Brenton Alexander

Implementation of a Total Joint Replacement-Focused Perioperative Surgical Home: A Management Case Report

BACKGROUND:The perioperative setting in the United States is noted for variable and fragmented care that increases the chance for errors and adverse outcomes as well as the overall cost of perioperative care. Recently, the American Society of Anesthesiologists put forward the Perioperative Surgical Home (PSH) concept as a potential solution to this problem. Although the PSH concept has been described previously, “real-life” implementation of this new model has not been reported. METHODS:Members of the Departments of Anesthesiology and Perioperative Care and Orthopedic Surgery, in addition to perioperative hospital services, developed and implemented a series of clinical care pathways defining and standardizing preoperative, intraoperative, postoperative, and postdischarge management for patients undergoing elective primary hip (n = 51) and knee (n = 95) arthroplasty. We report on the impact of the Total Joint Replacement PSH on length of hospital stay (LOS), incidence of perioperative blood transfusions, postoperative complications, 30-day readmission rates, emergency department visits, mortality, and patient satisfaction. RESULTS:The incidence of major complication was 0.0 (0.0–7.0)% and of perioperative blood transfusion was 6.2 (2.9–11.4)%. In-hospital mortality was 0.0 (0.0–7.0)% and 30-day readmission was 0.7 (0.0–3.8)%. All Surgical Care Improvements Project measures were at 100.0 (93.0–100.0)%. The median LOS for total knee arthroplasty and total hip arthroplasty, respectively, was (median (95% confidence interval [interquartile range]) 3 (2–3) [2–3] and 3 (2–3) [2–3] days. Approximately half of the patients were discharged to a location other than their customary residence (70 to skilled nursing facility, 1 to rehabilitation, 39 to home with organization health services, and 36 to home). CONCLUSIONS:We believe that our experience with the Total Joint Replacement PSH program provides solid evidence of the feasibility of this practice model to improve patient outcomes and achieve high patient satisfaction. In the future, the impact of LOS on cost will have to be better quantified. Specifically, future studies comparing PSH to traditional care will have to include consideration of postdischarge care, which are drivers of the perioperative costs.

Non-invasive continuous blood pressure monitoring: a review of current applications

Blood pressure monitoring has come a long way from the initial observations made by Reverend Hales in the 18th century. There are none that deny the importance of monitoring perioperative blood pressure; however, the limited ability of the current prevalent technology (oscillometric blood pressure monitoring) to offer continuous blood pressure measurements leaves room for improvement. Invasive monitoring is able to detect beat-to-beat blood pressure measurement, but the risks inherent to the procedure make it unsuitable for routine use except when this risk is outweighed by the benefits. This review focuses on the discoveries which have led up to the current blood pressure monitoring technologies, and especially the creation of those offering non-invasive but continuous blood pressure monitoring capabilities, including their methods of measurement and limitations.

Comparison of noninvasive cardiac output measurements using the Nexfin monitoring device and the esophageal Doppler

STUDY OBJECTIVE To evaluate the validity of cardiac output (CO) measurements obtained using the Nexfin device in comparison to those obtained with the esophageal Doppler in steady-state conditions and after phenylephrine administration. DESIGN Prospective observational study. SETTING Operating room of a North American academic medical center. PATIENTS 25 ASA physical status 1, 2, and 3 patients referred for abdominal or orthopedic surgeries. INTERVENTIONS After endotracheal intubation, patients who presented with a 20% or greater decrease in mean arterial pressure (MAP) received an intravenous (IV) bolus of 100 μg of phenylephrine. If MAP was still 20% lower than the patients baseline level at least 10 minutes after the first vasopressor treatment, a second bolus of 100 μg of phenylephrine was given. MEASUREMENTS CO was measured simultaneously by esophageal Doppler (CO(ED)) and Nexfin (CO(NXF)) at baseline and when blood pressure peaked after an IV 100 μg phenylephrine bolus. Comparisons were then made between the two devices to evaluate the ability of the Nexfin device to track changes in CO. MAIN RESULTS 66 pairs of data were obtained. Mean CO(ED) and CO(NXF) were 4.7 ± 1.8 L/min and 5.6 ± 2.0 L/min, respectively. There was a significant relationship between CO(ED) and CO(NXF) (r(2) = 0.82; P < 0.001). The agreement between CO(ED) and CO(NXF) was 0.88 ± 0.86 L/min (Bland Altman). The mean percent error (Critchley and Critchley) of CO(NXF) versus CO(ED) was 37%. Trending analysis found a 94% concordance between changes in CO(ED) and CO(NXF) after phenylephrine administration. CONCLUSIONS Intraoperative CO measurement using the Nexfin device has a strong correlation with CO measured by esophageal Doppler.

Impact Assessment of Perioperative Point-of-Care Ultrasound Training on Anesthesiology Residents

Background:The perioperative surgical home model highlights the need for trainees to include modalities that are focused on the entire perioperative experience. The focus of this study was to design, introduce, and evaluate the integration of a whole-body point-of-care (POC) ultrasound curriculum (Focused periOperative Risk Evaluation Sonography Involving Gastroabdominal Hemodynamic and Transthoracic ultrasound) into residency training. Methods:For 2 yr, anesthesiology residents (n = 42) received lectures using a model/simulation design and half were also randomly assigned to receive pathology assessment training. Posttraining performance was assessed through Kirkpatrick levels 1 to 4 outcomes based on the resident satisfaction surveys, multiple-choice tests, pathologic image evaluation, human model testing, and assessment of clinical impact via review of clinical examination data. Results:Evaluation of the curriculum demonstrated high satisfaction scores (n = 30), improved content test scores (n = 37) for all tested categories (48 ± 16 to 69 ± 17%, P < 0.002), and improvement on human model examinations. Residents randomized to receive pathology training (n = 18) also showed higher scores compared with those who did not (n = 19) (9.1 ± 2.5 vs. 17.4 ± 3.1, P < 0.05). Clinical examinations performed in the organization after the study (n = 224) showed that POC ultrasound affected clinical management at a rate of 76% and detected new pathology at a rate of 31%. Conclusions:Results suggest that a whole-body POC ultrasound curriculum can be effectively taught to anesthesiology residents and that this training may provide clinical benefit. These results should be evaluated within the context of the perioperative surgical home.

Accuracy and precision of non-invasive cardiac output monitoring devices in perioperative medicine: a systematic review and meta-analysis†

Cardiac output (CO) measurement is crucial for the guidance of therapeutic decisions in critically ill and high-risk surgical patients. Newly developed completely non-invasive CO technologies are commercially available; however, their accuracy and precision have not recently been evaluated in a meta-analysis. We conducted a systematic search using PubMed, Cochrane Library of Clinical Trials, Scopus, and Web of Science to review published data comparing CO measured by bolus thermodilution with commercially available non-invasive technologies including pulse wave transit time, non-invasive pulse contour analysis, thoracic electrical bioimpedance/bioreactance, and CO2 rebreathing. The non-invasive CO technology was considered acceptable if the pooled estimate of percentage error was <30%, as previously recommended. Using a random-effects model, sd, pooled mean bias, and mean percentage error were calculated. An I2 statistic was also used to evaluate the inter-study heterogeneity. A total of 37 studies (1543 patients) were included. Mean CO of both methods was 4.78 litres min−1. Bias was presented as the reference method minus the tested methods in 15 studies. Only six studies assessed the random error (repeatability) of the tested device. The overall random-effects pooled bias (limits of agreement) and the percentage error were −0,13 [−2.38 , 2.12] litres min−1 and 47%, respectively. Inter-study sensitivity heterogeneity was high (I2=83%, P<0.001). With a wide percentage error, completely non-invasive CO devices are not interchangeable with bolus thermodilution. Additional studies are warranted to demonstrate their role in improving the quality of care.

Clinical review: Does it matter which hemodynamic monitoring system is used?

Hemodynamic monitoring and management has greatly improved during the past decade. Technologies have evolved from very invasive to non-invasive, and the philosophy has shifted from a static approach to a functional approach. However, despite these major changes, the critical care community still has potential to improve its ability to adopt the most modern standards of research methodology in order to more effectively evaluate new monitoring systems and their impact on patient outcome. Today, despite the huge enthusiasm raised by new hemodynamic monitoring systems, there is still a big gap between clinical research studies evaluating these monitors and clinical practice. A few studies, especially in the perioperative period, have shown that hemodynamic monitoring systems coupled with treatment protocols can improve patient outcome. These trials are small and, overall, the corpus of science related to this topic does not yet fit the standard of clinical research methodology encountered in other specialties such as cardiology and oncology. Larger randomized trials or quality improvement processes will probably answer questions related to the real impact of these systems.

Comparison of the didactic lecture with the simulation/model approach for the teaching of a novel perioperative ultrasound curriculum to anesthesiology residents ☆

STUDY OBJECTIVE To expose residents to two methods of education for point-of-care ultrasound, a traditional didactic lecture and a model/simulation-based lecture, which focus on concepts of cardiopulmonary function, volume status, and evaluation of severe thoracic/abdominal injuries; and to assess which method is more effective. DESIGN Single-center, prospective, blinded trial. SETTING University hospital. SUBJECTS Anesthesiology residents who were assigned to an educational day during the two-month research study period. MEASUREMENTS Residents were allocated to two groups to receive either a 90-minute, one-on-one didactic lecture or a 90-minute lecture in a simulation center, during which they practiced on a human model and simulation mannequin (normal pathology). Data points included a pre-lecture multiple-choice test, post-lecture multiple-choice test, and post-lecture, human model-based examination. Post-lecture tests were performed within three weeks of the lecture. An experienced sonographer who was blinded to the education modality graded the model-based skill assessment examinations. Participants completed a follow-up survey to assess the perceptions of the quality of their instruction between the two groups. MAIN RESULTS 20 residents completed the study. No differences were noted between the two groups in pre-lecture test scores (P = 0.97), but significantly higher scores for the model/simulation group occurred on both the post-lecture multiple choice (P = 0.038) and post-lecture model (P = 0.041) examinations. Follow-up resident surveys showed significantly higher scores in the model/simulation group regarding overall interest in perioperative ultrasound (P = 0.047) as well understanding of the physiologic concepts (P = 0.021). CONCLUSIONS A model/simulation-based based lecture series may be more effective in teaching the skills needed to perform a point-of-care ultrasound examination to anesthesiology residents.

The Ability of esCCO and ECOM Monitors to Measure Trends in Cardiac Output During Alveolar Recruitment Maneuver After Cardiac Surgery: A Comparison with the Pulmonary Thermodilution Method.

BACKGROUND:Alveolar recruitment maneuvers (ARMs) are known to improve perioperative morbidity but can transiently impact cardiac output (CO). This reproducible hemodynamic perturbation creates a clinical opportunity to test multiple devices during acute changes in CO. The objective of this study was to evaluate the ability of 2 minimally invasive CO monitors, the ECOM™ (Endotracheal Cardiac Output Monitor) and the esCCO™ (estimated Continuous Cardiac Output), to measure trends in CO during an ARM in postoperative cardiac surgical patients. METHODS:Twenty-seven mechanically ventilated patients were studied in the postoperative intensive care unit setting. Hemodynamic measurements were made at 3 distinct time points: (1) before an ARM at zero end-expiratory pressure; (2) during an ARM at 15 cm H2O positive end-expiratory pressure; and (3) after the ARM again at zero end-expiratory pressure. Reference CO was obtained from intermittent bolus thermodilution (TDco) using a pulmonary artery catheter. At each of the 3 time points, mean values of 3 CO measurements from each device were collected simultaneously, as well as the corresponding changes in arterial pressure. The coefficient of variation of the 3 sets for each patient at each time point allowed for the calculation of the precision error for each device. Differences between absolute values of CO using the 2 tested methods and TDco were assessed using a Bland-Altman plot. Additionally, the agreement and responsiveness of the changes in CO (&Dgr;TDco, &Dgr;ESco, and &Dgr;ECco for changes in TDco, esCCO, and ECOM, respectively) and mean arterial pressure (MAP) were assessed using both a 4-quadrant plot with the coefficient of correlation concordance (CCC) and a polar plot diagram. A polar concordance rate above 80% was considered clinically acceptable. RESULTS:Eighty-one sets of 3 CO values were analyzed. Precision error of TDco was approximately 5.1% (interquartile range: 2.8–7.1). Between esCCO and TDco, the mean bias was +0.7 L/min with limits of agreement of −2.1 L/min and +3.5 L/min. Between ECOM and TDco, the mean bias was +0.2 L/min with limits of agreement of −2.0 L/min and +2.4 L/min. The CCC between &Dgr;ECco and &Dgr;TDco (0.82 [95% confidence interval (CI), 0.72–0.89]) was significantly higher (P = 0.0053) than the CCC between &Dgr;ESco and &Dgr;TDco (0.42 [95% CI, 0.20–0.59]), but not statistically different (P = 0.16) than the CCC between &Dgr;MAP and &Dgr;TDco (0.69 [95% CI, 0.54–0.80]). Polar plot analysis showed an angular bias with radial agreement limits of −29° ± 38° between &Dgr;ESco and &Dgr;TDco and −15° ± 29° between &Dgr;ECco and &Dgr;TDco. Four-quadrant concordance rate was 81% (95% CI, 74–88) between &Dgr;ESco and &Dgr;TDco and 100% between &Dgr;ECco and &Dgr;TDco. Polar concordance rates were 41% (95% CI, 34–48) between &Dgr;ESco and &Dgr;TDco and 85% (95% CI, 79–90) between &Dgr;ECco and &Dgr;TDco. CONCLUSIONS:Compared to pulmonary artery catheter thermodilution, both ECOM and esCCO underestimate changes in CO during an ARM in postoperative cardiac surgical patients. However, &Dgr;ECco is within the angular limits of acceptable agreement and may be as efficient as invasive arterial pressure monitoring to track CO changes. In contrast, esCCO is not able to adequately track CO in these specific conditions.

Guiding Goal-Directed Therapy

Several studies have demonstrated that perioperative hemodynamic optimization (or “goal directed therapy”) using minimally invasive hemodynamic monitoring technologies has the ability to improve postoperative patients’ outcome with lower complication rates, shorter hospital lengths of stay, and lower cost of surgery. This specific concept of goal-directed therapy (GDT) uses perioperative cardiac output monitoring and manipulation of physiologic parameters (dynamic parameters of fluid responsiveness) to guide intravenous fluids and inotropic therapy with the goal of ensuring adequate tissue perfusion. Recently, the evidence related to the implementation of GDT strategies has been considered strong enough to allow for the creation of national recommendations in the UK, in France, and by the European Society of Anaesthesiology. The aims of the programs are to apply best practices to high-risk surgical patients and requires the participation of all clinicians involved in patients’ care. Considering the potential clinical and economic benefits of GDT protocols and the positive recommendations from influential scientific societies, more and more hospitals around the world have become interested in implementing hemodynamic optimization in their departments. This review provides the information about the evolution of hemodynamic monitoring from invasive to the more recent noninvasive devices, and how these devices can be used in the operating rooms through well-defined algorithms of GDT.

Continuous noninvasive hemoglobin monitoring: ready for prime time?

Purpose of reviewDetermination of hemoglobin (Hb) concentration is essential for the detection of anemia and hemorrhage and is widely used to evaluate a patient for a possible blood transfusion. Although commonly accepted as intrinsic to the process, traditional laboratory measurements of Hb are invasive, intermittent, and time-consuming. Noninvasive Hb (NIHb)-monitoring devices have recently become available and promise the potential for detecting sudden changes in a patients Hb level. In addition to reduced delays in clinical intervention, these devices also allow for a reduction in patient discomfort, infection risk, required personnel, and long-term costs. Unfortunately, it has been shown that many clinical factors can influence their accuracy. Recent findingsMany studies have been published on the accuracy and precision of NIHb-monitoring devices in various clinical settings. A recent meta-analysis has shown a small mean difference but wide limits of agreement between NIHb and laboratory measurements, indicating that caution should be used by physicians when making clinical decisions based on this device. SummaryNIHb measurements may currently be considered to be a supplemental tool for monitoring trends in Hb concentration, but are not currently developed enough to replace an invasive approach. Moreover, further studies are still required before implementing NIHb in the clinical decision-making process. Specifically, no studies have demonstrated that this technology improves clinical outcomes or patient safety.