AGING AND SURGERY
Anticoagulation Management in Individuals with Hip Fracture Lauren J. Gleason, MD,*† Daniel A. Mendelson, MD, MS,* Stephen L. Kates, MD,‡ and Susan M. Friedman, MD, MPH*
OBJECTIVES: To determine the interventions taken to lower international normalized ratio (INR) in individuals with hip fracture using warfarin before admission for hip fracture surgery in a geriatric fracture center (GFC) and compare outcomes with those of individuals not taking warfarin. DESIGN: Cohort study using retrospective chart review. SETTING: University-affiliated community teaching hospital. PARTICIPANTS: Individuals aged 60 and older admitted to a GFC for surgical repair of a nonpathological, nonperiprosthetic hip fracture between April 2006 and April 2012. MEASUREMENTS: Descriptive data collected from a quality improvement registry with additional information for individuals taking warfarin obtained from chart review. RESULTS: Of the 1,080 individuals included in the analysis, 84 (7.8%) were taking warfarin on admission. Participants using warfarin had a higher average Charlson Comorbidity Index (3.8 vs 3.1, P < .001). Atrial fibrillation was the most common indication for anticoagulation (83.3%). Average INR before surgery was 1.7 (range 1.2–3.6). Vitamin K, fresh frozen plasma, or both were given to 100% of those taking warfarin with an admission INR of 2.0 or greater. There was a trend toward longer time to surgery in those taking warfarin than in those not taking warfarin (28.9 vs 21.7 hours, P = .05). Length of stay was longer for those taking warfarin than those not taking warfarin (4.8 vs 4.2 days, P = .04). Neither time to surgery nor length of stay were significantly different after adjustment for baseline comorbidity. Participants taking warfarin were not found to have any significant differences in thromboembolic event rates, bleeding complications rates, mortality, or 30-day readmission after surgery than those not taking warfarin on admission.
From the *Division of Geriatrics, Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York; †Gerontology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and ‡Department of Orthopaedic Surgery, School of Medicine and Dentistry, University of Rochester, Rochester, New York. Address correspondence to Lauren J. Gleason, LMOB 1B, 110 Francis Street, Boston, MA 02215. E-mail: [email protected] DOI: 10.1111/jgs.12591
JAGS 62:159–164, 2014 © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society
CONCLUSION: Active management in a GFC model to reverse anticoagulation before surgery may facilitate earlier surgery without increasing observed complications. J Am Geriatr Soc 62:159–164, 2014.
Key words: hip fracture; anticoagulation; transfusion; co-management
O
lder adults are often anticoagulated with warfarin for various medical conditions, including atrial fibrillation (AF), thromboembolic disease (hypercoagulable states, deep venous thrombosis, pulmonary embolism), and prosthetic heart valves, to prevent arterial or venous thrombosis. Hip fractures are a common problem in older adults, with more than 90% occurring in individuals aged 65 and older.1 The incidence of hip fractures and the prevalence of AF increase exponentially with older age.2–4 Anticoagulation with warfarin represents a challenge in individuals with hip fracture because there is an urgency to perform surgery in a timely manner to decrease the likelihood of adverse events, such as delirium,5 pneumonia, pressure ulceration, and mortality.6,7 There is a concurrent need to reverse anticoagulation to permit timely surgery. Limited evidence is available to help guide perioperative management of individuals taking warfarin, especially those who present with hip fractures,8 and few studies have compared outcomes in individuals who are anticoagulated before surgery with those not on anticoagulation.9–13 Most expert opinions recommend achieving an international normalized ratio (INR) of 1.5 or less13–15 before surgery, but the authors of the current study are not aware of any studies that have correlated outcomes and preoperative INR values in individuals with hip fracture. Evidence to manage treatment of individuals with hip fracture undergoing anticoagulation with warfarin is lacking, and commonly accepted practices are derived from principles of elective surgeries.14,15 The objectives of this study were to record the interventions taken to lower INR before surgery in individuals with hip fracture taking warfarin and to compare postoperative
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outcomes with those of individuals with fracture not taking warfarin. Surgical outcomes, incidence of in-hospital complications, blood product use, and 30-day outcomes were recorded.
METHODS Descriptive data were collected from all individuals aged 60 and older admitted to a geriatric fracture center (GFC)16 for surgical repair of nonpathological, nonperiprosthetic, low-impact hip fracture between April 3, 2006, and April 31, 2012. The GFC is a geriatric-orthopedic comanaged care model based at a 261-bed universityaffiliated community teaching hospital. Data on age, sex, race, ethnicity, place of residence, comorbid illnesses defined in the Charlson Comorbidity Index,17 activity of daily living (ADL) independence adapted from the Katz model,18 type of surgery, complications after surgery, time to surgery, length of stay, in-hospital mortality, 30-day mortality from time of surgery, and 30-day readmission from time of discharge from the hospital were collected for a quality improvement registry. Individuals in hospice were included in 30-day mortality statistics but excluded from the analysis of 30-day readmission. Complications after surgery were further divided into bleeding complications and thromboembolic complications. Bleeding complications included gastrointestinal bleeding, hemorrhagic cerebrovascular accident (CVA), intracranial bleeding, retroperitoneal bleeding, and wound hematoma. Thromboembolic complications included pulmonary embolism (PE), deep vein thrombosis (DVT), or thromboembolic CVA. A research nurse who reviews clinical diagnoses found in the medical records and interviews individuals or their surrogates at their 1-month follow-up managed the quality improvement database. Additional information was collected through a separate chart review for participants taking warfarin on admission as identified through the quality improvement registry. The information collected on these participants included INR on admission, INR before surgery (INR most proximate to start of surgery), INR at discharge (last INR obtained), type of fracture, vitamin K administration, and units of blood product administered. Data analyzed
JAGS
were from the index hospitalization. Information from individuals transferred from outside hospitals such as laboratory values and vitamin K administration performed at the outside facility were excluded. Subjects in the warfarin group were included in the analysis only if there was an intention to take them to surgery because the objective was to compare perioperative outcomes. One individual was included in the analysis despite dying before surgery. Five individuals were excluded from the warfarin group: three who geriatricians determined to be nonoperative on admission because they had multiple comorbidities, one who fractured a hip while in the hospital for gastrointestinal bleeding, and one who had been managed at an outside hospital off warfarin for multiple days and had a normal INR on admission. Data were analyzed using StatView version 5.0.1 for Windows (SAS Institute, Inc., Cary, NC). Data were analyzed using Student t-tests, one-way analyses of variance, and chi-square and Fisher exact tests where appropriate. Logistic regression models adjusting for baseline participant differences were constructed to evaluate outcomes. P < .05 was considered statistically significant. Approval Board was obtained from the University of Rochester research subjects review board before the study was begun.
RESULTS One thousand eighty individuals were included in the 6-year analysis between April 2006 and April 2012; 84 (7.8%) participants were taking warfarin at the time of admission. The mean age of participants was 85.0 (range 60.1–105.0), with no statistically significant difference in age between those taking and not taking warfarin. Participants undergoing anticoagulation with warfarin had more comorbidities, as indicated by a higher average Charlson Comorbidity Index (3.8 vs 3.1, P < .001). The warfarin group had a greater prevalence of congestive heart failure, peripheral vascular disease, cerebrovascular disease, and lymphoma. Dementia was more prevalent in the group not taking warfarin (Table 1). Atrial fibrillation was the most common indication for anticoagulation (83.3%), followed by thromboembolic diseases (17.9%) and mechanical heart valve (4.8%), with six participants (7.1%) having
Table 1. Baseline Participant Characteristics Characteristic
Overall, N = 1,080
Warfarin Users, n = 84
Warfarin Nonusers, n = 996
P-Value
Age, average Female, % Caucasian, % Community dwelling, % Charlson comorbidity index, mean Congestive heart failure, % Peripheral vascular disease, % Cerebrovascular disease, % Dementia, % Diabetes mellitus without end organ damage, % Diabetes mellitus with end organ damage, % Activity of daily living independence score, meana
85.0 76.4 95.8 50.6 3.1 20.7 30.0 15.7 48.5 13.5 6.8 4.0
85.1 75.0 95.2 53.6 3.8 45.2 44.0 26.2 35.7 19.0 11.9 4.4
85.0 76.5 95.9 50.4 3.1 18.7 28.8 14.9 49.6 13.0 6.3 4.0
.90 .10 .78 .57
Anticoagulation Management in Individuals with Hip Fracture Lauren J. Gleason, MD,*† Daniel A. Mendelson, MD, MS,* Stephen L. Kates, MD,‡ and Susan M. Friedman, MD, MPH*
OBJECTIVES: To determine the interventions taken to lower international normalized ratio (INR) in individuals with hip fracture using warfarin before admission for hip fracture surgery in a geriatric fracture center (GFC) and compare outcomes with those of individuals not taking warfarin. DESIGN: Cohort study using retrospective chart review. SETTING: University-affiliated community teaching hospital. PARTICIPANTS: Individuals aged 60 and older admitted to a GFC for surgical repair of a nonpathological, nonperiprosthetic hip fracture between April 2006 and April 2012. MEASUREMENTS: Descriptive data collected from a quality improvement registry with additional information for individuals taking warfarin obtained from chart review. RESULTS: Of the 1,080 individuals included in the analysis, 84 (7.8%) were taking warfarin on admission. Participants using warfarin had a higher average Charlson Comorbidity Index (3.8 vs 3.1, P < .001). Atrial fibrillation was the most common indication for anticoagulation (83.3%). Average INR before surgery was 1.7 (range 1.2–3.6). Vitamin K, fresh frozen plasma, or both were given to 100% of those taking warfarin with an admission INR of 2.0 or greater. There was a trend toward longer time to surgery in those taking warfarin than in those not taking warfarin (28.9 vs 21.7 hours, P = .05). Length of stay was longer for those taking warfarin than those not taking warfarin (4.8 vs 4.2 days, P = .04). Neither time to surgery nor length of stay were significantly different after adjustment for baseline comorbidity. Participants taking warfarin were not found to have any significant differences in thromboembolic event rates, bleeding complications rates, mortality, or 30-day readmission after surgery than those not taking warfarin on admission.
From the *Division of Geriatrics, Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, New York; †Gerontology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and ‡Department of Orthopaedic Surgery, School of Medicine and Dentistry, University of Rochester, Rochester, New York. Address correspondence to Lauren J. Gleason, LMOB 1B, 110 Francis Street, Boston, MA 02215. E-mail: [email protected] DOI: 10.1111/jgs.12591
JAGS 62:159–164, 2014 © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society
CONCLUSION: Active management in a GFC model to reverse anticoagulation before surgery may facilitate earlier surgery without increasing observed complications. J Am Geriatr Soc 62:159–164, 2014.
Key words: hip fracture; anticoagulation; transfusion; co-management
O
lder adults are often anticoagulated with warfarin for various medical conditions, including atrial fibrillation (AF), thromboembolic disease (hypercoagulable states, deep venous thrombosis, pulmonary embolism), and prosthetic heart valves, to prevent arterial or venous thrombosis. Hip fractures are a common problem in older adults, with more than 90% occurring in individuals aged 65 and older.1 The incidence of hip fractures and the prevalence of AF increase exponentially with older age.2–4 Anticoagulation with warfarin represents a challenge in individuals with hip fracture because there is an urgency to perform surgery in a timely manner to decrease the likelihood of adverse events, such as delirium,5 pneumonia, pressure ulceration, and mortality.6,7 There is a concurrent need to reverse anticoagulation to permit timely surgery. Limited evidence is available to help guide perioperative management of individuals taking warfarin, especially those who present with hip fractures,8 and few studies have compared outcomes in individuals who are anticoagulated before surgery with those not on anticoagulation.9–13 Most expert opinions recommend achieving an international normalized ratio (INR) of 1.5 or less13–15 before surgery, but the authors of the current study are not aware of any studies that have correlated outcomes and preoperative INR values in individuals with hip fracture. Evidence to manage treatment of individuals with hip fracture undergoing anticoagulation with warfarin is lacking, and commonly accepted practices are derived from principles of elective surgeries.14,15 The objectives of this study were to record the interventions taken to lower INR before surgery in individuals with hip fracture taking warfarin and to compare postoperative
0002-8614/14/$15.00
160
GLEASON ET AL.
JANUARY 2014–VOL. 62, NO. 1
outcomes with those of individuals with fracture not taking warfarin. Surgical outcomes, incidence of in-hospital complications, blood product use, and 30-day outcomes were recorded.
METHODS Descriptive data were collected from all individuals aged 60 and older admitted to a geriatric fracture center (GFC)16 for surgical repair of nonpathological, nonperiprosthetic, low-impact hip fracture between April 3, 2006, and April 31, 2012. The GFC is a geriatric-orthopedic comanaged care model based at a 261-bed universityaffiliated community teaching hospital. Data on age, sex, race, ethnicity, place of residence, comorbid illnesses defined in the Charlson Comorbidity Index,17 activity of daily living (ADL) independence adapted from the Katz model,18 type of surgery, complications after surgery, time to surgery, length of stay, in-hospital mortality, 30-day mortality from time of surgery, and 30-day readmission from time of discharge from the hospital were collected for a quality improvement registry. Individuals in hospice were included in 30-day mortality statistics but excluded from the analysis of 30-day readmission. Complications after surgery were further divided into bleeding complications and thromboembolic complications. Bleeding complications included gastrointestinal bleeding, hemorrhagic cerebrovascular accident (CVA), intracranial bleeding, retroperitoneal bleeding, and wound hematoma. Thromboembolic complications included pulmonary embolism (PE), deep vein thrombosis (DVT), or thromboembolic CVA. A research nurse who reviews clinical diagnoses found in the medical records and interviews individuals or their surrogates at their 1-month follow-up managed the quality improvement database. Additional information was collected through a separate chart review for participants taking warfarin on admission as identified through the quality improvement registry. The information collected on these participants included INR on admission, INR before surgery (INR most proximate to start of surgery), INR at discharge (last INR obtained), type of fracture, vitamin K administration, and units of blood product administered. Data analyzed
JAGS
were from the index hospitalization. Information from individuals transferred from outside hospitals such as laboratory values and vitamin K administration performed at the outside facility were excluded. Subjects in the warfarin group were included in the analysis only if there was an intention to take them to surgery because the objective was to compare perioperative outcomes. One individual was included in the analysis despite dying before surgery. Five individuals were excluded from the warfarin group: three who geriatricians determined to be nonoperative on admission because they had multiple comorbidities, one who fractured a hip while in the hospital for gastrointestinal bleeding, and one who had been managed at an outside hospital off warfarin for multiple days and had a normal INR on admission. Data were analyzed using StatView version 5.0.1 for Windows (SAS Institute, Inc., Cary, NC). Data were analyzed using Student t-tests, one-way analyses of variance, and chi-square and Fisher exact tests where appropriate. Logistic regression models adjusting for baseline participant differences were constructed to evaluate outcomes. P < .05 was considered statistically significant. Approval Board was obtained from the University of Rochester research subjects review board before the study was begun.
RESULTS One thousand eighty individuals were included in the 6-year analysis between April 2006 and April 2012; 84 (7.8%) participants were taking warfarin at the time of admission. The mean age of participants was 85.0 (range 60.1–105.0), with no statistically significant difference in age between those taking and not taking warfarin. Participants undergoing anticoagulation with warfarin had more comorbidities, as indicated by a higher average Charlson Comorbidity Index (3.8 vs 3.1, P < .001). The warfarin group had a greater prevalence of congestive heart failure, peripheral vascular disease, cerebrovascular disease, and lymphoma. Dementia was more prevalent in the group not taking warfarin (Table 1). Atrial fibrillation was the most common indication for anticoagulation (83.3%), followed by thromboembolic diseases (17.9%) and mechanical heart valve (4.8%), with six participants (7.1%) having
Table 1. Baseline Participant Characteristics Characteristic
Overall, N = 1,080
Warfarin Users, n = 84
Warfarin Nonusers, n = 996
P-Value
Age, average Female, % Caucasian, % Community dwelling, % Charlson comorbidity index, mean Congestive heart failure, % Peripheral vascular disease, % Cerebrovascular disease, % Dementia, % Diabetes mellitus without end organ damage, % Diabetes mellitus with end organ damage, % Activity of daily living independence score, meana
85.0 76.4 95.8 50.6 3.1 20.7 30.0 15.7 48.5 13.5 6.8 4.0
85.1 75.0 95.2 53.6 3.8 45.2 44.0 26.2 35.7 19.0 11.9 4.4
85.0 76.5 95.9 50.4 3.1 18.7 28.8 14.9 49.6 13.0 6.3 4.0
.90 .10 .78 .57
