Incentive Spirometry in Non-critically Ill Hospitalized Patients With Acute Respiratory Failure

In recent years the focus in medicine has shifted towards efficient utilization of resources and improving patient outcomes. Incentive spirometry (IS) is a tool that mimics the natural process of yawning or sighing by allowing the user to take deep breaths in a controlled setting. This is a lung inflating maneuver that has been suggested to decrease the rate of pulmonary complications. The focus of utilization of IS and current studies has been predominantly on the post-operative surgical patient population. The mechanism of pulmonary complications in surgical patients is mixed in etiology possibly related to anesthesia, analgesics, pain and immobility leading to shallow breathing and subsequent atelectasis with concurrent hypoxia and risk of infection. The use of lung expanding maneuvers such as that provided by IS are thought to counteract shallow breathing thereby improving pulmonary outcomes. However, contrary to physiological theory, multiple studies and meta-analysis have failed to demonstrate its efficacy. The results of these studies are in direct conflict with what is expected scientifically.

The authors of this paper set out to find the reason for discordant data in existing literature, and found that there have been multiple methodological limitations associated with existing studies; hence, interpretation and recommendations based on current data should be done with caution. The common denominator in repeated criticisms of existing studies is lack of reporting on patient compliance with IS after it is prescribed. This is a major confounder, in clinical experience IS is often observed sitting dormant at patients' bedside. These observations are in synchrony with criticisms reported in literature and raise serious questions about validity of existing data that should be acknowledged. Despite lack of convincing evidence, IS is routinely prescribed by physicians in hospital medicine. IS is a low cost tool, nevertheless, the increasing frequency of its use is accumulating to a larger proportion of health care costs. This calls for further evaluation with a study of higher methodological quality to address the limitations of prior studies.

The scope of this study is different than that of existing studies in that it will evaluate the utility of IS in general medical patients. The sub-set of patients that are the focus of this study are those admitted with the chief complaint of "shortness of breath." The disease process in the former group leading to shortness of breath includes fluid over-load such as that in congestive heart failure, or an underlying lung process such as pneumonia, COPD, and/or pulmonary embolism. There is a parallel between mechanism of hypoxia in these patients and surgical patients in that these patients too often have pain and take high doses of analgesics, have shallow monotonous breathing and are immobile for long periods of time. From a physiological standpoint sustained maximal inhalation maneuvers may reverse and prevent progression of atelectasis by maintaining airway patency in all patients with shallow breathing of varying etiology not just the surgical sub-set.

In a tertiary center community teaching hospital the effectiveness of IS in general medical wards will be evaluated using a single center randomized clinical trial. The goal is to offer a study that overcomes the limitations of prior studies. Lack of strong evidence based data has led to inconsistencies in practice of physicians leading to higher health care costs. The authors hope to design a study of high methodological quality to assess the effectiveness of IS in medical patients; thereby closing the knowledge gap in evidence based practices that may aid physicians in their decision to utilize IS.