This patient may be suffering from a waterjet injury. Evaluation and management should parallel that of a gunshot injury. The external manifestations of the injury cannot be used to predict the extent of internal damage. Initial management should include stabilization and a thorough neurovascular examination. X-rays can be used to assess subcutaneous air and foreign bodies distant from the site of injury. Injuries to the extremities can involve extensive nerve, muscle, vessel damage, as well as cause a distal compartment syndrome. Injuries to the torso can involve internal organ damage. Surgical consultation should be obtained. Aggressive irrigation and debridement is recommended. Surgical decompression and exploration may also be necessary. Angiographic studies are recommended preoperatively if arterial injury is suspected. Bandages with a hygroscopic solution (MgSO₄) and hyperbaric oxygen treatment have been used as adjunctive therapy to decrease pain, edema and subcutaneous emphysema. Unusual infections with uncommon organisms in immunocompetent patients have been seen; the source of the water is important in deciding on initial, empiric antibiotic treatment, and broad-spectrum intravenous antibiotics should be administered. Cultures should be obtained.

WJTA Industry Best Practices for the Use of High Pressure Waterjetting Equipment (Second Edition, January 2021), Section 4.1.1

This patient may be suffering from a high pressure suction injury. An extreme pressure to a body part may lead to severe underlying internal body damage that cannot be seen from the outer skin. While bruising may vary, it can be also be delayed and should not be the primary basis for predicting internal damage. Case studies have shown a severe suction to a major body part (an entire arm for example) can lead to massive pooling of blood in that area, thereby causing circulatory collapse. Close monitoring of vital signs with ability for quick fluid replacement and resuscitation should be of high importance. Additional concerns would be a compartment syndrome to the affected muscular area, large hematomas that may need to be drained, and varying sizes of skin disruption/lacerations. Consider surgical consultation. Imaging should be considered to assess internal soft tissue damage. These injuries usually occur in non-sterile environments, lending themselves to the potential for contaminated wounds. Tetanus status may need to be updated.

WJTA Recommended Practices for the Use of Industrial Vacuum Equipment (Fourth Edition, August 2021), Section 2.1