So what's the natural history of a truly incarcerated hernia after ED reduction and, subsequently, is it safe to send an infant home for an elective repair? I've had different experiences ranging from admitting infants and repairing their hernia after 24-48 hours (giving time for edema/tissue swelling to resolve) to discharging them home (to "reliable" parents) for a scheduled elective repair.
This subject was addressed by Baguley et al (Pediatr Surg Int 1992.7:366-7). The authors looked at 94 infants with incarcerated inguinal hernias and compared those who were admitted to those who were sent home. In 20% of patients admitted, the hernia reincarcerated prior to it's repair. A much higher rate of reincarceration (74%) in the discharged group reflected the longer time interval before operative repair (Mean 10 days compared to 2 days for the inpatient group). In comparison, 35% of infants with known inguinal hernias (but no history of incarceration), experience hernia incarceration while waiting for their elective operation, a median time of 22 days (Stylianos et al. J Ped Surg 1993;4:582-3).
The paper does not address the issue of potential bowel ischemia/necrosis and the need to monitor infants until that possibility is ruled out. This may have been a source of selection bias, where infants with hernias that were more difficult to reduce were admitted, while those who were reduced more easily were allowed to go home.
The way I see it, and based on this limited study, and given the 1/5 chance of reincarceration within a couple of days, it seems safest to keep patients inhouse until the hernia is repaired.
On the other hand, it is also reasonable to discharge patients home, as long as they live close enough to a center where the incarceration can be promptly treated if it recurs, have guardians who understand the signs and symptoms of incarceration and the need to address them promptly, perform the "elective repair" within 72 hours, and the patient is observed long enough to r/o the presence of compromised bowel after the hernia is reduced.
As to the issue of the 24 to 48 hour delay in repair resulting in a safer operation, secondary to resolution of tissue edema and inflammation, there does not seem to be any data to support or negate that concept.
