October 2002 / Volume 47 / Number 10 / Page 1158
A Dyspnea Evaluation Protocol for Respiratory Therapists: A Feasibility Study
Even when adequate arterial blood gas values and acid-base balance are restored, mechanical ventilation does not invariably alleviate dyspnea experienced by patients in respiratory failure. Because they are endotracheally intubated, mechanically ventilated patients are unable to speak and therefore cannot complain about shortness of breath or other forms of distress unless asked specifically. Although mechanically ventilated patients often appear apprehensive or resistive when short of breath, there are no physical findings associated specifically with dyspnea. Thus, shortness of breath can develop or become worse during mechanical ventilation without the awareness of bedside caregivers.
Clinical investigators have begun to study the prevalence and severity of dyspnea experienced by patients undergoing mechanical ventilation, using symptom assessment scales or numerical or visual analogue scales. Published studies have shown that these scales can serve as useful tools for quantifying dyspnea during the progress of respiratory failure and in response to therapy.
The observation that dyspnea in mechanically ventilated patients can be evaluated quantitatively raises the question of whether systematic dyspnea assessment can facilitate clinical quality improvement efforts and thus improve regular patient care. Nurses at many hospitals now routinely assess mechanically ventilated patients for the presence and severity of pain, especially after trauma or surgery. Might similar approaches also be employed to detect and treat shortness of breath during mechanical ventilation? If so, respiratory therapists (RTs) may be ideally suited to conduct those assessments. RTs routinely perform and record detailed physiologic assessments of mechanically ventilated patients, at frequent intervals throughout the day and night. Along with the assessment of the ventilator settings and alarms it is also important to assess the patient-ventilator interface. An evaluation of patient dyspnea is essential in that assessment. Addition of a brief dyspnea assessment to physiologic evaluations might add little time to regularly scheduled bedside visits. Therapists are suitably trained to evaluate dyspnea in the context of the other information on respiratory and ventilator function obtained during their visits. RTs may also be able to alleviate dyspnea directly in some instances by such interventions as adjusting the ventilator, suctioning the airway, or administering a bronchodilator.
In this study we sought to evaluate the feasibility of adding a brief dyspnea evaluation protocol to routine bedside assessments of mechanically ventilated patients in the medical and surgical intensive care units (ICUs) of a university teaching hospital by measuring the average time required to complete the protocol and the compliance rate of RTs assigned to use the protocol. This study also afforded an opportunity to estimate the prevalence of dyspnea in the diverse population of patients undergoing mechanical ventilation at our hospital.