Sildenafil Attenuates Pulmonary Hypertension Following Fat Embolism in an Anaesthetised Rat Model

Release of fat and bone marrow during medullary pressurisation leads to fat embolism and pulmonary hypertension resulting in serious cardiorespiratory complications. This study aimed to determine whether pre-treatment with the phosphodiesterase type 5-inhibitor, Sildenafil, prevents pulmonary artery hypertension in an animal model. The animals either received Sildenafil (5 mg kg-1) or saline intra peritoneally 15 minutes prior to medullary pressurisation with bone cement. Cardiovascular parameters were recorded throughout the procedure. At the end radiopaque contrast was injected into the pulmonary circulation; the lungs were then harvested and imaged using micro CT. Medullary pressurisation in the control animals caused pulmonary hypertension and systemic hypotension. This was associated with a decrease in the area of perfusion of the lungs. These changes were attenuated by pretreatment with Sildenafil. We conclude that in this animal model fat embolism causes similar cardiovascular changes as observed in clinical practice and pretreatment with Sildenafil attenuates these effects.