Patterns of Failure of a Standardized Perioperative Venous Thromboembolism Prophylaxis Protocol Ryan Macht MD, Michael Cassidy MD, Pamela Rosenkranz RN BSN MEd, Joseph Caprini MD FACS, David McAneny MD FACS
Disclosure Slide No financial disclosures to report
Background Venous thromboembolism (VTE) events can result in significant morbidity and mortality following operations Numerous well known risk-factors for VTE allow for risk assessment Increasing emphasis on perioperative VTE prevention Financial penalties Public reporting
Caprini Protocol at Boston Medical Center Mandatory standardized electronic VTE risk assessment Score calculated before and after operations and upon discharge Caprini Score Risk Category 3 to 4 Moderate 5 to 8 High Recommended Prophylaxis Compression boots AND Unfractionated Heparin OR Low Molecular Weight Heparin Compression boots AND Unfractionated Heparin OR Low Molecular Weight Heparin Recommended Duration of Chemoprophylaxis During hospitalization 7-10 days total Automated risk-stratified prophylaxis orders 9 Highest Compression boots AND Unfractionated Heparin OR Low Molecular Weight Heparin 30 days total
Audience Response Question At your institution, extended courses of outpatient VTE prophylaxis are given to patients who are determined to be at a particularly high risk of VTE based upon risk calculation: A. Never B. Rarely C. Sometimes D. Often E. Always
5 BMC General Surgery VTE Risk Adjusted Data 4.5 4 3.5 Risk-Adjusted Ratio 3 2.5 2 1.5 1 0.5 0 July 2008- June 2009 CY 2009 July 2009- June 2010 CY 2010 July 2010- June 2011 CY 2011 July 2011- June 2012 CY 2012 July 2012 - June 2013 CY 2013 July 2013- June 2014 CY 2014 July 2014- June 2015 CY 2015
Objective To determine the characteristics of patients who developed VTE events despite a highly effective, standardized perioperative riskstratified prophylaxis program
Audience Response Question Which factor contributes most to VTE failures at your institution? A. Missed administration of prophylaxis doses B. Chemical prophylaxis not being ordered appropriately C. No standardized system for risk assessment and prophylaxis ordering D. High-risk patient factors despite prophylaxis E. Patient non-compliance with intermittent pneumatic compression devices F. Unsure
Methods Retrospective review of non-trauma General Surgery patients who developed a documented VTE event from February 2011 to December 2014 VTE patients identified with NSQIP and UHC databases Characteristics were recorded including demographics, diagnoses, operations, risk profile, prophylaxis prescribed, and compliance with the regimen Comparison were made to patients who did not develop VTEs
Results Overall VTE rate: 0.3% 27 patients failed the VTE prophylaxis protocol 16 PE (59%), 10 DVT (37%), 1 PE and DVT (4%) Mean Age: 59 CapriniScores ranged from 4 to 10, mean 6.5 15/27 (56%) patients with an ICU admission
Of the patients who developed VTEs: Only 15% had missed 1 dose of pharmacologic prophylaxis during hospitalization 52% had a perioperative infection Pre-existing infection: appendicitis (2), necrotizing fasciitis (2), cholecystitis(2), abscess (2), diverticulitis (1), pneumonia (1) Post-op infection: SSI (3), pneumonia (2), UTI (2) 22% had malignancies
Timing of the VTE Post-op day of VTE diagnosis ranged from 1d to 57d (mean 13d) Five VTEs manifested following discharge 1 patient prescribed extended prophylaxis 3 patients (all with CapriniScore of 5) were eligible for an extended course but did not receive it 1 patient had an underestimation of the Capriniscore due to an initial lack of awareness of a family history of VTE Only 22% had some an aspect of protocol non-compliance
Limitations Retrospective and descriptive analysis with small number of patients with VTE Only performed univariateanalyses and unable to know if factors confer an independent risk for VTE May have missed VTE patients due to limitations in NSQIP and UHC databases
Future Directions Current Caprini protocol includes Extended prophylaxis Modify with Enhanced prophylaxis for high risk patients (multiple operations, emergency operations, perioperative sepsis) Increased dose or BID schedule Earlier administration of LMWH instead of unfractionated heparin Individualized dosing for high risk patients based on anti-factor Xalevels, TEG, or other lab values
Conclusions Emergency operations, multiple operations, and perioperative infections seem to confer dramatic hazards for VTEs despite standard prophylaxis These factors are not currently captured in the Caprinirisk model but may be significant modifiers of risk that should prompt reassessment Consideration of enhanced prophylaxis should be given for high risk patients Cassidy et al, JACS 2016; 222(6): 1074-80