Respiratory distress: a model of responses and behaviors to an asphyxial threat for patients who are unable to self-report

Objective Scoring of Physiologically Induced Dyspnea by Non-Invasive RF Sensors

OBJECTIVE

Dyspnea, also known as the patient's feeling of difficult or labored breathing, is one of the most common symptoms for respiratory disorders. Dyspnea is usually self-reported by patients using, for example, the Borg scale from 0 - 10, which is however subjective and problematic for those who refuse to cooperate or cannot communicate. The objective of this paper was to develop a learning-based model that can evaluate the correlation between the self-report Borg score and the respiratory metrics for dyspnea induced by exertion and increased airway resistance.

METHODS

A non-invasive wearable radio-frequency sensor by near-field coherent sensing was employed to retrieve continuous respiratory data with user comfort and convenience. Self-report dyspnea scores and respiratory features were collected on 32 healthy participants going through various physical and breathing exercises. A machine learning model based on the decision tree and random forest then produced an objective dyspnea score.

RESULTS

For unseen data as well as unseen participants, the objective dyspnea score can be in reasonable agreement with the self-report score, and the importance factor of each respiratory metrics can be assessed.

CONCLUSION

An objective dyspnea score can potentially complement or substitute the self-report for physiologically induced dyspnea.

SIGNIFICANCE

The method can potentially formulate a baseline for clinical dyspnea assessment and help caregivers track dyspnea continuously, especially for patients who cannot report themselves.

Respiratory Distress Observation Scale Italian Version: Cultural-Linguistic Validation and Psychometric Properties

Dyspnea can be assessed using self-rating scales but, as death approaches, self-reporting becomes difficult. The validated Respiratory Distress Observation Scale measures dyspnea distress. The aim of this study was to develop the Italian version of the Respiratory Distress Observation Scale and to examine its psychometric properties. This was a cross-sectional study, analyzing cultural and linguistic validation, content validity, and psychometric properties. Eighty-nine palliative care subjects were enrolled to validate the Italian version of the Respiratory Distress Observation Scale. Patients had an average age of 74.5 (SD, 11.6) years, and 52% (n = 46) were female. Fourteen experts in palliative care evaluated the Italian Respiratory Distress Observation Scale in terms of the content validity ratio and the content validity index (CVI). The Italian Respiratory Distress Observation Scale was reported with an internal consistency (Cronbach α value) of .72 and an overall substantial interrater reliability (Cohen κ method). The Italian Respiratory Distress Observation Scale achieved a scale-level CVI of 93%, an items-level CVI of greater than 86%, and a minimum content validity ratio value of 0.71. A weak positive correlation was found between the Respiratory Distress Observation Scale and the Dyspnea Visual Analog Scale scores (0.374; P < .001). The Italian Respiratory Distress Observation Scale showed good reliability and validity for patients in palliative care. The Respiratory Distress Observation Scale measured respiratory distress in patients nearest to death.

Exploration and Development of a Simpler Respiratory Distress Observation Scale (modRDOS-4) as a Dyspnea Screening Tool: A Prospective Bedside Study

Introduction: End-of-life patients face difficulties in reporting respiratory distress. The Respiratory Distress Observation Scale (RDOS) is a well-known tool; however, field implementation has been challenging from ground feedback. We sought to develop a simpler scale. Setting: Patients referred for palliative consult in a tertiary hospital in Singapore were recruited. Methods: A priori, we identified 18 dyspnea physical signs and documented their presence through bedside observation. Dyspnea severity was self-reported. The cohort was randomly split into training and test sets. Partial least square regression with leave-one-out cross-validation was used to develop a four-point model from the training set. Using the test set, data fit was compared using Akaike and Bayesian Information Criterion. Discrimination was assessed using receiver operating characteristics. Results: Of 122 patients, mean age was 67.9 years (range 23-93, standard deviation 12.9), 71.3% had a primary cancer diagnosis, and 58.1% were chair/bedbound with a Palliative Performance Scale of ≤50. Median reported dyspnea scale was 5 (interquartile range 3-7). Our model (modRDOS-4) consisted of four predictors (grunting, respiratory rate, accessory muscle use, paradoxical breathing). A modRDOS-4 of ≥6 identified moderate-to-severe dyspnea with a sensitivity of 0.78 and specificity of 0.90. Using the test set, with the modRDOS-4, the Akaike Information Criterion (AIC) is 149.8, Bayesian Information Criteria (BIC) is 154.1, and the receiver operating characteristics (ROC) is 0.74. With the original RDOS, the AIC is 145.2, BIC is 149.5, and ROC is 0.76. Conclusion: For a quick assessment of dyspnea, we developed a four-item tool with a pilot web-based nomogram. External validation is needed.

Incidence and Risk Model Development for Severe Tachypnea Following Terminal Extubation

BACKGROUND

Palliative ventilator withdrawal (PVW) in the ICU is a common occurrence.

RESEARCH QUESTION

The goal of this study was to measure the rate of severe tachypnea as a proxy for dyspnea and to identify characteristics associated with episodes of tachypnea.

STUDY DESIGN AND METHODS

This study assessed a retrospective cohort of ICU patients from 2008 to 2012 mechanically ventilated at a single academic medical center who underwent PVW. The primary outcome of at least one episode of severe tachypnea (respiratory rate > 30 breaths/min) within 6 h after PVW was measured by using detailed physiologic and medical record data. Multivariable logistic regression was used to examine the association between patient and treatment characteristics with the occurrence of a severe episode of tachypnea post extubation.

RESULTS

Among 822 patients undergoing PVW, 19% and 30% had an episode of severe tachypnea during the 1-h and 6-h postextubation period, respectively. Within 1 h postextubation, patients with the following characteristics were more likely to experience tachypnea: no pre-extubation opiates (adjusted OR [aOR], 2.08; 95% CI, 1.03-4.19), lung injury (aOR, 3.33; 95% CI, 2.19-5.04), Glasgow Coma Scale score > 8 (aOR, 2.21; 95% CI, 1.30-3.77), and no postextubation opiates (aOR, 1.90; 95% CI, 1.19-3.00).

INTERPRETATION

Up to one-third of ICU patients undergoing PVW experience severe tachypnea. Administration of pre-extubation opiates (anticipatory dosing) represents a key modifiable factor that may reduce poor symptom control.

Detection and management of dyspnea in mechanically ventilated patients

PURPOSE OF REVIEW

In ICU patients, dyspnea is one of the most prominent and distressing symptom. We sought to summarize current data on the prevalence and prognostic influence of dyspnea in the ICU setting and to provide concise and useful information for dyspnea detection and management.

RECENT FINDINGS

As opposed to pain, dyspnea has been a neglected symptom with regard to detection and management. Many factors contribute to the pathogenesis of dyspnea. Among them, ventilator settings seem to play a major role. Dyspnea affects half of mechanically ventilated patient and causes immediate intense suffering [median dyspnea visual analog scale of 5 (4-7)]. In addition, it is associated with delayed extubation and with an increased risk of intubation and mortality in those receiving noninvasive ventilation. However, one-third of critically ill patients are noncommunicative, and therefore, at high risk of misdiagnosis. Heteroevaluation scales based on physical and behavioral signs of respiratory discomfort are reliable and promising alternatives to self-report.

SUMMARY

Dyspnea is frequent and severe in critically ill patients. Implementation of observational scale will help physicians to access to noncommunicative patient's respiratory suffering and tailor its treatment. Further studies on the prognostic impact and management strategies are needed.

Conformity in Prescription and Administration of Respiratory Distress Protocols in a Tertiary Care Hospital in the Province of Quebec: RELIEVE Study

BACKGROUND

Respiratory distress protocols (RDPs) are protocolized prescriptions comprised of 3 medications (a benzodiazepine, an opioid, and an anticholinergic) administered simultaneously as an emergency treatment for respiratory distress in palliative care patients in the province of Quebec, Canada. However, data on appropriate use that justifies the combination of all 3 components is scarce and based on individual pharmacodynamic properties along with expert consensus.

OBJECTIVES

Our study aimed to evaluate the conformity and the effectiveness of RDPs prescribed and administered to hospitalized adult patients.

METHODS

This was a prospective and descriptive study conducted in a single center. Prescription and administration conformity were assessed based on predefined appropriateness criteria.

RESULTS

A total of 467 adult patients were prescribed a RDP, 175 administrations were documented, and 78 patients received at least 1 RDP. Prescription conformity was assessed on 1473 separate occasions over the trial period. Overall prescription conformity was found to be 37% (95% confidence interval [CI]: 33.6-40.4), and administration conformity was 37.7% (95% CI: 26.2-50.7). Low administration conformity was primarily explained by incorrect indications for RDP use. Seemingly important determinants of higher conformity were prescriber's speciality in palliative care, use of preprinted orders, pharmacist involvement, and hospitalization in the palliative care unit.

CONCLUSION

This study highlights important gaps in the use of RDPs in our institution. Health-care provider training appears necessary in order to ensure adequate conformity and allow for further evaluation of RDP effectiveness.

Validity, Reliability, and Diagnostic Accuracy of the Respiratory Distress Observation Scale for Assessment of Dyspnea in Adult Palliative Care Patients

BACKGROUND

The prevalence and severity of dyspnea increase at the end of life. Many of these patients have difficulty in reporting their symptoms. Accurate surrogate measures are needed for appropriate assessment and treatment. The Respiratory Distress Observation Scale (RDOS) is proposed as a possible scale although more external validation is needed. We set out to validate the RDOS in the context of palliative care patients near the end of life.

MEASURES

We prospectively studied 122 palliative care patients in a tertiary hospital in Singapore. Prior RDOS training was done using a standardized instructional video. Dyspnea was assessed by RDOS, Dyspnea Numerical Rating Scale, and Dyspnea Categorical Scale. Pain was assessed by Pain Numerical Rating Scale. We measured RDOS inter-rater reliability, convergent validity, and divergent validity. We used area under receiver operating characteristics curve (AUC) analysis to examine the discriminant properties of RDOS using dyspnea self-report as benchmark.

RESULTS

RDOS had good inter-rater reliability with an intraclass correlation of 0.947 (95% CI 0.919-0.976). It showed moderate-to-strong correlation with Dyspnea Numerical Rating Scale (r = 0.702) and Dyspnea Categorical Scale (r = 0.677) and negligible correlation to Pain Numerical Rating Scale (r = 0.080). It showed good discriminant properties of identifying patients with moderate and severe dyspnea with an AUC of 0.874 (95% CI 0.812-0.936). RDOS ≥ 4 predicted patients with moderate and severe dyspnea with a sensitivity of 76.6%, specificity of 86.2%, positive predictive value of 86.0%, and negative predictive value of 76.9%.

CONCLUSIONS

The RDOS shows promise and clinical utility as an observational dyspnea assessment tool. Further studies in uncommunicative patients are needed to determine clinical usefulness and generalizability of results.

Ensuring Breathing Comfort at the End of Life: The Integral Role of the Critical Care Nurse

This article describes the author's program of clinical research focused on assessment and treatment of respiratory distress among critically ill patients at the end of life. Dyspnea is a subjective experience of breathing discomfort that occurs in the presence of cardiopulmonary and neuromuscular diseases. Dyspnea is one of the most common and most distressing symptoms experienced by critically ill patients. Many critically ill patients, particularly those not expected to survive, become cognitively impaired or unconscious and lose the ability to report symptoms, although dyspnea can be known only from a patient's report. When self-reporting ability is lost, the critical care nurse must rely on signs indicative of a patient's respiratory distress. The critically ill patient unable to self-report is vulnerable to under-recognition of symptom distress and subsequent over-treatment or undertreatment. When the patient is dying, there is only 1 chance to optimize the assessment and treatment of symptoms.

Interferences between breathing, experimental dyspnoea and bodily self-consciousness

Dyspnoea, a subjective experience of breathing discomfort, is a most distressing symptom. It implicates complex cortical networks that partially overlap with those underlying bodily self-consciousness, the experience that the body is one's own within a given location (self-identification and self-location, respectively). Breathing as an interoceptive signal contributes to bodily self-consciousness: we predicted that inducing experimental dyspnoea would modify or disrupt this contribution. We also predicted that manipulating bodily self-consciousness with respiratory-visual stimulation would possibly attenuate dyspnoea. Twenty-five healthy volunteers were exposed to synchronous and asynchronous respiratory-visual illumination of an avatar during normal breathing and mechanically loaded breathing that elicited dyspnoea. During normal breathing, synchronous respiratory-visual stimulation induced illusory self-identification with the avatar and an illusory location of the subjects' breathing towards the avatar. This did not occur when respiratory-visual stimulation was performed during dyspnoea-inducing loaded breathing. In this condition, the affective impact of dyspnoea was attenuated by respiratory-visual stimulation, particularly when asynchronous. This study replicates and reinforces previous studies about the integration of interoceptive and exteroceptive signals in the construction of bodily self-consciousness. It confirms the existence of interferences between experimental dyspnoea and cognitive functions. It suggests that respiratory-visual stimulation should be tested as a non-pharmacological approach of dyspnoea treatment.

Underestimation of Patient Breathlessness by Nurses and Physicians during a Spontaneous Breathing Trial

RATIONALE

Breathlessness is a prevalent and distressing symptom in intensive care unit patients. There is little evidence of the ability of healthcare workers to assess the patient's experiences of breathing. Patient perception of breathing is essential in symptom management, and patient perception during a spontaneous breathing trial (SBT) might be related to extubation success.

OBJECTIVES

To assess mechanically ventilated patients' experiences of breathlessness during SBT.

METHODS

This was a prospective observational multicenter study of 100 mechanically ventilated patients. We assessed the agreement between nurses, physicians, and patients' 11-point Numerical Rating Scales scores of breathlessness, perception of feeling secure, and improvement of respiratory function at the end of an SBT (most performed with some level of support). We also determined the association between breathlessness and demographic factors or respiratory observations.

MEASUREMENTS AND MAIN RESULTS

Sixty-two patients (62%) reported moderate or severe breathlessness (Numerical Rating Scales ≥ 4). The median intensity of breathlessness reported by patients was five compared with two by nurses and physicians (P < 0.001). Patients felt less secure and reported less improvement of respiratory function compared with nurses' and physicians' ratings. About half of the nurses and physicians underestimated breathlessness (difference score, ≤-2) compared with the patients' self-reports. Underestimation of breathlessness was not associated with professional competencies. There were no major differences in objective assessments of respiratory function in patients with moderate or severe breathlessness, and no apparent relationship between breathlessness during the SBT and extubation outcome.

CONCLUSIONS

Patients reported higher breathlessness after SBT compared with nurses and physicians. Clinical trial registered with www.clinicaltrials.gov (NCT 01928277).

Dyspnea related to reversibly-binding P2Y12 inhibitors: A review of the pathophysiology, clinical presentation and diagnostics

Dyspnea is a common symptom physiologically associated with strenuous exercise and pathologically reflecting well-known diseases and conditions that are predominantly pulmonary, cardiovascular, and weight-related in origin. Dyspnea improves with appropriate measures that enhance physical performance and treatment of the underlying diseases. Dyspnea is less commonly triggered by other causes such as the environment (e.g., ozone), drugs, and others, some of which do not seem to affect bronchopulmonary function as evidenced by normal results of comprehensive pulmonary function testing. In cardiovascular medicine, dyspnea has recently attracted attention because it has been reported that this symptom occurs more frequently with the administration of the new oral reversibly-binding platelet P2Y12 receptor inhibitors ticagrelor [1-6], cangrelor [7-10], and elinogrel [11]. This paper succinctly addresses the current understanding of the pathophysiology, clinical presentation, and diagnostics of dyspnea, associated either with bronchopulmonary function impairment, as triggered mainly by pulmonary and cardiovascular diseases, or without bronchopulmonary function impairment, as induced by endogenous or external compounds such as drugs in order to provide a context for understanding, recognizing and managing P2Y12 inhibitor-induced dyspnea.

Oxygen is nonbeneficial for most patients who are near death

CONTEXT

Clinicians prescribe and administer oxygen in response to reports of dyspnea, in the face of dropping oxygen saturation, as a "routine" comfort intervention, or to support anxious family members. Oxygen may produce nasal irritation and increase the cost of care.

OBJECTIVES

To determine the benefit of administering oxygen to patients who are near death.

METHODS

A double-blind, repeated-measure observation with the patient as his/her own control was conducted. The Respiratory Distress Observation Scale(©) measured presence and intensity of distress at baseline and at every gas or flow change. Medical air, oxygen, and no flow were randomly alternated every 10 minutes via nasal cannula with patients who were near death, at risk for respiratory distress, with no distress at the baseline of testing. Each patient had two encounters under each condition, yielding six encounters per patient.

RESULTS

Patients were 66% female, 34% white, and 66% African American, and ages 56-97 years. Patients had heart failure (25%), chronic obstructive pulmonary disease (34%), pneumonia (41%), or lung cancer (9%). Most (91%) patients tolerated the protocol with no change in respiratory comfort. Three patients (9%) displayed distress and were restored to baseline oxygen; one patient died during the protocol while displaying no distress. Repeated-measure analysis of variance revealed no differences in the Respiratory Distress Observation Scale under changing gas and flow conditions.

CONCLUSION

The routine application of oxygen to patients who are near death is not supported. The n-of-1 trial of oxygen in clinical practice is appropriate in the face of hypoxemic respiratory distress.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

Patients who are near death are frequently unable to self-report dyspnea

BACKGROUND

Standard measures of dyspnea rely on the patient's self-report. Declining consciousness and/or cognitive function and nearness to death may interfere with dyspnea reporting making the patient vulnerable to undertreatment or overtreatment.

METHODS

An observational design was used with 89 consecutive patients referred for inpatient palliative care consultation. Patients were included if they were at risk for dyspnea because of one or more of the following: lung cancer, chronic obstructive pulmonary disease (COPD), heart failure, or pneumonia. Patients were asked "Are you short of breath?" and asked to quantify any distress by pointing to a visual analogue scale (VAS). Other measures included: consciousness, cognitive state, terminal illness severity, and patient demographics.

RESULTS

More than half of the patients (54%) were unable to provide a yes or no response. Only 20 of 41 (49%) able to respond with yes or no were able to quantify any distress with the VAS. Ability to self-report was positively associated with consciousness (p < 0.01), cognitive state (p < 0.01), and terminal illness severity (p < 0.01). A significant inverse relationship was found between consciousness and terminal illness severity (p < 0.01). Declines in consciousness and cognitive state were strongly correlated with nearness to death (p < 0.01).

CONCLUSIONS

Declining consciousness and/or cognitive state are expected when patients are near death. The ability to give even the simplest self-report (yes or no) about dyspnea is lost in the near-death phase of terminal illness, yet the ability to experience distress may persist and may be overlooked and undertreated or overtreated. Other methods for symptom assessment are needed in this context.

A Respiratory Distress Observation Scale for patients unable to self-report dyspnea

BACKGROUND

Standard measures of dyspnea rely on self-report. Cognitive impairment and nearness to death may interfere with symptom distress reporting leading to underrecognition and overtreatment or undertreatment. Previous psychometric testing of the Respiratory Distress Observation Scale (RDOS) demonstrated internal consistency and convergent validity with dyspnea self-report and discriminant validity with pain and no dyspnea. Additional testing was needed with patients unable to self-report. The aim of this study was to establish further the reliability and construct validity of a revised RDOS.

METHODS

An observational design was used with 89 consecutive patients referred for inpatient palliative care consultation and at risk for dyspnea who had one or more of lung cancer, chronic obstructive pulmonary disease (COPD), heart failure, or pneumonia. Patients were observed and the RDOS scored once each day for up to three days after the initial consultation. Other measures included: dyspnea self-report, neurologic diagnoses, opioid or benzodiazepine use, peripheral oxygen saturation, end-tidal carbon dioxide level, consciousness, cognitive state, nearness to death, and patient demographics.

RESULTS

Perfect interrater reliability across data collectors was achieved. No differences in RDOS scoring were found by patient demographics. RDOS was associated with use of oxygen (p < 0.01), oxygen saturation (p < 0.01) and nearness to death (p < 0.01). A significant decrease in RDOS was found over time corresponding with treatment (p < 0.01). The reliability of this 8-item scale using Cronbach alpha is 0.64.

CONCLUSIONS

Declining consciousness and/or cognition are expected when patients are near death. The RDOS performed well when tested with terminally ill patients who were at risk for respiratory distress, most of whom could not self-report dyspnea. The tool is sensitive to detect changes over time and measure response to treatment. The RDOS is simple to use; scoring takes less than 5 minutes. The RDOS has clinical and research utility to measure and trend respiratory distress and response to treatment.

Efficacy of guided imagery with theta music for advanced cancer patients with dyspnea: a pilot study

BACKGROUND

Dyspnea is a frequent and devastating symptom among advanced cancer patients for which improved and low-cost palliative techniques are needed.

METHODS

A one-group repeated measures research design investigated the efficacy of guided imagery (GI) with theta music (M) on dyspnea in advanced cancer patients. The intervention consisted of four periods: (a) pretest; (b) intervention with peaceful non-M; (c) intervention with 10 min of GI with M (GI/M), with the first and last 3 min being M only (i.e., the middle 4 min was GI/M); and (d) posttest. Dyspnea outcome was measured with the Modified Borg Scale (MBS) for self-reported evaluation of dyspneic symptoms. Physiological parameters measured were pulse oxygen saturation (SpO(2)), end-tidal CO( 2) (EtCO(2)), heart rate (HR), and respiratory rate (RR). Posttest qualitative data were obtained via interview for subjective patient experience.

RESULTS

Participants included 53 patients, 33% with lung cancer. GI/M produced a significant decrease in MBS scores; 90% of the subjects gave positive qualitative reviews of GI/M. SpO(2) did not change significantly over time. GI/M significantly increased EtCO(2), decreased RR, and decreased HR.

DISCUSSION

This study demonstrates that GI/M is a useful intervention for palliative care of patients with dyspnea. M alone was demonstrated to be effective, while soothing non-M was not effective. GI/M was more effective than M alone. GI/M should be considered low-cost end-of-life palliative care for dyspnea.