Study on the safety and effectiveness of low-dose vs. regular-dose fondaparinux in preventing venous thromboembolism prophylaxis following total knee arthroplasty.

Background: This study aims to evaluate the effectiveness and safety of low-dose (1.5 mg) fondaparinux for venous thromboembolism (VTE) prophylaxis in patients post-total knee arthroplasty (TKA). Methods: We retrospectively identified 314 patients who carried out the primary TKAs and received fondaparinux for VTE chemoprophylaxis between July 2020 and December 2021. A total of 141 TKA patients were excluded according to the exclusion criteria. Two groups of patients were established: the low-dose group included 84 patients who injected 1.5 mg of fondaparinux, and the regular-dose group included 89 patients who injected 2.5 mg of fondaparinux. The pre-operative blood analysis and coagulation assays were performed. The surgical time, the incidence of symptomatic VET, blood loss, wound complication, bleeding, drainage, and mortality of patients were determined and assessed. Results: The pre-operative blood analysis, body mass index, sex, age, and coagulation assays of patients in both groups were comparable. In terms of symptomatic pulmonary embolism and deep vein thrombosis, there was no significant difference (variation) between the two groups. However, patients in both groups showed a substantial difference in terms of blood loss, drain volume, wound complication, and transfusion rate. Conclusion: In prevention of VET in patients post-TKA, low-dose fondaparin is as effective as conventional dose fondaparinux. A significant decrease in blood loss, post-surgical transfusion rates, and wound complications were detected in patients given low-dose fondaparinux compared to those receiving regular-dose fondaparinux.

(E)-2-Meth-oxy-N'-(4-nitro-benzyl-idene)benzohydrazide.

In the title compound, C(15)H(13)N(3)O(4), the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two benzene rings is 6.8 (2)°. The C-N-NH-C torsion angle is 3.4 (3)°. The mol-ecule possesses an intra-molecular N-H⋯O hydrogen bond. In the crystal structure, adjacent mol-ecules are linked through inter-molecular C-H⋯O hydrogen bonds, forming dimers.

(E)-N'-[1-(2-Hydroxy-phen-yl)ethyl-idene]-3-methoxy-benzohydrazide.

In the title compound, C(16)H(16)N(2)O(3), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 26.9 (2)°. In the crystal structure, the mol-ecular packing is stabilized by intra-molecular O-H⋯N and inter-molecular N-H⋯O hydrogen bonds. The inter-molecular hydrogen bonding forms chains parallel to the b axis.

(E)-N'-(5-Bromo-2-methoxy-benzyl-idene)-3-methoxy-benzohydrazide.

In the title compound, C(16)H(15)BrN(2)O(3), there are two independent mol-ecules (A and B) in the asymmetric unit. The major difference between the two mol-ecules is the dihedral angle formed by the aromatic rings [72.6 (2) and 18.8 (2)° for A and B, respectively]. The benzohydrazide groups are not planar and the mol-ecules exist in trans configurations with respect to the methyl-idene units. The mol-ecular packing is stabilized by two inter-molecular N-H⋯O hydrogen bonds, forming chains parallel to the c axis. Only the A mol-ecules of the asymmetric unit are held together by π-π inter-actions [centroid-centroid distance = 3.714 (3) Å].

(E)-N'-(4-Hydroxy-benzyl-idene)-4-hydroxy-benzohydrazide methanol solvate.

The title compound, C(14)H(12)N(2)O(3)·CH(4)O, consists of a Schiff base mol-ecule and a methanol mol-ecule of crystallization. The Schiff base mol-ecule is nearly planar, the dihedral angle between the planes of the two benzene rings being 7.2 (2)°. The mol-ecule exists in the trans configuration with respect to the methyl-idene unit. In the crystal structure, the Schiff base and methanol mol-ecules are linked through O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds, forming a three-dimensional network.

(E)-4-Hydr-oxy-N'-(4-nitro-benzyl-idene)benzohydrazide.

The mol-ecule of the title compound, C(14)H(11)N(3)O(4), is approximately planar, the dihedral angle between the planes of the two substituted benzene rings being 2.54 (7)°. The mol-ecule exists in a trans configuration with respect to the central methyl-idene unit. In the crystal structure, mol-ecules are linked through inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (101). The O/N-H⋯O and C-H⋯O inter-actions form a pair of bifurcated acceptor bonds involving the cabon-yl/nitro O atom, generating an R(2) (1)(6) motif.

(E)-N'-(2-Chloro-5-nitro-benzyl-idene)-4-methoxy-benzohydrazide.

In the title compound, C(15)H(12)ClN(3)O(4), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 0.4 (3)°. In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O hydrogen bonds, forming chains parallel to the c axis.

(E)-N'-(5-Bromo-2-methoxy-benzyl-idene)-4-methoxy-benzohydrazide.

In the title compound, C(16)H(15)BrN(2)O(3), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 75.6 (2)°. In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O hydrogen bonds involving carbonyl and amine functionalities, to form chains parallel to the c cell axis.