Experience of morphine therapy for refractory dyspnea as palliative care in advanced heart failure patients

Effect of Morphine Used to Relieve Dyspnea Due to Heart Failure on Delirium

Background: Delirium management is crucial in palliative care. Morphine effectively relieves dyspnea due to heart failure. However, the effect of morphine, which is used to relieve dyspnea due to heart failure, on the incidence of delirium has not been examined to date. Objective: To evaluate the effect of morphine, which is used to relieve dyspnea due to heart failure, on delirium. Design: Retrospective observational study. Setting/Subjects: Subjects were identified from Osaka University Hospital records, located in Japan, from January 1, 2010, to September 30, 2021. The case group consisted of admissions for heart failure or cardiomyopathy registered in electronic medical records. Morphine was administered to relieve dyspnea due to heart failure, and no surgeries or procedures were performed. The control group consisted of admissions for heart failure or cardiomyopathy in the Diagnosis Procedure Combination (DPC) database, which did not include administration of morphine, oxycodone, or fentanyl during the hospitalization period and patients did not undergo surgery or any other procedure. Measurements: The incidence of delirium was assessed. Results: The odds ratios for morphine in the multivariate logistic regression analysis with propensity score and univariate logistic regression analysis after propensity score matching were 1.406 (95% confidence interval (CI) [0.249-7.957]) and 1.034 (95% CI [0.902-1.185]), respectively. Conclusions: Morphine, which is used to relieve dyspnea due to heart failure, had minimal effect on the incidence of delirium. This information is likely to be beneficial for the future use of morphine in the management of dyspnea in patients with heart failure.

Effectiveness and safety of morphine administration for refractory dyspnoea among hospitalised patients with advanced heart failure: the Morphine-HF study

OBJECTIVES

Morphine is effective in alleviating dyspnoea in patients with cancer. We aimed to investigate the effectiveness and safety of morphine administration for refractory dyspnoea in patients with advanced heart failure (HF).

METHODS

We conducted a multicentre, prospective, observational study of hospitalised patients with advanced HF in whom morphine was administered for refractory dyspnoea. Morphine effectiveness was evaluated by dyspnoea intensity changes, assessed regularly by both a quantitative subjective scale (Visual Analogue Scale (VAS; graded from 0 to 100 mm)) and an objective scale (Support Team Assessment Schedule-Japanese (STAS-J; graded from 0 to 4 points)). Safety was assessed by vital sign changes and new-onset severe adverse events, including nausea, vomiting, constipation and delirium based on the Common Terminology Criteria for Adverse Events.

RESULTS

From 15 Japanese institutions between September 2020 and August 2022, we included 28 hospitalised patients with advanced HF in whom morphine was administered (mean age: 83.8±8.7 years, male: 15 (54%), New York Heart Association class IV: 26 (93%) and mean left ventricular ejection fraction: 38%±19%). Both VAS and STAS-J significantly improved from baseline to day 1 (VAS: 67±26 to 50±31 mm; p=0.02 and STAS-J: 3.3±0.8 to 2.6±1.1 points; p=0.006, respectively), and thereafter the improvements sustained through to day 7. After morphine administration, vital signs including blood pressure, pulse rate and oxygen saturation did not change, and no new-onset severe adverse events occurred through to day 7.

CONCLUSIONS

This study suggested acceptable effectiveness and safety for morphine administration in treating refractory dyspnoea in hospitalised patients with advanced HF.

Analysis of cardiohemodynamic and electrophysiological effects of morphine along with its toxicokinetic profile using the halothane-anesthetized dogs

Although morphine has been used for treatment-resistant dyspnea in end-stage heart failure patients, information on its cardiovascular safety profile remains limited. Morphine was intravenously administered to halothane-anesthetized dogs (n=4) in doses of 0.1, 1 and 10 mg/kg/10 min with 20 min of observation period. The low and middle doses attained therapeutic (0.13 µg/mL) and supratherapeutic (0.97 µg/mL) plasma concentrations, respectively. The low dose hardly altered any of the cardiovascular variables except that the QT interval was prolonged for 10-15 min after its start of infusion. The middle dose reduced the preload and afterload to the left ventricle for 5-15 min, then decreased the left ventricular contractility and mean blood pressure for 10-30 min, and finally suppressed the heart rate for 15-30 min. Moreover, the middle dose gradually but progressively prolonged the atrioventricular conduction time, QT interval/QTcV, ventricular late repolarization period and ventricular effective refractory period without altering the intraventricular conduction time, ventricular early repolarization period or terminal repolarization period. A reverse-frequency-dependent delay of ventricular repolarization was confirmed. The high dose induced cardiohemodynamic collapse mainly due to vasodilation in the initial 2 animals by 1.9 and 3.3 min after its start of infusion, respectively, which needed circulatory support to treat. The high dose was not tested further in the remaining 2 animals. Thus, intravenously administered morphine exerts a rapidly appearing vasodilator action followed by slowly developing cardiosuppressive effects. Morphine can delay the ventricular repolarization possibly through IKr inhibition in vivo, but its potential to develop torsade de pointes will be small.

Clinical Use of Oral Opioid Therapy for Dyspnea in Patients With Advanced Heart Failure - A Single-Center Retrospective Study

Background: For patients with advanced heart failure, palliative care, including opioids, is needed as a treatment for refractory dyspnea. However, little evidence has been reported on the efficacy and safety of opioids, and their use is not well established. Methods and Results: We have introduced a protocol for the use of opioids for dyspnea in patients with advanced heart failure admitted to Saitama Citizens Medical Center. Following this protocol, differences in clinical variables and outcome were investigated between patients in whom opioids were initiated intravenously or subcutaneously (i.v./s.c. group; n=13) and patients in whom they were initiated orally (oral group; n=18). In a comparison of baseline characteristics, significantly more patients in the oral group had a history of hospitalization for heart failure within the past year, and significantly more patients were treated with dobutamine and tolvaptan. After initiation of opioid treatment, both groups showed improvement in dyspnea; however, serial changes in vital signs were significantly greater in the i.v./s.c. group. The survival rate was significantly higher in the oral group (P<0.0001), with 33% of patients discharged alive. Conclusions: The clinical use of oral opioids using a single-center protocol is reported, suggesting that oral opioids may be practical and effective for dyspnea in patients with advanced heart failure.

Efficacy of Morphine Combined with Mechanical Ventilation in the Treatment of Heart Failure with Cardiac Magnetic Resonance Imaging under Artificial Intelligence Algorithms

This study was aimed at exploring the efficacy of morphine combined with mechanical ventilation in the treatment of heart failure with artificial intelligence algorithms. The cardiac magnetic resonance imaging (MRI) under the watershed segmentation algorithm was proposed, and the local grayscale clustering watershed (LGCW) model was designed in this study. A total of 136 patients with acute left heart failure were taken as the research objects and randomly divided into the control group (conventional treatment) and the experimental group (morphine combined with mechanical ventilation), with 68 cases in each group. The left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF), N-terminal pro-brain natriuretic peptide (NT-proBNP), arterial partial pressure of oxygen (PaO₂), and arterial partial pressure of carbon dioxide (PaCO₂) were observed. The results showed that the mean absolute deviation (MAD) and maximum mean absolute deviation (max-MAD) of the LGCW model were lower than those of the fuzzy k-nearest neighbor (FKNN) algorithm and local gray-scale clustering model (LGSCm). The Dice metric was also significantly higher than that of other algorithms with statistically significant differences (P < 0.05). After treatment, LVEDD, LVESD, and NT-proBNP of patients in the experimental group were significantly lower than those in the control group, and LVEF in the experimental group was higher than that in the control group (P < 0.05). PaO₂ of patients in the experimental group was also significantly higher than that in the control group (P < 0.05). It suggested that the LGCW model had a better segmentation effect, and morphine combined with mechanical ventilation gave a better clinical efficacy in the treatment of acute left heart failure, improving the patients' cardiac function and arterial blood gas effectively.

Adverse Drug Reactions in Japanese Patients with End-Stage Heart Failure Receiving Continuous Morphine Infusion: A Single-Center Retrospective Cohort Study

BACKGROUND

Opioids have been reported to be effective for refractory dyspnea in patients with advanced heart failure (HF) in the palliative care setting.

OBJECTIVE

The aim of this study was to evaluate the incidence of adverse drug reactions (ADRs) and their relationship with morphine dose/duration or renal insufficiency in patients with end-stage HF receiving continuous morphine infusion.

METHODS

We retrospectively studied 38 patients with end-stage HF receiving continuous intravenous or subcutaneous morphine infusion for the relief of breathlessness between 2014 and 2019 (mean age 78 years). The endpoints were nausea/vomiting, respiratory depression, and drowsiness, which are common morphine-related ADRs.

RESULTS

Of 38 patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion, 14 (37%) experienced ADRs. The median estimated glomerular filtration rate (eGFR) was lower in patients with than in those without ADRs (16 [range 9-48] vs. 41 [range 8-133], respectively; p = 0.011). The ADRs with the highest incidence were drowsiness (n = 13), nausea/vomiting (n =5), and respiratory depression (n =3). There were no differences in the maintenance dose or duration of morphine administration between patients with and without ADRs. A baseline eGFR of 32 mL/min/1.73 m² was a good cutoff value for ADR prediction (sensitivity 86%, specificity 96%). A baseline eGFR < 32 mL/min/1.73 m² was significantly associated with the occurrence of morphine-related ADRs (odds ratio 6.63, 95% confidence interval 1.19-37.01).

CONCLUSIONS

Our results showed that 37% of patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion experienced ADRs, especially drowsiness. Patients with eGFR < 32 mL/min/1.73 m² were likely to experience morphine-related ADRs.