Preventing Unintentional Scald Burns: Moving Beyond Tap Water

METHODS

The University of Chicago Burn Center tracks admissions through its burn registry, a database that uses the National Trauma Registry System software program (Digital Innovation, Inc, Forest Hill, MD) The burn registrar pools information from several sources, including the hospital's information systems department and finance department, medical records, and conference meetings with medical staff members, and enters the data into the registry. The burn registry included admissions from January 1, 2002, through December 31, 2004. This study identified 140 children <5 years of age who were admitted with scald burns; all available charts were reviewed by a single reviewer (Dr Lowell). The University of Chicago Hospitals institutional review board approved this study and granted a waiver of informed consent.

The medical record charge sheet was reviewed for age (in months), gender, and length of stay of the patient. The physicians' admission notes were reviewed for location and severity of the burn. Daily progress notes and operative notes were reviewed for wound management, complications during hospitalization, resulting disability, and disposition.

Social workers' notes were reviewed for details regarding how the burn happened. The burn center requires a social worker evaluation for all children <5 years of age who are admitted with scald burns. There were 13 charts that did not have social workers' notes, 6 of which were for short hospitalizations (1–2 days) and 2 of which were incomplete charts. For the remaining 5 charts, it was not clear why there was no note. Two social workers are assigned to the burn center, and their notes detail the circumstances surrounding each injury. These notes provide data regarding the scalding substance, the heating source, the container that held the substance, the building and specific room where the burn occurred, the caregiver who was present at the time of the injury, and a descriptive mechanism of the injury. Unique categories for mechanism of injury were created for each recorded scald, based on the action that led to the injury. Intentional burns, as determined by the hospital's child protective services team, and cases deemed undetermined pending further investigation were excluded from review. Because the prevention of tap water scalds (setting hot water heater temperatures to ≤120°F) is different from that of other scalds, we excluded those injuries from the analysis.

Data were analyzed by using SPSS 11.5 (SPSS, Chicago, IL). Analysis of variance computations and stepwise linear regression analyses were used to determine predictors of mechanism of injury, by using transformed variables for age (in 3-month increments until ages 3 and 4), scalding substance, container, and heating source. A separate model was used for each mechanism of injury. The χ² statistic was used to assess differences in proportions between groups. All tests were 2-tailed, and P < .05 was considered significant.

RESULTS

From January 1, 2002, through December 31, 2004, 640 patients were admitted to the burn center. Of those patients, 203 (31.7%) were children <5 years of age, 140 (69.0%) of whom sustained scald burns. Of the 137 scald injuries reviewed, 118 (86.1%) were unintentional injuries, 14 of which were tap water scalds. When it was known, the source of injury for all intentional scalds was tap water. The remaining 104 non–tap water scalds were examined in greater detail.

Boys (n = 64; 61.5%) were injured more commonly than girls (n = 40; 38.5%). Scald injuries peaked in children 10 to 21 months of age, as shown in Fig 1. Seventy-four patients (71.2%) were injured in their primary home. Sixty-five patients (62.5%) were injured while under the care of their primary caregiver.

• Download figure
• Open in new tab
• Download powerpoint

FIGURE 1

Frequency of non–tap water scalds according to age group.

Table 1 shows the frequencies of scalding substance, heating source, container, and location (room) of the injury for non–tap water scalds. These scalds most frequently occurred in the kitchen/dining area with hot foods or beverages. Forty-nine scalds (47.1%) occurred during food or drink preparation, and 19 (18.3%) occurred during food or drink consumption. Eleven (10.6%) occurred between preparation and consumption (for example, while the food or drink was cooling or while the food or drink was being carried elsewhere).

The medical consequences of non–tap water scalds were significant. A total of 47 children (45.2%) underwent split-thickness skin grafting, and 45 children (43.3%) suffered burns to ≥10% of their body surface area. Complications included wound infection or bacteremia (6 cases; 5.8%), graft hematoma (1 case; 1.0%), febrile seizure (1 case; 1.0%), and prolonged intubation (3 cases; 2.9%), with 1 case ultimately requiring tracheostomy. The median length of stay in the hospital was 8 days. Seven patients (6.7%) were transferred to an inpatient rehabilitation facility.

The 5 most common mechanisms of injury were as follows: 41 patients (39.4%) pulled over a cup, bowl, or cookware onto themselves (without climbing); the hot substance was spilled onto 16 patients (15.4%) by someone else; 11 (10.6%) patients climbed to reach the hot substance; 9 patients (8.7%) opened the microwave oven and removed the heated substance, scalding themselves; and 5 patients (4.8%) were scalded while being carried. The remaining mechanisms of injury included 3 patients (2.9%) who were scalded as a result of pulling on an appliance cord or tablecloth and 2 patients (1.9%) who were scalded while eating. A total of 10 mechanisms (9.6%) were in the “other” category, and 7 mechanisms (6.7%) were unknown. Figure 2 depicts the 5 most common mechanisms of injury on a scale similar to that used in the Denver II developmental screening tool (DDM, Denver, CO).

• Download figure
• Open in new tab
• Download powerpoint

FIGURE 2

Mechanisms of injury and childhood development. Each mechanism of scald injury is plotted against age in a manner similar to the Denver II developmental assessment. The demarcations within each bar represent the age by which 10%, 50%, and 75% of cases occurred for the specified mechanism of injury.

Table 2 lists the results of the stepwise regression analysis to determine significant predictors of mechanism of injury. Age group, container, and scalding substance were the independent variables that significantly predicted the mechanisms of injury listed.

The 9 children who opened the microwave oven and pulled out the hot substance included two 18-month-old children, one 19-month-old child, one 29-month-old child, three 3-year-old children, and two 4-year-old children. Three of those children, 1 of whom was 18 months of age, pulled a chair or stepstool to the microwave to climb and reach the unit. Two other children, both of whom were 3 years of age, were described as trying to “help.” Two children specifically opened the microwave after the bell rang. One child opened a microwave oven that was temporarily on the floor; the locations of the other microwave ovens were not specified. None of these 9 children actually operated the microwave (ie, they were not attempting to heat the substance themselves). Five of the 9 heated substances were noodles or noodle soup, and 3 were cups of hot water. Four children (44.4%) required split-thickness skin grafting for their burns, and 1 required outpatient rehabilitation.

Older children, ranging in age from 7 to 14 years, were involved in the younger child's scald injury in 17 cases (16.3%). In 11 cases, it was specified that the older child was cooking or had cooked the hot substance; in the remaining 6 cases, it was not specified whether the older child had cooked the hot substance. The scalding substances were hot food/soup (8 of 17 cases; 47.1%), water used for cooking (5 of 17 cases; 29.4%), grease/oil (3 of 17 cases; 17.6%), and hot tea (1 of 17 cases; 5.9%). Of the 8 hot food/soup scalds, 5 were attributable to noodle soup. Of the 5 hot water scalds, 4 were attributable to water used to cook hot dogs. Scalds occurring with older children more frequently involved noodle soup (P < .05) or hot dog water (P < .05), compared with those not occurring with older children.

The mechanisms of injury in these cases involving an older child were as follows: the hot substance was spilled onto 7 patients (41.2%) by the older child, 6 patients (35.3%) pulled the hot substance onto themselves, 3 patients (17.6%) were scalded while being carried by the older child, and 1 patient (5.9%) was scalded while eating food prepared by the older child. Scalds involving older children more frequently occurred through the spilled mechanism (P < .05) and the carried mechanism (P < .05), compared with those not occurring with older children. Ten (58.8%) of these 17 children required split-thickness skin grafting for their burns, 1 child underwent prolonged intubation necessitating tracheostomy and inpatient rehabilitation, and 1 child required outpatient rehabilitation.

DISCUSSION

Although the results of this analysis are generally consistent with previously published, descriptive, epidemiological features of unintentional scald burns among children,^{4,5,8,10,17–19} 2 findings have not, to our knowledge, been described previously. We found that children as young as 18 months were scalded after opening a microwave oven and removing the hot substance and that a significant subset of scalds involved older children.

Microwave ovens represent an accessible scald hazard. To our knowledge, the concept of a child opening a microwave as a mechanism of injury has not received attention. Keeping children safe from opening and removing hot food from microwave ovens was not found in the major injury prevention resources.^13,20–22 Many current models of microwave ovens have a child lock option that requires the user to hold the start or stop/clear button for 3 to 4 seconds to prevent the microwave from being operated, but this option does not prevent the microwave from being opened once something has been heated, which was the mechanism through which all 9 children were scalded in this study. There are several potential reasons children may be attracted to microwave ovens, that is, they may be imitating the activities of parents and siblings, they may view microwave ovens as they do other toys, or they may be acting on a behavioral response to hearing the bell, with the subsequent reward of eating and a potential reward for trying to help. A child lock mechanism that effectively prohibits a young child from opening the door once something has been heated would help to prevent this specific mechanism of injury. Such an engineering fix would be an innovative “passive” means of preventing scalds attributable to this mechanism.

An unexpected finding was the frequency with which other, older children were involved in the scald injury. Seventeen scalds involved children 7 to 14 years of age. Some of these older children had cooked the scalding substance, whereas others were holding the substance or were just supervising the younger child at the time of the injury. Convenience foods such as noodle soup and hot dogs were represented more frequently in this group, compared with food- and drink-related scalds not involving older children. The mechanism of injury also differed significantly in this subset; the substance was spilled onto the patient by the older child more frequently and the patient was being carried by the older child more frequently, compared with food- and drink-related scalds not involving older children.

The differences between these groups make sense. Older children are more likely to cook easy-to-make foods such as noodle soups (including ramen noodles) or hot dogs. They may not have the same perception of the potential hazard of hot liquids, preparing or carrying them while toddlers are present. Children in this 7- to 14-year age range also may lack the motor coordination that older teenagers and adults have, resulting in more-frequent spills. A study examining injury history scores of 18- to 36-month-old children and older sibling supervision revealed that young children with a history of more-frequent injuries were supervised by their older siblings more often, compared with younger children with a history of fewer injuries; Morrongiello and Lasenby²³ suggested that the higher injury rate among children supervised more often by their older siblings may be attributable to noncompliance of the younger child toward requests about safety from the older sibling, rather than poor supervision on the older sibling's part. The involvement of older children in scald injuries could be incorporated into anticipatory guidance, educational materials, or scald-prevention campaigns. Further examination of the role and limitations of older children as caregivers is necessary to understand injury risk for young children.

As might be expected, age was a significant predictor of mechanism of injury. Scalds caused by patients who climbed to reach the scalding substance involved 16- to 24-month-old children, which correlates with their ability to walk well and to walk up steps. More than one half of the scalds caused by patients who opened the microwave involved 3- and 4-year-old children, but scalds occurred in children as young as 18 months of age, which correlates with their ability to imitate activities and to help in the house. Two of the 5 scalds that occurred while the patient was being carried involved 0- to 3-month-old children, which correlates with their premobile status. As depicted in Fig 2, the mechanisms of injury correlate logically with the gross motor, fine motor, and personal/social skills expected of the different age groups.

Scalding substance predicted the mechanism of injury in 3 categories. Grease/oil was associated with scalds involving spills onto the child. Four of those injuries resulted from the cookware being knocked off the stove in some manner. Water heated for cooking purposes was associated with scalds caused by children pulling over the scalding substance, and water heated for washing purposes was associated with scalds caused by children climbing to reach the hot substance. In fact, hot water, including water for washing and water for cooking, accounted for 6 of the 11 “climbed” injuries. Whether parents have a perception of hot water being less a scald hazard for this older group of children is uncertain.

Our study is subject to several limitations. Our data were from children whose burns required hospitalization, and they may not represent the full spectrum of scalds to young children. The relatively small sample, from a single center, limits the ability to generalize the results. Although the regression analysis identified variables that were predictive of certain mechanisms of injury, there remains unexplained variance, because we might have identified correlates to injury that are specific to our unique population.

Our findings highlight the need for innovation in child scald prevention. Scald prevention for young children traditionally has focused on setting hot water heater temperatures to ≤120°F.^10,12–15 However, nearly 90% of child scalds do not involve tap water. Common, non–tap water, scald-prevention advice found in The Injury Prevention Program sheets²⁰ and other online resources^21,22 do not adequately address many of the mechanisms of injury found in our study. “Never carry your infant and hot liquids, such as coffee, or foods at the same time”^20,22 addresses the fifth most common mechanism of injury. “Turn pot handles toward the back of the range”²¹ addresses a subset of the most common mechanism of injury; 5 of the 41 patients who pulled a cup, bowl, or cookware onto themselves did so by pulling on the pot handle. Other advice includes keeping hot substances out of reach of children^20–22 and keeping children away from the stove.²¹ These recommendations address the first, second, and third most common mechanisms of injury; to be successful, however, scald-prevention programs need to find effective means of having these concepts/messages result in behavior changes among caregivers. This is particularly challenging, given that focus group data from low-income neighborhoods near our hospital suggest that parents sometimes overestimate their ability to control the risk of a scald to a child in their care.²⁴

CONCLUSIONS

Most scalds of young children are caused by hot cooking or drinking liquids and are multifactorial in etiology. Current prevention strategies do not adequately address the 2 newly recognized mechanisms of injury described. Toddlers can access and open microwave ovens, pull the heated substance out, and scald themselves. An engineering fix could be used to prevent young children from opening a microwave in which a food or liquid has been heated. Older children cooking convenience foods are involved in a significant number of scalds. Identifying preadolescents who cook or help in the kitchen and educating them regarding the risk of scald injury to young children may help prevent this subset of injuries. Future studies that elucidate the complex nature of scalds are needed to guide innovative strategies to help prevent scald injuries in young children.