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Biomedical subjects

Scott R Gunn

Publications and source records attributed to Scott R Gunn.

8 recordsLinked to original sources

Ability of pulse contour and esophageal Doppler to estimate rapid changes in stroke volume.

OBJECTIVE: Two technologies to acquire beat-to-beat stroke volume values exist, pulse contour analysis and esophageal Doppler monitoring. Pulse contour analysis assumes fixed aortic impedance. Esophageal Doppler assumes a constant proportional descending aortic flow and diameter. These assumptions may not be correct as arterial tone or myocardial contractility vary. We tested these relationships in the setting of rapidly changing stroke volumes and different cardiovascular states over a period of 10-15 cardiac cycles. DESIGN AND SETTING: In a university research facility we compared beat-to-beat changes in stroke volume as measure by aortic root flow probe or conductance catheter to pulse contour analysis and stroke distance as measured by esophageal Doppler. SUBJECTS: Five purpose-bred research hounds. INTERVENTIONS: To obtain a wide range of rapidly changing stroke volumes measurements were made during transient inferior vena cava occlusion. Data were gathered under baseline conditions and during norepinephrine, nitroprusside, and dobutamine infusions. MEASUREMENTS AND RESULTS: The pulse contour stroke volumes and esophageal Doppler stroke distance paralleled flow probe stroke volumes under all conditions (R(2)=0.89 for all measures). However, the absolute changes and proportional changes and the absolute values for both surrogate measures differed from absolute stroke volumes. Bland-Altman analysis showed no consistent bias or degree of precision across all animals under any given cardiovascular state. CONCLUSIONS: Both pulse contour stroke volumes and esophageal Doppler derived stroke distance estimates yield significant correlations with aortic root flow probe. However, the absolute values, absolute changes, or proportional changes may not reflect actual stroke volumes as cardiovascular state varies, making their use in estimating absolute changes in stroke volume potentially inaccurate.

Animals↗

Equipment review: the success of early goal-directed therapy for septic shock prompts evaluation of current approaches for monitoring the adequacy of resuscitation.

A recent trial utilizing central venous oxygen saturation (SCVO2) as a resuscitation marker in patients with sepsis has resulted in its inclusion in the Surviving Sepsis Campaign guidelines. We review the evidence behind SCVO2 and its relationship to previous trials of goal-directed therapy. We compare SCVO2 to other tools for assessing the adequacy of resuscitation including physical examination, biochemical markers, pulmonary artery catheterization, esophageal Doppler, pulse contour analysis, echocardiography, pulse pressure variation, and tissue capnometry. It is unlikely that any single technology can improve outcome if isolated from an organized pattern of early recognition, algorithmic resuscitation, and frequent reassessment. This article includes a response to the journal's Health Technology Assessment questionnaire by the manufacturer of the SCVO2 catheter.

Biomarkers↗

Critical care medicine training and certification for emergency physicians.

Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine and critical care medicine. Critical care is a continuum that includes out-of-hospital, emergency department (ED), and ICU care teams. Both emergency medicine and critical care medicine require expertise in treating life-threatening acute illness, with many critically ill patients often presenting first to the ED. Increased patient volumes and acuity have resulted in longer ED lengths of stay and more critical care delivery in the ED. However, the majority of critical care medicine fellowships do not accept emergency medicine residents, and those who do successfully complete a fellowship do not have access to a US certification examination in critical care medicine. Despite these barriers, interest in critical care medicine training among emergency physicians is increasing. Dual emergency medicine- and critical care medicine-trained physicians will not only help alleviate the intensivist shortage but also strengthen critical care delivery in the ED and facilitate coordination at the ED-ICU interface. We therefore propose that all accreditation bodies work cooperatively to create a route to critical care medicine certification for emergency physicians who complete a critical care fellowship.

Certification↗

Critical care medicine training and certification for emergency physicians.

Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine and critical care medicine. Demand for critical care services is increasing. Unless the supply of intensivists increases, critically ill patients will not have access to intensivists. Recent critical care society recommendations include increased graduate medical education support and expansion of the J-1 visa waiver program for foreign medical graduates. This article proposes additional recommendations, based on strengthening the relationship between emergency medicine (EM) and critical care medicine (CCM). Critical care is a continuum that includes prehospital, emergency department (ED), and intensive care unit (ICU) care teams. Both EM and CCM require expertise in treating life-threatening acute illness, with many critically ill patients often presenting first to the ED. Increased patient volumes and acuity have resulted in longer ED lengths of stay and more critical care delivery in the ED. However, the majority of CCM fellowships do not accept EM residents, and those who successfully complete a fellowship do not have access to a U.S. certification exam in CCM. Despite these barriers, interest in CCM training among EM physicians is increasing. Dual EM/CCM-trained physicians not only will help alleviate the intensivist shortage but also will strengthen critical care delivery in the ED and facilitate coordination at the ED-ICU interface. We therefore propose that all accreditation bodies work cooperatively to create a route to CCM certification for emergency physicians who complete a critical care fellowship.

Certification↗