Joe E. Wathen

Predictors of Airway and Respiratory Adverse Events With Ketamine Sedation in the Emergency Department: An Individual-Patient Data Meta-analysis of 8,282 Children

STUDY OBJECTIVE Although ketamine is one of the most commonly used sedatives to facilitate painful procedures for children in the emergency department (ED), existing studies have not been large enough to identify clinical factors that are predictive of uncommon airway and respiratory adverse events. METHODS We pooled individual-patient data from 32 ED studies and performed multiple logistic regressions to determine which clinical variables would predict airway and respiratory adverse events. RESULTS In 8,282 pediatric ketamine sedations, the overall incidence of airway and respiratory adverse events was 3.9%, with the following significant independent predictors: younger than 2 years (odds ratio [OR] 2.00; 95% confidence interval [CI] 1.47 to 2.72), aged 13 years or older (OR 2.72; 95% CI 1.97 to 3.75), high intravenous dosing (initial dose > or =2.5 mg/kg or total dose > or =5.0 mg/kg; OR 2.18; 95% CI 1.59 to 2.99), coadministered anticholinergic (OR 1.82; 95% CI 1.36 to 2.42), and coadministered benzodiazepine (OR 1.39; 95% CI 1.08 to 1.78). Variables without independent association included oropharyngeal procedures, underlying physical illness (American Society of Anesthesiologists class >or = 3), and the choice of intravenous versus intramuscular route. CONCLUSION Risk factors that predict ketamine-associated airway and respiratory adverse events are high intravenous doses, administration to children younger than 2 years or aged 13 years or older, and the use of coadministered anticholinergics or benzodiazepines.

Predictors of Emesis and Recovery Agitation With Emergency Department Ketamine Sedation: An Individual-Patient Data Meta-Analysis of 8,282 Children

STUDY OBJECTIVE Ketamine is widely used in emergency departments (EDs) to facilitate painful procedures; however, existing descriptors of predictors of emesis and recovery agitation are derived from relatively small studies. METHODS We pooled individual-patient data from 32 ED studies and performed multiple logistic regression to determine which clinical variables would predict emesis and recovery agitation. The first phase of this study similarly identified predictors of airway and respiratory adverse events. RESULTS In 8,282 pediatric ketamine sedations, the overall incidence of emesis, any recovery agitation, and clinically important recovery agitation was 8.4%, 7.6%, and 1.4%, respectively. The most important independent predictors of emesis are unusually high intravenous (IV) dose (initial dose of > or =2.5 mg/kg or a total dose of > or =5.0 mg/kg), intramuscular (IM) route, and increasing age (peak at 12 years). Similar risk factors for any recovery agitation are low IM dose (<3.0 mg/kg) and unusually high IV dose, with no such important risk factors for clinically important recovery agitation. CONCLUSION Early adolescence is the peak age for ketamine-associated emesis, and its rate is higher with IM administration and with unusually high IV doses. Recovery agitation is not age related to a clinically important degree. When we interpreted it in conjunction with the separate airway adverse event phase of this analysis, we found no apparent clinically important benefit or harm from coadministered anticholinergics and benzodiazepines and no increase in adverse events with either oropharyngeal procedures or the presence of substantial underlying illness. These and other results herein challenge many widely held views about ED ketamine administration.

Effect of Ondansetron on the Incidence of Vomiting Associated With Ketamine Sedation in Children: A Double-Blind, Randomized, Placebo-Controlled Trial

STUDY OBJECTIVE We investigate the effect of ondansetron on the incidence of vomiting in children who receive intravenous (IV) ketamine for procedural sedation and analgesia in the emergency department (ED). METHODS In this double-blind, randomized, placebo-controlled trial in a childrens hospital ED, patients receiving IV ketamine (1 mg/kg) for ED procedures were randomized to receive either IV ondansetron (0.15 mg/kg; maximum 4 mg) or identical placebo. We recorded whether vomiting occurred in the ED postsedation or up to 12 hours after discharge with telephone follow-up and compared ED length of stay and parental satisfaction. RESULTS One hundred twenty-seven children were randomized to placebo and 128 to ondansetron. The groups were similar in age, sex, and fasting duration. ED vomiting was less common with ondansetron: 6 of 128 (4.7%) versus 16 of 127 (12.6%), P=.02, difference 7.9% (95% confidence interval 1.1% to 14.7%), number needed to treat 13. Follow-up was successful in 82.7%, with vomiting in the ED or after discharge less frequent with ondansetron: 10 of 128 (7.8%) versus 24 of 127 (18.9%), P=.01, difference 11.1% (95% confidence interval 2.7% to 19.5%), number needed to treat 9. ED length of stay and parental satisfaction were similar between groups. CONCLUSION IV ondansetron significantly reduces the incidence of vomiting associated with IV ketamine procedural sedation in children.

Usefulness of the serum electrolyte panel in the management of pediatric dehydration treated with intravenously administered fluids

Background. The serum electrolyte panel (SEP) is a frequently ordered laboratory test, but it has unproven usefulness in the treatment of dehydrated pediatric patients. Our study purpose was to evaluate the usefulness of routinely ordering a SEP in the treatment of dehydrated pediatric patients receiving intravenous fluids (IVFs). Methods. Children 2 months to 9 years of age who were receiving IVFs because of dehydration were prospectively studied in a pediatric emergency department (PED). Historical data, physical examination findings, degree of dehydration, and SEP results were recorded. After patient evaluation, attending physicians documented whether they would have ordered a SEP. Outcome measurements included changes in clinical management on the basis of SEP results, as well as correlations of dispositions and unscheduled return visits (URVs) with SEP results. Results. A total of 182 patients were enrolled in the study. One hundred eleven patients had mild dehydration, 55 moderate dehydration, and 16 severe dehydration. Eighty-eight patients (48%; 95% confidence interval: 41–56%) had ≥1 abnormal SEP value. Clinically relevant findings included bicarbonate levels of <16 mmol/L for 28% of patients, hypoglycemia for 9.9%, hypokalemia for 6.0%, and hypernatremia for 3.0%. The attending physicians predicted that a SEP would be clinically important for 34% of all patients. There was a 58% sensitivity in detecting which children would have clinically significant SEP results. Overall, SEP results changed clinical management in 10.4% of cases. One hundred sixty-five (91%) of the patients were discharged from the PED (including 48 who were initially observed), of whom 7 (3.8%) had URVs to the PED within 72 hours and were given additional IVFs. Seventeen patients were admitted (median: 2.6 days), 2 of whom had URVs after hospital discharge for additional IVFs. Conclusions. On the basis of initial presentation, attending physicians were poor at predicting which children would have clinically significant SEP results. Low bicarbonate values were correlated with observation unit use but not with hospitalization or URVs. The observation unit provided effective care for a subset of dehydrated patients, avoiding the need for hospitalization. Obtaining a SEP can provide useful information for the treatment of some children receiving IVFs because of dehydration.

Evaluation of the Standardized Assessment of Concussion in a Pediatric Emergency Department

OBJECTIVE: The Standardized Assessment of Concussion (SAC) is a validated tool for identifying the effects of mild traumatic brain injury (mTBI). Previous research focused on sport-related sideline evaluation of adolescents and adults. Our goal was to evaluate performance of the SAC among subjects with and without head injury in a pediatric emergency department (ED). METHODS: This was an observational study of children 6 to 18 years of age who presented to an ED with blunt head injury (case-patients) or minor extremity injury (controls). SAC and graded-symptom-checklist scores were compared. American Academy of Neurology concussion grades, presence of loss of consciousness and posttraumatic amnesia were also compared with SAC and graded-symptom-checklist scores among case-patients. RESULTS: Three hundred forty-eight children were enrolled. SAC scores trended lower (greater cognitive deficits) for case-patients compared with controls but did not reach significance. Graded-symptom-checklist scores were significantly higher among case-patients. Presence of altered mental status magnified this effect. There was no correlation between SAC scores and other indicators of mTBI. There was a positive correlation between graded-symptom-checklist scores and posttraumatic amnesia and American Academy of Neurology concussion grade. CONCLUSIONS: The graded symptom checklist reliably identified mTBI symptoms for all children aged 6 years and older. SAC scores tended to be lower for case-patients compared with controls but did not reach significance. Patients with altered mental status at the time of injury manifest an increased number and severity of symptoms. Additional research into strategies to identify cognitive deficits related to mTBI and classify mTBI severity in children is needed.

Detailed concussion symptom analysis in a paediatric ED population

Primary objective: To examine the frequency of acute mild traumatic brain injury (mTBI) symptoms in children using a concussion symptom inventory and to identify which symptoms are most useful in identifying mTBI. It was hypothesized that symptoms associated with mTBI are more common in children with head injury than orthopaedic injury and certain symptoms are more useful than others in identifying mTBI. Research design: Prospective case-control study conducted in a paediatric trauma centre emergency department. Methods and procedures: Children of 6–18 years old with head injury or a minor extremity injury were enrolled. Symptoms were assessed using a graded symptom checklist. Symptom frequency was compared using a chi-square test. The association between individual symptoms with AMS was evaluated with logistic regression analysis. Main outcomes and results: Children with head injury displayed more frequent symptoms than controls. Head-injured cases with altered mental status (AMS) demonstrated the most frequent and severe symptoms (median symptom scores: control = 1, cases without AMS = 5, cases with AMS = 10; p < 0.001). Headache, nausea, dizziness, blurred/double vision and not feeling ‘sharp’ were associated with AMS. Conclusions: Symptoms associated with mTBI are more frequent in children with head injury. AMS magnifies this effect. A symptom inventory is integral to the evaluation of mTBI in children; a smaller set of dichotomized symptoms may be as useful as and more easily administered than lengthier symptom scales.

Utility of Serum Electrolytes in the Management of Dehydration 391

Background: The serum electrolyte panel (SEP) is a frequently ordered laboratory test and of unproved utility in the management of dehydrated pediatric patients. Many clinicians believe that the bicarbonate level may be predictive of patient outcome. Our purpose is to study the incidence of SEP abnormalities and assess their role in management.Methods: Children between the ages of 2 months and 18.8 years receiving intravenous fluids for dehydration were prospectively studied. Historical data, physical examination findings, degree of dehydration and SEP were obtained. Attending physicians documented prior to knowing laboratory results whether they would have ordered a SEP. Outcome measures included changes of management based on SEP, disposition, and return visits within 48 hours. Results: 206 patients were entered with a median age of 19.2 months. 123 patients presented with mild (≤5%), 81 with moderate (6-10%) and 2 with severe dehydration (>10%). The incidence of SEP abnormalities was 46% for one or more abnormal values. 29% had BUN levels > 17mg/dl, 26% had bicarbonate levels 150mmol/L. Considering the 54 patients with bicarbonates <16mmol/L; 27 were discharged home, 22 were placed into observation and 5 were admitted. At 95% significance, bicarbonate was lower in those placed into the observation unit versus those discharged home. There was no correlation between low bicarbonate and admission rates or return visits. The attending thought a SEP was needed in 33% of the cases. Knowing the SEP did not change management in 91%. In 17 patients the SEP changed management; 5 with low glucose values received glucose sooner, 5 with low bicarbonate levels were observed longer, 3 with reassuring values were sent home sooner, and 2 with low potassium levels received potassium. There were 10 return visits requiring IV fluids within 48 hours, 8 (2 with bicarbonates <16) were admitted. Conclusion: Although there were a large number of SEP abnormalities, there was minimal effect on clinical management or patient outcome. Low bicarbonate levels were predictive of observation unit placement but not for need of hospitalization or patient return visits.