The efficiency of throboprophylaxis with low molecular weight heparin in hip fracture patients for the prevention of its potential consequence, pulmonary embolism

Introduction: The rapid increase of the elderly comes with a logarithmically increasing incidence of osteoporosis and as a result, with osteoporotic hip fractures. These fractures are responsible for significant mobility limitation and they are accompanied with high complication rates. One of the most important complications in hip fractures is deep venous thrombosis (DVT) and its potential consequence, pulmonary embolism (PE), that are related with high morbidity and significant mortality. Aim: In this study we tried to demonstrate the efficiency of throboprophylaxis with low molecular weight heparin (LMWH) in the reduction of DVT and PE, in hip fracture patients and to assess the safety of LMWH (Nadroparine Calcium) during surgery and during the postoperative hospitalization period. Materials and Methods: We performed a prospective randomised study on elderly patients that were admitted with a hip fracture to the Department of Orthopaedics of “Laiko” Hospital, Athens, Greece, between 1994-1996. Seventy-two patients (53 women, 19 men; mean age, 78 years; range, 55-90 years) were included. Patients with predisposing factors for venous thrombosis were excluded. They were randomly divided in two groups (group Α, 36 patients; group Β, 36 patients). In group A, patients received LMWH (Nadroparine Calcium), preoperatively and until the 12th postoperative day, while in group B, patients received classic heparin for the same period. Patients of both groups underwent ascending venography of the operated limb on the 12th-14th postoperative day, while during their hospitalization they were daily monitored for clinical symptoms of DVT or PE and received laboratory exams. Bleeding, infection and other complications were recorded, and statistical analysis of the study results followed. Results: Venographic data showed that a total of 17 patients (23,6%) developed DVT. In group A, thrombosis was documented in 9 of the 36 patients, while in group B in 8 of the 36 patients. However, there was no statistical difference in DVT incidence between the groups (p>0.05) or correlation between thrombosis and fracture type (p>0.05). DVT presented a trend to occur in older patients and to those with a higher bone mass index (BMI), but no statistically significant correlation was found between DVT and these variables (age, p=0.056 and BMI, p=0.061). Additionally, no correlation between gender and DVT was recorded (p>0.05). Overall, 5 pa- tients developed PE. PE was documented in 3 of the 36 patients (8,3%) of group A, while one of these patients developed massive PE that led to death. PE was also documented in 2 of the 36 patients (5,6%) of group B, while one episode was also fatal. No difference in the PE inci- dence was observed between the study groups (p>0.05). There was no higher bleeding in any of the two groups during surgery, however the postoperative decrease of hematocrit, the post- operative bleeding incidences and the need for blood transfusion were higher in group B (p0.05) ή συσχέτιση μεταξύ φλεβοθρόμβωσης και τύπου κατάγματος (p>0.05). Η ΕΒΦΘ φάνηκε να έχει μια τάση να παρουσιάζεται σε ασθενείς μεγαλύτερης ηλικίας και σε εκείνους με μεγαλύτερο δείκτη μάζας σώματος (BMI), αλλά δε διαπιστώθηκαν στατιστικά σημαντικές διαφορές στις μεταβλητές αυτές (ηλικία, p=0.056 και BMI, p=0.061). Το φύλο επίσης δε φάνηκε να συσχετίζεται με την ΕΒΦΘ (p>0.05). Συνολικά, 5 ασθενείς (6,9%) παρουσίασαν ΠΕ. Στην ομάδα Α, 3 από τους 36 ασθενείς (8,3%) παρουσίασαν ΠΕ, ενώ ένας μαζική ΠΕ που τον οδήγησε στο θάνατο. Στην ομάδα Β, 2 από τους 36 ασθενείς (5,6%) παρουσίασαν ΠΕ, ενώ ένα επεισόδιο ήταν επίσης θανατηφόρο. Δεν παρατηρήθηκε διαφορά στη συχνότητα ΠΕ μεταξύ των ομάδων (p>0.05). Διεγχειρητικά, δεν κατεγράφη υψηλότερη αιμορραγική διάθεση σε κάποια ομάδα ασθενών, ωστόσο η μετεγχειρητική πτώση του αιματοκρίτη, τα επεισόδια αιμορραγίας και η ανάγκη μετάγγισης αίματος ήταν μεγαλύτερα στην ομάδα Β (p