Haemodynamic monitoring during noncardiac surgery: past, present, and future.

During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery - and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential. We therefore revisit the pathophysiologic rationale for intraoperative monitoring of haemodynamic variables, describe the history, current use, and future technological developments of monitoring methods, and finally briefly summarise the evidence that haemodynamic management can improve patient-centred outcomes.

Outcomes of heparinized adult veno-arterial extracorporeal membrane oxygenation patients managed with low and high activated partial thromboplastin time targets: A systematic review and meta-analysis.

INTRODUCTION: There are no randomized controlled trials comparing low and high activated partial thromboplastin time (aPTT) targets in heparinized adult veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) patients. Our systematic review and meta-analysis summarized complication rates in adult VA ECMO patients treated with low and high aPTT targets. METHODS: Studies published from January 2000 to May 2022 were identified using Pubmed, Embase, Cochrane Library, and LILACS (Latin American and Caribbean Health Sciences Literature). Studies were included if aPTT was primarily used to guide heparin anticoagulation. For the low aPTT group, we included studies where aPTT goal was ≤60 seconds and for the high aPTT group, we included studies where aPTT goal was ≥60 seconds. Proportional meta-analysis with a random effects model was used to calculate pooled complication rates for patients in the two aPTT groups. RESULTS: Twelve studies met inclusion criteria (5 in the low aPTT group and 7 in the high aPTT group). The pooled bleeding complication incidence for low aPTT studies was 53.6% (95% CI = 37.4%-69.4%, I2 = 60.8%) and for high aPTT studies was 43.8% (95% CI = 21.7%-67.1%, I2 = 91.8%). No studies in the low aPTT group reported overall thrombosis incidence, while three studies in the high aPTT group reported overall thrombosis incidence. The pooled thrombosis incidence for high aPTT studies was 16.1% (95% CI = 9.0%-24.5%, I2 = 13.1%). CONCLUSIONS: Adult ECMO patients managed with low and high aPTT goals appeared to have similar bleeding and other complication rates further highlighting the need for a randomized controlled trial.

Moderate exercise-induced dynamics on key sepsis-associated signaling pathways in the liver.

BACKGROUND: There is a clear relationship between quantitative measures of fitness (e.g., VO2 max) and outcomes after surgical procedures. Whether or not fitness is a modifiable risk factor and what underlying biological processes drive these changes are not known. The purpose of this study was to evaluate the moderate exercise training effect on sepsis outcomes (survival) as well as the hepatic biological response. We chose to study the liver because it plays a central role in the regulation of immune defense during systemic infection and receives blood flow directly from the origin of infection (gut) in the cecal ligation and puncture (CLP) model. METHODS: We randomized 50 male (♂) and female (♀) Sprague-Dawley rats (10 weeks, 340 g) to 3 weeks of treadmill exercise training, performed CLP to induce polymicrobial "sepsis," and monitored survival for five days (Part I). In parallel (Part II), we randomized 60 rats to control/sedentary (G1), exercise (G2), exercise + sham surgery (G3), CLP/sepsis (G4), exercise + CLP [12 h (G5) and 24 h (G6)], euthanized at 12 or 24 h, and explored molecular pathways related to exercise and sepsis survival in hepatic tissue and serum. RESULTS: Three weeks of exercise training significantly increased rat survival following CLP (polymicrobial sepsis). CLP increased inflammatory markers (e.g., TNF-a, IL-6), which were attenuated by exercise. Sepsis suppressed the SOD and Nrf2 expression, and exercise before sepsis restored SOD and Nrf2 levels near the baseline. CLP led to increased HIF1a expression and oxidative and nitrosative stress, the latter of which were attenuated by exercise. Haptoglobin expression levels were increased in CLP animals, which was significantly amplified in exercise + CLP (24 h) rats. CONCLUSIONS: Moderate exercise training (3 weeks) increased the survival in rats exposed to CLP, which was associated with less inflammation, less oxidative and nitrosative stress, and activation of antioxidant defense pathways.

The Ability of Military Critical Care Air Transport Members to Visually Estimate Percent Systolic Pressure Variation.

INTRODUCTION: Inappropriate fluid management during patient transport may lead to casualty morbidity. Percent systolic pressure variation (%SPV) is one of several technologies that perform a dynamic assessment of fluid responsiveness (FT-DYN). Trained anesthesia providers can visually estimate and use %SPV to limit the incidence of erroneous volume management decisions to 1-4%. However, the accuracy of visually estimated %SPV by other specialties is unknown. The aim of this article is to determine the accuracy of estimated %SPV and the incidence of erroneous volume management decisions for Critical Care Air Transport (CCAT) team members before and after training to visually estimate and utilize %SPV. MATERIAL AND METHODS: In one sitting, CCAT team providers received didactics defining %SPV and indicators of fluid responsiveness and treatment with %SPV ≤7 and ≥14.5 defining a fluid nonresponsive and responsive patient, respectively; they were then shown ten 45-second training arterial waveforms on a simulated Propaq M portable monitor's screen. Study subjects were asked to visually estimate %SPV for each arterial waveform and queried whether they would treat with a fluid bolus. After each training simulation, they were told the true %SPV. Seven days post-training, the subjects were shown a different set of ten 45-second testing simulations and asked to estimate %SPV and choose to treat, or not. Nonparametric limits of agreement for differences between true and estimated %SPV were analyzed using Bland-Altman graphs. In addition, three errors were defined: (1) %SPV visual estimate errors that would label a volume responsive patient as nonresponsive, or vice versa; (2) incorrect treatment decisions based on estimated %SPV (algorithm application errors); and (3) incorrect treatment decisions based on true %SPV (clinically significant treatment errors). For the training and testing simulations, these error rates were compared between, and within, provider groups. RESULTS: Sixty-one physicians (MDs), 64 registered nurses (RNs), and 53 respiratory technicians (RTs) participated in the study. For testing simulations, the incidence and 95% CI for %SPV estimate errors with sufficient magnitude to result in a treatment error were 1.4% (0.5%, 3.2%), 1.6% (0.6%, 3.4%), and 4.1% (2.2%, 6.9%) for MDs, RNs, and RTs, respectively. However, clinically significant treatment errors were statistically more common for all provider types, occurring at a rate of 7%, 10%, and 23% (all P < .05). Finally, students did not show clinically relevant reductions in their errors between training and testing simulations. CONCLUSIONS: Although most practitioners correctly visually estimated %SPV and all students completed the training in interpreting and applying %SPV, all groups persisted in making clinically significant treatment errors with moderate to high frequency. This suggests that the treatment errors were more often driven by misapplying FT-DYN algorithms rather than by inaccurate visual estimation of %SPV. Furthermore, these errors were not responsive to training, suggesting that a decision-making cognitive aid may improve CCAT teams' ability to apply FT-DYN technologies.

Variation in Hospitalization Costs, Charges, and Lengths of Hospital Stay for Coronavirus Disease 2019 Patients Treated With Venovenous Extracorporeal Membrane Oxygenation in the United States: A Cohort Study.

OBJECTIVES: The aim was to characterize hospitalization costs, charges, and lengths of hospital stay for COVID-19 patients treated with venovenous (VV) extracorporeal membrane oxygenation (ECMO) in the United States during 2020. Secondarily, differences in hospitalization costs, charges, and lengths of hospital stay were explored based on hospital-level factors. DESIGN: Retrospective cohort study. SETTING: Multiple hospitals in the United States. PARTICIPANTS: Adult patients with COVID-19 who were on VV ECMO in 2020 and had data in the national inpatient sample. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics and baseline comorbidities were recorded for patients. Primary study outcomes were hospitalization costs, charges, and lengths of hospital stay. Study outcomes were compared after stratification by hospital region, bed size, and for-profit status. The median hospitalization cost for the 3,315-patient weighted cohort was $200,300 ($99,623, $338,062). Median hospitalization charges were $870,513 ($438,228, $1,553,157), and the median length of hospital stay was 30 days (17, 46). Survival to discharge was 54.4% for all patients in the cohort. Median hospitalization cost differed by region (p = 0.01), bed size (p < 0.001), and for-profit status (p = 0.02). Median hospitalization charges also differed by region (p = 0.04), bed size (p = 0.002), and for-profit status (p < 0.001). Length of hospital stay differed by region (p = 0.03) and bed size (p < 0.001), but not for-profit status (p = 0.40). Hospitalization costs were the lowest, and charges were highest in private-for-profit hospitals. Large hospitals also had higher costs, charges, and hospital stay lengths than small hospitals. CONCLUSIONS: In this retrospective cohort study, hospitalization costs and charges for patients with COVID-19 on VV ECMO were found to be substantial but similar to what has been reported previously for patients without COVID-19 on VV ECMO. Significant variation was observed in costs, charges, and lengths of hospital stay based on hospital-level factors.

Evolving Endotracheal Tube Preferences and Practices: Intensivist Knowledge Gaps and Sex Disparities.

OBJECTIVES: The complex management of intubation-related laryngeal injury makes prevention vital. The purpose of this study is to assess endotracheal tube (ETT) practices and preferences among intensivists at our institution. METHODS: Chart review of intubated patients and intensivist survey were simultaneously performed in January 2016 and August 2022. A height-to-ETT size ratio (H:ETT) was calculated for each patient in the 2022 cohort. Intubated patients were followed until tracheostomy, extubation, or death occurred. Surveys assessed intensivist preferences for ETT size and management of intubated patients. RESULTS: 300 ICU patients were included. The mean ETT size for males decreased from 7.73 ± 0.30 in 2016 to 7.57 ± 0.25 in 2022 (p < 0.001). The average H:ETT of men was higher than females (p = 0.004), indicating that females in this population were intubated with larger ETTs relative to their height compared to males. Whereas the majority (66.7%) of intensivists endorse 7.0 ETTs as the standard for women, the majority (70%) of women at our institution are intubated with a 7.5 ETT or larger. Of intubated patients in the ICU, 23 (19.5%) were intubated for 11 days or longer. CONCLUSIONS: Compared to men, women are intubated with larger-than-preferred ETTs relative to height. Additionally, patients in our study were intubated for longer than preferred based on intensivist surveys, putting this population at higher risk for acute laryngeal injury (AlgI)-related laryngotracheal stenosis (LTS). Further studies should seek to identify similar trends and barriers to reducing ALgI-related LTS. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3080-3086, 2023.

Anesthetic Management of Laparoscopic Adrenalectomy for a Patient with Concomitant Pheochromocytoma and Bilateral Carotid Artery Stenosis.

Symptomatic carotid stenosis and pheochromocytoma both require timely surgical intervention. Following a transient ischemic attack (TIA), a 46-year-old man was diagnosed with bilateral carotid artery stenosis and scheduled for carotid endarterectomy. He was a poor candidate for minimally invasive options due to prior neck radiation. Simultaneously, he began experiencing difficulty with diabetes management and elevated blood pressures and was ultimately diagnosed with pheochromocytoma. This unique situation required coordination to determine the appropriate timing of the two interventions. This case highlights the importance of communication and coordination amongst medical specialists and consideration for anesthetic management of patients with concomitant pheochromocytoma and carotid stenosis.

Cardiac Enhanced Recovery Program Implementation and Its Effect on Opioid Administration in Adult Cardiac Surgery.

In light of the worsening opioid epidemic and nationwide parenteral opioid shortage, our institution created an enhanced recovery after surgery (ERAS) protocol. Our objective was to evaluate our initial experience transitioning to ERAS in cardiac surgery. An institutional cardiac ERAS protocol was implemented in April 2018, consisting of opioid-sparing analgesia, liberalization of fasting and activity restrictions, and goal-directed standardization of perioperative care. Clinical outcomes, opioid administration, and pain scores of patients undergoing nonemergent cardiac surgery were reviewed from March 2017 to July 2018. Patients were propensity score matched into pre-ERAS and transition-to-ERAS (t-ERAS) cohorts and compared by univariate analysis. Of 467 patients, 236 patients were well-matched (118 per cohort). The transition to ERAS resulted in a 79% reduction in morphine equivalents through postoperative day 1 (359.3 mg pre-ERAS vs 75.4 mg ERAS, P < 0.0001). Despite less opioid utilization, t-ERAS patients reported lower pain scores (median 4.88 vs 4.14, P = 0.011). There was no difference in mortality (2% vs 0%, P = 0.498) or postoperative complications including initial hours ventilated (5.3 vs 5.2 hours, P = 0.380), prolonged ventilation (9.3% vs 6.8%, P = 0.473), renal failure (3.4% vs 2.5%, P = 0.701), and ICU length of stay (58.3 vs 70.4 hours, P = 0.272). The transition to cardiac ERAS resulted in significantly reduced opioid administration and improved patient pain scores while maintaining excellent outcomes. Well-supported, multidisciplinary teams of cardiac surgeons, anesthesiologists, and intensivists can dramatically reduce opioid use without sacrificing pain control or excellent clinical outcomes.

Molecular and Cellular Response of the Myocardium (H9C2 Cells) Towards Hypoxia and HIF-1α Inhibition.

Introduction: Oxidative phosphorylation is an essential feature of Animalian life. Multiple adaptations have developed to protect against hypoxia, including hypoxia-inducible-factors (HIFs). The major role of HIFs may be in protecting against oxidative stress, not the preservation of high-energy phosphates. The precise mechanism(s) of HIF protection is not completely understood. Materials and Methods: To better understand the role of hypoxia-inducible-factor-1, we exposed heart/myocardium cells (H9c2) to both normoxia and hypoxia, as well as cobalt chloride (prolyl hydroxylase inhibitor), echniomycin (HIF inhibitor), A2P (anti-oxidant), and small interfering RNA to beclin-1. We measured cell viability, intracellular calcium and adenosine triphosphate, NADP/NADPH ratios, total intracellular reactive oxidative species levels, and markers of oxidative and antioxidant levels measured. Results: Hypoxia (1%) leads to increased intracellular Ca2+ levels, and this response was inhibited by A2P and echinomycin (ECM). Exposure of H9c2 cells to hypoxia also led to an increase in both mRNA and protein expression for Cav 1.2 and Cav 1.3. Exposure of H9c2 cells to hypoxia led to a decrease in intracellular ATP levels and a sharp reduction in total ROS, SOD, and CAT levels. The impact of hypoxia on ROS was reversed with HIF-1 inhibition through ECM. Exposure of H9c2 cells to hypoxia led to an increase in Hif1a, VEGF and EPO protein expression, as well as a decrease in mitochondrial DNA. Both A2P and ECM attenuated this response to varying degrees. Conclusion: Hypoxia leads to increased intracellular Ca2+, and inhibition of HIF-1 attenuates the increase in intracellular Ca2+ that occurs with hypoxia. HIF-1 expression leads to decreased adenosine triphosphate levels, but the role of HIF-1 on the production of reactive oxidative species remains uncertain. Anti-oxidants decrease HIF-1 expression in the setting of hypoxia and attenuate the increase in Ca2+ that occurs during hypoxia (with no effect during normoxia). Beclin-1 appears to drive autophagy in the setting of hypoxia (through ATG5) but not in normoxia. Additionally, Beclin-1 is a powerful driver of reactive oxidative species production and plays a role in ATP production. HIF-1 inhibition does not affect autophagy in the setting of hypoxia, suggesting that there are other drivers of autophagy that impact beclin-1.

A systemic congestive index (systemic pulse pressure to central venous pressure ratio) predicts adverse outcomes in patients undergoing valvular heart surgery.

BACKGROUND AND AIMS: Invasive hemodynamics may provide a more nuanced assessment of cardiac function and risk phenotyping in patients undergoing cardiac surgery. The systemic pulse pressure (SPP) to central venous pressure (CVP) ratio represents an integrated index of right and left ventricular function and thus may demonstrate an association with valvular heart surgery outcomes. This study hypothesized that a low SPP/CVP ratio would be associated with mortality in valvular surgery patients. METHODS: This retrospective cohort study examined adult valvular surgery patients with preoperative right heart catheterization from 2007 through 2016 at a single tertiary medical center (n = 215). Associations between the SPP/CVP ratio and mortality were investigated with univariate and multivariate analyses. RESULTS: Among 215 patients (age 69.7 ± 12.4 years; 55.8% male), 61 died (28.4%) over a median follow-up of 5.9 years. A SPP/CVP ratio <7.6 was associated with increased mortality (relative risk 1.70, 95% confidence interval [CI] 1.08-2.67, p = .019) and increased length of stay (11.56 ± 13.73 days vs. 7.93 ± 4.92 days, p = .016). It remained an independent predictor of mortality (adjusted odds ratio 3.99, 95% CI 1.47-11.45, p = .008) after adjusting for CVP, mean pulmonary artery pressure, aortic stenosis, tricuspid regurgitation, smoking status, diabetes mellitus, dialysis, and cross-clamp time. CONCLUSIONS: A low SPP/CVP ratio was associated with worse outcomes in patients undergoing valvular heart surgery. This metric has potential utility in preoperative risk stratification to guide patient selection, prognosis, and surgical outcomes.

Use of epidurography in the perioperative and acute pain setting.

Ensuring proper placement of epidural catheters is critical to improving their reliability for pain control and maintaining confidence in their continued use. This article will seek to address the role of objective confirmation of successful epidural placement via either single view or continuous epidural contrast studies, each creating an 'epidurogram.' Furthermore, the pertinent anatomical corollaries of continuous fluoroscopy used frequently in chronic pain medicine, from which these techniques emerged, will be addressed. Technical radiographic information needed to better understand and troubleshoot these studies is also included. Image examples which highlight the patterns key for successful interpretation of epidurograms will be provided. The aim of this paper was to provide an anesthesiologist unfamiliar with fluoroscopic evaluation of epidural catheters with the tools necessary to successfully conduct and interpret such an examination.

A Novel Hemodynamic Index of Post-operative Right Heart Dysfunction Predicts Mortality in Cardiac Surgical Patients.

INTRODUCTION: This study aimed to investigate whether mortality following cardiac surgery was associated with the pulmonary artery pulsatility index (PAPi): pulmonary artery pulse pressure divided by central venous pressure (CVP), and a novel index: mean pulmonary artery pressure (mPAP) minus CVP. METHODS: This retrospective analysis investigated all cardiac surgery patients in the Society of Thoracic Surgeons registry at a single academic medical center from January 2017 through March 2020 (n = 1510). The primary and secondary outcomes were mortality at 1 year and serum creatinine increase during index surgical admission, respectively. CVP, mPAP, PAPi, mPAP-CVP gradient, mean arterial pressure (MAP), and cardiac index (CI) were sampled continually from invasive hemodynamic monitors post-operatively. Associations with mortality were tested with univariate and multivariate analyses. The relationship with serum creatinine was investigated with Pearson's correlation at alpha = .05. RESULTS: One-year mortality was observed in 44/1200 patients (3.7%). On univariate analysis, mortality was associated with minimums for mPAP, MAP, and CI and maximums for CVP, mPAP, PAPi, mPAP-CVP gradient, and CI (all P < .10). Model selection revealed that the only independently predictive parameters were minimum MAP (AOR = .880 [.819-.944]), maximum mPAP-CVP gradient (AOR = 1.082 [1.031-1.133]), and maximum CI (AOR = 1.421 [.928-2.068]), with model c-statistic = .770. A maximum mPAP-CVP gradient >20.5 predicted mortality with 54.5% sensitivity and 79.30% specificity, maintaining significance on survival analysis (P < .001). Peak increase in serum creatinine from baseline demonstrated a weak association with all parameters (max |r| = .33). CONCLUSIONS: Mortality was not predicted by the post-operative PAPi; rather, it was independently predicted by the mPAP-CVP gradient, MAP, and CI.

Intraoperative administration of isoflurane improves survival in rats exposed to caecal ligation and puncture.

Background: Emerging data suggest that volatile anaesthetic agents may be protective during critical illness. Methods: Three-month-old Sprague Dawley rats were randomly allocated to one of four groups: isoflurane during surgery followed by 3 days of isoflurane 0.8% (and intralipid i.v.), propofol during surgery and 314 µg kg-1 h-1 propofol for 3 days, isoflurane during surgery and intralipid for 3 days, and propofol during surgery and intralipid for 3 days. After induction with propofol or isoflurane, rats breathed oxygen 100% spontaneously via a nose cone. Propofol or intralipid was administered through a 22-gauge jugular vein i.v. catheter. Caecal ligation and puncture was performed through a paramedian incision. The surgical concentration of isoflurane was kept at 2%, and propofol was maintained at 800 µg kg-1 h-1. After recovery and 3 days of exposure to intralipid or anaesthetic agents, the rats were allowed to roam free in an adequately vented, temperature- and humidity-controlled cage with food and water ad libitum. Results: Rats that received isoflurane for 3 days survived longer than the postoperative propofol group (P=0.0002, log-rank test). Among rats receiving no postoperative anaesthetic, those receiving isoflurane during surgery survived longer than those that received propofol during surgery group (P=0.0081). Conclusions: Exposure to isoflurane, as opposed to propofol, may improve survival in rats exposed to caecal ligation and puncture.

Wireless wearables for postoperative surveillance on surgical wards: a survey of 1158 anaesthesiologists in Western Europe and the USA.

Background: Several continuous monitoring solutions, including wireless wearable sensors, are available or being developed to improve patient surveillance on surgical wards. We designed a survey to understand the current perception and expectations of anaesthesiologists who, as perioperative physicians, are increasingly involved in postoperative care. Methods: The survey was shared in 40 university hospitals from Western Europe and the USA. Results: From 5744 anaesthesiologists who received the survey link, there were 1158 valid questionnaires available for analysis. Current postoperative surveillance was mainly based on intermittent spot-checks of vital signs every 4-6 h in the USA (72%) and every 8-12 h in Europe (53%). A majority of respondents (91%) considered that continuous monitoring of vital signs should be available on surgical wards and that wireless sensors are preferable to tethered systems (86%). Most respondents indicated that oxygen saturation (93%), heart rate (80%), and blood pressure (71%) should be continuously monitored with wrist devices (71%) or skin adhesive patches (54%). They believed it may help detect clinical deterioration earlier (90%), decrease rescue interventions (59%), and decrease hospital mortality (54%). Opinions diverged regarding the impact on nurse workload (increase 46%, decrease 39%), and most respondents considered that the biggest implementation challenges are economic (79%) and connectivity issues (64%). Conclusion: Continuous monitoring of vital signs with wireless sensors is wanted by most anaesthesiologists from university hospitals in Western Europe and in the USA. They believe it may improve patient safety and outcome, but may also be challenging to implement because of cost and connectivity issues.

Preoperative REM sleep is associated with complication development after colorectal surgery.

BACKGROUND: While total sleep duration and rapid eye movement (REM) sleep duration have been associated with long-term mortality in non-surgical cohorts, the impact of preoperative sleep on postoperative outcomes has not been well studied. METHODS: In this secondary analysis of a prospective observational cohort study, patients who recorded at least 1 sleep episode using a consumer wearable device in the 7 days before elective colorectal surgery were included. 30-day postoperative outcomes among those who did and did not receive at least 6 h of total sleep, as well as those who did and did not receive at least 1 h of rapid eye movement (REM) sleep, were compared. RESULTS: 34 out of 95 (35.8%) patients averaged at least 6 h of sleep per night, while 44 out of 82 (53.7%) averaged 1 h or more of REM sleep. Patients who slept less than 6 h had similar postoperative outcomes compared to those who slept 6 h or more. Patients who averaged less than 1 h of REM sleep, compared to those who achieved 1 h or more of REM sleep, had significantly higher rates of complication development (29.0% vs. 9.1%, P = 0.02), and return to the OR (10.5% vs. 0%, P = 0.04). After adjustment for confounding factors, increased REM sleep duration remained significantly associated with decreased complication development (increase in REM sleep from 50 to 60 min: OR 0.72, P = 0.009; REM sleep ≥ 1 h: OR 0.22, P = 0.03). CONCLUSION: In this cohort of patients undergoing elective colorectal surgery, those who developed a complication within 30 days were less likely to average at least 1 h of REM sleep in the week before surgery than those who did not develop a complication. Preoperative REM sleep duration may represent a risk factor for surgical complications; however additional research is necessary to confirm this relationship.

Wearable technology and the association of perioperative activity level with 30-day readmission among patients undergoing major colorectal surgery.

BACKGROUND: The proliferation of wearable technology presents a novel opportunity for perioperative activity monitoring; however, the association between perioperative activity level and readmission remains underexplored. This study sought to determine whether physical activity data captured by wearable technology before and after colorectal surgery can be used to predict 30-day readmission. METHODS: In this prospective observational cohort study of adults undergoing elective major colorectal surgery (January 2018 to February 2019) at a single institution, participants wore an activity monitor 30 days before and after surgery. The primary outcome was return to baseline percentage, defined as step count on the day before discharge as a percentage of mean preoperative daily step count, among readmitted and non-readmitted patients. RESULTS: 94 patients had sufficient data available for analysis, of which 16 patients (17.0%) were readmitted within 30 days following discharge. Readmitted patients achieved a lower return to baseline percentage compared to patients who were not readmitted (median 15.1% vs. 31.8%; P = 0.004). On multivariable analysis adjusting for readmission risk and hospital length of stay, an absolute increase of 10% in return to baseline percentage was associated with a 40% decreased risk of 30-day readmission (odds ratio 0.60; P = 0.02). Analysis of the receiver operating characteristic curve identified 28.9% as an optimal return to baseline percent threshold for predicting readmission. CONCLUSIONS: Achieving a higher percentage of an individual's preoperative baseline activity level on the day prior to discharge after major colorectal surgery is associated with decreased risk of 30-day hospital readmission.

Outcome of Organ Dysfunction in the Perioperative Period.

While intraoperative mortality has diminished greatly over the last several decades, the risk of death within 30 days of surgery remains stubbornly high and is ultimately related to perioperative organ failure. Perioperative strokes, while rare (<2% in noncardiac surgery), are associated with a more than 10-fold increase in mortality. Rapid identification and treatment are key to maximizing long-term outcomes. Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are separate but related perioperative neurological disorders, both of which are associated with poor long-term outcomes. To date, there are few known interventions that can ameliorate the risk of perioperative central nervous system dysfunction. Major adverse cardiac events (MACE) are a major contributor to adverse clinical outcomes following surgical procedures. Recently, advances in diagnostic strategies (eg, high-sensitivity cardiac troponin [hs-cTn] assays) have improved our understanding of MACE. Recently, the dabigatran in patients with myocardial injury after noncardiac surgery (MINS; Management of myocardial injury After NoncArdiac surGEry) trial demonstrated that a direct thrombin inhibitor could improve outcomes following MINS. While the risk of acute respiratory distress syndrome (ARDS) after surgery is approximately 0.2%, other less severe complications (eg, pneumonia, reintubation) are closer to 2%. While intensive care unit (ICU) concepts related to ARDS have migrated into the operating room, whether or not adverse pulmonary outcomes impact long-term outcomes in surgical patients remains a matter of debate. The standardization of acute kidney injury (AKI) definition has improved the ability of clinicians to measure and study the incidence of this important source of perioperative morbidity. AKI is associated with increased mortality as well as nonrenal morbidity (eg, myocardial infarction) after major surgery. Gastrointestinal complications after surgery range from ileus (common in abdominal procedures and associated with an increased length of stay) to less common complications such as mesenteric ischemia and gastrointestinal bleeding, both of which are associated with very high mortality. Outside of cardiothoracic surgery, the incidence of perioperative hepatic injury is not well described but, in this population, is associated with worsened long-term outcomes. Hyperglycemia is a common perioperative complication and occurs in patients undergoing both cardiac and noncardiac surgery. Both hyper- and hypoglycemia are associated with worsened long-term outcomes in cardiac and noncardiac surgery. Better diagnosis and increased understanding of perioperative organ injury has led to an increased appreciation for the specific role that particular organ systems play in poor long-term outcomes and has set the stage for targeted therapeutic interventions.

Apophenia and anesthesia: how we sometimes change our practice prematurely.

Human beings are predisposed to identifying false patterns in statistical noise, a likely survival advantage during our evolutionary development. Moreover, humans seem to prefer "positive" results over "negative" ones. These two cognitive features lay a framework for premature adoption of falsely positive studies. Added to this predisposition is the tendency of journals to "overbid" for exciting or newsworthy manuscripts, incentives in both the academic and publishing industries that value change over truth and scientific rigour, and a growing dependence on complex statistical techniques that some reviewers do not understand. The purpose of this article is to describe the underlying causes of premature adoption and provide recommendations that may improve the quality of published science.

RéSUMé: Les êtres humains ont tendance à identifier de fausses corrélations dans le bruit de fond statistique, ce qui nous a probablement conféré un avantage en matière de survie au cours de notre développement évolutionnaire. De plus, l'être humain semble préférer les résultats « positifs ¼ aux résultats « négatifs ¼. Ces deux caractéristiques cognitives posent un cadre expliquant l'adoption hâtive d'études faussement positives. À cette prédisposition s'ajoutent la tendance des revues à « surenchérir ¼ pour les manuscrits prometteurs ou notables, les incitatifs tant dans les milieux académiques qu'éditoriaux, qui préfèrent le changement à la vérité et à la rigueur scientifique, et une dépendance croissante à l'égard de techniques statistiques complexes que certains réviseurs ne comprennent pas. L'objectif de cet article est de décrire les causes sous-jacentes d'adoption prématurée de nouveautés et de proposer des recommandations afin d'améliorer la qualité de la science publiée.