Comparison of differences in cohort (forwards) and case control (backwards) methodological approaches for validation of the Hypotension Prediction Index.

BACKGROUND: The Hypotension Prediction Index (the index) software is a machine learning algorithm that detects physiological changes that may lead to hypotension. The original validation used a case control (backwards) analysis that has been suggested to be biased. We therefore conducted a cohort (forwards) analysis and compared this to the original validation technique. METHODS: We conducted a retrospective analysis of data from previously reported studies. All data were analysed identically with 2 different methodologies and receiver operating characteristic curves (ROC) constructed. Both backwards and forwards analyses were performed to examine differences in area under the ROC for HPI and other haemodynamic variables to predict a MAP < 65mmHg for at least 1 minute 5, 10 and 15 minutes in advance. RESULTS: Two thousand and twenty-two patients were included in the analysis, yielding 4,152,124 measurements taken at 20 second intervals. The area-under-the-curve for the index predicting hypotension analysed by backward and forward methodologies respectively was 0.957 (95% CI, 0.947-0.964) vs 0.923 (95% CI, 0.912-0.933) 5 minutes in advance, 0.933 (95% CI, 0.924-0.942) vs 0.923 (95% CI, 0.911-0.933) 10 minutes in advance , and 0.929 (95% CI, 0.918-0.938) vs. 0.926 (95% CI, 0.914-0.937) 15 minutes in advance. No other variable had an area-under-the-curve > 0.7 except for MAP. Area-under-the-curve using forward analysis for MAP predicting hypotension 5, 10, and 15 minutes in advance was 0.932 (95% CI, 0.920-0.940), 0.929 (95% CI, 0.918-0.938), and 0.932 (95% CI, 0.921-0.940). The R 2 for the variation in the index due to MAP was 0.77. CONCLUSION: Using an updated methodology, we found the utility of the HPI index to predict future hypotensive events is high, with an area under the receiver-operating-characteristics curve similar to that of the original validation method.

Adult Cardiac Surgery-Associated Acute Kidney Injury: Joint Consensus Report.

OBJECTIVES: Acute kidney injury (AKI) is increasingly recognized as a source of poor patient outcomes after cardiac surgery. The purpose of the present report is to provide perioperative teams with expert recommendations specific to cardiac surgery-associated AKI (CSA-AKI). METHODS: This report and consensus recommendations were developed during a joint, in-person, multidisciplinary conference with the Perioperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society. Multinational practitioners with diverse expertise in all aspects of cardiac surgical perioperative care, including clinical backgrounds in anesthesiology, surgery and nursing, met from October 20 to 22, 2021, in Sacramento, California, and used a modified Delphi process and a comprehensive review of evidence to formulate recommendations. The quality of evidence and strength of each recommendation were established using the Grading of Recommendations Assessment, Development, and Evaluation methodology. A majority vote endorsed recommendations. RESULTS: Based on available evidence and group consensus, a total of 13 recommendations were formulated (4 for the preoperative phase, 4 for the intraoperative phase, and 5 for the postoperative phase), and are reported here. CONCLUSIONS: Because there are no reliable or effective treatment options for CSA-AKI, evidence-based practices that highlight prevention and early detection are paramount. Cardiac surgery-associated AKI incidence may be mitigated and postsurgical outcomes improved by focusing additional attention on presurgical kidney health status; implementing a specific cardiopulmonary bypass bundle; using strategies to maintain intravascular euvolemia; leveraging advanced tools such as the electronic medical record, point-of-care ultrasound, and biomarker testing; and using patient-specific, goal-directed therapy to prioritize oxygen delivery and end-organ perfusion over static physiologic metrics.

Indicators of haemodynamic instability and left ventricular function in a porcine model of esmolol induced negative inotropy.

To investigate if the Hypotension Prediction Index was an early indicator of haemodynamic instability in a negative inotropy porcine model, and to assess the correlation of commonly measured indicators of left ventricular systolic function. Eight anaesthetised pigs were volume resuscitated and then underwent an incremental infusion of esmolol hydrochloride (0-3000 mg/hr), following which it was then reduced in a stepwise manner. Full haemodynamic measurements were taken at each stage and measurements of left ventricular systolic function including left ventricular stroke work index, ejection fraction and peripheral dP/dT were obtained. At an infusion rate of 500 mg/hr of esmolol there were no significant changes in any measured variables. At 1000 mg/hr MAP was on average 11 mmHg lower (95% CI 1 to 11 mmHg, p = 0.027) with a mean of 78 mmHg, HPI increased by 33 units (95% CI 4 to 62, p = 0.026) with a mean value of 63. No other parameters showed significant change from baseline values. Subsequent increases in esmolol showed changes in all parameters except SVV, SVR and PA mean. Correlation between dP/dt and LVSWI was 0.85 (95% CI 0.77 to 0.90, p < 0.001), between LVEF and dP/dt 0.39 (95% CI 0.18 to 0.57, p < 0.001), and between LSWI and LVEF 0.41 (95% CI 0.20 to 0.59, p < 0.001). In this model haemodynamic instability induced by negative inotropy was detected by the HPI algorithm prior to any clinically significant change in commonly measured variables. In addition, the peripheral measure of left ventricular contractility dP/dt correlates well with more established measurements of LV systolic function.

Association of Upper Gastrointestinal Surgery of Great Britain and Ireland (AUGIS)/Perioperative Quality Initiative (POQI) consensus statement on intraoperative and postoperative interventions to reduce pulmonary complications after oesophagectomy.

BACKGROUND: Pulmonary complications are the most common morbidity after oesophagectomy, contributing to mortality and prolonged postoperative recovery, and have a negative impact on health-related quality of life. A variety of single or bundled interventions in the perioperative setting have been developed to reduce the incidence of pulmonary complications. Significant variation in practice exists across the UK. The aim of this modified Delphi consensus was to deliver clear evidence-based consensus recommendations regarding intraoperative and postoperative care that may reduce pulmonary complications after oesophagectomy. METHODS: With input from a multidisciplinary group of 23 experts in the perioperative management of patients undergoing surgery for oesophageal cancer, a modified Delphi method was employed. Following an initial systematic review of relevant literature, a range of anaesthetic, surgical, and postoperative care interventions were identified. These were then discussed during a two-part virtual conference. Recommendation statements were drafted, refined, and agreed by all attendees. The level of evidence supporting each statement was considered. RESULTS: Consensus was reached on 12 statements on topics including operative approach, pyloric drainage strategies, intraoperative fluid and ventilation strategies, perioperative analgesia, postoperative feeding plans, and physiotherapy interventions. Seven additional questions concerning the perioperative management of patients undergoing oesophagectomy were highlighted to guide future research. CONCLUSION: Clear consensus recommendations regarding intraoperative and postoperative interventions that may reduce pulmonary complications after oesophagectomy are presented.

Delivery of drinking, eating and mobilising (DrEaMing) and its association with length of hospital stay after major noncardiac surgery: observational cohort study.

BACKGROUND: Enhanced recovery pathways are associated with improved postoperative outcomes. However, as enhanced recovery pathways have become more complex and varied, compliance has reduced. The 'DrEaMing' bundle re-prioritises early postoperative delivery of drinking, eating, and mobilising. We investigated relationships between DrEaMing compliance, postoperative hospital length of stay (LOS), and complications in a prospective multicentre major surgical cohort. METHODS: We interrogated the UK Perioperative Quality Improvement Programme dataset. Analyses were conducted in four stages. In an exploratory cohort, we identified independent predictors of DrEaMing. We quantified the association between delivery of DrEaMing (and its component variables) and prolonged LOS in a homogenous colorectal subgroup and assessed generalisability in multispecialty patients. Finally, LOS and complications were compared across hospitals, stratified by DrEaMing compliance. RESULTS: The exploratory cohort comprised 22 218 records, the colorectal subgroup 7230, and the multispecialty subgroup 5713. DrEaMing compliance was 59% (13 112 patients), 60% (4341 patients), and 60% (3421), respectively, but varied substantially between hospitals. Delivery of DrEaMing predicted reduced odds of prolonged LOS in colorectal (odds ratio 0.51 [0.43-0.59], P<0.001) and multispecialty cohorts (odds ratio 0.47 [0.41-0.53], P<0.001). At the hospital level, complications were not the primary determinant of LOS after colorectal surgery, but consistent delivery of DrEaMing was associated with significantly shorter LOS. CONCLUSIONS: Delivery of bundled and unbundled DrEaMing was associated with substantial reductions in postoperative LOS, independent of the effects of confounder variables. Consistency of process delivery, and not complications, predicted shorter hospital-level length of stay. DrEaMing may be adopted by perioperative health systems as a quality metric to support improved patient outcomes and reduced hospital length of stay.

Association between perioperative fluid management and patient outcomes: a multicentre retrospective study.

BACKGROUND: Postoperative complications increase hospital length of stay and patient mortality. Optimal perioperative fluid management should decrease patient complications. This study examined associations between fluid volume and noncardiac surgery patient outcomes within a large multicentre US surgical cohort. METHODS: Adults undergoing noncardiac procedures from January 1, 2012 to December 31, 2017, with a postoperative length of stay ≥24 h, were extracted from a large US electronic health record database. Patients were segmented into quintiles based on recorded perioperative fluid volumes with Quintile 3 (Q3) serving as the reference. The primary outcome was defined as a composite of any complications during the surgical admission and a postoperative length of stay ≥7 days. Secondary outcomes included in-hospital mortality, respiratory complications, and acute kidney injury. RESULTS: A total of 35 736 patients met the study criteria. There was a U-shaped pattern with highest (Q5) and lowest (Q1) quintiles of fluid volumes having increased odds of complications and a postoperative length of stay ≥7 days (Q5: odds ratio [OR] 1.51 [95% confidence interval {CI}: 1.30-1.74], P<0.001; Q1: OR 1.20 [95% CI: 1.04-1.38], P=0.011) compared with Q3. Patients in Q5 had greater odds of more severe acute kidney injury compared with Q3 (OR 1.52 [95% CI: 1.22-1.90]; P<0.001) and respiratory complications (OR 1.44 [95% CI: 1.17-1.77]; P<0.001). CONCLUSIONS: Both very high and very low perioperative fluid volumes were associated with an increase in complications after noncardiac surgery.

Hemodynamic and Intestinal Microcirculatory Changes in a Phenylephrine Corrected Porcine Model of Hemorrhage.

BACKGROUND: Intraoperative hypotension is a common event, and a recent study suggests that maintenance of blood pressure may reduce complications. The splanchnic circulation provides a reservoir of blood that can be mobilized during hemorrhage; hence, intestinal microcirculation is sensitive to volume changes. The aim of this study was to assess the impact of hemorrhage on intestinal microcirculation and hemodynamics, and the effects of phenylephrine on these parameters. METHODS: Eight anesthetized, mechanically ventilated Yorkshire/Landrace crossbreed pigs were studied. Graded hemorrhage was performed with the removal of 20% of blood volume in 5% increments. Hemodynamic and intestinal microcirculatory measurements were performed at each stage with side-stream dark field microscopy, following which mean arterial pressure (MAP) was corrected with phenylephrine to baseline values and measurements repeated. A repeated measurement 1-way analysis of variance (ANOVA) was used to compared changes from baseline measurements. RESULTS: The mean baseline microcirculation score was 42 (standard deviation [SD] = 5). A 5% hemorrhage decreased the microcirculation score by a mean difference of 19 (95% confidence interval [CI], 12-27; P < .0001), and an additional 5% hemorrhage further reduced the microcirculation score by a mean difference of 12 (95% CI, 4-19; P = .0001). Subsequent hemorrhage or administration of phenylephrine did not significantly change the microcirculation scores except when phenylephrine was administered at the 15% hemorrhage stage, which increased the microcirculation score by a mean difference of 7 (95% CI, 1-13; P = .003). All hemodynamic variables were returned to baseline values following hemorrhage by the phenylephrine infusion. CONCLUSIONS: Intestinal microcirculatory flow is reduced early in hemorrhage and is uncorrected by phenylephrine infusion. Hemodynamic changes associated with hemorrhage are corrected by phenylephrine and do not reflect microcirculatory flow status.

Effects of dietary nitrate supplementation on microvascular physiology at 4559 m altitude - A randomised controlled trial (Xtreme Alps).

Native highlanders (e.g. Sherpa) demonstrate remarkable hypoxic tolerance, possibly secondary to higher levels of circulating nitric oxide (NO) and increased microcirculatory blood flow. As part of the Xtreme Alps study (a randomised placebo-controlled trial of dietary nitrate supplementation under field conditions of hypobaric hypoxia), we investigated whether dietary supplementation with nitrate could improve NO availability and microvascular blood flow in lowlanders. Plasma measurements of nitrate, nitrite and nitroso species were performed together with measurements of sublingual (sidestream dark-field camera) and forearm blood flow (venous occlusion plethysmography) in 28 healthy adult volunteers resident at 4559 m for 1 week; half receiving a beetroot-based high-nitrate supplement and half receiving an identically-tasting low nitrate 'placebo'. Dietary supplementation increased plasma nitrate concentrations 4-fold compared to the placebo group, both at sea level (SL; 19.2 vs 76.9 µM) and at day 5 (D5) of high altitude (22.9 vs 84.3 µM, p < 0.001). Dietary nitrate supplementation also significantly increased both plasma nitrite (0.78 vs. 0.86 µM SL, 0.31 vs. 0.41 µM D5, p = 0.03) and total nitroso product (11.3 vs. 19.7 nM SL, 9.7 vs. 12.3 nM D5, p < 0.001) levels both at sea level and at 4559 m. However, plasma nitrite concentrations were more than 50% lower at 4559 m compared to sea level in both treatment groups. Despite these significant changes, dietary nitrate supplementation had no effect on any measured read-outs of sublingual or forearm blood flow, even when environmental hypoxia was experimentally reversed using supplemental oxygen. In conclusion, dietary nitrate supplementation does not improve microcirculatory function at 4559 m.

A national survey of anaesthetists' preferences for their own end of life care.

OBJECTIVES: To describe individual views, wishes, and preferences for end of life care and to report UK anaesthetists' personal perspectives. METHODS: The 'bigconversations' questionnaire was developed by modifying an existing framework for end of life discussions. An online cross-sectional survey of UK anaesthetists was then conducted using the questionnaire in January 2019. RESULTS: The bigconversations questionnaire was validated as measuring the important aspects of end of life care by an expert panel and was found to have moderate test-retest reliability. Responses were received from 760/1913 (40%) of those invited to take part. Overall, 698/760 (92%) of respondents wished to be well informed about their condition and prognosis and 518/760 (68%) wanted to be heavily involved in decision-making about their health. Meanwhile, 639/760 (84%) of respondents would choose to forego treatment aimed at prolonging life should that life be of poor quality. The desire to spend time with family was a theme which arose from the qualitative analysis. CONCLUSION: This study provides the first systematic description of UK doctors', specifically anaesthetists', personal preferences for end of life care. Broad trends were identified: to be well informed; to avoid high-intensity medical treatments if terminally unwell; to spend remaining time with family and friends; and to be symptom-free and well cared for. However, a substantial minority expressed different, indeed opposite, opinions. This variation highlights that good quality end of life care must be driven by discussion of an individual's values, wishes, and preferences.

Metabolic basis to Sherpa altitude adaptation.

The Himalayan Sherpas, a human population of Tibetan descent, are highly adapted to life in the hypobaric hypoxia of high altitude. Mechanisms involving enhanced tissue oxygen delivery in comparison to Lowlander populations have been postulated to play a role in such adaptation. Whether differences in tissue oxygen utilization (i.e., metabolic adaptation) underpin this adaptation is not known, however. We sought to address this issue, applying parallel molecular, biochemical, physiological, and genetic approaches to the study of Sherpas and native Lowlanders, studied before and during exposure to hypobaric hypoxia on a gradual ascent to Mount Everest Base Camp (5,300 m). Compared with Lowlanders, Sherpas demonstrated a lower capacity for fatty acid oxidation in skeletal muscle biopsies, along with enhanced efficiency of oxygen utilization, improved muscle energetics, and protection against oxidative stress. This adaptation appeared to be related, in part, to a putatively advantageous allele for the peroxisome proliferator-activated receptor A (PPARA) gene, which was enriched in the Sherpas compared with the Lowlanders. Our findings suggest that metabolic adaptations underpin human evolution to life at high altitude, and could have an impact upon our understanding of human diseases in which hypoxia is a feature.

Perioperative Quality Initiative consensus statement on intraoperative blood pressure, risk and outcomes for elective surgery.

BACKGROUND: Intraoperative mortality is now rare, but death within 30 days of surgery remains surprisingly common. Perioperative myocardial infarction is associated with a remarkably high mortality. There are strong associations between hypotension and myocardial injury, myocardial infarction, renal injury, and death. Perioperative arterial blood pressure management was thus the basis of a Perioperative Quality Initiative consensus-building conference held in London in July 2017. METHODS: The meeting featured a modified Delphi process in which groups addressed various aspects of perioperative arterial pressure. RESULTS: Three consensus statements on intraoperative blood pressure were established. 1) Intraoperative mean arterial pressures below 60-70 mm Hg are associated with myocardial injury, acute kidney injury, and death. Injury is a function of hypotension severity and duration. 2) For adult non-cardiac surgical patients, there is insufficient evidence to recommend a general upper limit of arterial pressure at which therapy should be initiated, although pressures above 160 mm Hg have been associated with myocardial injury and infarction. 3) During cardiac surgery, intraoperative systolic arterial pressure above 140 mm Hg is associated with increased 30 day mortality. Injury is a function of arterial pressure severity and duration. CONCLUSIONS: There is increasing evidence that even brief durations of systolic arterial pressure <100 mm Hg and mean arterial pressure <60-70 mm Hg are harmful during non-cardiac surgery.

Perioperative Quality Initiative consensus statement on postoperative blood pressure, risk and outcomes for elective surgery.

BACKGROUND: Postoperative hypotension and hypertension are frequent events associated with increased risk of adverse outcomes. However, proper assessment and management is often poorly understood. As a part of the PeriOperative Quality Improvement (POQI) 3 workgroup meeting, we developed a consensus document addressing this topic. The target population includes adult, non-cardiac surgical patients in the postoperative phase outside of the ICU. METHODS: A modified Delphi technique was used, evaluating papers published in MEDLINE examining postoperative blood pressure monitoring, management, and outcomes. Practice recommendations were developed in line with National Institute for Health and Care Excellence guidelines. RESULTS: Consensus recommendations were that (i) there is evidence of harm associated with postoperative systolic arterial pressure <90 mm Hg; (ii) for patients with preoperative hypertension, the threshold at which harm occurs may be higher than a systolic arterial pressure of 90 mm Hg; (iii) there is insufficient evidence to precisely define the level of postoperative hypertension above which harm will occur; (iv) a greater frequency of postoperative blood pressure measurement is likely to identify risk of harm and clinical deterioration earlier; and (v) there is evidence of harm from withholding beta-blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors in the postoperative period. CONCLUSIONS: Despite evidence of associations with postoperative hypotension or hypertension with worse postoperative outcome, further research is needed to define the optimal levels at which intervention is beneficial, to identify the best methods and timing of postoperative blood pressure measurement, and to refine the management of long-term antihypertensive treatment in the postoperative phase.

Perioperative Quality Initiative consensus statement on the physiology of arterial blood pressure control in perioperative medicine.

BACKGROUND: Perioperative arterial blood pressure management is a physiologically complex challenge influenced by multiple factors. METHODS: A multidisciplinary, international working subgroup of the Third Perioperative Quality Initiative (POQI) consensus meeting reviewed the (patho)physiology and measurement of arterial pressure as applied to perioperative medicine. We addressed predefined questions by undertaking a modified Delphi analysis, in which primary clinical research and review articles were identified using MEDLINE. Strength of recommendations, where applicable, were graded by National Institute for Health and Care Excellence (NICE) guidelines. RESULTS: Multiple physiological factors contribute to the perioperative physiological importance of arterial pressure: (i) arterial pressure is the input pressure to organ blood flow, but is not the sole determinant of perfusion pressure; (ii) blood flow is often independent of changes in perfusion pressure because of autoregulatory changes in vascular resistance; (iii) microvascular dysfunction uncouples microvascular blood flow from arterial pressure (haemodynamic incoherence). From a practical clinical perspective, we identified that: (i) ambulatory measurement is the optimal method to establish baseline arterial pressure; (ii) automated and invasive arterial pressure measurements have inherent physiological and technical limitations; (iii) individualised arterial pressure targets may change over time, especially in the perioperative period. There remains a need for research in non-invasive, continuous arterial pressure measurements, macro- and micro-circulatory control, regional perfusion pressure measurement, and the development of sensitive, specific, and continuous measures of cellular function to evaluate blood pressure management in a physiologically coherent manner. CONCLUSION: The multivariable, complex physiology contributing to dynamic changes in perioperative arterial pressure may be underappreciated clinically. The frequently unrecognised dissociation between arterial pressure, organ blood flow, and microvascular and cellular function requires further research to develop a more refined, contextualised clinical approach to this routine perioperative measurement.

Perioperative Quality Initiative consensus statement on preoperative blood pressure, risk and outcomes for elective surgery.

BACKGROUND: A multidisciplinary international working subgroup of the third Perioperative Quality Initiative consensus meeting appraised the evidence on the influence of preoperative arterial blood pressure and community cardiovascular medications on perioperative risk. METHODS: A modified Delphi technique was used, evaluating papers published in MEDLINE on associations between preoperative numerical arterial pressure values or cardiovascular medications and perioperative outcomes. The strength of the recommendations was graded by National Institute for Health and Care Excellence guidelines. RESULTS: Significant heterogeneity in study design, including arterial pressure measures and perioperative outcomes, hampered the comparison of studies. Nonetheless, consensus recommendations were that (i) preoperative arterial pressure measures may be used to define targets for perioperative management; (ii) elective surgery should not be cancelled based solely upon a preoperative arterial pressure value; (iii) there is insufficient evidence to support lowering arterial pressure in the immediate preoperative period to minimise perioperative risk; and (iv) there is insufficient evidence that any one measure of arterial pressure (systolic, diastolic, mean, or pulse) is better than any other for risk prediction of adverse perioperative events. CONCLUSIONS: Future research should define which preoperative arterial pressure values best correlate with adverse outcomes, and whether modifying arterial pressure in the preoperative setting will change the perioperative morbidity or mortality. Additional research should define optimum strategies for continuation or discontinuation of preoperative cardiovascular medications.

Preoperative chronic beta-blocker prescription in elderly patients as a risk factor for postoperative mortality stratified by preoperative blood pressure: a cohort study.

BACKGROUND: Recent data suggest that beta blockers are associated with increased perioperative risk in hypertensive patients. We investigated whether beta blockers were associated with an increased risk in elderly patients with raised preoperative arterial blood pressure. METHODS: We conducted a propensity-score-matched cohort study of primary care data from the UK Clinical Practice Research Datalink (2004-13), including 84 633 patients aged 65 yr or over. Conditional logistic regression models, including factors that were significantly associated with the outcome, were constructed for 30-day mortality after elective noncardiac surgery. The effects of beta blockers (primary outcome), renin-angiotensin system (RAS) inhibitors, calcium-channel blockers, thiazides, loop diuretics, and statins were investigated at systolic and diastolic arterial pressure thresholds. RESULTS: Beta blockers were associated with increased odds of postoperative 30-day mortality in patients with systolic hypertension (defined as systolic BP >140 mm Hg; adjusted odds ratio [aOR]: 1.92; 95% confidence interval [CI]: 1.05-3.51). After excluding patients for whom prior data suggest benefit from perioperative beta blockade (patients with prior myocardial infarction or heart failure), rather than adjusting for them, the point estimate shifted slightly (aOR: 2.06; 95% CI: 1.09-3.89). Compared with no use, statins (aOR: 0.35; 95% CI: 0.17-0.75) and thiazides (aOR: 0.28; 95% CI: 0.10-0.78) were associated with lower mortality in patients with systolic hypertension. CONCLUSIONS: These data suggest that the safety of perioperative beta blockers may be influenced by preoperative blood pressure thresholds. A randomised controlled trial of beta-blocker withdrawal, in select populations, is required to identify a causal relationship.

American Society for Enhanced Recovery and Perioperative Quality Initiative-4 Joint Consensus Statement on Persistent Postoperative Opioid Use: Definition, Incidence, Risk Factors, and Health Care System Initiatives.

Persistent postoperative opioid use is thought to contribute to the ongoing opioid epidemic in the United States. However, efforts to study and address the issue have been stymied by the lack of a standard definition, which has also hampered efforts to measure the incidence of and risk factors for persistent postoperative opioid use. The objective of this systematic review is to (1) determine a clinically relevant definition of persistent postoperative opioid use, and (2) characterize its incidence and risk factors for several common surgeries. Our approach leveraged a group of international experts from the Perioperative Quality Initiative-4, a consensus-building conference that included representation from anesthesiology, surgery, and nursing. A search of the medical literature yielded 46 articles addressing persistent postoperative opioid use in adults after arthroplasty, abdominopelvic surgery, spine surgery, thoracic surgery, mastectomy, and thoracic surgery. In opioid-naïve patients, the overall incidence ranged from 2% to 6% based on moderate-level evidence. However, patients who use opioids preoperatively had an incidence of >30%. Preoperative opioid use, depression, factors associated with the diagnosis of substance use disorder, preoperative pain, and tobacco use were reported risk factors. In addition, while anxiety, sex, and psychotropic prescription are associated with persistent postoperative opioid use, these reports are based on lower level evidence. While few articles addressed the health policy or prescriber characteristics that influence persistent postoperative opioid use, efforts to modify prescriber behaviors and health system characteristics are likely to have success in reducing persistent postoperative opioid use.

Barriers to advance care planning with patients as perceived by nurses and other healthcare professionals: A systematic review.

INTRODUCTION: Advance care planning is a means for patients to communicate their wishes, fears and desires for future health decisions should they lose the ability to consider or communicate these. Despite being supported by governments and healthcare leaders, uptake amongst the general population remains low. Nurses play a crucial role in promoting and engaging with these discussions given their close relationship with patients and families in a range of clinical settings. AIM: To describe the barriers that nurses and healthcare professionals believe prevent them from exploring advance care planning with their patients. METHOD: We carried out a systematic review of peer-reviewed journal articles from the databases MEDLINE, Embase, CINAHL Plus, Web of Science and ProQuest Central, guided by the PRISMA checklist. RESULTS: Eleven articles were identified: all were self-reporting surveys using a mix of open and closed questions. They originated in the USA, Canada, Australia and Ireland. The participants included various healthcare professionals, with the majority of studies focussing on nurses. The two most important barriers to advance care planning are lack of education and insufficient time. Advance care planning appears to be well supported, and nurses and healthcare professionals report themselves to be comfortable and confident to take on the responsibility. CONCLUSION: There is a need for greater education and training for nurses and healthcare professionals. In particular, there needs to be better understanding of professional and legal responsibilities. The need for sufficient time to be made available to allow these conversations, in often busy settings, will need institutional and financial support. RELEVANCE TO CLINICAL PRACTICE: Increased training and knowledge are likely to lead to more positive attitudes and greater confidence for nurses, and other healthcare professionals, which should help support and encourage patient engagement with advance care planning.

Effect of a Nurse-Led Preventive Psychological Intervention on Symptoms of Posttraumatic Stress Disorder Among Critically Ill Patients: A Randomized Clinical Trial.

Importance: A meta-analysis of outcomes during the 6 months after intensive care unit (ICU) discharge indicate a prevalence for clinically important posttraumatic stress disorder (PTSD) symptoms of 25%. Objective: To determine whether a nurse-led preventive, complex psychological intervention, initiated in the ICU, reduces patient-reported PTSD symptom severity at 6 months. Design, Setting, and Participants: A multicenter, parallel-group, cluster-randomized clinical trial with integrated economic and process evaluations conducted in 24 ICUs in the United Kingdom. Participants were critically ill patients who regained mental capacity following receipt of level 3 (intensive) care. A total of 2961 eligible patients were identified from September 2015 to January 2017. A total of 2048 were approached for participation in the ICU, of which 1458 provided informed consent. Follow-up was completed December 2017. Interventions: Twenty four ICUs were randomized 1:1 to the intervention or control group. Intervention ICUs (n = 12; 669 participants) delivered usual care during a baseline period followed by an intervention period. The preventive, complex psychological intervention comprised promotion of a therapeutic ICU environment plus 3 stress support sessions and a relaxation and recovery program delivered by trained ICU nurses to high-risk (acutely stressed) patients. Control ICUs (n = 12; 789 participants) delivered usual care in both baseline and intervention periods. Main Outcomes and Measures: The primary clinical outcome was PTSD symptom severity among survivors at 6 months measured using the PTSD Symptom Scale-Self-Report questionnaire (score range, 0-51, with higher scores indicating greater symptom severity; the minimal clinically important difference was considered to be 4.2 points). Results: Among 1458 enrolled patients (mean [SD] age, 58 [16] years; 599 women [41%]), 1353 (93%) completed the study and were included in the final analysis. At 6 months, the mean PTSD Symptom Scale-Self-Report questionnaire score in intervention ICUs was 11.8 (baseline period) compared with 11.5 (intervention period) (difference, -0.40 [95% CI, -2.46 to 1.67]) and in control ICUs, 10.1 (baseline period) compared with 10.2 (intervention period) (difference, 0.06 [95% CI, -1.74 to 1.85]) between periods. There was no significant difference in PTSD symptom severity at 6 months (treatment effect estimate [difference in differences] of -0.03 [95% CI, -2.58 to 2.52]; P = .98). Conclusions and Relevance: Among critically ill patients in the ICU, a nurse-led preventive, complex psychological intervention did not significantly reduce patient-reported PTSD symptom severity at 6 months. These findings do not support the use of this psychological intervention. Trial Registration: ISRCTN53448131.

Sustained vasomotor control of skin microcirculation in Sherpas versus altitude-naive lowlanders: Experimental evidence from Xtreme Everest 2.

NEW FINDINGS: What is the central question of this study? Do Sherpa highlanders, when exposed to graded hypobaric hypoxia, exhibit enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders? What is the main finding and its importance? Sherpas, when exposed to hypobaric hypoxia at high altitude, demonstrated superior preservation of their peripheral microcirculatory perfusion, a greater oxygen unloading rate and sustained microvascular reactivity with enhanced vasomotion, when compared with altitude-naive lowlanders. These differences have not been reported previously and may improve our understanding of the multifactorial responses to sustained environmental hypoxia. ABSTRACT: Enhanced oxygen delivery, consequent to an increased microvascular perfusion, has been postulated to play a key role in the physiological adaptation of Tibetan highlanders to the hypobaric hypoxia encountered at high altitude. We tested the hypothesis that Sherpas, when exposed to graded hypobaric hypoxia, demonstrate enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders. Eighty-three lowlanders [39 men and 44 women, 38.8 (13.1) years old; mean (SD)] and 61 Sherpas [28 men and 33 women, 27.9 (6.9) years old] were studied on ascent to Everest Base Camp over 11 days. Skin blood flux and tissue oxygen saturation were measured simultaneously using combined laser Doppler fluximetry and white light spectroscopy at baseline, 3500 and 5300 m. In both cohorts, ascent resulted in a decline in the sympathetically mediated microvascular constrictor response (P < 0.001), which was more marked in lowlanders than in Sherpas (P < 0.001). The microvascular dilator response evaluated by postocclusive reactive hyperaemia was significantly greater in Sherpas than in lowlanders at all sites (P < 0.002). Spectral analysis of the blood flux signals revealed enhanced myogenic (vasomotion) activity in Sherpas, which was unaffected by ascent to 5300 m. Although skin tissue oxygenation was lower in Sherpas than in lowlanders, the oxygen unloading rate was faster, and deoxyhaemoglobin levels higher, at all altitudes. Together, these data suggest that Sherpas, when exposed to hypobaric hypoxia, demonstrated superior preservation of peripheral microcirculatory perfusion compared with altitude-naive lowlanders. The physiological differences in local microvasculature vasomotor and neurovascular control may play a key role in Sherpa adaptation to high-altitude hypobaric hypoxia by sustaining local perfusion and tissue oxygenation.