History of Cardiac Arrhythmia and CAD Prolong Stay in Hospital
after Major Orthopedic Surgery
Boris Mraovic, M.D., Brian R. Hipszer, Ph.D., Jeffery I. Joseph, D.O., Edward C. Pequignot, M.S., Inna Chervoneva. Ph.D., Zvi Grunwald, M.D.
Department of Anesthesiology, Thomas Jefferson University, Philadelphia, PA
Abstract
Univariate analysis of length of stay after hip and knee surgery
Geometric means
(days)
Introduction: Hospital administrators and third party payers desire a short hospital postoperative length of stay (LOS). Risk factors
that affect LOS after orthopedic surgery were reported but influence of patients comorbidities on hospital LOS after the surgery are less
known.(1,2) We investigated which preoperative comorbidities are associated with increased LOS after total hip and knee arthroplasty.
Over all
Methods: After obtaining IRB approval, we retrospectively reviewed the medical records of patients undergoing elective total hip or total
knee replacement from January 2001 to April 2006. Detailed preoperative comorbidities were recorded. Data were analyzed using logistic
regression and robust ANOVA. Data are reported as geometric mean and odds ratios with 95% confidence interval in parentheses.
Age (yrs) (overall mean [SD])
Results: Data from 7282 patients were included in the study. The median LOS was 3 days (mean 3.46 days, range 1-58). Multivariate
analysis showed that odds ratios for prolonged LOS were significantly increased by sex, 1.04 (1.03,1.05; p<0.001) male versus female; age,
1.01 (1.01,1.01; p<0.001) per decade of life; ASA status, 1.01 (1.00, 1.02; p=0.003) ASA status 3+4 versus 1+2; duration of surgery, 1.14
(1.12, 1.15, p<0.001) if >137 min; bilateral surgery, 1.15 (1.14,1.17;p<0.001) versus unilateral; and revision surgery, 1.04 (1.03,1.06;
p<0.001) versus primary. BMI did not affect LOS, 1.00 (1.00,1.00; p=0.311). History of (h/o) cardiac arrhythmia significantly increased
odds ratios by 1.02 (1.00,1.04; p= 0.024) and h/o coronary artery disease (CAD) by 1.01 (1.00,1.02;p= 0.032). H/o cardiac valve disease, congestive heart failure, HTN, pulmonary disease, malignancy, diabetes, stroke, hematological disease, and dislipidemia did not
significantly increased the odds ratios.
Discussion: The influence of patient comorbidities on LOS after hip and knee surgery is sparse. Our data confirm
recognized risk factors: age, length of surgery, ASA status, revision surgery and bilateral surgery; but of multiple comorbidities only h/o
CAD and cardiac arrhythmias independently prolonged hospital LOS. Recognizing the preoperative risk factors that prolong LOS after
joint arthroplasty can enable physicians and administrators to better anticipate hospital bed utilization.
References:
J Hospital Medicine. 2008;3:218–227.
J Arthroplasty. 1998;13:186-190.
Sex
Female
Male
BMI (kg/m2) (overall mean [SD])
ASA PS
Surgery:
Knee
Hip
Revisions
Primary
Bilateral Knee
Unilateral Knee
OR Time (min) mean [SD]
Year of surgery
Introduction:
Hospital administrators and third party payers desire a short hospital postoperative length of stay
(LOS). Forrest et al. found that only age correlated with LOS after elective total hip and knee
arthroplasty, but BMI and patients; comorbidities were not found to correlate with LOS.(1)
Hypertension, diabetes and obesity were found to increase risk of complications after orthopedic
surgery but influence of patients comorbidities on hospital LOS after the surgery are less known.
(2)
We investigated which preoperative comorbidities are associated with increased LOS after total
hip and knee arthroplasty.
Arrhythmia
CAD
CHF
Valve Disease
Pulmonary
Endocrinological
Diabetes
Hematological
Sleep Apnea
Stroke
Hypertension
Dislipidemia
Malignancy
GI
Liver disease
Rheumatoid Art
DVT
Renal
UTI
Transfusions
P values
n=7172 (100%)
3.46
n=4090 (56.2%)
n=3192 (43.8%)
3.42
3.31
<0.001
<50 yrs
>50-60 yrs
>60-70 yrs
>70-80 yrs
>80 yrs
63.7 [12.2]
3.19
3.31
3.39
3.45
3.56
<0.001*
<25 kg/m2
>25-30 kg/m2
>30-40 kg/m2
>40 kg/m2
30.1 [6. 2]
3.34
3.33
3.41
3.49
<0.001*
1+2
2+4
3.33
3.43
0.026
n=3203 (44.0%)
n=4079 (56.0%)
n=811 (11.1%)
n=6471 (88.9%)
n=735 (10.1%)
n=2468 (33.9%)
3.54
3.25
3.56
3.36
4.14
3.29
<0.001*
< 86
86-107
108-136
>137
117 [44]
3.17
3.21
3.38
3.81
<0.001*
2001
2002
2003
2004
2005
3.78
3.49
3.37
3.24
3.27
n=439 (6.0%)
n=1091 (15.0%)
n=149 (2.1%)
n= 677 (9.3%)
n=1231 (16.9%)
n=918 (12.6%)
n= 862 (11.8%)
n=390 (5.4%)
n=392 (5.4%)
n=299 (4.1%)
n=3874 (53.2%)
n=1370 (18.8%)
n=491 (6.7%)
n=1944 (26.7%)
n=201 (2.8%)
n=210 (2.9%)
n=258 (3.5%)
n= 23 (0.32%)
n=75 (1.03%)
n=1357 (18.6%)
3.53
3.49
3.91
3.39
3.43
3.48
3.52
3.45
3.42
3.50
3.43
3.37
3.44
3.42
3.39
3.38
3.47
3.56
3.37
3.74
Results:
<0.001*
Data from 7282 patients were included in the study. The median LOS was 3 days (mean 3.46
days, range 1-58). Multivariate analysis showed that odds ratios for prolonged LOS were
significantly increased by sex, 1.04 (1.03,1.05; p<0.001) male versus female; age, 1.01 (1.01,1.01;
p<0.001) per decade of life; ASA status, 1.01 (1.00, 1.02; p=0.003) ASA status 3+4 versus 1+2;
duration of surgery, 1.14 (1.12, 1.15, p<0.001) if >137 min; bilateral surgery, 1.15 (1.14,1.17;
p<0.001) versus unilateral; and revision surgery, 1.04 (1.03,1.06; p<0.001) versus primary. BMI
did not affect LOS, 1.00 (1.00,1.00; p=0.311). History of (h/o) cardiac
arrhythmia significantly increased odds ratios by 1.02 (1.00,1.04; p= 0.024) and h/o coronary
artery disease (CAD) by 1.01 (1.00,1.02; p= 0.032). H/o cardiac valve disease, congestive heart
failure, HTN, pulmonary disease, malignancy, diabetes, stroke, hematological disease, and
dislipidemia did not significantly increased the odds ratios.
The analysis confirms that the intention to decrease LOS was successful in our hospital.
Compared to 2001, LOS was on average 9% (7, 11) shorter in 2002, 12% (10, 13) in 2003,
15% (14, 16) in 2004 and 16% (14, 17) in 2005/2006, p<0.001.
<0.001*
Multivariate analysis of length of stay after hip and knee surgery
Ratio of Geometric means
(95% CI)
P values
<0.001*
1.04 (1.03,1.05)
<0.001*
Age per decade
1.01 (1.01, 1.01)
<0.001*
BMI
1.00 (1.00, 1.00)
0.311
ASA PS 2+4/1+2
1.01 (1.00, 1.02)
0.003*
Surgery:
Hip/Knee
Primary/Revisions
Bilateral/Unilateral Knee
0.97 (0.93, 1.01)
0.96 (0.94, 0.97)
1.15 (1.14, 1.17)
0.126
<0.001*
<0.001*
OR Time (min)
1.00 (1.00, 1.00))
<0.001*
Year of surgery
0.96 (0.96, 0.96)
<0.001*
Arrhythmia
CAD
CHF
Valve Disease
Pulmonary
Endocrinological
Diabetes
Hematological
Sleep Apnea
Stroke
Hypertension
Dislipidemia
Malignancy
1.02 (1.00, 1.04)
1.01 (1.00, 1.02)
1.01 (0.98, 1.04)
1.00 (0.98, 1.01)
0.99 (0.98, 1.01)
1.00 (0.99, 1.01)
0.96 (0.90, 1.02)
1.01 (0.99, 1.02)
1.01 (0.99, 1.03)
1.00 (0.98, 1.02)
1.00 (0.99, 1.01)
1.00 (0.99, 1.01)
1.00 (0.98, 1.02)
0.024*
0.032*
0.537
0.683
0.316
0.665
0.214
0.488
0.367
0.933
0.741
0.443
0.930
Sex
0.112
0.014*
0.004*
0.229
0.249
0.004*
<0.001*
0.081
0.817
0.217
<0.001*
0.162
0.040
0.061
0.980
0.858
0.040*
0.757
0.531
<0.001*
* Statistically significant p<0.05
Methods:
Discussion:
After obtaining IRB approval, we retrospectively reviewed the medical records of
patients undergoing elective total hip or total knee replacement from January 2001
to April 2006. Patients with incomplete records were excluded. Detailed preoperative
co-morbidities were recorded. Data were analyzed using logistic regression and robust
ANOVA. Data are reported as geometric mean and odds ratios with 95% confidence
interval in parentheses. A p value of < 0.05 was considered statistically significant.
The influence of patient co-morbidities on LOS after hip and knee surgery is sparse.
Our data confirm recognized risk factors: age, length of surgery, ASA status, revision
surgery and bilateral surgery; but of multiple co-morbidities only h/o CAD and cardiac
arrhythmias
independently
prolonged
hospital
LOS.
Recognizing
the
preoperative risk factors that prolong LOS after joint arthroplasty can enable physicians
and administrators to better anticipate hospital bed utilization.
Male/Female
* Statistically significant p<0.05
References:
1. Forrest,G et al. Factors Affecting Length of Stay and Need for Rehabilitation After Hip and Knee Arthroplasty.
J Arthroplasty. 1998;13:186-190.
2. Jain, NB et al. Comorbidities Increase Complication rates in Patients Having Arthroplasty. Clinical Orthopedics and
Related Research. 2005; 435: 232-238.
Disclosure: This research was conducted with support from the Investigator-Initiated Study Program of LifeScan, Inc