Risk factors for postoperative delirium in orthopaedic hip surgery patients: a database review

BACKGROUND

Postoperative delirium is a common problem affecting admitted patients that decreases patient satisfaction and increases the cost and complexity of care. The purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to compare rates and risk factors of postoperative delirium for total hip arthroplasty (THA) and hemiarthroplasty patients indicated for osteoarthritis or proximal femur fracture.

METHODS

The 2021 NSQIP database was queried for patients using Current Procedural Terminology (CPT) codes for THA and hemiarthroplasty and ICD-10 codes for osteoarthritis or proximal femur fracture. Demographic, past medical history, preoperative labs, and functional status data were recorded. Procedural data were also collected. Finally, postoperative outcomes and complications were reviewed.

RESULTS

Overall, 16% of patients had postoperative delirium. Delirium patients were older on average (82.4 years vs. 80.7 years, p < 0.001), had a lower BMI (19.5 vs. 24.8, p < 0.001), were more likely to have a history of dementia (54.6% vs. 13.6%, p < 0.001), were less likely to have an independent functional status (p < 0.001) or live alone (p < 0.001), and were more likely to have sustained a recent fall (p < 0.001). Delirium patients were more likely to be hyponatremic or hypernatremic (p = 0.002), anemic (p < 0.001), and severely dehydrated (p < 0.001), among other lab abnormalities. Delirium patients were also more likely to experience additional postoperative complications, including pneumonia, pulmonary embolism, urinary tract infection, stroke, cardiac arrest, sepsis, and unplanned reoperation and readmission after discharge (all p < 0.05).

CONCLUSIONS

In this study, factors associated with postoperative delirium in patients undergoing hemiarthroplasty and THA were identified, including older age, lower BMI, certain medical conditions, decreased functional status, certain lab abnormalities, and postoperative complications. These findings can be used by clinicians to better inform care and to determine when orthopaedic joint replacement patients may be at an increased risk for postoperative delirium.

Outcomes of Heart Transplant Donation After Circulatory Death

BACKGROUND

Heart transplantation using donation after circulatory death (DCD) allografts is increasingly common, expanding the donor pool and reducing transplant wait times. However, data remain limited on clinical outcomes.

OBJECTIVES

We sought to compare 6-month and 1-year clinical outcomes between recipients of DCD hearts, most of them recovered with the use of normothermic regional perfusion (NRP), and recipients of donation after brain death (DBD) hearts.

METHODS

We conducted a single-center retrospective observational study of all adult heart-only transplants from January 2020 to January 2023. Recipient and donor data were abstracted from medical records and the United Network for Organ Sharing registry, respectively. Survival analysis and Cox regression were used to compare the groups.

RESULTS

During the study period, 385 adults (median age 57.4 years [IQR: 48.0-63.7 years]) underwent heart-only transplantation, including 122 (32%) from DCD donors, 83% of which were recovered with the use of NRP. DCD donors were younger and had fewer comorbidities than DBD donors. DCD recipients were less often hospitalized before transplantation and less likely to require pretransplantation temporary mechanical circulatory support compared with DBD recipients. There were no significant differences between groups in 1-year survival, incidence of severe primary graft dysfunction, treated rejection during the first year, or likelihood of cardiac allograft vasculopathy at 1 year after transplantation.

CONCLUSIONS

In the largest single-center comparison of DCD and DBD heart transplantations to date, outcomes among DCD recipients are noninferior to those of DBD recipients. This study adds to the published data supporting DCD donors as a safe means to expand the heart donor pool.

Alkaline Phosphatase is an Independent Risk Factor for Periprosthetic Fractures in Total Joint Arthroplasty

BACKGROUND

Serum alkaline phosphatase (ALP) is a biomarker for chronic low-grade inflammation along with hepatobiliary and bone disorders. High abnormal ALP levels in blood have been associated with metabolic bone disease and high bone turnover.

METHODS

All primary total hip and knee arthroplasties from 2005 to 2019 were queried from the National Surgical Quality Improvement Program database. Patients with available serum ALP levels were included and stratified to low (<44 IU/L), normal (44 to 147 IU/L), and high (>147 IU/L). A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor of complications.

RESULTS

The analysis included 324,592 patients, consisting of 11,427 low ALP, 305,977 normal ALP, and 7,188 high preoperative ALP level patients undergoing total joint arthroplasty. Adjusted multivariate logistic regression analysis showed high ALP level patients had an overall increased risk of readmission within 30 days of surgery compared with the control group (odds ratio [OR], 1.69; P < 0.01). High ALP patients also had an increased risk of postoperative periprosthetic fracture (OR, 1.6), postoperative wound infection (OR, 1.81), pneumonia (OR, 2.24), renal insufficiency (OR, 2.39), cerebrovascular disease (OR, 2.2), postoperative bleeding requiring transfusion (OR, 1.83), sepsis (OR, 2.35), length of stay > 2 days (OR, 1.47), Clostridium difficile infection (OR, 2.07), and discharge to a rehab facility (OR, 1.41) (all P < 0.05). A low ALP level was also associated with increased postoperative bleeding transfusion risk (OR, 1.12; P < 0.01) and developing a deep vein thrombosis (OR, 1.25; P = 0.03).

CONCLUSION

Abnormal serum ALP levels in patients undergoing primary total joint arthroplasty are associated with increased postoperative periprosthetic fracture risk and medical complications requiring increased length of stay and discharge to a rehabilitation facility.

The impact of dehydration on short-term postoperative complications in total knee arthroplasty

BACKGROUND

As healthcare economics shifts towards outcomes-based bundled payment models, providers must understand the evolving dynamics of medical optimization and fluid resuscitation prior to elective surgery. Dehydration is an overlooked modifiable risk factor that should be optimized prior to elective total knee arthroplasty (TKA) to reduce postoperative complications and inpatient costs.

METHODS

All primary TKA from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database, and patients were compared based on dehydration status: Blood Urea Nitrogen Creatinine ratio (BUN/Cr) < 20 (non-dehydrated), 20 ≤ BUN/Cr ≤ 25 (moderately-dehydrated), 25 < BUN/Cr (severely-dehydrated). A sub-group analysis involving only elderly patients > 65 years and normalized gender-adjusted Cr values was also performed.

RESULTS

The analysis included 344,744 patients who underwent TKA. Adjusted multivariate logistic regression analysis showed that the severely dehydrated cohort had a greater risk of non-home discharge, postoperative transfusion, postoperative deep vein thrombosis (DVT), and increased length of stay (LOS) (all p < 0.01). Among the elderly, dehydrated patients had a greater risk of non-home discharge, progressive renal insufficiency, urinary tract infection (UTI), postoperative transfusion, and extended LOS (all p < 0.01).

CONCLUSION

BUN/Cr > 20 is an important preoperative diagnostic tool to identify at-risk dehydrated patients. Providers should optimize dehydration to prevent complications, decrease costs, and improve discharge planning.

LEVEL OF EVIDENCE

Level III; Retrospective Case-Control Design; Prognosis Study.

Prior Diagnosis of COVID Has No Increased Complications in Total Joint Arthroplasty

Introduction

Although a substantial portion of the United States population has been infected with and recovered from Coronavirus Disease-19 (COVID-19), many patients may have persistent symptoms and complications from disease-driven respiratory disease, arrhythmias, and venous thromboembolism (VTE). With institutions resuming elective total joint arthroplasties (TJA), it is unclear whether a prior resolved diagnosis of COVID has any implications on postoperative outcomes.

Methods

All elective TJA performed in 2021 at our institution were retrospectively reviewed and a history of prior COVID+ result recorded. Baseline demographics, days from prior COVID+ result to surgery date, preoperative methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, and laboratory markers were obtained to determine baseline characteristics. Postoperative estimated blood loss (EBL), length of stay (LOS), rate of revision surgery, and discharge destination were compared between groups. Perioperative and postoperative rates of VTE, urinary tract infection (UTI), pneumonia, postoperative oxygen supplementation, cardiac arrhythmia, renal disease, sepsis, and periprosthetic joint infections within six months of surgery were recorded.

Results

Of the 155 elective TJA performed in 2021, 24 patients had a prior COVID+ diagnosis with a mean of 253 days from positive result to surgery date. There were no significant differences in baseline demographics, comorbidities, and preoperative lab markers between groups. Surgeries on patients with a prior COVID+ had a significantly higher EBL (260 vs 175cc), but postoperative outcomes of VTE, UTI, pneumonia, oxygen supplementation requirement, nares MRSA+, cardiac disease, and infection rates between groups were similar. Bivariate logistic regression revealed increased days from COVID+ diagnosis (>6 months) to surgery date were associated with a shorter LOS.

Conclusion

Although a prior COVID+ diagnosis had increased intraoperative blood loss, there were no significant differences in respiratory, infectious, cardiac, and thromboembolic complications up to six months after elective TJA. This study suggests that asymptomatic C+ patients receiving elective TJA do not require more aggressive prophylactic anticoagulation or antibiotic regimens to prevent VTE or perioperative infections. As institutions around the nation resume pre-COVID rates of arthroplasty surgeries, a prior diagnosis of COVID appears to have no effects on postoperative complications.

Early Blood Pressure Variables Associated With Improved Outcomes in VA-ECLS: The ELSO Registry Analysis

BACKGROUND

As utilization of veno-arterial extracorporeal life support (VA-ECLS) in treatment of cardiogenic shock (CS) continues to expand, clinical variables that guide clinicians in early recognition of myocardial recovery and therefore, improved survival, after VA-ECLS are critical. There remains a paucity of literature on early postinitiation blood pressure measurements that predict improved outcomes.

OBJECTIVES

The objective of this study is to help identify early blood pressure variables associated with improved outcomes in VA-ECLS.

METHODS

The authors queried the ELSO (Extracorporeal Life Support Organization) registry for cardiogenic shock patients treated with VA-ECLS or venovenous arterial ECLS between 2009 and 2020. Their inclusion criteria included treatment with VA-ECLS or venovenous arterial ECLS; absence of pre-existing durable right, left, or biventricular assist devices; no pre-ECLS cardiac arrest; and no surgical or percutaneously placed left ventricular venting devices during their ECLS runs. Their primary outcome of interest was the survival to discharge during index hospitalization.

RESULTS

A total of 2,400 CS patients met the authors' inclusion criteria and had complete documentation of blood pressures. Actual mortality during index hospitalization in their cohort was 49.5% and survivors were younger and more likely to be Caucasian, intubated for >30 hours pre-ECLS initiation, and had a favorable baseline SAVE (Survival After Veno-arterial ECMO) score (P < 0.05 for all). Multivariable regression analyses adjusting for SAVE score, age, ECLS flow at 4 hours, and race showed that every 10-mm Hg increase in baseline systolic blood pressure (HR: 0.92 [95% CI: 0.89-0.95]; P < 0.001), and baseline pulse pressure (HR: 0.88 [95% CI: 0.84-0.91]; P < 0.001) at 24 hours was associated with a statistically significant reduction in mortality.

CONCLUSIONS

Early (within 24 hours) improvements in pulse pressure and systolic blood pressure from baseline are associated with improved survival to discharge among CS patients treated with VA-ECLS.

Impact of increased donor distances following adult heart allocation system changes: A single center review of 1-year outcomes

BACKGROUND

On October 18, 2018, several changes to the donor heart allocation system were enacted. We hypothesize that patients undergoing orthotopic heart transplantation (OHT) under the new allocation system will see an increase in ischemic times, rates of primary graft dysfunction, and 1-year mortality due to these changes.

METHODS

In this single-center retrospective study, we reviewed the charts of all OHT patients from October 2017 through October 2019. Pre- and postallocation recipient demographics were compared. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

A total of 184 patients underwent OHT. Recipient demographics were similar between cohorts. The average distance from donor increased by more than 150 km (p = .006). Patients in the postallocation change cohort demonstrated a significant increase in the rate of severe left ventricle primary graft dysfunction from 5.4% to 18.7% (p = .005). There were no statistically significant differences in 30-day mortality or 1-year survival. Time on the waitlist was reduced from 203.8 to 103.7 days (p = .006).

CONCLUSIONS

Changes in heart allocation resulted in shorter waitlist times at the expense of longer donor distances and ischemic times, with an associated negative impact on early post-transplantation outcomes. No significant differences in 30-day or 1-year mortality were observed.

Prioritizing heart transplantation during the COVID-19 pandemic

Background

Coronavirus disease 2019 (COVID‐19) has significantly impacted the healthcare landscape in the United States in a variety of ways including a nation‐wide reduction in operative volume. The impact of COVID‐19 on the availability of donor organs and the impact on solid organ transplant remains unclear. We examine the impact of COVID‐19 on a single, large‐volume heart transplant program.

Methods

A retrospective chart review was performed examining all adult heart transplants performed at a single institution between March 2020 and June 2020. This was compared to the same time frame in 2019. We examined incidence of primary graft dysfunction, continuous renal replacement therapy (CRRT) and 30‐day survival.

Results

From March to June 2020, 43 orthotopic heart transplants were performed compared to 31 performed during 2019. Donor and recipient demographics demonstrated no differences. There was no difference in 30‐day survival. There was a statistically significant difference in incidence of postoperative CRRT (9/31 vs. 3/43; p = .01). There was a statistically significant difference in race (23 W/8B/1AA vs. 30 W/13B; p = .029).

Conclusion

We demonstrate that a single, large‐volume transplant program was able to grow volume with little difference in donor variables and clinical outcomes following transplant. While multiple reasons are possible, most likely the reduction of volume at other programs allowed us to utilize organs to which we would not have previously had access. More significantly, our growth in volume was coupled with no instances of COVID‐19 infection or transmission amongst patients or staff due to an aggressive testing and surveillance program.

A Dual-Lumen Bicaval Cannula for Venovenous Extracorporeal Membrane Oxygenation

BACKGROUND

Single-site, dual-lumen venovenous extracorporeal membrane oxygenation ECMO) facilitates mobilization, reduces recirculation, and mitigates insertion and infectious risks of an additional access site. This study reports the experience with a bicaval dual-lumen cannula that comprises a robust physical design allowing for easy and safe cannulation, precise positioning and monitoring, and appropriate physiologic support for patients with acute respiratory failure.

METHODS

Statistical analysis was performed from data gathered retrospectively from the electronic medical records of 20 adult patients who were cannulated for ECMO with this bicaval dual-lumen cannula from August 2018 through May 2019.

RESULTS

Gas exchange and blood flow were optimized in all patients after cannulation (median pH, 7.42 [interquartile range {IQR}, 7.39, 7.44], ratio of arterial partial pressure of oxygen to fraction of inspired oxygen, 186.5 [Pao₂:Fio₂, 116.5, 247.0]; pump flow, 3.9 L/min [IQR, 3.1, 4.3]). Eleven patients (55%) were able to be freed from mechanical ventilation after cannulation, 9 (45%) patients underwent a tracheostomy procedure while undergoing ECMO, and no patients required reintubation. No morbidity or mortality was related to the cannulation strategy or the catheter. Two patients required cannula repositioning. Survival to decannulation was 90%, and survival to hospital discharge was 80%.

CONCLUSIONS

The bicaval dual-lumen cannula maintains the advantages of upper body single-site configuration to provide the adjunctive respiratory support necessary to facilitate awakening and rehabilitation while minimizing the use of invasive mechanical ventilation. This cannula introduces design qualities that may offer advantages for acute respiratory failure requiring venovenous ECMO.

Abstract 058: Sirt3 Impairment and SOD2 Hyperacetylation Drive Vascular Oxidative Stress and Hypertension

Aging is associated with increased incidence of hypertension and a decline of the mitochondrial energy regulator deacetylase Sirt3. A major mitochondrial antioxidant enzyme, SOD2, is inhibited by acetylation and its deacetylation by Sirt3 restores SOD2 activity. We hypothesized that loss of Sirt3 activity increases vascular oxidative stress due to SOD2 hyperacetylation and that this promotes hypertension. The combination of angiotensin II and TNFα, which is produced by inflammatory cells in hypertension, synergistically reduced Sirt3 expression, induced SOD2 acetylation and increased mitochondrial superoxide (O 2 • - ) in human aortic endothelial cells (HAEC). mitoEbselen, which scavenges mitochondrial H 2 O 2 , prevented SOD2 acetylation in HAEC and normalized mitochondrial O 2 • - suggesting redox-dependent modulation of Sirt3. In intact mice, chronic AngII infusion (490 ng/kg/min) reduced vascular Sirt3 expression by 20%, caused Sirt3 S-glutathionylation, SOD2 hyperacetylation and reduced SOD2 activity by 42%. Mice transgenic for mitochondria-targeted catalase exhibited reduced Sirt3 S-glutathionylation, no SOD2 hyperacetylation, maintenance of SOD2 activity and no increase in mitochondrial O 2 • - . The functional role of Sirt3 S-glutathionylation was further supported by mitoEbselen treatment of WT and Sirt3 -/- mice after the onset of AngII-induced hypertension. mitoEbselen reduced vascular oxidative stress and hypertension in WT but not in Sirt3 -/- mice. In Sirt3 -/- mice, low dose AngII (200 ng/kg/min) caused greater hypertension (150 mm Hg) than in WT (128 mm Hg, P<0.01) and AngII-infused Sirt3 -/- mice produced less nitric oxide that WT, as detected by electron spin resonance (70 pmol/aorta vs 110 WT+AngII, P< 0.01). We further showed that treatment with the mitochondria targeted SOD2 mimetic mitoTEMPO, initiated after the onset of AngII-induced hypertension lowered blood pressure and improved vasodilatation in both WT and Sirt3 -/- mice, further supporting a role of mitochondrial O 2 • - in hypertension. These data indicate that reduced Sirt3 activity occurs in hypertension due to S-glutathionylation and that this leads to SOD2 hyperacetylation and inactivation, promoting vascular oxidative stress and blood pressure elevation.

Abstract 071: Cytokine-angiotensin II Interplay in Cyclophilin D-mediated Vascular Oxidative Stress and Hypertension

Vascular inflammation and oxidative stress interact in a feed-forward fashion to promote vascular disease and hypertension. We hypothesized that angiotensin II and inflammatory cytokines encountered in hypertension co-operatively induce superoxide (O 2 • - ) production by mitochondrial complex I and that efforts to reduce complex I O 2 • - will reduce hypertension. Treatment of human aortic endothelial cells in culture with angiotensin II (10 nM), IL17A (10 nM) and TNFα (1 nM), factors known to contribute to the hypertensive milieu, co-operatively induced mitochondrial O 2 • - from 340 to 958 pmol/mg protein as measured by HPLC and MitoSOX. This response was abolished by the complex I inhibitor rotenone. We further tested a potential role of Cyclophilin D (CypD), the redox sensitive regulatory subunit of the mitochondrial transition pore in complex I O 2 • - production. Both the specific CypD inhibitor Sanglifehrin A and knockdown of CypD by siRNA prevented endothelial cell O 2 • - production in response to Ang/IL17/TNF. We also found that this cytokine-angiotensin II milieu induced S-glutathionylation of CypD and that scavenging mitochondrial H 2 O 2 with mitoEbselen prevents this and eliminates CypD dependent complex I O 2 • - production. We further studied the functional role of oxidative stress induced by Ang/IL17/TNF in isometric tension studies of mouse aortic rings. Twenty-four hour treatment of organoid cultured vessels with AngII/IL17/TNF reduced endothelium-dependent vasodilatation to acetylcholine and this was prevented by knockdown of CypD and was not observed in vessels of mice with overexpression of mitochondrial SOD or mitochondrial catalase. The in vivo role of CypD in regulation of vascular O 2 • - and blood pressure was further studied in mice infused with angiotensin II (490 ng/kg/min). Treatment with Sanglifehrin A after the onset of hypertension reduced blood pressure from 162 to 133 mmHg (P<0.01), reduced vascular O 2 • - and improved endothelium-dependent vasodilation. These studies have defined a novel role of Cyclophilin D as a cause of vascular dysfunction and hypertension and have provided a new target for treatment of this disease.

Permissible limits of flexor digitorum profundus tendon advancement--an anatomic study

Lacerations of the profundus tendon distal to the superficialis insertion can be treated by advancement of the proximal cut end of the tendon to its insertion. In the English-language literature, limits cited for the distance a profundus tendon can be safely advanced vary from 0.75 to 2.5 cm and appear to be based on clinical impressions. Our cadaver model suggested the degree of tendon advancement tolerable was 1 cm. A delicate balance exists in the profundus tendon system, and this should be considered when surgical advancement is contemplated.

Retroperitoneal fibrosis with hydronephrosis as a complication of the Dwyer procedure

The first reported urological complication of Dwyer Instrumentation for scoliosis is presented. This patient demonstrated ureteral obstruction secondary to retroperitoneal fibrosis temporally associated with this procedure. Routine IVP following surgery is recommended for early detection of urinary complication.