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Physician-led perioperative surgical home models are developing as a method for improving the American health care system. These models are novel, team-based approaches that help to provide continuity of care throughout the perioperative period. Another avenue for improving care for surgical patients is the use of enhanced recovery after surgery pathways. These are well-described methods that have shown to improve perioperative outcomes. An established perioperative surgical home model can help implementation, efficiency, and adherence to enhanced recovery after surgery pathways. For these reasons, the Tennessee Valley Healthcare System, Nashville Veterans Affairs Medical Center created an Anesthesiology Perioperative Care Service that provides comprehensive care to surgical patients from their preoperative period through the continuum of their hospital course and postdischarge follow-up. In this brief report, we describe the development, implementation, and preliminary outcomes of the service.

Background Accurate assessment of volume status to direct dialysis remains a clinical challenge. Despite current attempts at volume-directed dialysis, inadequate dialysis and intradialytic hypotension (IDH) are common occurrences. Peripheral venous waveform analysis has recently been developed as a method to accurately determine intravascular volume status through algorithmic quantification of changes in the waveform that occur at different volume states. A noninvasive method to capture peripheral venous signals is described (Non-Invasive Venous waveform Analysis, NIVA). The objective of this proof-of-concept study was to characterize changes in NIVA signal with dialysis. We hypothesized that there would be a change in signal after dialysis and that the rate of intradialytic change in signal would be predictive of IDH. Methods Fifty subjects undergoing inpatient hemodialysis were enrolled. A 10-mm piezoelectric sensor was secured to the middle volar aspect of the wrist on the extremity opposite to the access site. Signals were obtained fifteen minutes before, throughout, and up to fifteen minutes after hemodialysis. Waveforms were analyzed after a fast Fourier transformation and identification of the frequencies corresponding to the cardiac rate, with a NIVA value generated based on the weighted powers of these frequencies. Results Adequate quality (signal to noise ratio > 20) signals pre- and post- dialysis were obtained in 38 patients (76%). NIVA values were significantly lower at the end of dialysis compared to pre-dialysis levels (1.203 vs 0.868, p < 0.05, n = 38). Only 16 patients had adequate signals for analysis throughout dialysis, but in this small cohort the rate of change in NIVA value was predictive of IDH with a sensitivity of 80% and specificity of 100%. Conclusions This observational, proof-of-concept study using a NIVA prototype device suggests that NIVA represents a novel and non-invasive technique that with further development and improvements in signal quality may provide static and continuous measures of volume status to assist with volume directed dialysis and prevent intradialytic hypotension.

Background Measuring fluid status during intraoperative hemorrhage is challenging, but detection and quantification of fluid overload is far more difficult. Using a porcine model of hemorrhage and over-resuscitation, it is hypothesized that centrally obtained hemodynamic parameters will predict volume status more accurately than peripherally obtained vital signs. Methods Eight anesthetized female pigs were hemorrhaged at 30 ml/min to a blood loss of 400 ml. After each 100 ml of hemorrhage, vital signs (heart rate, systolic blood pressure, mean arterial pressure, diastolic blood pressure, pulse pressure, pulse pressure variation) and centrally obtained hemodynamic parameters (mean pulmonary artery pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac output) were obtained. Blood volume was restored, and the pigs were over-resuscitated with 2,500 ml of crystalloid, collecting parameters after each 500-ml bolus. Hemorrhage and resuscitation phases were analyzed separately to determine differences among parameters over the range of volume. Conformity of parameters during hemorrhage or over-resuscitation was assessed. Results During the course of hemorrhage, changes from baseline euvolemia were observed in vital signs (systolic blood pressure, diastolic blood pressure, and mean arterial pressure) after 100 ml of blood loss. Central hemodynamic parameters (mean pulmonary artery pressure and pulmonary capillary wedge pressure) were changed after 200 ml of blood loss, and central venous pressure after 300 ml of blood loss. During the course of resuscitative volume overload, changes were observed from baseline euvolemia in mean pulmonary artery pressure and central venous pressure after 500-ml resuscitation, in pulmonary capillary wedge pressure after 1,000-ml resuscitation, and cardiac output after 2,500-ml resuscitation. In contrast to hemorrhage, vital sign parameters did not change during over-resuscitation. The strongest linear correlation was observed with pulmonary capillary wedge pressure in both hemorrhage (r2 = 0.99) and volume overload (r2 = 0.98). Conclusions Pulmonary capillary wedge pressure is the most accurate parameter to track both hemorrhage and over-resuscitation, demonstrating the unmet clinical need for a less invasive pulmonary capillary wedge pressure equivalent. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Background A perioperative surgical home, the Anesthesia Perioperative Care Service (APCS), was created to execute enhanced recovery after surgery pathways for total knee and total hip arthroplasty patients at the Tennessee Valley Health System Nashville VA Medical Center. We hypothesized that the APCS would be associated with reduced length of stay, in-hospital and post-discharge opioid exposure, costs, and hospital readmissions. Methods Data were collected for all patients admitted to the Nashville VA Medical Center following their respective surgery, for 400 days after the initiation of the APCS and