Ceftriaxone concentration at the surgical site following systemic and isolated upper limb injection

This study was conducted to find out the equipotent dose of isolated upper limb injection of ceftriaxone in the upper limb (IUL) surgeries under tourniquet that would attain a peak bone marrow concentration (Cmax) similar to systemic (ST) 1 g injection.

Patients were allocated into two groups - ST and IUL. ST group (n = 5) received 1 g of ceftriaxone 20 min before tourniquet inflation, and IUL group received calculated dose (n = 5 in each dosage, i.e., 200, 100, 75, and 50 mg) diluted in 50 mL of normal saline distally after tourniquet inflation. Venous and bone marrow samples were collected at various time intervals intra- and post-operatively. Ceftriaxone concentration was analyzed by high-performance liquid chromatography.

There was no significant difference between Cmax following ST 1 g injection and IUL injection with 75 mg (155.8 ± 2.1 vs 158.5 ± 3.1 μg/mL, respectively; P = 0.1). There was significant difference in area under curve (AUC) and t½ between ST 1 g injection and IUL injection with 75 mg of ceftriaxone (AUC 1285 ± 67 vs 784.4 ± 28 μg/mL/h, respectively; P < 0.001), (t½ 5.2 ± 0.5 vs 4.7 ± 0.3 h, respectively; P < 0.001). None of the patients in the ST and IUL groups had post-operative infection up to a period of 1 week duration.

IUL injection with 75 mg of ceftriaxone can be equipotent and as effective as ST 1 g injection in upper limb orthopedic surgeries under tourniquet.