Effects of Postoperative Blood Pressure Management on Delirium Among Patients in the Intensive Care Unit After Cardiac Surgery: An Observational Cohort Study

OBJECTIVES

This study aimed to determine whether blood pressure control in the early postoperative period was associated with postoperative delirium in the cardiovascular intensive care unit (ICU).

DESIGN

Observational cohort study.

SETTING

Single large academic institution with a high volume of cardiac surgery.

PARTICIPANTS

Cardiac surgery patients admitted to the cardiovascular ICU after surgery.

INTERVENTIONS

Observational study.

MEASUREMENTS AND MAIN RESULTS

A total of 517 cardiac surgery patients had mean arterial pressure (MAP) data recorded minute-by-minute for 12 postoperative hours. The time spent in each of the 7 prespecified blood pressure bands was calculated, and the development of delirium was recorded in the ICU. A multivariate Cox regression model was developed using the least absolute shrinkage and selection operator approach to identify associations between time spent in each MAP range band and delirium. Compared with the reference band of 60-to-69 mmHg, longer durations spent in 3 bands were independently associated with a lower risk of delirium: 50-to-59 mmHg band (adjusted hazard ratio [HR] 0.907 [per 10 minutes]; 95% CI 0.861-0.955); 70-to-79 mmHg band (adjusted HR 0.923 [per 10 minutes]; 95% CI 0.902-0.944); 90-to-99 mmHg band (adjusted HR 0.898 [per 10 minutes]; 95% CI 0.853-0.945).

CONCLUSIONS

The MAP range bands above and below the authors' reference band of 60-to- 69 mmHg were associated with decreased risk of ICU delirium development; however, this was difficult to reconcile with a plausible biologic mechanism. Therefore, the authors did not find a correlation between early postoperative MAP control and increased risk of the development of ICU delirium after cardiac surgery.

Clinical Outcomes in Patients With Bacteremia and Concomitant Left Ventricular Assist Devices and Cardiac Implantable Electronic Devices

Infection remains a common cause of morbidity and mortality in patients with both left ventricular assist devices (LVADs) and cardiac implanted electronic devices (CIEDs) with limited data describing outcomes in patients who have both devices implanted. We performed a single-center, retrospective, observational cohort study of patients with both a transvenous CIED and LVAD who developed bacteremia. Ninety-one patients were evaluated. Eighty-one patients (89.0%) were treated medically and nine patients (9.9%) underwent surgical management. A multivariable logistic regression showed that blood culture positivity for >72 hours was associated with inpatient death, when controlled for age and management strategy (odds ratio [OR] = 3.73 [95% confidence interval {CI} = 1.34-10.4], p = 0.012). In patients who survived the initial hospitalization, the use of long-term suppressive antibiotics was not associated with the composite outcome of death or infection recurrence within 1 year, when controlled for age and management strategy (OR = 2.31 [95% CI = 0.88-2.62], p = 0.09). A Cox proportional hazards model showed that blood culture positivity for >72 hours was associated with a trend toward increased mortality in the first year, when controlled for age, management strategy, and staphylococcal infection (hazard ratio = 1.72 [95% CI = 0.88-3.37], p = 0.11). Surgical management was associated with a trend toward decreased mortality (hazard ratio = 0.23 [95% CI = 0.05-1.00], p = 0.05).

Comparing and Contrasting the Experiences of U.S. Medical Students During the COVID-19 and 1918 Influenza Pandemics

In March 2020, medical students across the United States were pulled from their in-person responsibilities and learning in response to COVID-19. Leaders in the U.S. medical education system then began the arduous task of determining when, and how, to restore their full scope of training. This challenge was complicated by a paucity of readily available historical information about U.S. medical students in pandemics. To fill this knowledge gap, the authors collaborated with a medical history archivist to describe the experience of U.S. medical students during the 1918 influenza pandemic and compare it with the modern day. The experiences and responsibilities of medical students differed tremendously between the 2 pandemics. In 1918, U.S. medical students typically were conscripted into clinical service if they did not volunteer, assuming the roles of physicians, physician assistants, and nurses, often with atypically high levels of autonomy. Medical students were at great risk during the 1918 pandemic; multiple medical schools recorded students dying from influenza. In contrast, during the early COVID-19 pandemic, U.S. medical students were removed from the clinical environment, even if they wanted to volunteer, assuming ancillary roles instead. Upon returning to the clinical environment, most were not permitted to care for COVID-19 patients. The few medical students who recorded personal narratives about 1918 felt that caring for patients with influenza significantly influenced their growth and development as future physicians. One of the few things U.S. medical education had in common between the 1918 and COVID-19 pandemics was a lack of preparedness that impaired readiness and increased confusion among medical students. As U.S. medical education reflects on its response to COVID-19, the authors hope that their findings will provide context for future discussions and decisions about the role of medical students in pandemics.

The Association Between Enhanced Recovery After Cardiac Surgery-Guided Analgesics and Postoperative Delirium

OBJECTIVES

Delirium is a common postoperative complication associated with death and long-term cognitive impairment. The authors studied the association between opioid-sparing anesthetics, incorporating Enhanced Recovery After Cardiac Surgery (ERACS)-guided analgesics and postoperative delirium.

DESIGN

The authors performed a retrospective review of nonemergent coronary, valve, or ascending aorta surgery patients.

SETTING

A tertiary academic medical institution.

PARTICIPANTS

The study authors analyzed a dataset of elective adult cardiac surgical patients. All patients ≥18 years undergoing elective cardiac surgery from November 2, 2017 until February 2, 2021 were eligible for inclusion.

INTERVENTIONS

The ERACS-guided multimodal pain regimen included preoperative oral acetaminophen and gabapentin, and intraoperative intravenous lidocaine, ketamine, and dexmedetomidine.

MEASUREMENTS AND MAIN RESULTS

Delirium was measured by bedside nurses using the Confusion Assessment Method for the intensive care unit (ICU). Delirium occurred in 220 of the 1,675 patients (13.7%). The use of any component of the multimodal pain regimen was not associated with delirium (odds ratio [OR]: 0.85 [95% CI: 0.63-1.16]). Individually, acetaminophen was associated with reduced odds of delirium (OR: 0.60 [95% CI: 0.37-0.95]). Gabapentin (OR: 1.36 [95% CI: 0.97-2.21]), lidocaine (OR: 0.86 [95% CI: 0.53-1.37]), ketamine (OR: 1.15 [95% CI: 0.72-1.83]), and dexmedetomidine (OR: 0.79 [95% CI: 0.46-1.31]) were not individually associated with postoperative delirium. Individual ERACS elements were associated with secondary outcomes of hospital length of stay, ICU duration, postoperative opioid administration, and postoperative intubation duration.

CONCLUSIONS

The use of an opioid-sparing perioperative ERACS pain regimen was not associated with reduced postoperative delirium, opioid consumption, or additional poor outcomes. Individually, acetaminophen was associated with reduced delirium.

Does Intentional Support of Degree Programs in General Surgery Residency Affect Research Productivity or Pursuit of Academic Surgery? A Multi-Institutional Study

OBJECTIVE

To determine whether pursuit of an advanced degree during dedicated research time (DRT) in a general surgery residency training program impacts a resident's research productivity.

DESIGN

A retrospective, multi-institutional cohort study.

SETTING

General surgery residency programs that were approved to graduate more than 5 categorical residents per year and that offered at least 1 year of DRT were contacted for participation in the study. A total of 10 general surgery residency programs agreed to participate in the study.

PARTICIPANTS

Residents who started their residency between 2000 and 2012 and spent at least one full year in DRT (n = 511) were included. Those who completed an advanced degree were compared on the following parameters to those who did not complete one: total number of papers, first-author papers, the Journal Citation Reports impact factors of publication (2018, or most recent), and first position after residency or fellowship training.

RESULTS

During DRT, 87 (17%) residents obtained an advanced degree. The most common degree obtained was a Master of Public Health (MPH, n = 42 (48.8%)). Residents who did not obtain an advanced degree during DRT published fewer papers (median 8, [interquartile range 4-12]) than those who obtained a degree (9, [6-17]) (p = 0.002). They also published fewer first author papers (3, [2-6]) vs (5, [2-9]) (p = 0.002) than those who obtained a degree. Resident impact factor (RIF) was calculated using Journal Citation Reports impact factor and author position. Those who did not earn an advanced degree had a lower RIF (adjusted RIF, 84 ± 4 vs 134 ± 5, p < 0.001) compared to those who did. There was no association between obtaining a degree and pursuit of academic surgery (p = 0.13) CONCLUSIONS: Pursuit of an advanced degree during DRT is associated with increased research productivity but is not associated with pursuit of an academic career.

Quantifying Ciliary Dynamics during Assembly Reveals Stepwise Waveform Maturation in Airway Cells

Motile cilia are essential for clearance of particulates and pathogens from airways. For effective transport, ciliary motor proteins and axonemal structures interact to generate the rhythmic, propulsive bending, but the mechanisms that produce a dynamic waveform remain incompletely understood. Biomechanical measures of human ciliary motion and their relationships to ciliary assembly are needed to illuminate the biophysics of normal ciliary function and to quantify dysfunction in ciliopathies. To these ends, we analyzed ciliary motion by high-speed video microscopy of ciliated cells sampled from human lung airways compared with primary culture cells that undergo ciliogenesis in vitro. Quantitative assessment of waveform parameters showed variations in waveform shape between individual cilia; however, general trends in waveform parameters emerged, associated with progression of cilia length and stage of differentiation. When cilia emerged from cultured cells, beat frequency was initially elevated, then fell and remained stable as cilia lengthened. In contrast, the average bending amplitude and the ability to generate force gradually increased and eventually approached values observed in ex vivo samples. Dynein arm motor proteins DNAH5, DNAH9, DNAH11, and DNAH6 were localized within specific regions of the axoneme in the ex vivo cells; however, distinct stages of in vitro waveform development identified by biomechanical features were associated with the progressive movement of dyneins to the appropriate proximal or distal sections of the cilium. These observations suggest that the stepwise variation in waveform development during ciliogenesis is dependent on cilia length and potentially on outer dynein arm assembly.