Weight-adjusted low molecular weight heparin with surgery morning dose administration: Impact on hip hemiarthroplasty early infections

Table 1 Medical comorbidities in the prosthetic joint infection cases

Comorbidities	Cases
Diabetes mellitus	10
Heart failure	9
Chronic kidney disease	8
Hypothyroidism	4
Dementia	3
Epilepsy	3
Lymphoma	1

Table 2 Results for each patient’s group, n (%)

Measurement period	2007 to June 15, 2019	After June 15, 2019	P value (two-tailed z test)
Total number of hemiarthroplasty cases	1517	937
Number of cemented stem cases	1086 (71.58)	692 (73.8)	P = 0.2; z = -1.2 at a 95% confidence interval
Number of active smokers at the time of HA surgery	62 (4.09)	46 (4.9)	P = 0.33; z = -0.96 at a 95% confidence interval
Number of early PJI cases in the first 12 weeks	19 (1.25)	14 (1.49)	P = 0.6; z = -0.5 at a 95% confidence interval

The dose was routinely adjusted for renal function based on guidelines for surgical thromboprophylaxis. Adherence to the prescribed protocol was confirmed via review of the electronic medication administration record. HA: Hip hemiarthroplasty; PJI: Prosthetic joint infection.

Table 3 Characteristics of the cases with early postoperative infection, n (%)/mean ± SD

Measurement period	2007 to June 15, 2019 (n = 19)	After June 15, 2019 (n = 14)	P value
Age (years)	80.96 ± 12.1	78.6 ± 8.5	P = 0.5 (NS, t test1)
BMI	27.9 ± 7.1	25.6 ± 7	P = 0.36 (NS, t test)
Diabetes mellitus	4 (21)	7 (50)	P = 0.136 (NS, Fisher’s exact test)
Chronic kidney disease	5 (26.3)	3 (21.4)	P = 1 (NS, Fisher’s exact test)
Time of presentation (weeks)	5 ± 2.5	4.5 ± 2.6	P = 0.58 (NS, t test)

¹Unpaired t test.

BMI: Body mass index; NS: Not significant.

Table 4 Subgroup analysis after excluding the cases that died within 30 days post-op, n (%)

Measurement period	2007 to June 15, 2019	After June 15, 2019	P value (two-tailed z test)
Total number of hemiarthroplasty cases	1395	894
Number of early PJIs in the first 12 weeks	19 (1.36)	14 (1.56)	P = 0.69; z = -0.4 at a 95% confidence interval
Number of diabetic cases	43 (3.08)	35 (3.91)	P = 0.28; z = -1 at a 95% confidence interval
Number of cases with BMI ≥ 30	225 (16.12)	160 (17.89)	P = 0.27; z = -1 at a 95% confidence interval

BMI: Body mass index; PJIs: Prosthetic joint infections.