Acceptable ranges for vital signs during general anesthesia

Objective. Define the ranges for normal vital signs during general anesthesia.Methods. We studied 50 patients undergoing general anesthesia. We asked residents to state desirable ranges for each patient's systolic and diastolic blood pressure (BP), heart rate (HR), SpO₂, andPetCO₂ during induction, intubation, maintenance, and emergence from anesthesia. We called these ranges the clinical operating range (COR) and observed the frequency, duration, and magnitude of transgressions of these CORs. We also recorded whether the transgressions were treated or tolerated, or whether the COR values were changed.Results. Upper COR values in the maintenance phase for systolic BP were 38%±20% above the preoperative values and 30%±20% above the values recorded just before induction of anesthesia. Lower COR values in the maintenance phase for systolic BP were 27%±9% below preoperative, and 31%±11% below pre-induction values. For HR, upper and lower COR values in the maintenance phase were 53%±44% above and 38%±17% below preinduction values, respectively. Transgressions of COR values for BP and HR were common, treatment frequent, and redefinition of COR values rare.Conclusion. Clinicians recognize ranges for vital signs during uneventful anesthesia. These CORs may differ from one stage of anesthesia to the next. Transgressions of these ranges are common. Not all transgressions are treated.Reprints are not available.     

Transfusion has no effect on recurrence in hepatitis C after liver transplantation

Background: The literature suggests that blood product transfusions have a negative impact on the survival of liver transplant patients. We investigated the impact of intraoperative blood product usage on the survival of liver transplantation patients being transplanted for hepatitis C‐related end‐stage liver disease. In addition, we analyzed a potentially more sensitive metric, namely disease recurrence and fibrosis progression, obtained from follow‐up liver biopsies. Methods: We retrospectively studied 194 consecutive patients with hepatitis C virus (HCV) undergoing liver transplantation. To investigate the effect of red blood cell (RBC) or platelet transfusions on post‐transplant HCV recurrence, hepatic biopsy data from 4 months and 1 year after transplantation were studied. In addition, survival data were analyzed. Results: There was no effect of intraoperative RBC or platelet transfusion on either 1‐ or 5‐year patient survival following liver transplantation. There was no difference in HCV disease recurrence or progression of hepatic fibrosis at 4 months or 1 year attributable either to RBC or to platelet transfusion. Conclusion: This study was not able to confirm an effect on the survival of HCV‐infected liver transplant patients related to intraoperative transfusion of RBCs or platelets. In addition, these transfusions had no effect on HCV recurrence or fibrosis progression. This is not to condone a liberal transfusion practice, but rather to reassure that when clinically indicated, transfusion does not have a significant impact on patient survival or disease recurrence in HCV‐infected liver transplant patients.     

Partial right atrial inflow occlusion for controlled systemic hypotension during thoracic endovascular aortic repair

Controlled hypotension is sometimes necessary for accurate endograft deployment and adjunctive ballooning and stenting near the arch and proximal descending thoracic aorta. This article describes a technique in which a compliant occlusion balloon inflated in the right atrium is used to occlude the inflow from the inferior vena cava and reduce the cardiac preload. This reliably and effectively induces systemic hypotension to any desired level and is also able to be rapidly reversed. The technique has been used in 11 cases of thoracic endovascular aortic repairs with complete success and no procedure-related complications.     

An Integrated Coronary Circulation Teaching Model

Objectives: We present in this paper a model of the coronary circulation. This model is integrated with a model of the systemic circulation, and contains models for oxygen supply and demand. Methods: Three compartments are created: one for the right ventricle, one for the epicardial segment of the left ventricle and one for the endo-cardial segment of the left ventricle. The model was implemented in the Java programming language and contains a visual representation of the left and right ventricles which beat in real time. Color shading is used to represent the partial pressure of oxygen in the segments. A multitude of model parameters can be changed to simulate different scenarios. Results: The output of the model was characterized under different conditions and the results verified by clinicians. Conclusions: Educational models of human physiology can be very useful for a more indepth understanding of complete physiologic systems. The models must however have enough complexity, interaction with other systems, and realism to show the concepts being taught.     

A Randomized Trial of Heart Failure Disease Management in Skilled Nursing Facilities: Design and Rationale

BackgroundHeart failure (HF) disease management can improve health outcomes for older community dwelling patients with heart failure. HF disease management has not been studied in skilled nursing facilities, a major site of transitional care for older adults.Methods and anticipated resultsThe objective of this trial is to investigate if a HF- disease management program (HF-DMP) in skilled nursing facilities (SNF)s will decrease all-cause rehospitalizations for the first 60 days post-SNF admission. The trial is a randomized cluster trial to be conducted in 12 for-profit SNF in the greater Cleveland area. The study population is inclusive of patients with HF regardless of ejection fraction but excludes those patients on dialysis and with a life expectancy of 6 months or less. The HF-DMP includes 7 elements considered standard of care for patients with HF documentation of left ventricular function, tracking of weight and symptoms, medication titration, discharge instructions, 7-day follow-up appointment post-SNF discharge, and patient education. The HF-DMP is conducted by a research nurse tasked with adhering to each element of the program and regularly audited to maintain fidelity of the program. Additional outcomes include health status, self-care management, and discharge destination.ConclusionsThe SNF-Connect Trial is the first trial of its kind to assess if a HF-DMP will improve outcomes for patients in SNFs. This trial will provide evidence on the effectiveness of HF-DMP to improve outcomes for older frail HF patients undergoing postacute rehabilitation.