Nitin Puri

Inhaled Nitric Oxide and Inhaled Prostacyclin in Acute Respiratory Distress Syndrome: What is the Evidence?

The mortality for acute respiratory distress syndrome remains unacceptably high. Two vasodilators, inhaled prostacyclin and inhaled nitric oxide, are reviewed in this article. Knowledge of inhaled prostacyclin has grown substantially in the past 30 years, but less research exists about its utility in acute respiratory distress syndrome. Inhaled prostacyclin and other prostaglandin derivatives are used in acute respiratory distress syndrome with increasing frequency. Currently, only randomized controlled trials exist for inhaled nitric oxide in acute respiratory distress syndrome patients. Randomized controlled trials with consistent dosing methods are needed for both vasodilators to better define their role in the treatment of acute respiratory distress syndrome.

Excessive dynamic airway collapse for the internist: new nomenclature or different entity?

Excessive dynamic airway collapse (EDAC) refers to abnormal and exaggerated bulging of the posterior wall within the airway lumen during exhalation. This condition is pathological if the reduced airway lumen is <50% of the normal. It is a relatively new disease entity that is recognised more easily now with the increased use of multi-detector row CT. EDAC is often asymptomatic and diagnosed incidentally. Although the term excessive dynamic airway collapse is often used interchangeably with tracheobronchomalacia, both entities represent morphologically and physiologically distinct processes. Considering the confusion between the two entities, the prevalence of stand-alone EDAC remains unclear. The prevalence of tracheobronchomalacia and EDAC depends upon the patient population, associated comorbidities and underlying aetiologies, diagnostic tools used and criteria used to define the airway collapse. This review defines EDAC and describes its pathophysiology, precipitating factors, associated symptoms and potential treatments.

Can't We All Get Along?

Critical Care Medicine www.ccmjournal.org 2023 Approximately 55 years ago, Weil and Shubin (1) set up a four-bed shock unit in Los Angeles, a forebearer to the modern ICU. These cardiologists recognized the central role the heart played in shock, and they incorporated intensive hemodynamic monitoring into their units. The pulmonary artery catheter helped further the fields of cardiology and critical care by introducing a generation of trainees to hemodynamic alterations in the critically ill (2). Although critical care has evolved into its own specialty, coronary care units (CCU) and cardiac surgery ICUs (CSICU) within most training programs have remained largely insular, with only 0.8% of CCUs covered by cardiologists with a critical care background (3). The impact of this on critical care trainees is unclear although the potential for a knowledge gap around cardiovascular diseases exists. This has important implications for the practice of critical care as the burden of acute and chronic cardiovascular comorbidities among critically ill patients increases (4). In this issue of Critical Care Medicine, Hill et al (5) present a survey of critical care trainees to understand the state of cardiovascular critical care education in the United States. The response rate was low (134 of 1,771 surveys [7.6%]), including negligible response from the American West (0.7%). Also of note, 57.5% of respondents were in their first year of fellowship. Depending on the time of year, the trainees responded to the survey, the responses may be more reflective of general surgery, anesthesia, and internal medicine training. Hill et al (5) found significant differences in perceived adequacy of training for key cardiovascular critical care procedures with internal medicine–based critical care trainees the most confident of their skillset and pulmonary/ critical care medicine providers the least confident. Specifically, one of the reasons pulmonary/critical care medicine trainees did not feel comfortable is that only 27% participate in a CCU or CSICU rotation (5). The study highlights significant gaps in knowledge among trainees around intra-aortic balloon pump (IABP) counter pulsation and pacemaker management. This is important as up to 60% of intubated cardiogenic shock patients require IABP and 15% require a temporary pacemaker (6). This is particularly concerning because IABP is the most basic form of mechanical circulatory support, and because other forms of mechanical circulatory support including left ventricular assist devices and total artificial hearts are increasingly used. Intensivists of all backgrounds will need to care for them (7). The survey has serious implications beyond the general medical ICU population because this generation of trainees may be poorly equipped to care for patients in a CCU or a CSICU. These patient populations continue to have more medical comorbidities and are increasingly elderly, requiring more medical support (8, 9). Due to these reasons, the American Heart Association and Thoracic Surgeons have advocated the need for increased cardiovascular critical care training among their own workforce (10, 11). Yet, the cardiac surgery workforce is projected to be deficient by 2020 and as previously stated there is already a paucity of cardiology-trained intensivists (12). Although the deficiency of satisfactorily trained critical care providers for patients with primary cardiac disease was not the focus of this article, it is important to note that pulmonary, medical, surgical and anesthesia critical care doctors continue to provide care for patients in both CSICU and CCUs with varying models of care (10, 13). Although the major findings of the survey will likely hold true, a higher response with a larger sample size survey would be ideal. The most important first step in addressing the deficiencies noted is increased cooperation between cardiology and critical care. These two specialties have an intertwined history and need to work together to address educational and research deficiencies (14). Critical care programs must offer educational opportunities in CCUs and CSICUs. Hill et al (5) are also correct that critical care trainees would benefit from a standardized transthoracic echocardiography educational program to enable credentialing and competency (15). A model for this educational program can be taken from our Emergency Medicine colleagues, who have integrated this into their curriculum (16). This would guarantee dedicated echocardiography time and hopefully lead to enhanced understanding of hemodynamics in the post–pulmonary artery catheter era. An aging population, increasing comorbidities, and more advanced technologies will make critical care more challenging in the coming years. Hill et al (5) have highlighted an important issue for critical care training programs to tackle. Identifying key knowledge gaps among trainees and building bridges Copyright