Simplified dispatch-assisted CPR instructions outperform standard protocol.

OBJECTIVE: Dispatch-assisted chest compressions only CPR (CC-CPR) has gained widespread acceptance, and recent research suggests that increasing the proportion of compression time during CPR may increase survival from out-of-hospital cardiac arrest. We created a simplified CC-CPR protocol to reduce time to start chest compressions and to increase the proportion of time spent delivering chest compressions. This simplified protocol was compared to a published protocol, Medical Priority Dispatch System (MPDS) Version 11.2, recommended by the National Academies of Emergency Dispatch. METHODS: Subjects were randomized to the MPDS v11.2 protocol or a simplified protocol. Data was recorded from a Laerdal Resusci Anne Skillreporter manikin. A simulated emergency medical dispatcher, contacted by cell phone, delivered standardized instructions for both protocols. Outcomes included chest compression rate, depth, hand position, full release, overall proportion of compressions without error, time to start of CPR and total hands-off chest time. Proportions were analyzed by Wilcoxon's Rank Sum tests and time variables with Welch ANOVA and Wilcoxon's Rank Sum test. All tests used a two-sided alpha-level of 0.05. RESULTS: One hundred and seventeen subjects were randomized prospectively, 58 to the standard protocol and 59 to the simplified protocol. The average age of subjects in both groups was 25 years old. For both groups, the compression rate was equivalent (104 simplified versus 94 MPDS, p = 0.13), as was the proportion with total release (1.0 simplified versus 1.0 MPDS, p = 0.09). The proportion to the correct depth was greater in the simplified protocol (0.31 versus 0.03, p < 0.01), as was the proportion of compressions done without error (0.05 versus 0.0, p = 0.16). Time to start of chest compressions and total hands-off chest time were better in the simplified protocol (start time 60.9s versus 78.6s, p < 0.0001; hands-off chest time 69 s versus 95 s, p < 0.0001). The proportion with correct hand position, however, was worse in the simplified protocol (0.35 versus 0.84, p < 0.01). CONCLUSIONS: The simplified protocol was as good as, or better than the MPDS v11.2 protocol in every aspect studied except hand position, and the simplified protocol resulted in significant time savings. The protocol may need modification to ensure correct hand position. Time savings and improved quality of CPR achieved by the new set of instructions could be important in strengthening critical links in the cardiac chain of survival.

Chloral hydrate versus midazolam for sedation of children for neuroimaging: a randomized clinical trial.

OBJECTIVE: The comparative safety and efficacy of chloral hydrate and midazolam for sedation of children has not been adequately studied. METHODS: In a double-blind randomized trial, at a single university hospital, we enrolled 40 children, ages 2 months to 8 years, in an out-patient neuroimaging study. Children judged to require sedation were enrolled during a 14-month period ending August 1995. They received identically appearing liquids of equal volume of either chloral hydrate (75 mg/kg, maximum 2 g) or midazolam (0.5 mg/kg, maximum 10 mg) by mouth. Children were monitored for changes in arterial blood pressure, oxygen saturation, pulse, respiration and anxiety. Efficacy was judged by evaluating the child's ability to complete the intended scan. Supplemental dosing was administered to children who were judged inadequately sedated 30 minutes after the initial medication. RESULTS: Interim analysis demonstrated a significant sedation failure rate. Of 40 enrolled children, 33 completed the protocol. Efficacy was significantly improved for the chloral hydrate group for both ability to perform the scan, chloral hydrate = 11/11 (100%, 95% CI = 72-100) vs. midazolam = 11/22 (50%, 95% CI = 29-71), and the need for supplementary dosing, chloral hydrate = 1/11 (9%, 95% CI = 0-26) vs midazolam = 12/22 (55%, 95% CI = 34-76), P<0.05. Mean duration of sedation was not significantly different. No physiological deterioration occurred and no oxygen administration was required. CONCLUSIONS: We conclude that, in these doses, oral chloral hydrate may provide more effective sedation than midazolam for brief neuroimaging studies in young children.

Glottal patency during experimental cortical seizures in piglets.

OBJECTIVE: Systemically-induced seizures produce glottal airflow obstruction in anesthetized pigs, resulting in hypercapnia and respiratory acidosis. Cortically-induced seizures may be more representative of human seizure disorders. The purpose of this study was to describe glottal area patency (GAP) in piglets during cortically-induced seizures. METHODS: Nineteen spontaneously breathing, lightly anesthetized (alphaxalone-alphadolone IV) piglets (aged 10 +/- 2 days) were instrumented for recording nasal airflow, subglottic pressure, and electrocorticogram. Glottal visualization was achieved supraglottically using a 1.2-mm fiberoptic scope inserted through the thyrohyoid membrane. Following baseline-control, hypoxic-rebreathing, and new baseline recordings, seizures were induced using subcortical injections of crystalline penicillin G (100,000 units/ injection). Five consecutive-breath representative epochs were digitized from baseline-control, hypoxic-rebreathing, and seizure conditions. For each breath, GAP was measured at the onset of inspiratory pressure, peak of inspiratory effort (Ip), and onset of expiration. RESULTS: The piglets were physiologic at baseline-control and new baseline conditions, and showed expected increases in ventilation and GAP during rebreathing experiments. GAP was maximum at Ip under baseline and rebreathing conditions, but was significantly decreased and airway resistances were increased during seizure conditions (p < 0.05, ANOVA). CONCLUSIONS: Generalized seizure activity results in reduced GAP at the peak of inspiratory effort. Increased work of breathing during seizures is created by direct mechanical obstruction at the level of the larynx.

Effects of experimental cortical seizures on respiratory motor nerve activities in piglets.

Airway obstruction at the level of the larynx causes respiratory insufficiency during experimental seizures in spontaneously breathing, anesthetized piglets (T. E. Terndrup and W. E. Fordyce, Pediatr. Res., 38: 61-66, 1995). To investigate further the neural mechanisms of this obstruction, the activities of the phrenic nerve (PH) and the recurrent laryngeal motor branches to the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles were analyzed in 11 anesthetized, vagotomized, paralyzed, and ventilated piglets. After a control recording period, seizures were induced by subcortical penicillin G injections. Compared with baseline conditions, nerve activities became irregular during seizures. Extraneous TA bursts during PH activation were evident in all piglets during seizures. During ictal phases of seizures, the peak integrated activities of the PH and the expiratory component of the PCA, but not TA or inspiratory PCA activities, were significantly decreased compared with interictal phases. During seizures, a significant delay in the onset of the inspiratory component of PCA activation with respect to the onset of the PH was observed. This study helps to explain respiratory impairment during cortical seizures by providing evidence of impaired timing of activation of laryngeal dilator mechanisms and coordination with those activating the diaphragm. Cyclical PH inhibition during high-intensity cortical discharges may provide a secondary mechanism producing respiratory insufficiency during seizures.

Clinical issues in acute childhood seizure management in the emergency department.

Generalized tonic-clonic seizure activity in infants and children frequently leads to an emergency department visit, often after emergency medical service personnel, such as paramedics, provide initial evaluation and treatment. Important subsets of patients who present to the emergency department include those with non-seizure-mediated movements, those with nongeneralized seizure activity, those with complications of anticonvulsant therapy, and those with status epilepticus. Recognizing, diagnosing, and treating these conditions and minimizing complications are key issues to be considered in the refinement of emergency department practice. Of the children with seizures who are seen in the emergency department, those with febrile convulsions or exacerbations of underlying seizure disorders predominate, while those with new-onset epilepsy or other seizure disorders account for a smaller proportion. Current issues in the emergency department management of seizures in children include: (1) modifying interventions to stabilize patients and simultaneously minimize the physiologic deterioration accompanying generalized seizures; (2) selection, initiation, administration, and refinement of anticonvulsant therapy; (3) minimizing complications of prolonged seizures and their treatment; (4) rapid recognition and treatment of life-threatening illnesses that underlie seizure presentations; (5) selection of appropriate diagnostic measures; and (6) use of electroencephalography in selected patients.

Estimation of contact tympanic membrane temperature with a noncontact infrared thermometer.

STUDY OBJECTIVE: To investigate the agreement between contact tympanic membrane (TM) and noncontact infrared ear thermometers in children. METHODS: Twenty-three children (ages .5 to 10 years) undergoing elective tympanostomy tube placement were studied. An assistant used standard technique to record temperature with an infrared ear thermometer before and after TM temperature was obtained with a bead thermistor placed against the anterior-inferior quadrant of the TM. RESULTS: Mean temperatures were not significantly different: initial IR ear, 36.66 degrees +/-.33 degrees C; TM, 36.71 degrees +/- .42 degrees C; final infrared ear, 36.57 degrees +/- .33 degrees C. The mean bias (difference between initial individual IR ear and TM temperatures) of -.05 degrees +/-.29 degrees C and the 95% limits of agreement of +.53 degrees to -.63 degrees C indicate an acceptable confidence (error range within 3.2% of average TM temperature) for use of the initial infrared ear temperature as an estimate of TM temperature. CONCLUSION: The IR ear thermometer provides an accurate estimate of TM temperature in healthy children and may accurately reflect core body temperature.

Comparison of infrared ear thermometer derived and equilibrated rectal temperatures in estimating pulmonary artery temperatures.

OBJECTIVES: To investigate the clinical accuracy of infrared ear thermometer derived and equilibrated rectal temperatures in estimating core body temperature. The clinical bias (i.e., mean difference between body sites), and variability (SD of the differences) of simultaneous temperatures were compared with pulmonary artery temperatures. Clinical repeatability (pooled SD of triplicate reading differences) was also examined for three ear infrared thermometers. DESIGN: Prospective clinical study. SETTING: A multidisciplinary, adult intensive care unit. PATIENTS: Twenty patients with an existing pulmonary artery catheter were studied in a multidisciplinary, adult intensive care unit. INTERVENTIONS: A single operator using optimum ear infrared technique and masked to ear and rectal temperatures recorded triplicate measurements with each of three infrared ear thermometers, each over a 4-min period with each infrared thermometer, while an assistant recorded temperatures. Infrared and rectal temperatures were compared with a simultaneous pulmonary artery temperature. MEASUREMENTS AND MAIN RESULTS: Infrared ear thermometers and rectal thermometers were calibrated daily, and pulmonary artery catheters were calibrated on removal from the patient. Patients were grouped into afebrile and febrile groups, based on initial pulmonary artery temperature. Bias and variability were compared between thermometers using analysis of variance. Clinical bias, but not variability, was significantly different between three ear infrared thermometers (0.16 +/- 0.46 degrees C, 0.07 +/- 0.38 degrees C, and -0.22 +/- 0.47 degrees C). The repeatability was not different between ear infrared thermometers (range 0.13 degrees C to 0.14 degrees C). Rectal temperature had a significantly greater bias (average 0.3 degrees C), but less variability (average 0.2 degrees C). Bias was increased, and variability decreased for both rectal and infrared ear temperatures when pulmonary artery temperature was increased. CONCLUSIONS: The three infrared ear thermometers studied provided a closer estimate of core body temperature than equilibrated rectal temperature. Clinical bias was greatest in febrile vs. afebrile intensive care unit patients.

Comparative review of the adverse effects of sedatives used in children undergoing outpatient procedures.

Children often fear medical procedures and interventions. Sedative agents enhance the care of these children who undergo outpatient procedures by decreasing anxiety, increasing cooperativity, and providing amnesia. Although higher dosages and intravenous administration of sedatives often produce improved sedation, adverse effects and complications are more frequent. The goals of therapeutic efficacy and safety must be balanced in all patients. The presence or anticipation of anxiety and pain helps in deciding whether to use a sedative alone, or a regimen also providing analgesia. The patient's clinical cardiorespiratory or neurological status, other relative contraindications, the duration of the intended procedure, and the presence or absence of an intravenous line will help in choosing specific drugs. Drug complications are a common cause of adverse events in patients. The combination of a sedative and analgesic, especially a benzodiazepine and an opioid given intravenously, is associated with a higher risk of serious complications. The practitioner responsible for the administration of a sedative to a child must be competent in its use and have the ability to detect and manage complications. Patients who are deeply sedated should be continuously monitored and observed by an individual dedicated to this task. Vital signs and oxygen saturation should be documented at frequent intervals and the patient should be appropriately monitored until discharge criteria have been met. The risk of serious complications with these agents may be reduced with vigorous monitoring and a judicious choice of dosage.

Respiratory motor nerve activities during experimental seizures in cats.

We evaluated respiratory motor nerve activities during experimental seizures induced with subcortical penicillin. The activities of the phrenic (PH), nasolabial (NL), and hypoglossal (HG) nerves and the recurrent laryngeal motor branches to the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles were analyzed in 13 anesthetized, vagotomized, paralyzed, and ventilated cats. During ictal and interictal phases of seizures, nerve activities became irregular and peak integrated nerve activities increased, particularly in the case of the PH nerve. The ictal phase of seizures was associated with increased tonic activity and decreased phasic respiratory discharges, particularly in the cases of the HG, NL, and PCA nerves. During some prolonged ictal discharges, entrainment of nerve activities by cortical spiking was associated with irregular uncoordinated activation, particularly in the TA nerve. These studies help explain respiratory impairment during seizures by providing evidence of impaired coordination between activation of muscles that regulate upper airway patency and activation of the diaphragm.

Glottal patency during experimental seizures in piglets.

Tracheostomized cats and piglets demonstrate respiratory stimulation during experimental seizures, whereas airway intact piglets demonstrate hypoventilation and increased subglottic resistances. The purpose of this study was to characterize the role of the vocal folds in contributing to these increased subglottic resistances during experimental seizures. A controlled animal study was performed in six anesthetized, spontaneously breathing, hyperoxic piglets who had subglottic pressure and airflow measured. A fiberoptic video scope directed into the cephalad trachea recorded subglottic images of the vocal folds. Glottal area patency (GAP) was evaluated at inspiratory onset (Io), peak inspiratory pressure (Ip), and expiratory onset (Eo) for four to five consecutive breaths under baseline control, ictal, interictal, and anticonvulsant conditions. Seizures were induced with i.v. pentylenetetrazol or bicuculline. Normalized GAP was greatest at Ip under all conditions, except anticonvulsant. During ictal periods, piglets demonstrated significant reductions in mean GAP throughout the respiratory cycle (Io, 98%; Ip, 78%; Eo, 98%), compared with baseline (p < 0.001, repeat measures analysis of variance). During ictal discharges, hypoventilation and glottal obstruction resulted in significant reductions in mean arterial pH (-0.35) and PaO2 (-39 kPa) and elevations in PaCO2 (+8.1 kPa), compared with baseline conditions. During interictal conditions mean GAP at Ip was increased, whereas at Eo (-66%) GAP was reduced, compared with control. These data demonstrate that the vocal folds are tonically adducted throughout the respiratory cycle during ictal phases and have increased expiratory adduction during interictal phases of seizures induced with standard i.v. convulsants in hyperoxic piglets.

Terbutaline vs albuterol for out-of-hospital respiratory distress: randomized, double-blind trial.

OBJECTIVE: To determine the efficacy and safety of single doses of subcutaneous terbutaline (TERB) or nebulized albuterol (ALB) during out-of-hospital treatment for respiratory distress from asthma or chronic obstructive pulmonary disease. METHODS: Patients aged > 18 years who had respiratory distress were enrolled in a double-placebo, double-blind, randomized trial. Paramedics measured respiratory severity using an empiric score [respiratory rate, wheezing, speech, and peak expiratory flow rate (PEFR)], and the patients rated their own respiratory distress using a visual analog scale (VAS). The patients received O2 plus ALB (2.5 mg) and saline injection (n = 40) or TERB (0.25 mg) and saline aerosol (n = 43). RESULTS: The groups were similar with respect to age, gender, initial empiric scores (median score 9 for both groups), PEFRs (89 +/- 84 L/min, mean +/- SD, for ALB vs 97 +/- 84 L/min for TERB), and respiratory distress VAS scores. Both groups showed significant improvement in their respiratory distress VAS scores by the time of ED arrival. The ALB group had a greater improvement in respiratory distress VAS score than did the TERB group (p < 0.05). Empiric scores, PEFR scores, and hospital admission frequencies were not significantly different. No complication was observed. CONCLUSION: The out-of-hospital administration of either aerosolized ALB or subcutaneous TERB reduced respiratory severity. Albuterol provided greater subjective improvement in respiratory distress.

The role of the upper airway in contributing to respiratory responses during experimental seizures in piglets.

Recent data demonstrating stimulation of respiration during seizures are at odds with the frequent clinical finding of respiratory impairment in patients with generalized seizures. To determine the role of the upper airway in contributing to these clinical observations, a study was performed in 12 weanling piglets. An arterial catheter and epidural electrodes were placed in ketamine-anesthetized piglets. In intact piglets, all airflow was measured through a snug-fitting nasal mask whereas pressure was measured with a subglottic catheter. Tracheostomized piglets had airflow and pressure measured at the trachea. Seizures were induced with i.v. injections of pentylenetetrazol. Peak inspiratory flow resistance was calculated by averaging three epochs of five to seven consecutive breaths. Epochs of greater than 20 s in duration with a tidal volume of < 10 mL were termed apnea. Apnea was considered central when airway pressure was > -2 cm H2O and obstructive when < -10 cm H2O. After 20 min of untreated seizures, intact piglets had significant respiratory and metabolic acidosis, whereas tracheostomized piglets had significant increases in Ve and mild metabolic acidosis. Apnea and obstruction were observed frequently in intact piglets. Resistance was unchanged during seizures in tracheostomized piglets, whereas a nearly 4-fold increase in inspiratory resistance was observed in intact piglets. We conclude that upper airway patency and resistances are important determinants of respiratory responses during generalized seizures in piglets.

Determination of normal ear temperature with an infrared emission detection thermometer.

STUDY OBJECTIVE: To determine normal body temperature with an infrared emission detection ear thermometer. DESIGN: Cross-sectional convenience sample. SETTING: Four acute and long-term health care facilities. PARTICIPANTS: Subjects who denied recent potentially febrile illness and ingestion of medications affecting normal body temperature. RESULTS: Two thousand four hundred forty-seven subjects aged 12 hours to 103 years were enrolled. Ear temperatures were normally distributed for each of eight age groups. There were differences in mean temperature among different age groups (P < .001, by ANOVA) and a striking cutoff at adolescence; the mean temperature for children aged 3 days to 10 years was 36.78 +/- 0.47 degrees C, as compared to 36.51 +/- 0.46 degrees C for subjects 11 years and older (P < .001, by t test). Temperatures were higher in female subjects and showed the characteristic diurnal variation of normal body temperature in five subjects studied longitudinally. The reproducibility of the ear thermometer was better than that of a commonly used electronic thermometer at the oral and axillary sites. CONCLUSION: The infrared emission detection ear thermometer is an accurate means of assessing normal body temperature without using corrective offsets to estimate temperature at other body sites. On the basis of these data, the 95th percentile for infrared emission detection temperature in children younger than 11 years old was 37.6 degrees C. The 99th percentile was 37.9 degrees C for children younger than 11 years old and 37.6 degrees C for people 11 years or older. Because only 1% of normal people have an infrared emission detection temperature higher than these values, these may represent appropriate cutoffs for fever screening using this device.

Respiratory drive during status epilepticus and its treatment: comparison of diazepam and lorazepam.

In order to examine the respiratory effects of tonic-clonic seizures and their treatment with i.v. diazepam or lorazepam, we utilized a spontaneously breathing piglet seizure model. A tracheostomy, arterial catheter, and epidural electrodes were inserted and pigs were maintained under ketamine anesthesia. After baseline recordings, seizures were induced with a pentylenetetrazol (PTZ) bolus and a 20 min infusion (5-6 mg/kg/min). After 10 min of PTZ infusion, randomly assigned animals received diazepam (D; N = 7; 0.5 mg/kg), lorazepam (L; N = 7; 0.2 mg/kg), or 0.9% saline (C; N = 7; controls) by rapid peripheral vein injection. Minute ventilation (Ve), Pa(CO2), and the pressure change in response to airway occlusion at end-expiration (P0.1) were measured at standard intervals. All groups had comparable increases in respiratory drive during untreated seizures. Changes in Ve and P0.1 were reduced to at or below baseline values in groups D and L, but not C, from 2 to 45 min after treatment (P < 0.05). No significant changes were observed in Pa(CO2) after either intervention. Following anticonvulsants, the cumulative duration of seizures was significantly reduced in L and D groups, compared to C (P < 0.05). We conclude that increases in respiratory drive occur during tonic-clonic seizures induced with PTZ. Amelioration of seizure activity with lorazepam or diazepam results in a reduction in respiratory drive, but not respiratory failure, in this tracheostomized model.

Nasal versus oral midazolam for sedation of anxious children undergoing laceration repair.

STUDY OBJECTIVE: To compare the efficacy and safety of a single dose of midazolam, as an oral solution of 0.5 mg/kg, or nasal drops of 0.25 mg/kg, in children undergoing emergency department laceration repair. DESIGN: Double-blind, double-placebo, randomized trial. Children underwent standard wound care when judged to demonstrate a reduction in anxiety following study medication. PARTICIPANTS: Fifty-eight patients between 1 and 10 years of age with uncomplicated lacerations judged to be anxious by emergency physicians. RESULTS: An anxiety score and vital signs were recorded at routine intervals. Groups were comparable with respect to age, laceration characteristics, initial vital signs, and anxiety scores. Both groups demonstrated reductions (mean +/- SD) in anxiety scores over time (P < .05; maximum at 10 minutes; 1.2 +/- 0.9 mm for nasal and 0.8 +/- 1.3 for oral), with no significant differences between groups (repeat-measures ANOVA). Median observer-rated effectiveness using a visual analog scale (maximum effectiveness, 10 mm) was not significantly different between groups: nasal, 7.6 mm and oral, 6.9 (Mann-Whitney U test: minimum detectable difference, 0.7, with alpha = 0.05 and beta = 0.2). Complications were judged to be minor only, and were more frequent in the nasal group (5 of 28, 4 with nasal burning) versus 1 of 26 in the oral group. Time from midazolam to ED discharge was not significantly different between groups: nasal, 54 +/- 15 minutes and oral, 57 +/- 16 minutes. CONCLUSION: A single dose of oral or nasal midazolam results in reduced anxiety and few complications in selected children undergoing laceration repair in the ED. The oral route was associated with fewer administration problems.