Dyspnea: applying research to bedside practice

Predicting outcome for ambulance patients with dyspnea: a prospective cohort study

OBJECTIVE

To validate the discrimination and classification accuracy of a novel acute dyspnea scale for identifying outcomes of out-of-hospital patients with acute dyspnea.

METHODS

Prospective observational population-based study in the North Denmark Region. We included patients from July 1, 2017 to September 24, 2019 assessed as having acute dyspnea by the emergency dispatcher or by emergency medical services (EMS) personnel. Patients rated dyspnea using the 11-point acute dyspnea scale. The primary outcomes were hospitalization >2 days, ICU admission within 48 hours of ambulance run, and 30-day mortality. We used 5-fold cross-validation and area under receiver operating curves (AUC) to assess predictive properties of the acute dyspnea scale score alone and combined with vital data, age, and sex.

RESULTS

We included 3144 EMS patients with reported dyspnea. Median acute dyspnea scale score was 7 (interquartile range 5 to 8). The outcomes were: 1966 (63%) hospitalized, 164 (5%) ICU stay, and 224 (9%) died within 30 days of calling the ambulance. The acute dyspnea scale score alone showed poor discrimination for hospitalization (AUC 0.56, 95% confidence intervals: 0.54-0.58), intensive care unit admission (0.58, 0.53-0.62), and mortality (0.46, 0.41-0.50). Vital signs (respiratory rate, blood oxygen saturation, blood pressure, and heart rate) showed similarly poor discrimination for all outcomes. The combination of [vital signs + acute dyspnea scale score] showed better discrimination for hospitalization, ICU admission, and mortality (AUC 0.71-0.72). Patients not able to report an acute dyspnea scale score worse outcomes on all parameters.

CONCLUSION

The dyspnea scale showed poor accuracy and discrimination when predicting hospitalization, stay at intensive care unit, and mortality on its own. However, the dyspnea scale may be beneficial as performance measure and indicator of out-of-hospital care.

Patient experience of severe acute dyspnoea and relief during treatment in ambulances: a prospective observational study

Background

Acute dyspnoea is common among ambulance patients, but little is known of the patients’ experience of symptom. We aimed to investigate ambulance patients initial perceived intensity of acute dyspnoea, and whether they experienced relief during prehospital treatment. Furthermore, to investigate the validity and feasibility of using a subjective dyspnoea score in the ambulance, and its association with objectively measured vital signs.

Methods

We performed a prospective observational study in the North Denmark Region from 1. July 2017 to 30. March 2019. We studied patients over the age of 18 to whom an ambulance was dispatched. Patients with acute dyspnoea assessed either at the emergency call or by ambulance professionals on scene were included. Patients were asked to assess dyspnoea on a 0 to 10 verbal numeric rating scale at the primary contact with the ambulance personnel and immediately before release at the scene or arrival at the hospital. Patients received usual prehospital medical treatment. We used visual inspection and Wilcoxon matched-pairs signed-ranks test, to assess dyspnoea scores and change hereof. Scatterplots and linear regression analyses were used to assess associations between the dyspnoea score and vital signs.

Results

We included 3199 patients with at least one dyspnoea score. Of these, 2219 (69%) had two registered dyspnoea scores. The initial median dyspnoea score for all patients was median 8 (interquartile range 6–10). In 1676 (76%) of patients with two scores, the first score decreased from 8 (6–9) to 4 (2–5) during prehospital treatment. The score was unchanged for 370 (17%) and increased for 51 (2%) patients. Higher respiratory rate, blood pressure, and heart rate was seen with higher dyspnoea scores whereas blood oxygen saturation lowered.

Conclusions

We found that acute dyspnoea scored by ambulance patients, was high on a verbal numerical rating scale but decreased before arrival at hospital, suggesting relief of symptoms. The acute dyspnoea score was statistically associated with vital signs, but of limited clinical relevance; this stresses the importance of patients’ experience of symptoms. To this end, the dyspnoea scale appears feasible in the prehospital setting.

Dyspnoea in patients receiving noninvasive ventilation for acute respiratory failure: prevalence, risk factors and prognostic impact: A prospective observational study

Dyspnoea is a frequent and intense symptom in intubated patients, but little attention has been paid to dyspnoea during noninvasive mechanical ventilation in the intensive care unit (ICU).The objectives of this study were to quantify the prevalence, intensity and prognostic impact of dyspnoea in patients receiving noninvasive ventilation (NIV) for acute respiratory failure (ARF) based on secondary analysis of a prospective observational cohort study in patients who received ventilatory support for ARF in 54 ICUs in France and Belgium. Dyspnoea was measured by a modified Borg scale.Among the 426 patients included, the median (interquartile range) dyspnoea score was 4 (3-5) on admission and 3 (2-4) after the first NIV session (p=0.001). Dyspnoea intensity ≥4 after the first NIV session was associated with the Sequential Organ Failure Assessment Score (odds ratio (OR) 1.12, p=0.001), respiratory rate (OR 1.03, p=0.032), anxiety (OR 1.92, p=0.006), leaks (OR 2.5, p=0.002) and arterial carbon dioxide tension (OR 0.98, p=0.025). Dyspnoea intensity ≥4 was independently associated with NIV failure (OR 2.41, p=0.001) and mortality (OR 2.11, p=0.009), but not with higher post-ICU burden and altered quality of life.Dyspnoea is frequent and intense in patients receiving NIV for ARF and is associated with a higher risk of NIV failure and poorer outcome.

The prospective association of perceived criticism with dyspnea in chronic lung disease

OBJECTIVE

Perceived criticism from family members influences mental health. The link between perceived criticism and physical health has not been thoroughly investigated. The objective of this study was to examine the association of perceived criticism with dyspnea in chronic obstructive pulmonary disease (COPD).

METHODS

401 individuals with alpha-1 antitrypsin deficiency-associated COPD completed questionnaires at baseline, 1- and 2-year follow-up. Perceived criticism at baseline was examined as a predictor of dyspnea at all three time points using a linear mixed model that adjusted for demographic and health characteristics.

RESULTS

There was an interaction between perceived criticism and psychological distress (p=0.038). Perceived criticism was associated with dyspnea only among individuals with elevated psychological distress (b=0.32, SE=0.13, p=0.018).

CONCLUSION

Further research is needed to replicate these findings and determine the extent to which they apply to other common subjective physical symptoms such as pain.

Symptoms experienced by intensive care unit patients at high risk of dying

OBJECTIVE

To provide a focused, detailed assessment of the symptom experiences of intensive care unit patients at high risk of dying and to evaluate the relationship between delirium and patients' symptom reports.

DESIGN

Prospective, observational study of patients' symptoms.

SETTING

Two intensive care units in a tertiary medical center in the western United States.

PATIENTS

One hundred seventy-one intensive care unit patients at high risk of dying.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were interviewed every other day for up to 14 days. Patients rated the presence, intensity (1 = mild; 2 = moderate; 3 = severe), and distress (1 = not very distressing; 2 = moderately distressing; 3 = very distressing) of ten symptoms (that is, pain, tired, short of breath, restless, anxious, sad, hungry, scared, thirsty, confused). The Confusion Assessment Method-Intensive Care Unit was used to ascertain the presence of delirium. A total of 405 symptom assessments were completed by 171 patients. Patients' average age was 58 ± 15 yrs; 64% were males. Patients were mechanically ventilated during 34% of the 405 assessments, and 22% died in the hospital. Symptom prevalence ranged from 75% (tired) to 27% (confused). Thirst was moderately intense, and shortness of breath, scared, confusion, and pain were moderately distressful. Delirium was found in 34.2% of the 152 patients who could be evaluated. Delirious patients were more acutely ill and received significantly higher doses of opioids. Delirious patients were significantly more likely to report feeling confused (43% vs. 22%, p = .004) and sad (46% vs. 31%, p = .04) and less likely to report being tired (57% vs. 77%, p = .006) than nondelirious patients.

CONCLUSIONS

Study findings suggest that unrelieved and distressing symptoms are present for the majority of intensive care unit patients, including those with delirium. Symptom assessment in high-risk intensive care unit patients may lead to more focused interventions to avoid or minimize unnecessary suffering.