Noelle Saillant

Platelet dysfunction in injured patients

A renewed understanding of Trauma Induced Coagulopathy (TIC) has implicated platelets as a crucial mediator and potential therapeutic target in hemostasis. While the importance of abnormal coagulation tests is well described in trauma, there is a paucity of data regarding the role of platelets in coagulopathy. New coagulation models, namely the cell-based-model of hemostasis, have refocused attention toward the platelet and endothelium as key regulators of clot formation. Although platelet dysfunction has been associated with worse outcomes in trauma, the mechanisms which platelet dysfunction contributes to coagulopathy are poorly understood. The goal of this review article is to outline recent advances in understanding hemostasis and the ensuing cellular dysfunction that contributes to the exsanguination of a critically injured patient.

Venous thromboembolism after major venous injuries: Competing priorities

BACKGROUND Venous thromboembolism (VTE) after major vascular injury (MVI) is particularly challenging because the competing risk of thrombosis and embolization after direct vessel injury must be balanced with risk of bleeding after surgical repair. We hypothesized that venous injuries, repair type, and intraoperative anticoagulation would influence VTE formation after MVI. METHODS A multi-institution, retrospective cohort study of consecutive MVI patients was conducted at three urban, Level I centers (2005–2013). Patients with MVI of the neck, torso, or proximal extremities (to elbows/knees) were included. Our primary study endpoint was the development of VTE (DVT or pulmonary embolism [PE]). RESULTS The 435 major vascular injury patients were primarily young (27 years) men (89%) with penetrating (84%) injuries. When patients with (n = 108) and without (n = 327) VTE were compared, we observed no difference in age, mechanism, extremity injury, tourniquet use, orthopedic and spine injuries, damage control, local heparinized saline, or vascular surgery consultation (all p > 0.05). VTE patients had greater Injury Severity Score (ISS) (17 vs. 12), shock indices (1 vs. 0.9), and more torso (58% vs. 35%) and venous (73% vs. 48%) injuries, but less often received systemic intraoperative anticoagulation (39% vs. 53%) or postoperative enoxaparin (47% vs. 61%) prophylaxis (all p < 0.05). After controlling for ISS, hemodynamics, injured vessel, intraoperative anticoagulation, and postoperative prophylaxis, multivariable analysis revealed venous injury was independently predictive of VTE (odds ratio, 2.7; p = 0.002). Multivariable analysis of the venous injuries subset (n = 237) then determined that only delay in starting VTE chemoprophylaxis (odds ratio, 1.3/day; p = 0.013) independently predicted VTE after controlling for ISS, hemodynamics, injured vessel, surgical subspecialty, intraoperative anticoagulation, and postoperative prophylaxis. Overall, 3.4% of venous injury patients developed PE, but PE rates were not related to their operative management (p = 0.72). CONCLUSION Patients with major venous injuries are at high risk for VTE, regardless of intraoperative management. Our results support the immediate initiation of postoperative chemoprophylaxis in patients with major venous injuries. LEVEL OF EVIDENCE Therapeutic/care management, level IV.

LC-MS Analysis of Human Platelets as a Platform for Studying Mitochondrial Metabolism

Perturbed mitochondrial metabolism has received renewed interest as playing a causative role in a range of diseases. Probing alterations to metabolic pathways requires a model in which external factors can be well controlled, allowing for reproducible and meaningful results. Many studies employ transformed cellular models for these purposes; however, metabolic reprogramming that occurs in many cancer cell lines may introduce confounding variables. For this reason primary cells are desirable, though attaining adequate biomass for metabolic studies can be challenging. Here we show that human platelets can be utilized as a platform to carry out metabolic studies in combination with liquid chromatography-tandem mass spectrometry analysis. This approach is amenable to relative quantification and isotopic labeling to probe the activity of specific metabolic pathways. Availability of platelets from individual donors or from blood banks makes this model system applicable to clinical studies and feasible to scale up. Here we utilize isolated platelets to confirm previously identified compensatory metabolic shifts in response to the complex I inhibitor rotenone. More specifically, a decrease in glycolysis is accompanied by an increase in fatty acid oxidation to maintain acetyl-CoA levels. Our results show that platelets can be used as an easily accessible and medically relevant model to probe the effects of xenobiotics on cellular metabolism.

Systemic intraoperative anticoagulation during arterial injury repair: Implications for patency and bleeding.

BACKGROUND The role of systemic intraoperative anticoagulation (SIAC) during surgical repair of major arterial injuries is controversial. Any potential improvement in arterial patency must be weighed against the risk of hemorrhage in these critically injured patients. We hypothesized that SIAC would increase arterial patency without increasing bleeding complications. METHODS We conducted a multi-institution, retrospective cohort study of trauma patients with major vascular injury from 2005 to 2013 in three Level I centers. Arterial injuries of the neck, torso, and proximal extremities requiring operative management were included. Our primary endpoint was maintenance of arterial patency during index hospitalization. Complications related to bleeding were assessed. The association between SIAC and arterial patency was evaluated using chi-square, t test, and multiple logistic regression modeling. RESULTS Of 323 study patients, most were male (88%) and injured by gunshot wounds (69%). Patients repaired with SIAC (n = 154) were compared to those repaired without SIAC (n = 169). No difference in age, gender, mechanism, admission heart rate, or concomitant injury was detected between the groups (all p > 0.05). SIAC use was associated with greater arterial patency rates (93% vs. 85%, p = 0.02) without increasing return to OR for bleeding (4% vs. 6%, p = 0.29). After controlling for gender, admission hemodynamics, ISS, injury location, and postoperative anticoagulation, multivariable regression determined that SIAC patients were 2.6 times more likely (OR 2.6, 95% CI 1.1–6.2, p = 0.03) to maintain patency. Patients who maintained arterial patency were then less likely to return to the OR (9% vs. 78%, p < 0.001) with shorter intensive care unit (median 3 vs. 9 days, p < 0.01) and hospital length of stay (median 13 vs. 21 days, p < 0.01). CONCLUSION Patients who underwent operative repair of arterial injuries utilizing SIAC experienced better arterial patency without additional bleeding complications as compared to those repaired without SIAC. Our data suggest that SIAC may improve arterial patency rates after repair and the attributable bleeding risk of SIAC may be overstated. LEVEL OF EVIDENCE Therapeutic/care management, level IV.

Technological advancements in the care of the trauma patient.

IntrodutionMedical technology has benefited many types of patients, but trauma care has arguably benefited more from technologic development than almost any other field.MethodsA literature review to identify key technological advances in the care of trauma patients was performed.ResultsThe advances in trauma care are in great measure due to the integration of many different systems. Medical technology impacts care in the field at the site of the trauma, in the transport to trauma facilities, and care at the trauma center itself. Once at the hospital, technology has impacted care in the trauma bay, intensive care units, the operating room, and in postoperative and long-term care settings. The integration of advancements, however, needs to be examined in a careful systematic fashion to insure that patients will actually derive benefit.

Are surgeons reluctant to accurately report intraoperative adverse events? A prospective study of 1,989 patients

Background: The true incidence of intraoperative adverse events (iAEs) remains unknown. Methods: All patients undergoing abdominal surgery at an academic institution between January and July 2016 were included in a prospective fashion. At the end of surgery, using a secure REDCap database, the surgeon was given the Institute of Medicine definition of intraoperative adverse events and asked whether an intraoperative adverse event had occurred. Blinded reviewers systematically examined all operative reports for intraoperative adverse events and their severity. The response rate and the intraoperative adverse event rate reported by surgeons were calculated. The latter was compared with the rate of intraoperative adverse events detected by operative report review. The severity of intraoperative adverse events was assessed based on a previously validated intraoperative adverse event classification system. Results: A total of 1,989 operations were included. The surgeons’ response rate was 71.9%, reporting intraoperative adverse events in 107 operations (7.5%). Of those intraoperative adverse events, 26 (24.3%) were not described in the operative report. Operative report review revealed intraoperative adverse events in 417 operations (21.0%). Most injuries were of lower severity (85.8% were either class I or II). The surgeons’ response rate was similar in operations with and without intraoperative adverse events (69.8% versus 72.5%, P=.28), but they underreported low severity intraoperative adverse events—only 13.2% of class I compared with 35.3%, 36.8%, and 55.6% of injury classes II, III, and IV respectively (P<.001). Conclusion: Surgeons are willing to report intraoperative adverse events, but systematically and significantly underreport them, especially if they are of lower severity. This is potentially related to the absence of a clear intraoperative adverse event definition or their personal interpretation of their clinical significance.

Variation of Opioid Prescribing Patterns among Patients undergoing Similar Surgery on the Same Acute Care Surgery Service of the Same Institution: Time for Standardization?

Background Diversion of unused prescription opioids is a major contributor to the current United States opioid epidemic. We aimed to study the variation of opioid prescribing in emergency surgery. Methods Between October 2016 and March 2017, all patients undergoing laparoscopic appendectomy, laparoscopic cholecystectomy, or inguinal hernia repair in the acute care surgery service of 1 academic center were included. For each patient, we systematically reviewed the electronic medical record and the prescribing pharmacy platform to identify: (1) history of opioid abuse, (2) opioid intake 3 months preoperatively, (3) number of opioid pills prescribed, (4) prescription of nonopioid pain medications (eg, acetaminophen, ibuprofen), and (5) the need for opioid prescription refills. The mean and range of opioid pills prescribed, as well as their oral morphine equivalent, were calculated. Results A total of 255 patients were included (43.5% laparoscopic appendectomy, 44.3% laparoscopic cholecystectomy, and 12.1% inguinal hernia repair). The mean age was 47.5 years, 52.1% were female, 11.4% had a history of opioid use, and 92.5% received opioid prescriptions upon hospital discharge. Only 70.9% of patients were instructed to use nonopioid pain medications. The mean and range of opioid pills prescribed were 17.4; 0–56 (laparoscopic appendectomy), 17.1; 0–75 (laparoscopic cholecystectomy), and 20.9; 0–50 (inguinal hernia repair), while the range of prescribed oral morphine equivalent was 0–600 mg for laparoscopic appendectomy/laparoscopic cholecystectomy and 0–375 mg for inguinal hernia repair. No patients required any opioid medication refills. Conclusion Even within the same surgical service, wide variation of opioid prescription was observed. Guidelines that standardize pain management may help prevent opioid overprescribing.

Preoperative Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is a Risk Factor for Surgical Site Infections after Laparoscopic Cholecystectomy.

BACKGROUND We sought to examine whether preoperative endoscopic retrograde cholangio-pancreatography (ERCP) increases the risk of surgical site infections (SSI) after laparoscopic cholecystectomy. METHODS Patients admitted to an academic hospital from 2010 to 2016, who were older than 18 and had a laparoscopic or a laparoscopic converted to open cholecystectomy for complicated biliary tract disease were included. We compared those who had a preoperative ERCP to those who did not. Our primary endpoint was the rate of SSI. RESULTS A total of 640 patients were included. Of them, 122 (19.1%) received preoperative ERCP and 518 (80.9%) did not. The former had different preoperative diagnoses compared to non-ERCP patients (choledocholithiasis [35.2%-7.0%], acute cholecystitis [31.2%-76.4%], gallstone pancreatitis [20.5%-16.2%], and cholangitis [13.1%-0.4%], p < 0.001). The rate of SSI was higher in the preoperative ERCP group (11.5%-4.0%, p = 0.005). In a multivariable analysis conversion to open (OR = 2.57, 95% CI = 1.06-6.21, p = 0.037) and preoperative ERCP (OR = 3.12, 95% CI = 1.34-7.22, p = 0.008) were the only independent predictors of SSI. CONCLUSION Preoperative ERCP is associated with a threefold increase in the risk of SSI after laparoscopic cholecystectomy.

Cervical spinal cord injury after blunt assault: Just a pain in the neck?

BACKGROUND We aimed to determine the incidence, risk factors, and outcomes of cervical spinal cord injury (CSCI) after blunt assault. METHODS The ACS National Trauma Data Bank (NTDB) 2012 Research Data Set was used to identify victims of blunt assault using the ICD-9 E-codes 960.0, 968.2, 973. ICD-9 codes 805.00, 839.00, 806.00, 952.00 identified cervical vertebral fractures/dislocations and CSCI. Multivariable analyses were performed to identify independent predictors of CSCI. RESULTS 14,835 (2%) out of 833,311 NTDB cases were blunt assault victims and thus included. 217 (1%) had cervical vertebral fracture/dislocation without CSCI; 57 (0.4%) had CSCI. Age ≥55 years was independently predictive of CSCI; assault by striking/thrown object, facial fracture, and intracranial injury predicted the absence of CSCI. 25 (0.02%) patients with CSCI underwent cervical spinal fusion. CONCLUSIONS CSCI is rare after blunt assault. While the odds of CSCI increase with age, facial fracture or intracranial injury predicts the absence of CSCI. SUMMARY The incidence, risk factors, and outcomes of cervical spinal cord injury (CSCI) after blunt assault was investigated. 14,835 blunt assault victims were identified; 217 had cervical vertebral fracture/dislocation without CSCI; 57 had CSCI. Age ≥55 years was found to independently predict CSCI, while assault by striking/thrown object, facial fracture, and intracranial injury predicted the absence of CSCI.

Thrombocytopenia in the Surgical Intensive Care Unit

Thrombocytopenia is the most prevalent hematologic disorder in the ICU. Defined as a as a platelet count ≤150 × 109/L, thrombocytopenia is observed in 30–50 % of critically ill patients [1]. The consequences of thrombocytopenia range from a mild, asymptomatic phenomenon to microvascular failure. A drop in platelet count by >30 % is an independent risk factor for death and a stronger predictor of mortality than the Acute Physiology and Chronic Health Evaluation (APACHE) II score [2, 3]. Multiple etiologies may contribute to a low platelet count. This chapter will specifically review the diagnosis and management of thrombocytopenia in the surgical ICU patient.