Lawn mower injuries can be serious, with significant infectious complications, because of the force generated by the rotating blade. The majority of lawn mower injuries in children occur in those younger than five years who are either bystanders (60 percent) or passengers on a riding mower (15 percent). The remaining 25 percent are injuries in young operators of these machines. Children eight to 14 years of age who are injured are often inexperienced users of lawn mowers. The average length of hospitalization for a child injured in a mower accident is 10 to 24 days. Most of these children need multiple surgical procedures, and up to 64 percent require some form of amputation. An estimated 2,000 children per year are permanently impaired as a result of lawn mower injury. Campbell describes the infectious complications of lawn mower injuries in children.
Injuries to the distal lower and upper extremities are most common. Inoculation of debris and the presence of devitalized tissue commonly lead to infection that is often polymicrobial. It is sometimes difficult to determine whether organisms cultured from injured tissue represent wound contamination or actual infection. Common organisms that cause infection are skin flora or organisms present in the soil, water or plant material contaminating the wound. These organisms include staphylococcus, diphtheroids, Escherichia coli, Enterococcus faecalis, Pseudomonas species, Serratia marcescens and soil organisms that are not usually pathogenic, such as Stenotrophomonas maltophilia. Anaerobic and fungal organisms may also be present in the soil, making it necessary to process specimens appropriately to detect these fastidious organisms.
Acute management of lawn mower injuries includes immediate and vigorous surgical debridement with pulsed lavage as soon after the injury as possible. All particulate debris should be removed from the wound. Intraoperative cultures are appropriate to identify the colonizing organisms. Broad-spectrum empiric antibiotic prophylaxis is indicated. Cefazolin is often used for treatment of contaminated traumatic wounds; in cases of severe tissue destruction or open fracture, an aminoglycoside or a semisynthetic penicillin with activity against gram-negative organisms may be added. Penicillin G or clindamycin may also be used because of the risk of infection by anaerobic organisms from the soil. In the absence of infection, antibiotic prophylaxis should be continued for five to 10 days. Tetanus immune globulin is administered if the child has not received a minimum of three doses of tetanus toxoid. If the child's immunization status is unknown or if the child has not received a dose of tetanus toxoid in the past five years, tetanus toxoid should be administered.
The wound should be reassessed 24 to 72 hours after injury to allow for further cultures, if necessary, and to watch for the development of early granulation tissue. Skin grafting may be needed after healthy granulation tissue forms.
The author concludes that lawn mower injuries and associated infectious complications can have significant morbidity in children. Children younger than 14 years should not be allowed to operate ride-on lawn mowers, and adolescents should be trained in the use of these machines before independent use. Young children should be kept indoors when a lawn mower of any type is in use.