The major goal of this study was to evaluate physicians’ attitudes toward diagnostic approaches and the treatment of severe acute dyspnea in a patient with advanced cancer. The main findings showed that evidence-based first-line therapy with opioids was not the first choice of experienced senior physicians or physicians in training. Both groups of MDs ranked oxygen therapy and betamimetics as first-line treatment options. Furthermore, comparing the choices of different diagnostic options between the groups revealed a significant difference for the use of blood gas analysis (p=0.01), measuring oxygen saturation (p=0.048), and a trend toward a difference for auscultation.
In severely ill patients, appropriate symptom alleviation is the cornerstone of good medical care, and diagnostic procedures should always be accompanied by a consideration of their clinical consequences. Auscultation was chosen by almost all the senior physicians, whereas only about 80% of the physicians in training considered this to be an important diagnostic tool (p=0.076). Percussion was chosen rarely by both groups (37.8% of senior doctors vs. 25.0% of physicians in training, p=not significant). Other first-line investigations did not show any significant differences between the two groups. The measurement of oxygen saturation is often used in the assessment of dyspnea, but it is of limited value [5]. However, 82.9% of the senior physicians, but only 62.5% of the physicians in training, would choose this option (p=0.01). Second-line and third-line investigations, were only rarely chosen by both groups.
Our study also showed differences in the ranking and use of therapeutic options. Whereas the treatment of pain with opioids has become routine not only for doctors familiar with the concepts of palliative care, dyspnea in patients with advanced cancer or other palliative care situations remains difficult. Respiratory depression is a major concern, leading to the restrained application of opioids in this situation [27]. Borasio et al. evaluated attitudes toward patient care at the end of life by surveying 411 medical directors of neurological departments in Germany. The results revealed that 32% thought that it was illegal to administer analgesics in doses that risk respiratory depression, and 45% believed that treating terminal dyspnea with morphine was the same as euthanasia [28]. A French study asked 791 general practitioners and oncologists whether they would prescribe morphine as a first-line therapy to patients with terminal lung cancer suffering from dyspnea associated with cough and great anxiety. Half of the oncologists and 40% of the general practitioners stated that they would prescribe morphine in the presented case. The prescriptive attitude correlated with the physician’s age, professional background, communication skills, and attitudes toward terminally ill patients [29]. In our evaluation, 9.5% of all the MDs would apply opioids orally, 55.2% subcutaneously, and 39% intravenously in the presented case of a patient with advanced lung cancer and refractory dyspnea.
In summary, the management of dyspnea in terminally ill patients might often be inadequate [28, 29]. There is no higher risk of respiratory depression or increase of pCO2, even in opioid-naive patients [30, 31]. In addition to non-pharmacological therapies, the only validated treatment for ameliorating patients’ dyspnea is opioids administered either orally or parenterally [7, 32]. Thus far, no data support the assumption that the use of opioids for dyspnea management is associated with a reduction in the patient’s life expectancy. On the contrary, patients who receive appropriate symptom management might have prolonged survival due to a reduction in physical and psychological stress and exhaustion [11]. In cancer patients, the adverse effects of opioids, such as sleepiness, hypercapnia, or nausea, are infrequent, and the occurrence of transient sedation may also be related to sleep deprivation due to uncontrolled dyspnea [24]. Conversely, despite the use of opioids to control dyspnea, there have been no controlled trials to compare the efficacy of various agents, routes of administration, the starting dose, and the optimal dosage. A few controlled trials with low sample sizes studied the use of morphine in cancer patients, administered orally, subcutaneously, intravenously, intramuscularly, or nebulized [33–37]. Thus, it remains unclear which opioid is most effective and whether there are differences between the agents. Furthermore, data about the optimal starting dose and the best mode of application need to be evaluated in larger randomized trials [5]. Interestingly, in our study, the physicians in training would apply opioids subcutaneously significantly more often than the senior physicians (p=0.017).
Next to opioids, our study also explored the use of additional pharmacologic treatment options. Although no data support the use of bronchodilators (e.g., β-2 agonists) as a first-line treatment, 28 of the physicians in training chose this option, maybe by assuming a bronchospastic component as an explanation of the patient’s dyspnea. Another explanation could be that physicians in training are less reluctant to use a bronchodilator than an opioid. Regarding benzodiazepines, 32.5% of all the participating MDs would apply these drugs in the given scenario. So far, there is no evidence of a beneficial effect of benzodiazepines in controlling dyspnea, although recent research has concluded that midazolam as an upfront therapy might be beneficial for patients [9, 38–40]. However, a Cochrane review recommended the use of benzodiazepines only if first-line treatment has failed [38].
Oxygen as the initial therapeutic approach was ranked first in both groups and was among the treatment options chosen by 93.3% of all the MDs. In advanced cancer patients, two randomized studies compared the effects of supplemental oxygen and ambient air on dyspnea. Oxygen significantly increased oxygen saturation compared to ambient air in hypoxemic cancer patients at rest [24]. However, Booth et al. reported that ambient air was just as effective as oxygen in relieving dyspnea [41]. Until now, there have been no consensus guidelines on the use of supplemental oxygen for dyspneic cancer patients, but it appears reasonable to apply this option in dyspneic cancer patients with hypoxemia.
Finally, a previous study evaluated the attitudes of fourth-year medical students toward diagnostic and therapeutic approaches in a similar situation. Among the 423 participants, 92% considered oxygen the most important treatment option. However, 32.6% would also suggest the use of opioids as an option, which is comparable to our study results [42].