Association of ketamine use during procedural sedation with oxygen desaturation and healthcare utilisation: a multicentre retrospective hospital registry study.

BACKGROUND: We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists. METHODS: We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge. RESULTS: Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [ORadj] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARDadj] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, ORadj 1.35, 95% CI 1.25-1.45, P<0.001; ARDadj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, ORadj 2.91, 95% CI 1.85-4.58, P<0.001; ARDadj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, ORadj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg-1). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (ORadj 1.11, 95% CI 1.02-1.21, P=0.012; ARDadj 0.25%, 95% CI 0.05-0.46%, P=0.014). CONCLUSIONS: Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients.

Loss of Independent Living in Patients Undergoing Transcatheter or Surgical Aortic Valve Replacement: A Retrospective Cohort Study.

BACKGROUND: The recommendation for transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) in patients 65 to 80 years of age is equivocal, leaving patients with a difficult decision. We evaluated whether TAVR compared to SAVR is associated with reduced odds for loss of independent living in patients ≤65, 66 to 79, and ≥80 years of age. Further, we explored mechanisms of the association of TAVR and adverse discharge. METHODS: Adult patients undergoing TAVR or SAVR within a large academic medical system who lived independently before the procedure were included. A multivariable logistic regression model, adjusting for a priori defined confounders including patient demographics, preoperative comorbidities, and a risk score for adverse discharge after cardiac surgery, was used to assess the primary association. We tested the interaction of patient age with the association between aortic valve replacement (AVR) procedure and loss of independent living. We further assessed whether the primary association was mediated (ie, percentage of the association that can be attributed to the mediator) by the procedural duration as prespecified mediator. RESULTS: A total of 1751 patients (age median [quartiles; min-max], 76 [67, 84; 23-100]; sex, 56% female) were included. A total of 27% (222/812) of these patients undergoing SAVR and 20% (188/939) undergoing TAVR lost the ability to live independently. In our cohort, TAVR was associated with reduced odds for loss of independent living compared to SAVR (adjusted odds ratio [OR adj ] 0.19 [95% confidence interval {CI}, 0.14-0.26]; P < .001). This association was attenuated in patients ≤65 years of age (OR adj 0.63 [0.26-1.56]; P = .32) and between 66 and 79 years of age (OR adj 0.23 [0.15-0.35]; P < .001), and magnified in patients ≥80 years of age (OR adj 0.16 [0.10-0.25]; P < .001; P -for-interaction = .004). Among those >65 years of age, a shorter procedural duration mediated 50% (95% CI, 28-76; P < .001) of the beneficial association of TAVR and independent living. CONCLUSIONS: Patients >65 years of age undergoing TAVR compared to SAVR had reduced odds for loss of independent living. This association was partly mediated by shorter procedural duration. No association between AVR approach and the primary end point was found in patients ≤65 years of age.

To Swan or Not to Swan: Indications, Alternatives, and Future Directions.

The pulmonary artery catheter (PAC) has revolutionized bedside assessment of preload, afterload, and contractility using measured pulmonary capillary wedge pressure, calculated systemic vascular resistance, and estimated cardiac output. It is placed percutaneously by a flow-directed balloon-tipped technique through the venous system and the right heart to the pulmonary artery. Interest in the hemodynamic variables obtained from PACs paved the way for the development of numerous less-invasive hemodynamic monitors over the past 3 decades. These devices estimate cardiac output using concepts such as pulse contour and pressure analysis, transpulmonary thermodilution, carbon dioxide rebreathing, impedance plethysmography, Doppler ultrasonography, and echocardiography. Herein, the authors review the conception, technologic advancements, and modern use of PACs, as well as the criticisms regarding the clinical utility, reliability, and safety of PACs. The authors comment on the current understanding of the benefits and limitations of alternative hemodynamic monitors, which is important for providers caring for critically ill patients. The authors also briefly discuss the use of hemodynamic monitoring in goal-directed fluid therapy algorithms in Enhanced Recovery After Surgery programs.

Preoperative Opioid Use Disorder Is Associated With Poorer Outcomes After Coronary Bypass and Valve Surgery: A Multistate Analysis, 2007-2014.

OBJECTIVE: To determine the effect of preoperative opioid use disorder (OUD) on postoperative outcomes in patients undergoing coronary artery bypass grafting (CABG) and heart valve surgery. DESIGN: Retrospective, observational study using data from the State Inpatient Database and the Healthcare Cost and Utilization Project. SETTING: Inpatient data from Florida, California, New York, Maryland, and Kentucky between 2007 and 2014. PARTICIPANTS: A total of 377,771 CABG patients and 194,469 valve surgery patients age ≥18 years. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The prevalence of OUD was 2,136 (0.57%) in the CABG group and 2,020 (1.04%) in the valve surgery group. There was no significant difference in mortality between the OUD and non-OUD groups in both surgical cohorts (both p > 0.05). On adjusted analyses, preoperative OUD was significantly associated with increased adjusted odds ratios (aORs) of 30-day hospital readmission (CABG aOR 1.47 [95% confidence interval {CI} 1.30-1.66]; valve surgery aOR 1.41 [95% CI 1.27-1.56]) and 90-day hospital readmission (CABG aOR 1.47 [95% CI 1.31-1.64]; valve surgery aOR 1.33 [95% CI 1.23-1.43]). Preoperative OUD was significantly associated with increased adjusted risk ratios (aRRs) of hospital length of stay (CABG aRR 1.13 [95% CI 1.10-1.16]; valve surgery aRR 1.63 [95% CI 1.54-1.72]) and total hospitalization charges (CABG aRR 1.05 [95% CI 1.03-1.07]; valve surgery aRR 1.28 [95% CI 1.24-1.32]). CONCLUSION: Preoperative OUD is significantly associated with poorer outcomes after cardiac surgery, including increased 30- and 90-day readmissions, hospital length of stay, and total hospitalization charges. Opioid use should be considered a modifiable risk factor in cardiac surgery, and interventions should be attempted preoperatively.

Insurance Status and Socioeconomic Factors Affect Early Mortality After Cardiac Valve Surgery.

OBJECTIVE: To characterize the effects markers of socioeconomic status (SES), including race and ethnicity, health insurance status, and median household income by zip code on in-patient mortality after cardiac valve surgery. DESIGN: Retrospective cohort study of adult valve surgery patients included in the State Inpatient Databases and Healthcare Cost and Utilization Project. The primary outcome was mortality during the index admission. Bivariate analyses and multivariate regression models were used to assess the independent effects of race and ethnicity, payer status, and median income by patient zip code on in-hospital mortality. DESIGN: Multistate database of hospitalizations from 2007 to 2014 from New York, Florida, Kentucky, California, and Maryland. PARTICIPANTS: In total, 181,305 patients ≥18 years old underwent mitral or aortic valve repair or replacement and met the inclusion criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Mortality rates were higher among black (5.59%) than white patients (4.28%, p < 0.001) and among Medicaid (4.66%), Medicare (5.22%), and uninsured (4.58%) patients compared with private insurance (2.45%, p < 0.001). After controlling for age, sex, presenting comorbidities, urgent or emergent operative status, and hospital case volume, mortality odds remained significantly elevated for black (odds ratio [OR] 1.127, confidence interval [CI] 1.038-1.223), uninsured (OR 1.213, CI 1.020-1.444), Medicaid (OR 1.270, 95% CI 1.116-1.449) and Medicare (OR 1.316, 95% CI 1.216-1.415) patients. CONCLUSIONS: Markers of low SES, including race/ethnicity, insurance status, and household income, are associated with increased risk of in-hospital mortality following cardiac valve surgery. Further research is warranted to understand and help decrease mortality risk in underinsured, less-wealthy and non-white patients undergoing cardiac valve surgery.

Use of Pulmonary Artery Pulsatility Index in Cardiac Surgery.

OBJECTIVE: This study evaluated whether the pulmonary artery pulsatility index (PAPi) collected before and after cardiopulmonary bypass (CPB) is predictive and diagnostic of new onset right ventricular (RV) failure in the elective cardiac surgical population. DESIGN: This was a prospective observational study of patients who underwent cardiac surgery between 2017 and 2019. SETTING: Weill Cornell Medicine, a single large academic medical center. PARTICIPANTS: The study comprised 119 patients undergoing elective cardiac surgery. INTERVENTIONS: Cardiopulmonary bypass, transesophageal echocardiography, pulmonary artery catheter, and elective cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Echocardiographic and hemodynamic data were collected at 2 time points: pre-CPB and post-chest closure/post-CPB. Patients with and without post-CPB RV dysfunction fractional area of change (<35%) were compared, and receiver operating characteristic curves were constructed. One hundred and nineteen patients undergoing elective surgery-coronary artery bypass grafting (23%), aortic valve replacement (21%), aortic surgery (19%), and combined surgery (37%)-were evaluated. Post-CPB RV dysfunction was associated with lower pre-CPB PAPi values (2.0 ± 1.0 v 2.5 ± 1.2; p = 0.001 and p = 0.03) and higher pre-CPB central venous pressure (8.3 ± 3.6 and 6.9 ± 2.7; p = 0.003 and p = 0.02, respectively). Pre-CPB PAPi (0.98 [95% confidence interval {CI} 0.96-0.99]), end systolic area (0.99 [95% CI 0.98-0.99]), and end diastolic area (1.01 [95% CI 1.001-1.02]) were independently associated with RV dysfunction in multivariable modeling, with a lower PAPi and end systolic area and higher end diastolic area demonstrating a greater risk of RV dysfunction post-CPB (post-CPB area under the curve for PAPi 0.80 [95% CI 0.71-0.88; sensitivity = 0.68, specificity = 0.93, optimal cutoff = 1.9]). CONCLUSIONS: PAPi measured pre-CPB is a potential predictor and marker of post-CPB RV dysfunction and may have diagnostic utility in cardiac surgery. Additional, large-scale studies are needed to confirm this finding.

The impact of hospital safety-net burden on mortality and readmission after CABG surgery.

BACKGROUND AND AIM: Safety-net hospitals (SNHs) serve high proportions of uninsured and Medicaid patients. Data conflict as to the impact of hospital safety-net status on perioperative complications. Our goal was to assess the effect of hospital safety-net burden on mortality and readmission following coronary artery bypass graft (CABG) surgery. METHODS: A retrospective analysis was performed using five State Inpatient Databases (2007-2014) for isolated CABG surgery. High, medium, and low burden hospitals were those with the highest, middle, and lowest tertiles of uninsured and Medicaid admissions, respectively. We compared patient demographics and hospital characteristics by safety-net status. Multivariable logistic regression models assessed adjusted odds of in-hospital mortality and 30- and 90-day readmission. RESULTS: About 304 080 patients were included in our analysis. On univariate analysis, high burden hospitals had higher inpatient mortality (2.06% vs 1.71%; P < .001) and 30 day- (16.3% vs 15.3%; P < .001) and 90-day readmission rates (24.6% vs 23.0%; P < .001). On multivariate analysis, high-burden status was not associated with significantly increased adjusted odds of inpatient mortality (OR, 1.047; 95% CI, 0.878-1.249), or readmission at 30 (OR, 1.035; 95% CI, 0.958-1.118) or 90 days (OR, 1.040; 95% CI, 0.968-1.117). CONCLUSION: SNHs do not have worse mortality and readmission outcomes following CABG, after adjusting for patient and hospital characteristics. These findings are reassuring regarding the quality of cardiac surgery care provided to underinsured patient groups. More research is needed to further elucidate trends in outcomes.

A phenomenological approach to jet noise: the two-source model.

This is a review of the two-source model of jet noise. The model was developed phenomenologically a number of years ago. One of the principal results associated with this model was the identification of two similarity jet noise spectra. This was accomplished through extensive comparisons with a large set of NASA spectrum data. It was found that these two noise spectra when combined appropriately would fit measured noise spectra of jets in any direction regardless of jet temperature and Mach number. Other experimental data in support of the two-source model have since been found. They are discussed in this paper. One of the purposes of this paper is to elaborate on the flow physics of turbulence, noise generation mechanisms and directivity that are the underpinnings of the model. More recent works show the similarity spectra are applicable, well beyond their original database, to noise of military jets, rockets and even volcanoes. This article is part of the theme issue 'Frontiers of aeroacoustics research: theory, computation and experiment'.

Understanding the Relationship between Chronic Systemic Disease and Lichen Sclerosus Urethral Strictures.

PURPOSE: Lichen sclerosus is a chronic, inflammatory skin condition of the genitalia of unknown origin that accounts for nearly 10% of urethral stricture disease. In this study we determine systemic comorbidities associated with lichen sclerosus in men. MATERIALS AND METHODS: We analyzed data from 1,151 men who were enrolled in a multi-institutional prospective urethroplasty outcomes database. Individuals were grouped by stricture etiology, and baseline demographics, medical histories and patient reported outcome measures were retrospectively compared across groups. RESULTS: Of the 1,151 men in the database 81 (7.0%) were noted to have lichen sclerosus related urethral stricture disease. Average patient age was 46.06 ± 16.52 years, with those with lichen sclerosus being significantly older than those without lichen sclerosus (51.26 ± 13.84 vs 45.68 ± 16.64, p = 0.0011). Men with lichen sclerosus were more likely to have hypertension, hyperlipidemia and diabetes, and to use tobacco products. Controlling for age, men with lichen sclerosus related urethral stricture disease had a higher body mass index (aOR 1.089, 95% CI 1.050-1.130), and were more likely to have hypertension (aOR 2.028, 1.21-3.41) and be active tobacco users (aOR 2.0, 1.36-3.40). Mean preoperative patient reported outcome measures scores for urinary and sexual function were similar. Controlling for stricture length and location, the adjusted odds of surgical failure were higher for lichen sclerosus related urethral stricture disease (aOR 1.9, 95% CI 0.9-4.2). CONCLUSIONS: Lichen sclerosus related urethral stricture disease is associated with chronic systemic diseases. This association may implicate a systemic inflammatory and/or autoimmune pathophysiology. A 2-hit mechanism implicating local and systemic factors for lichen sclerosus related urethral stricture disease development and progression is hypothesized.

Measuring and Predicting Patient Dissatisfaction after Anterior Urethroplasty Using Patient Reported Outcomes Measures.

PURPOSE: Subjective measures of success after urethroplasty have become increasingly valuable in postoperative monitoring. We examined patient reported satisfaction following anterior urethroplasty using objective measures as a proxy for success. MATERIALS AND METHODS: Men 18 years old or older with urethral strictures undergoing urethroplasty were prospectively enrolled in a longitudinal, multi-institutional urethroplasty outcomes database. Preoperative and postoperative assessment included questionnaires to assess lower urinary tract symptoms, pain, satisfaction and sexual health. Analyses controlling for stricture recurrence (defined as the inability to traverse the reconstructed urethra with a flexible cystoscope) were performed to determine independent predictors of dissatisfaction. RESULTS: At a mean followup of 14 months we found a high 89.4% rate of overall postoperative satisfaction in 433 patients and a high 82.8% rate in those who would have chosen the operation again. Men with cystoscopic recurrence were more likely to report dissatisfaction (OR 4.96, 95% CI 2.07-11.90) and men reporting dissatisfaction had significantly worse uroflowmetry measures (each p <0.02). When controlling for recurrence, multivariate analysis revealed that urethra and bladder pain (OR 1.71, 95% CI 1.05-2.77 and OR 2.74, 95% CI 1.12-6.69, respectively), a postoperative decrease in sexual activity (OR 4.36, 95% CI 2.07-11.90) and persistent lower urinary tract symptoms (eg straining to urinate OR 3.23, 1.74-6.01) were independent predictors of dissatisfaction. CONCLUSIONS: Overall satisfaction after anterior urethroplasty is high and traditional measures of surgical success strongly correlate with satisfaction. However, independently of the anatomical appearance of the reconstructed urethra, postoperative pain, sexual dysfunction and persistent lower urinary tract symptoms were predictors of patient dissatisfaction.

Acute Kidney Injury and Renal Replacement Therapy: A Review and Update for the Perioperative Physician.

Post-operative acute kidney injury is a devastating complication with significant morbidity and mortality associated with it. The perioperative anesthesiologist is in a unique position to potentially mitigate the risk of postoperative AKI, however, understanding the pathophysiology, risk factors and preventative strategies is paramount. There are also certain clinical scenarios, where renal replacement therapy may be indicated intraoperatively including severe electrolyte abnormalities, metabolic acidosis and massive volume overload. A multidisciplinary approach including the nephrologist, critical care physician, surgeon and anesthesiologist is necessary to determine the optimal management of these critically ill patients.

Mechanical Circulatory Support: Primer for Consultant Specialists.

Mechanical life support therapies exist in many forms to temporarily replace the function of vital organs. Generally speaking, these tools are supportive therapy to allow for organ recovery but, at times, require transition to long-term mechanical support. This review will examine nonrenal extracorporeal life support for cardiac and pulmonary support as well as other mechanical circulatory support options. This is intended as a general primer and overview to assist nephrologist consultants participating in the care of these critically ill patients who often experience acute renal injury as a result of cardiopulmonary shock and from their exposure to mechanical circulatory support.