Evaluation of multiple modes of oximetry monitoring as an index of splanchnic blood flow in a newborn lamb model of hypoxic, ischemic, and hemorrhagic stress.

Early and aggressive treatment of circulatory failure is associated with increased survival, highlighting the need for monitoring methods capable of early detection. Vasoconstriction and decreased oxygenation of the splanchnic circulation are a sentinel response of the cardiovasculature during circulatory distress. Thus, we measured esophageal oxygenation as an index of decreased tissue oxygen delivery caused by three types of ischemic insult, occlusive decreases in mesenteric blood flow, and hemodynamic adaptations to systemic hypoxia and simulated hemorrhagic stress. Five anesthetized lambs were instrumented for monitoring of mean arterial pressure, mesenteric artery blood flow, central venous hemoglobin oxygen saturation, and esophageal and buccal microvascular hemoglobin oxygen saturation (StO2). The sensitivities of oximetry monitoring to detect cardiovascular insult were assessed by observing responses to graded occlusion of the descending aorta, systemic hypoxia due to decreased FIO2, and acute hemorrhage. Decreases in mesenteric artery flow during aortic occlusions were correlated with decreased esophageal StO2 (R = 0.41). During hypoxia, esophageal StO2 decreased significantly within 1 min of initiation, whereas buccal StO2 decreased within 3 min, and central venous saturation did not change significantly. All modes of oximetry monitoring and arterial blood pressure were correlated with mesenteric artery flow during acute hemorrhage. Esophageal StO2 demonstrated a greater decrease from baseline levels as well as a more rapid return to baseline levels during reinfusion of the withdrawn blood. These experiments suggest that monitoring esophageal StO2 may be useful in the detection of decreased mesenteric oxygen delivery as may occur in conditions associated with hypoperfusion or hypoxia.

Telemedicine pre-anesthesia evaluation: a randomized pilot trial.

OBJECTIVE: Pre-anesthesia evaluation allows discovery of conditions affecting perioperative planning, but when inadequate it may be associated with delays, cancellations, and preventable adverse events. Not all patients who could benefit will keep appointments. Telemedicine pre-anesthesia evaluation may provide for safe patient care while reducing patient inconvenience and cost. Herein we investigate the impact of telemedicine pre-anesthesia evaluation on perioperative processes. SUBJECTS AND METHODS: This was a single-center prospective randomized trial in 200 adults scheduled for head and neck surgery at Loma Linda University Medical Center, Loma Linda, CA. Consenting patients not meeting criteria for telephone pre-anesthesia evaluation were randomly assigned to the in-person or telemedicine group. The primary outcome measure was inadequate evaluation caused surgical delay or cancellation. Secondary measures included prediction of difficult airway management and concordance of physical examination. RESULTS: After consent, 40 patients met criteria for telephone screening. Five patients canceled surgery, none for inadequate pre-anesthesia evaluation; thus 155 were randomized. Delay occurred in 1 telemedicine patient awaiting results performed outside our system. Missing documentation at the time of the visit was less common for telemedicine. Difficult airway management was predicted equally but had low positive predictive value. Heart and lung examinations were highly concordant with day of surgery documentation. Patients and providers were highly satisfied with both evaluation modalities. CONCLUSIONS: Telemedicine and in-person evaluations were equivalent, with high patient and provider satisfaction. Telemedicine provides potential patient time and cost saving benefits without more day of surgery delay in our system. A prospective trial of patients from multiple surgical specialty clinics is warranted.

Outcome impact of goal directed fluid therapy during high risk abdominal surgery in low to moderate risk patients: a randomized controlled trial.

Intraoperative goal directed fluid therapy (GDT) guided by an arterial pressure-based cardiac output system has been reported to improve gastrointestinal (GI) recovery in high-risk patients. This study evaluates the impact of this approach on GI recovery in low to moderate risk patients undergoing major abdominal surgery. IRB approved randomized controlled trial in low to moderate risk adults scheduled for major surgery. Patients were randomized to standard (n = 20) or GDT (n = 18) groups, whose fluids were managed to maintain stroke volume variation (SVV) <12 %. The primary outcome measure was GI recovery. Additional measures included quality of recovery score. Continuous, non-normally distributed by Mann-Whitney test; ordinal and nominal by Chi square analysis. GDT patients had lower average intraoperative SVV. The GDT group had faster return of GI function (p = 0.004) and higher quality of recovery scores. In low to moderate risk patients undergoing major abdominal surgery, intraoperative GDT guided by SVV optimization was associated with faster restoration of GI recovery and higher quality of recovery scores. These results suggest that outcome benefits related to the use of an intraoperative goal directed fluid protocol guided by SVV are not limited to high-risk patients.