edema and pneumonia, and (4) vascular diseases such as acute or chronic pulmonary embolism. This article reviews the more common causes of ARF from each group, including the pathological mechanisms and the principles of critical care management, focusing on the supportive, specific, and adjunctive therapies for each condition.