Anthony Carlese

Monitoring of the Adult Patient on Venoarterial Extracorporeal Membrane Oxygenation

Venoarterial extracorporeal membrane oxygenation (VA ECMO) provides mechanical support to the patient with cardiac or cardiopulmonary failure. This paper reviews the physiology of VA ECMO including the determinants of ECMO flow and gas exchange. The efficacy of this therapy may be determined by assessing patient hemodynamics and device flow, overall gas exchange support, markers of adequate oxygen delivery, and pulsatility of the arterial blood pressure waveform.

Pulseless Oximetry: A Preliminary Evaluation

BACKGROUND Pulse oximetry fails when pulsations are weak or absent, common in patients with continuous flow left ventricular assist devices (LVADs). We developed a method to measure arterial oxygenation (Sao2) noninvasively in pulseless patients with LVADs. METHODS The technique involves 5- to 10-s occlusions of radial and ulnar arteries on one hand. A fingertip is transilluminated alternately with light-emitting diodes emitting 660 nm (red) and 905 nm (infrared). During the approximately 1 s after release of occlusion, changing attenuance of each wavelength is measured and their red/infrared arterial blood attenuance ratio (R/IR) calculated. We studied five normal subjects breathing hyperoxic, normoxic, or hypoxic gas mixtures to establish a calibration curve, using standard pulse oximetry as the gold standard. We also studied seven pulseless patients with LVADs (two studied twice) at clinically determined oxygenation. RESULTS Normal subject data showed close correlation of oxygen saturation by pulse oximetry (Spo2) with R/IR, (Spo2 = 111 - [26.7 × R/IR]; R2 = 0.975). For patients with LVADs, predicted Sao2 (from the calibration curve) tended to underestimate measured Sao2 (from arterial blood) by a clinically insignificant 1.1 ± 1.6 percentage points (mean ± SD), maximum 3.4 percentage points. CONCLUSIONS Preliminary results in a small number of patients demonstrate that pulseless oximetry can be used to estimate arterial saturation with acceptable accuracy. A noninvasive oximeter that does not rely on pulsatile flow would be a valuable advance in assessing oxygenation in patients with LVADs, for whom the only current option is arterial puncture, which is painful, risks arterial injury, and only provides a snapshot evaluation of oxygenation.

Being a Successful Medically Trained Surgical Intensivist Valuable Lessons Gained From Experience

Despite the growing demand for board- certified intensivists in the United States, the roles for medically trained intensivists (MTIs) in leadership positions in surgical ICUs remain limited. This report explores some of the challenges facing internal medicine (IM) critical care fellows who are considering careers as surgical intensivists or MTIs who are moving to a surgical ICU. A practical framework is provided for attaining these jobs and thriving in these positions once obtained. The article explores the nuances between medical and surgical ICUs and concludes by describing how surgical critical care can be a gratifying career for the IM-trained intensivist and an asset to the surgical ICU.

Severe Burnout Is Common Among Critical Care Physician Assistants: Retracted

Objectives: To determine the prevalence of and risk factors for burnout among critical care medicine physician assistants. Design: Online survey. Settings: U.S. ICUs. Subjects: Critical care medicine physician assistant members of the Society of Critical Care Medicine coupled with personal contacts. Interventions: None. Measurements and Main Results: We used SurveyMonkey to query critical care medicine physician assistants on demographics and the full 22-question Maslach Burnout Inventory, a validated tool comprised of three subscales—emotional exhaustion, depersonalization, and achievement. Multivariate regression was performed to identify factors independently associated with severe burnout on at least one subscale and higher burnout scores on each subscale and the total inventory. From 431 critical care medicine physician assistants invited, 135 (31.3%) responded to the survey. Severe burnout was seen on at least one subscale in 55.6%—10% showed evidence of severe burnout on the “exhaustion” subscale, 44% on the “depersonalization” subscale, and 26% on the “achievement” subscale. After multivariable adjustment, caring for fewer patients per shift (odds ratio [95% CI]: 0.17 [0.05–0.57] for 1–5 vs 6–10 patients; p = 0.004) and rarely providing futile care (0.26 [0.07–0.95] vs providing futile care often; p = 0.041) were independently associated with having less severe burnout on at least one subscale. Those caring for 1–5 patients per shift and those providing futile care rarely also had a lower depersonalization scores; job satisfaction was independently associated with having less exhaustion, less depersonalization, a greater sense of personal achievement, and a lower overall burnout score. Conclusions: Severe burnout is common in critical care medicine physician assistants. Higher patient-to-critical care medicine physician assistant ratios and provision of futile care are risk factors for severe burnout.