Intraoperative Deaths: Who, Why, and Can We Prevent Them?

INTRODUCTION

Intraoperative deaths (IODs) are rare but catastrophic. We systematically analyzed IODs to identify clinical and patient safety patterns.

METHODS

IODs in a large academic center between 2015 and 2019 were included. Perioperative details were systematically reviewed, focusing on (1) identifying phenotypes of IOD, (2) describing emerging themes immediately preceding cardiac arrest, and (3) suggesting interventions to mitigate IOD in each phenotype.

RESULTS

Forty-one patients were included. Three IOD phenotypes were identified: trauma (T), nontrauma emergency (NT), and elective (EL) surgery patients, each with 2 sub-phenotypes (e.g., ELm and ELv for elective surgery with medical arrests or vascular injury and bleeding, respectively). In phenotype T, cardiopulmonary resuscitation was initiated before incision in 42%, resuscitative thoracotomy was performed in 33%, and transient return of spontaneous circulation was achieved in 30% of patients. In phenotype NT, ruptured aortic aneurysms accounted for half the cases, and median blood product utilization was 2,694 mL. In phenotype ELm, preoperative evaluation did not include electrocardiogram in 12%, cardiac consultation in 62%, stress test in 87%, and chest x-ray in 37% of patients. In phenotype ELv, 83% had a single peripheral intravenous line, and vascular injury was almost always followed by escalation in monitoring (e.g., central/arterial line), alert to the blood bank, and call for surgical backup.

CONCLUSIONS

We have created a framework for IOD that can help with intraoperative safety and quality analysis. Focusing on interventions that address appropriateness versus futility in care in phenotypes T and NT, and on prevention and mitigation of intraoperative vessel injury (e.g., intraoperative rescue team) or preoperative optimization in phenotype EL may help prevent IODs.

Low-Molecular Weight Heparin is Superior to Unfractionated Heparin for Elderly Trauma Patients

BACKGROUND

Several studies have demonstrated that low-molecular weight heparin (LMWH) is superior to unfractionated heparin (UFH) in trauma patients. The superiority of either one has not been established for the elderly. In this study, we compared LMWH to UFH in elderly trauma patients.

METHODS

A retrospective analysis of the American College of Surgeons' Trauma Quality Improvement Program database was performed for patients aged ≥65 y. Propensity score matching was performed to minimize confounders between the two groups. Outcomes included venous thromboembolic (VTE) and bleeding events.

RESULTS

Overall, 93,987 patients were identified (mean age 77.1 ± 7.3 y, females 55,035 [58.6%]), of which 67,738 (72.1%) patients received LMWH and 26,249 (27.9%) received UFH. After Propensity score matching, LMWH was associated with a lower incidence of deep venous thrombosis (1.7% versus 2.1%, P = 0.007) and pulmonary embolisms (0.6% versus 1%, P< 0.001). LMWH was also associated with fewer bleeding complications (transfusions: 2.8% versus 3.5%, P< 0.001, procedures: 0.7% versus 0.9%, P = 0.007). Sub-analyses showed that differences in VTE rates were identified in patients with mild injuries (Injury Severity Score [ISS] <16, 0.6% versus 1.9%, P< 0.001). Differences in bleeding complications were identified in patients with injuries of mild (ISS <16, transfusions: 3% versus 3.8%, P< 0.001, surgeries: 0.3% versus 0.4%, P= 0.015) and moderate severity (ISS 16-24, transfusions: 1.9% versus 2.7%, P= 0.038, surgeries: 1% versus 1.7%, P= 0.013).

CONCLUSION

LMWH prophylaxis is superior to UFH for VTE prevention among elderly trauma patients. LMWH prophylaxis is associated with fewer bleeding complications compared to UFH in patients with injuries of mild or moderate severity.

Abdominal Wall Thickness Predicts Surgical Site Infection in Emergency Colon Operations

BACKGROUND

Body mass index (BMI) does not reliably predict Surgical site infections (SSI). We hypothesize that abdominal wall thickness (AWT) would serve as a better predictor of SSI for patients undergoing emergency colon operations.

METHODS

We retrospectively evaluated our Emergency Surgery Database (2007-2018). Emergency colon operations for any indication were included. AWT was measured by pre-operative CT scans at 5 locations. Only superficial and deep SSIs were considered as SSI in the analysis. Univariate then multivariable analyses were used to determine predictors of SSI.

RESULTS

236 patients met inclusion criteria. The incidence of post-operative SSI was 25.8% and the median BMI was 25.8kg/m2 [22.5-30.1]. The median AWT between patients with and without SSI was significantly different (2.1cm [1.4, 2.8] and 1.8cm [1.2, 2.5], respectively). A higher BMI trended toward increased rates of SSI, but this was not statistically significant. In overweight (BMI 25-29.9kg/m2) and obese (BMI ≥30kg/m2) patients, SSI versus no SSI rates were (50.0% versus 41.9% and 47.4% versus 36.4%, P = 0.365 and 0.230) respectively. The incidence of SSI in patients with an average AWT < 1.8cm was 20% and 30% for patients with average AWT ≥1.8cm. On multivariable analysis, AWT ≥1.8cm at 2cm inferior to umbilicus was an independent predictor of SSI (OR 2.98, 95%CI 1.34-6.63, P = 0.007).

CONCLUSIONS

AWT is a better predictor of SSI than BMI. Preoperative imaging of AWT may direct intraoperative decisions regarding wound management. Future clinical outcomes research in emergency surgery should include abdominal wall thickness as an important patient variable.

Implications of the national Stop the Bleed campaign: The swinging pendulum of prehospital tourniquet application in civilian limb trauma

BACKGROUND

Prehospital tourniquet (PHT) utilization has increased in response to mass casualty events. We aimed to describe the incidence, therapeutic effectiveness, and morbidity associated with tourniquet placement in all patients treated with PHT application.

METHODS

A retrospective observational cohort study was performed to evaluate all adults with a PHT who presented at two Level I trauma centers between January 2015 and December 2019. Medically trained abstractors determined if the PHT was clinically indicated (placed for limb amputation, vascular hard signs, injury requiring hemostasis procedure, or significant documented blood loss). Prehospital tourniquets were further designated as appropriately or inappropriately applied (based on PHT anatomic placement location, occurrence of a venous tourniquet, or ischemic time defined as >2 hours). Statistical analyses were performed to generate primary and secondary results.

RESULTS

A total of 147 patients met study inclusion criteria, of which 70% met the criteria for trauma registry inclusion. Total incidence of PHT utilization increased from 2015 to 2019, with increasing proportions of PHTs placed by nonemergency medical service personnel. Improvised PHTs were frequently used. Prehospital tourniquets were clinically indicated in 51% of patients. Overall, 39 (27%) patients had a PHT that was inappropriately placed, five of which resulted in significant morbidity.

CONCLUSION

In summary, prehospital tourniquet application has become widely adopted in the civilian setting, frequently performed by civilian and nonemergency medical service personnel. Of PHTs placed, nearly half had no clear indication for placement and over a quarter of PHTs were misapplied with notable associated morbidity. Results suggest that the topics of clinical indication and appropriate application of tourniquets may be important areas for continued focus in future tourniquet educational programs, as well as future quality assessment efforts.

LEVEL OF EVIDENCE

Epidemiological, level III; Therapeutic, level IV.

Multisystem outcomes and predictors of mortality in critically ill patients with COVID-19: Demographics and disease acuity matter more than comorbidities or treatment modalities

BACKGROUND

We sought to describe characteristics, multisystem outcomes, and predictors of mortality of the critically ill COVID-19 patients in the largest hospital in Massachusetts.

METHODS

This is a prospective cohort study. All patients admitted to the intensive care unit (ICU) with reverse-transcriptase-polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection between March 14, 2020, and April 28, 2020, were included; hospital and multisystem outcomes were evaluated. Data were collected from electronic records. Acute respiratory distress syndrome (ARDS) was defined as PaO2/FiO2 ratio of ≤300 during admission and bilateral radiographic pulmonary opacities. Multivariable logistic regression analyses adjusting for available confounders were performed to identify predictors of mortality.

RESULTS

A total of 235 patients were included. The median (interquartile range [IQR]) Sequential Organ Failure Assessment score was 5 (3-8), and the median (IQR) PaO2/FiO2 was 208 (146-300) with 86.4% of patients meeting criteria for ARDS. The median (IQR) follow-up was 92 (86-99) days, and the median ICU length of stay was 16 (8-25) days; 62.1% of patients were proned, 49.8% required neuromuscular blockade, and 3.4% required extracorporeal membrane oxygenation. The most common complications were shock (88.9%), acute kidney injury (AKI) (69.8%), secondary bacterial pneumonia (70.6%), and pressure ulcers (51.1%). As of July 8, 2020, 175 patients (74.5%) were discharged alive (61.7% to skilled nursing or rehabilitation facility), 58 (24.7%) died in the hospital, and only 2 patients were still hospitalized, but out of the ICU. Age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.04-1.12), higher median Sequential Organ Failure Assessment score at ICU admission (OR, 1.24; 95% CI, 1.06-1.43), elevated creatine kinase of ≥1,000 U/L at hospital admission (OR, 6.64; 95% CI, 1.51-29.17), and severe ARDS (OR, 5.24; 95% CI, 1.18-23.29) independently predicted hospital mortality.Comorbidities, steroids, and hydroxychloroquine treatment did not predict mortality.

CONCLUSION

We present here the outcomes of critically ill patients with COVID-19. Age, acuity of disease, and severe ARDS predicted mortality rather than comorbidities.

LEVEL OF EVIDENCE

Prognostic, level III.

Systolic Blood Pressure <110 mm Hg as a Threshold of Hypotension in Patients with Isolated Traumatic Brain Injuries

Hypotension is a known risk factor for poor neurologic outcomes after traumatic brain injury (TBI). Current guidelines suggest that higher systolic blood pressure (SBP) thresholds likely confer a mortality benefit. However, there is no consensus on the ideal perfusion pressure among different age groups (i.e., recommended SBP ≥100 mm Hg for patients age 50-69 years; ≥ 110 mm Hg for all other adults). We hypothesize that admission SBP ≥110 mm Hg will be associated with improved outcomes regardless of age group. A retrospective database review of the 2010-2016 Trauma Quality Improvement Program database was performed for adults (≥ 18 years) with isolated moderate-to-severe TBIs (head Abbreviated Injury Scale [AIS] ≥3; all other AIS <3). Sub-analyses were performed after dividing patients by SBP and age; comparison groups were matched with propensity score matching. Primary outcomes were early (6 h, 12 h, and 1 day) and overall in-hospital mortality. Overall, 154,725 patients met the inclusion criteria (mean age 62.8 ± 19.8 years, 89,431 [57.8%] males, Injury Severity Score13.9 ± 6.8). Multi-variate logistic regression showed that the risk of in-hospital mortality decreased with increasing SBP, plateauing at 110 mm Hg. Among patients of all ages, SBP ≥110 mm Hg was associated with improved mortality (SBP 110-129 vs. 90-109 mm Hg: 12 h 0.4% vs. 0.8%, p = 0.001; 1 day 0.8% vs. 1.4%, p = 0.004; overall 3.2% vs. 4.9%, p < 0.001). Among patients age 50-69 years, SBP ≥110 mm Hg was associated with improved mortality (SBP 110-119 vs. 100-109 mm Hg: 12 h 0.3% vs. 0.9%, p = 0.018; 1 day 0.5% vs. 1.5%, p = 0.007; overall 2.7% vs. 4.3%, p = 0.015). In conclusion, SBP ≥110 mm Hg is associated with lower in-hospital mortality in adult patients with isolated TBIs, including patients age 50-69 years. SBP <110 mm Hg should be used to define hypotension in adult patients of all ages.

Direct Oral Anticoagulants Are a Potential Alternative to Low-Molecular-Weight Heparin for Thromboprophylaxis in Trauma Patients Sustaining Lower Extremity Fractures

BACKGROUND

Trauma patients are at a significant risk of venous thromboembolism (VTE), with lower extremity fractures (LEF) being independent risk factors. Use of direct oral anticoagusants (DOACs) for VTE prophylaxis is effective in elective orthopedic surgery, but currently not approved for trauma patients. The primary objective of this study was to compare the effectiveness and safety of thromboprophylaxis of DOACs with low-molecular-weight heparin (LMWH) in trauma patients sustaining LEF.

MATERIALS AND METHODS

We included adult trauma patients admitted to trauma quality improvement program participating trauma centers (between 2013 and 2016), who sustained LEF and were started on DOACs or LMWH for thromboprophylaxis after admission. Propensity score matching was performed to compare symptomatic VTE and bleeding control interventions between the groups.

RESULTS

Of 1,009,922 patients in trauma quality improvement program, 167,640 met inclusion criteria (165,009 received LMWH and 2631 received DOACs). After propensity score matching, 2280 predominantly elderly (median age: 67 y) isolated femur fracture patients (median ISS: 10) were included in each group (4560 patients in total). Symptomatic VTE occurred in 1.4% of patients in both matched groups (P = 0.992). Bleeding control interventions occurred less often in the DOAC group, albeit statistically insignificant (5.8% versus 6.0%, P = 0.772).

CONCLUSIONS

This study found similar rates of VTE and bleeding control measures for thromboprophylaxis with DOACs or LMWH in matched trauma patients with LEF. Further prospective research is warranted to consolidate the safety of DOAC thromboprophylaxis in trauma patients with LEF. Favorable oral administration and likely increased adherence could benefit this high-risk population.

Endothelial and platelet microparticles in patients with antiphospholipid antibodies

BACKGROUND

The antiphospholipid syndrome (APS) is the association of thrombosis and recurrent pregnancy loss and/or pregnancy morbidity with persistent antiphospholipid antibodies (aPL). Previous studies of microparticles in patients with APS/aPL have mainly been small and findings, contradictory.

OBJECTIVES

To quantify endothelial and platelet microparticle levels in patients with isolated antiphospholipid antibodies or primary antiphospholipid syndrome (PAPS).

PATIENTS/METHODS

We measured endothelial and platelet microparticle levels by flow cytometry in 66 aPL/PAPS patients and 18 healthy controls.

RESULTS

Levels of circulating platelet (CD41 and CD61) and endothelial microparticles (CD51 and CD105) were significantly increased in patients with PAPS and aPL compared to healthy controls. There were correlations between platelet and endothelial microparticles levels in all patients with aPL.

CONCLUSIONS

Platelet and endothelial microparticles are increased in all patient groups within this cohort of patients aPL. Whether they may have a role in the pathogenesis of APS merits further study.