A 43-year-old, previously healthy man is brought by his wife to a rural emergency department after he accidentally amputated most of his right thumb with a bandsaw. Initially, the stump bled profusely, but this stopped with the application of direct pressure. The patient's wife brought the amputated part in a plastic bag. The patient is right-hand dominant and works as a heavy equipment mechanic. Blood pressure is 128/86 mm Hg and pulse is 96/min. Physical examination shows a transverse amputation through the middle of the right thumb proximal phalanx, with exposed bone. The rest of the right hand and fingers are uninjured. The amputated part is in one piece without overt contamination. Transfer of the patient to a hospital with an on-call hand surgeon is arranged. Which of the following is the best way to transport the amputated digit?
This patient sustained a traumatic amputation of his dominant thumb. Thumb replantation will likely be attempted, especially given that his profession (ie, mechanic) requires manual dexterity and that the thumb provides an estimated 40% of hand function. Optimal care of the amputated part during transport improves the chances of replantation success.
Care of an amputated part, regardless of the level of injury (eg, digit, hand, forearm), begins with gentle removal (eg, saline irrigation) of gross contamination (eg, sawdust, debris). Afterward, the part should be wrapped in sterile, saline-moistened gauze and sealed in a plastic bag. The bag should be then placed in a container of ice water to be transported with the patient. Cooling of the amputated part decreases tissue metabolism and oxygen demand, thereby minimizing ischemic damage and prolonging the window of viability for replantation. An ice water bath (temperature ~0 C [32 F]) provides adequate cooling while minimizing the risk for frostbite, which can occur if the amputated part, or even the bag containing the part, is placed directly on ice (Choice D).
(Choices A and B) The amputated part should be kept moist (vs dry) to prevent desiccation of the exposed tissues, which can cause further tissue damage. It should not remain submerged in antiseptic solution because prolonged exposure can cause chemical injury. To decrease infection risk, the amputated part should instead be thoroughly cleansed (eg, saline irrigation) and prepped (eg, with povidone-iodine) in the operating room prior to attempted replantation. The digit should also be cooled (vs kept at body temperature or room temperature) to decrease tissue metabolism and ischemic damage.
(Choice C) Frostbitten digits typically undergo active rewarming by submersion in water warmed to 37-39 C (98.6-102.2 F). However, prolonged submersion in water (of any temperature) should not be performed on an amputated digit because it can injure digital vessels, making microsurgical vessel repair more difficult or impossible. In addition, cooling, not rewarming, of the amputated part should be performed.
Educational objective:
In cases of traumatic amputation, the amputated part should be transported by wrapping it in saline-moistened gauze, sealing it in a plastic bag, and placing the bag in a bath of ice water. Cooling of the amputated part prolongs the window for replantation.