Answer:
Injection injuries with paint or petroleum are associated with high morbidity. Physical examination can reveal an apparently minor skin injury, but the injury can quickly progress to a hand/extremity threatening emergency requiring aggressive surgical interventions. It is imperative to get a detailed history, including the material involved and the force of injection. If the pressure is low, the material is likely to have not travelled as far as when the material is injected under high pressure. Here, an injection into the hand can track along the planes in the hand, through the carpal tunnel and into the forearm. It is crucial not to let the minor entrance wound fool one into thinking the injury does not involve deep tissues, because significant tissue damage and potential digital loss can ensue. Local tissue injury results in inflammation and edema, followed by compression within the fascial compartments, and subsequent vascular and neurologic compromise.
Concerning the material injected, water and air are obviously less injurious than such agents as paint or petroleum (grease-containing compounds). Even if injected under high pressure, water and air are less toxic and cause less inflammation and tissue destruction than paint/petroleum. All cases of paint/petroleum injection need to be explored. Operative decompression requires excision of the entrance site and release of all involved fascial planes (digits, palm, and interosseus muscle compartments, carpal tunnel, and if necessary, the forearm). All nonviable and foreign material needs to be removed, and the wound irrigated copiously. If there is any question of the viability of the tissue secondary to ongoing necrosis, a second look operation should be performed. Once the inflammation is completely resolved, the wound can be closed secondarily. Hand therapy should be started as soon as the infection is controlled given that functional loss in these patients can be significant.