Effect of RSV bronchiolitis practice guidelines on resource utilization.

We sought to determine whether institution of respiratory syncytial virus (RSV) practice guidelines decreased resource utilization for a heterogeneous population of children hospitalized with RSV bronchiolitis. Patients less than 24 months old with RSV bronchiolitis at a pediatric referral center were identified by retrospective chart review for consecutive RSV seasons. Before the guidelines were instituted patients were less likely to have a documented physician's assessment of response to albuterol, were more likely to have received supplemental oxygen and cardiorespiratory monitoring, and to be discharged on an albuterol regimen. Patients received more albuterol treatments. After the guidelines were in place fewer resources were utilized in the care of patients with RSV bronchiolitis. RSV practice guidelines may simplify and streamline the care of a heterogeneous population of children with bronchiolitis.

Excess risk of severe acute illness in children with chronic health conditions.

UNLABELLED: We estimated the relative risk (RR) of an unscheduled pediatric intensive care unit (ICU) admission as a marker for severe acute illness in children with chronic health conditions, compared with previously healthy children. Potentially preventable events that lead to acute illness were identified to develop preventive strategies. METHODS: Children with chronic conditions were defined as those who have a chronic physical, developmental, behavioral, or emotional condition and who also require health and related services of a type or amount beyond that required by children generally. RR was estimated from admissions and regional population data. Potentially preventable events that lead to ICU admission of chronically ill children were identified retrospectively from hospital records. RESULTS: Children with chronic health conditions had an RR of 3.3 for an unscheduled ICU admission related to their chronic condition, compared with previously healthy individuals (95% confidence interval [CI] = 2.5-4.2). The risk of severe acute illness in the small subgroup that received technology-assisted care was much greater (RR = 373; 95% CI = 330-422) than for the large group of chronically ill patients who did not require technology-assisted care (RR = 2.3; 95% CI = 1.7-3.0), each expressed relative to previously healthy children. Acute illness related to chronic health conditions accounted for 45% of 251 unscheduled ICU admissions during the 1-year study. Thirty-two percent of admissions that were related to chronic conditions were judged to have been potentially preventable. Preventable events were more common for those who did not require technology-assisted care, occurring in 38% of admissions, compared with those who received technology-assisted care, for whom 19% of admissions involved a preventable event. Fifty-six percent of potentially preventable events involved the physical or social environment and decisions made by the family, whereas 64% could be attributed to health care system factors. CONCLUSIONS: Children with chronic health conditions account for a substantial share of severe acute illness in a region. Because their underlying conditions have already been identified, problems may be anticipated. The small number of children who receive technology-assisted care each have such a high risk of severe and unavoidable acute illness that individualized emergency care plans are justified. For the remainder of children with chronic conditions, investigation of health system strategies to improve families' ability to anticipate, minimize, or prevent related acute illness is warranted.

Post-intensive care unit pediatric hospital stay and estimated costs.

OBJECTIVE: For pediatric intensive care unit (ICU) survivors, to determine the proportion of hospital stay and estimated hospital costs accounted for by post-ICU care. DESIGN: Prospective study. SETTING: University teaching hospital. PATIENTS: Pediatric patients who survive an ICU admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Estimated relative daily costs were assumed as follows: ICU, with ventilator/ICU, not on ventilator/intermediate care unit/general pediatric hospital day, at 2:1:0.7:0.3, respectively. Estimated costs were expressed in arbitrary units as (number of days at each level of care) x (relative cost per day). The ICU phase was defined as the patient's first ICU admission only, and the post-ICU phase included intermediate care unit and general pediatric hospital days, as well as ICU readmission during the same hospitalization. Pre-ICU hospital activity was excluded from analysis. For 341 ICU survivors, post-ICU days (median, 4 days per patient) accounted for 62% of the total hospital stay. Post-ICU care accounted for one third of the total estimated hospital costs for ICU survivors. Patients with longer post-ICU stays could not be reliably identified at the time of ICU discharge according to their ICU length of stay, duration of mechanical ventilation in the ICU, age, ICU day 1 mortality probability, or diagnostic group (p>.05). CONCLUSIONS: Post-ICU care accounts for a substantial proportion of hospital stay and estimated costs for ICU survivors. These observations suggest that developing strategies to optimize hospital utilization at the time of ICU discharge may be important for controlling costs of recovery from critical illness.

Pediatric mortality probability estimated from pre-ICU severity of illness.

OBJECTIVE: The Pediatric Risk of Mortality (PRISM) score is a measure of illness severity based on abnormalities observed in the bedside examination and laboratory assessment. PRISM scores obtained after pediatric intensive care unit (PICU) admission predict mortality probability, but no previous efforts to evaluate mortality risk before PICU admission have been reported. Our study was performed on patients admitted to PICUs at four pediatric tertiary care centers to derive a quantitative estimate of hospital mortality probability as a function of PRISM scores obtained at referring hospitals before PICU transfer. Performance of the model was tested by evaluating accuracy of mortality predictions obtained from pre-ICU PRISM scores in a separate validation set of patients. METHODS: Patients were randomized to the derivation or validation sets. Data were recorded prospectively from observations made at hospitals referring to the study PICUs. Patients included 780 infants and children with medical and surgical emergencies and trauma. Electively admitted patients were excluded from analysis. RESULTS: The relationship between mortality probability (P) and the pre-ICU PRISM score is expressed by the equation: P = er/(1 + er). In this equation, r is an empirical function of the pre-ICU PRISM score: r = .197 x PRISM - 4.705. The mortality probability rises from near 0 at low scores, approaching 1 (certainty) above a PRISM score of 40. Mortality probability exceeds 10% at a score of 13 and exceeds 50% at a score of 24. Performance of predictions in the validation set of patients was evaluated for five categories of mortality probability. The observed number of deaths corresponded to predicted mortality across the range of illness severity. When compared for each tertiary institution, observed mortality rates were similar to predictions for three of four institutions. For data obtained at institution D, the observed mortality of 17% significantly exceeded the 7% predicted rate. In infants younger than 1 year, as well as children 1 year and older, observed mortality rates were similar to predicted. CONCLUSIONS: The pre-ICU PRISM score as a measure of illness severity provides an estimate of hospital mortality probability. Further investigation is required to determine the use of pre-ICU mortality estimates in making clinical decisions.

Comparison of neurons in rat medulla oblongata with fos immunoreactivity evoked by seizures, chemoreceptor, or baroreceptor stimulation.

Neurons in rat medulla oblongata with Fos immunoreactivity as a marker of synaptic excitation evoked by pentylenetetrazole-induced seizures were compared with cell populations activated by the stimulation of chemoreceptor and baroreceptor afferent pathways. Chemoreceptors were stimulated by placing rats in a hypoxic gas mixture (7% oxygen) for 2 h. Baroreceptors were activated by phenylephrine-induced hypertension. Seizures and hypoxia induced Fos immunoreactivity in neurons with similar anatomical distributions in the nucleus tractus solitarius, dorsal motor nucleus of the vagus, and ventrolateral medulla. Hypertension was associated with Fos immunoreactivity in an overlapping anatomical distribution compared to seizures and hypoxia, but in a more restricted pattern. A similar proportion of catecholaminergic cells of medulla oblongata (cells immunoreactive for catecholamine synthetic enzymes, tyrosine hydroxylase or phenylethanolamine-N-methyltransferase) had Fos immunostaining after seizures and hypoxia (P > 0.05), while significantly fewer were activated by hypertension (P < 0.05). The majority of tyrosine hydroxylase-immunoreactive cells in caudal ventrolateral medulla were activated by both seizures and hypoxia (mean per cents, 79 and 67%, respectively). Since cell populations activated by seizures and hypoxia are indistinguishable, and a majority of tyrosine hydroxylase-reactive cells in caudal ventrolateral medulla are independently activated by each stimulus, it may be inferred that some impulses originating from seizures and chemoreceptor afferent pathways converge to a common set of neurons. These observations identify neurons in rat medulla oblongata which may mediate the impact of seizures on central processing of chemoreceptor afferent activity.

Seizure-induced c-fos expression in rat medulla oblongata is not dependent on associated elevation of blood pressure.

This study was performed to determine whether c-fos immunoreactivity (IR) induced in medulla oblongata by pentylenetetrazole seizures is a consequence of seizure-associated blood pressure elevation and activation of baroreceptor afferent pathways, or occurs independently of hypertension. Immunohistochemical study of sections of medulla oblongata revealed that seizures are followed by induction of c-fos IR in nucleus tractus solitarius (NTS), dorsal motor nucleus of the vagus (DMN 10), and ventrolateral medulla (VLM), while there is negligible c-fos IR after saline sham injections. Seizures were associated with blood pressure elevation peaking at 31 +/- 17% (+/- SD) above baseline. Experimental hypertension at a similar level induced by i.p. phenylephrine also resulted in induction of c-fos IR in NTS. When seizures were preceded by antihypertensive treatment with the alpha-adrenergic antagonist, phentolamine, peak blood pressure tended to remain near the baseline level and lower than sham-injected controls. Normotensive seizures were associated with c-fos IR in NTS, DMN 10, and VLM similar to the pattern following hypertensive seizures. Seizure-induced activation of c-fos IR occurred despite normal blood pressure, and thus can be attributed to a direct effect of the seizure, and not to an indirect effect mediated by hypertension.

Activation of the c-fos gene in prodynorphin- and proenkephalin-expressing cells of nucleus tractus solitarius after seizures.

We performed studies to determine the anatomical regions and chemical phenotypes of neurons within the rat medulla oblongata activated by pentylenetetrazole-induced seizures. Activated cells were identified by their expression of the c-fos gene, detected by in situ hybridization for c-fos mRNA and immunocytochemistry for Fos protein. Activated cells were located predominantly in nucleus tractus solitarius (NTS), with c-fos mRNA appearing within 20 min after seizures (peak at 1-2 h), followed by Fos immunoreactivity visible at 1 h (peak at 2-4 h). Neither nonspecific noxious stimulation by intraperitoneal injection of saline nor brief exposure to hypoxic or hypercapnic gas mixtures to stimulate chemoreceptors reproduced this pattern of labeling. Prodynorphin or proenkephalin mRNA, detected by in situ hybridization, was colocalized with Fos immunoreactivity in many NTS cells. Thus, seizures activate neuronal pathways in the medulla oblongata which express genes for endogenous opioids. Potential long-term effects of seizures are suggested by the in situ hybridization finding that NTS prodynorphin mRNA increased 24 h after seizures compared to control levels.

Reduction of morbidity in interhospital transport by specialized pediatric staff.

OBJECTIVE: We prospectively compared the occurrence of morbidity during high-risk interhospital transport in two types of transport systems: specialized tertiary center-based vs. nonspecialized, referring hospital-based. DESIGN: Concurrent, prospective comparison of morbidity at two pediatric centers that use different types of transport team. SETTING: Two tertiary care pediatric intensive care units (ICU). The specialized team consisted of a pediatric resident, pediatric intensive care nurse, and a pediatric respiratory therapist. Comparison was made with referring institution transports by nonspecialized personnel to a second center. The two centers were similar in size and patient mix, with referral areas of similar population and rural/urban ratio. PATIENTS: One hundred forty-one patients transported to two tertiary pediatric ICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two types of events were assessed: vital signs and other observable clinical events were described as "physiologic deteriorations." Events such as loss of intravenous access, endotracheal tube mishaps, and exhaustion of oxygen supply were described as "intensive care-related adverse events." Pretransport severity of illness and therapy were described by Pediatric Risk of Mortality (PRISM) and Therapeutic Intervention Scoring System (TISS) scores. Only high-risk patients with PRISM scores of > or = 10 were analyzed. Intensive care-related adverse events occurred in one (2%) of 49 transports by the specialized team and 18 (20%) of 92 transports by nonspecialized personnel. The difference is statistically significant (p < .05). Physiologic deterioration was similar in the two groups occurring in five (11%) of 47 specialized team transports and 11 (12%) of 92 transports by the nonspecialized team. CONCLUSION: We conclude that specialized pediatric teams can reduce transport morbidity. This is the first published study to compare two models of pediatric transport using identical definitions of severity and morbidity.

Early postnatal development of thyrotropin-releasing hormone (TRH) expression, TRH receptor binding, and TRH responses in neurons of rat brainstem.

We investigated the postnatal development of the thyrotropin-releasing hormone (TRH)-containing raphe system in the brainstem of neonatal rats. Postnatal changes in TRH expression in nucleus (n.) raphe obscurus (ROb) and n. raphe pallidus (RPa) were evaluated by in situ hybridization using an 35S-labeled oligonucleotide probe complementary to TRH precursor mRNA. TRH mRNA expression was low at birth [postnatal day 0 (P0)], but was clearly evident by P7 and increased from that time to reach sustained high levels from P14 to P28. Consistent with this postnatal increase in TRH expression, we found increases in the density of TRH-immunoreactive (IR) fibers, which are derived from ROb and RPa, in the hypoglossal nucleus (nXII). TRH-IR fibers in nXII were very sparse at P0, but increased markedly over the first 2 postnatal weeks. The change in TRH innervation of nXII was closely matched by concomitant increases in 3H-methyl-TRH binding in nXII; specific TRH binding increased from very low levels at birth to high levels of P14. Finally, we recorded intracellularly the electrophysiological responses to TRH of hypoglossal motoneurons (HMs; n = 42) of neonatal rats (P0-P21) in a brainstem slice preparation. The response of neonatal HMs to TRH, in contrast to adult HMs, was highly variable. In some neonatal HMs, even at P0, TRH caused a depolarization with a decrease in input conductance (GN) that was characteristic of the response of all adult HMs. However, in other neonatal HMs, TRH was either without effect or caused a slight depolarization with no apparent change in GN, responses that were unlike those of adult HMs. A response was considered typical (i.e., "adult-like") if GN decreased to < 85% of control. The percentage of cells responding in a typical manner increased progressively from 25% at P0-P2 to 100% after P11. In addition, we found that the density of TRH-sensitive current (normalized to cell capacitance) increased with postnatal age in HMs that responded in a typical manner, suggesting that expression of the TRH-sensitive conductance is also developmentally regulated. Together, these data indicate that the TRH raphe neuronal system of the rat brainstem is not fully mature at the time of birth but develops over the first few postnatal weeks. This was true of levels of TRH mRNA in caudal raphe nuclei, density of TRH-IR fibers and 3H-methyl-TRH binding in nXII, and also the manner and magnitude of electrophysiological responses of HMs to exogenously applied TRH.

Central contribution to hypoventilation during severe inspiratory resistive loads.

OBJECTIVE: Recent observations suggest that central hypoventilation with slowing of respiratory frequency contributes to hypoventilation during severe inspiratory resistive loads. We carried out a study to further characterize this bradypneic response. DESIGN: Prospective, controlled laboratory study. SETTING: Basic science laboratory of a university hospital. SUBJECTS: Anesthetized adult cats (loading experiment n = 7, nonloaded hypercapnic controls n = 11). INTERVENTIONS: Experimental inspiratory loads increased transdiaphragmatic pressure to 75% of the maximum for each animal. Respiratory responses were observed at midrun or moderate conditions of respiratory insufficiency (defined as PaCO2 > or = 60 torr [> or = 8.0 kPa]) and failure (PaCO2 > or = 80 torr [> or = 10.6 kPa]). Nonloaded hypercapnic controls were studied with similar durations of exposure to CO2 in the same CO2 range. MEASUREMENTS: Inspiratory airflow, tidal volume, respiratory frequency, airway pressure, transdiaphragmatic pressure, transdiaphragmatic pressure response to phrenic nerve electrical stimulation, blood gas analysis. Severe inspiratory loads were applied to anesthetized adult cats to determine whether bradypnea could be observed in an anesthesized model that eliminated conscious responses. Experiments were performed in hyperoxic conditions to determine whether bradypnea develops in the absence of hypoxia. An additional control group was studied under hypercapnic conditions without loading to determine whether comparable hypercapnia is a sufficient stimulus to elicit bradypnea. RESULTS: From midrun until failure, minute ventilation decreased by 16% in loaded animals. Hypoventilation was associated with a decrease in respiratory frequency from 40.1 to 29.9 breaths/min, whereas tidal volume, spontaneous transdiaphragmatic pressure, and transdiaphragmatic pressure response to phrenic nerve electrical stimulation remained unchanged. Control animals had no significant reduction in ventilation or respiratory frequency over similar levels and durations of hypercapnia. CONCLUSIONS: Centrally mediated bradypnea contributed to hypoventilation in respiratory failure associated with inspiratory loading. Bradypnea preceded evidence of muscle fatigue. This change in respiratory cycle timing occurred under anesthesia, and thus, did not depend on conscious perception of dyspnea. Bradypnea does not depend on either hypercapnia or hypoxia.

Duration of intracranial pressure monitoring does not predict daily risk of infectious complications.

A group of 205 patients (115 children and 90 adults) with a total of 212 intracranial pressure (ICP) monitors were retrospectively studied with attention to daily cerebrospinal fluid cultures, duration of monitoring, associated cranial injuries, and hospital site of the ICP monitor (intensive care unit or operating room). Only closed ICP monitoring systems without irrigation or compliance testing were used, and all patients received antibiotics as prophylaxis throughout the monitoring period. There were no complications associated with monitor placement. Incidence histograms and regression analysis were used to determine the daily risk of subsequent infections, in addition to evaluating the cumulative risk of infection, as has been previously described in the literature. No relation between the duration of ICP monitoring and the rate of daily infection through the period of maximal monitoring (1-2 weeks) was found in this series. The overall incidence of infection was 7.1% with a median duration of monitoring of 7.2 days. The age of the patient (adult vs. child), site of ICP monitor placement, and nature of the underlying disease (trauma vs. nontrauma) had no significant effect on the development of monitor-related infections in our study. These data indicate that the decision to continue ICP monitoring can be based solely on the clinical necessity for further monitoring rather than on concerns for monitor removal to prevent infection.

Development of a piglet model of status epilepticus: preliminary results.

STUDY OBJECTIVE: Ventilation frequently is impaired during prolonged clinical seizures and their treatment. In a pilot study, respiratory, metabolic, and hemodynamic variables were studied during induced seizures in a lightly anesthetized, spontaneously breathing piglet model. PARTICIPANTS: Weanling, mixed-breed domestic piglets. INTERVENTIONS: Piglets were instrumented with a tracheostomy, arterial catheter, and epidural electrodes. Conditions included hyperoxia, normothermia, and ketamine maintenance infusion throughout recordings. After baseline recordings, 2 mg/kg IV bicuculline was administered. For further model validation, piglets were randomized to infusions of diazepam (three), lorazepam (two), or saline (control; five) groups after ten minutes of untreated seizures. MEASUREMENTS AND MAIN RESULTS: Integrated tidal volume, respiratory rate, PaCO2, pH, arterial pressure, rectal temperature, heart rate, and bipolar EEG waveforms were recorded and compared at intervals for 60 minutes. Vigorous tonic-clonic seizures occurred in all piglets, confirmed by sudden synchronization and large-amplitude EEG waveforms. Increases in heart rate, arterial pressure, tidal volume, respiratory rate, PaCO2, minute ventilation, and base deficit occurred in all piglets during seizures as compared with baseline. Five minutes after bicuculline was administered, increases in minute ventilation (4.5 +/- 0.4 L/min at baseline to 13 +/- 2.1 L/min) were accounted for by increases in both tidal volume and respiratory rate. More abrupt decreases in respiratory rate were observed in anticonvulsant-treated piglets as compared with controls. The duration of continuous seizure activity (12 +/- 1.0 minutes versus 21 +/- 3.3 minutes; P < .05) was reduced in anticonvulsant-treated piglets. CONCLUSION: Significant increases in ventilation occur during generalized seizures in tracheostomized piglets given bicuculline. Diazepam and lorazepam infusions ameliorate seizure activity and suppress increases in respiratory rate but not minute ventilation as compared with controls. Problems with this model included baseline variability, temperature instability, and that direct respiratory stimulation from the convulsant agent may have occurred.

Excess morbidity associated with interhospital transport.

A prospective study was performed to determine whether excess morbidity occurred in critically ill and injured pediatric patients during interhospital transport compared with morbidity in a control group. Control observations were made during the first 2 hours of pediatric intensive care unit (PICU) care of patients emergently admitted from within the same institution and not requiring interhospital transport. The first 2 PICU hours of control patients corresponded to the interval of transport in those who required interhospital transfer. Transport care was provided by nonspecialized teams from referring hospitals. Morbidity occurred in 20.9% of 177 transported patients, exceeding the morbidity rate of 11.3% in 195 control patients (P < .05). The difference in morbidity was due to intensive care-related adverse events (eg, plugged or dislodged endotracheal tubes, loss of intravenous access) in 15.3% and 3.6% of transported and control patients, respectively (P < .05). Physiologic deterioration occurred at similar rates of 7.9% and 8.7% in transported and control patients, respectively (P > .05). Slightly greater pre-ICU severity of illness in transported than control patients (median Pediatric Risk of Mortality Score = 10 and 7, respectively, P < .05) and greater pre-ICU therapy relative to severity (P < .05) in control patients are potential confounding sources of the morbidity differences. If patients are stratified into subgroups of similar pre-ICU severity, an excess of intensive care-related adverse events in transported patients remains evident in the severe subgroup (P < .05). Further investigation is warranted to determine whether specialized transport teams can reduce the excess morbidity associated with interhospital transport of critically ill and injured pediatric patients.

Can early bacterial complications of aspiration with respiratory failure be predicted?

We studied the early infectious complications of all children admitted for intensive care over a six-year period who were at high risk of having severe aspiration of gastric or pharyngeal secretions. Patients were only analyzed if they required mechanical ventilation for acute respiratory failure, had a blood culture obtained in the first 48 hours, and survived at least 24 hours. Infections were identified by positive blood cultures. Possible infections were defined as fever (over 38.5 degrees C), abnormal leukocyte count (greater than 10,000 or less than 5000), and a potential pathogen in tracheal secretions. Patients' diagnoses included near-drowning (13), aspirated foreign body (5), observed aspiration of gastric contents in a hospitalized patient (2), and hydrocarbon aspiration (1). Of 21 high-risk patients, five (23.8%) had infections and two (9.5%) had possible infections in the first 48 hours. In contrast, no late infections were seen. Infected patients tended to be older (P less than 0.05). No diagnostic features in the first two days of hospitalization reliably identified those who would develop early infections (P greater than 0.05). Since early life-threatening infection is common and cannot be reliably predicted by clinical signs, we recommend aggressive bacteriologic surveillance and the administration of IV antibiotics on admission to all patients in respiratory failure requiring mechanical ventilation after presumed aspiration of gastric or pharyngeal secretions.

The influence of diazepam or lorazepam on the frequency of endotracheal intubation in childhood status epilepticus.

Anticonvulsant management of status epilepticus (SE) may result in respiratory depression, often requiring endotracheal intubation (ETI). By examining rates of ETI in childhood SE after intravenous diazepam or lorazepam, when administered alone or in combination with phenytoin, the influence of anticonvulsants on the frequency of ETI during SE was determined. The medical records of 142 consecutive children younger than 16 years of age admitted from a university hospital ED with seizures during a 28-month period were retrospectively reviewed. SE was identified in 38 (27%) of cases. Records of children with SE were reviewed for demographic, seizure severity, and management variables. Twelve patients were excluded, ten of whom received concomitant phenobarbital. Patients receiving lorazepam had ETI rate of 27% (4/15), compared to 73% (8/11) in the diazepam group (P = 0.026, Fisher's exact). The groups were not significantly different in age, weight, sex, seizure type, seizure duration, and appropriate anticonvulsant dosage. A prospective, randomized trial comparing lorazepam and diazepam is warranted to confirm the apparent advantage of lorazepam in reducing respiratory depression.

Evaluation of resuscitation proficiency in simulations: the impact of a simultaneous cognitive task.

In order to evaluate the impact of simulation complexity on resuscitation skill performance, 15 pediatric residents were observed in bag-valve-mask ventilation on an infant manikin. Performance was evaluated in a simple exercise in which ventilation was performed as a single isolated task. For each subject, this was compared to performance when a cognitive task involving clinical problem solving was simultaneously presented. Performance was expressed as frequency, tidal volume, and estimated hypothetical alveolar Pco2 in each resuscitation. A correlation was observed (P less than 0.05) between simple and complex resuscitation simulations for each measure of performance. The only subject with inadequate performance in the complex exercise was also identified as deficient in the simple exercise. These observations suggest that an adequate evaluation of performance of some resuscitation skills may be obtained in simple, efficient simulation exercises.

A model for evaluation of gas exchange: mouth to mouth ventilation of infants by emergency medical technicians.

We describe a model for evaluating techniques of infant ventilation during resuscitation. The utility of the model is illustrated by testing performance of emergency medical technicians in mouth to mouth ventilation of a model 4 kg infant. Ventilation was generally adequate with mean (+/- S.D.) frequency 22 +/- 9 breaths per minute and tidal volume 40 +/- 13 ml. Gas delivered to the model consisted of PICO2 7 +/- 6 mmHg and FIO2 0.20 +/- 0.007. Assuming normal metabolic rate and respiratory dead space, alveolar gas composition resulting from the simulated resuscitations would be PACO2 = 31 +/- 20 and PAO2 = 110 +/- 19 mmHg. Nine of ten rescuers would have achieved satisfactory PACO2 less than or equal to 50 and PAO2 greater than or equal to 100. However, the rescuers' exhaled oxygen concentration is not adequate to correct hypoxemia if associated with hypoventilation or a wide alveolar to arterial oxygen gradient.

Resource use, efficiency, and outcome prediction in pediatric intensive care of trauma patients.

To study the impact of trauma patients on Pediatric Intensive Care Units (PICUs), 164 trauma patients' data from 1,075 consecutive admissions to five PICUs were reviewed. Resource use (Therapeutic Intervention Scoring System [TISS] points) and mortality risks (Physiologic Stability Index [PSI] and Pediatric Risk of Mortality [PRISM] scores) were obtained daily for all patients. Trauma patients constituted 15.2% of all PICU patients, and used 14.9% of patient care days and 14.5% of TISS points. Efficiency of trauma patient care was 75% overall compared to 79% overall for nontrauma patients (p less than 0.001). Trauma patient mortality was 9.8%. Tests for goodness of fit showed the PSI and PRISM scores to be accurate outcome predictors for trauma patients (PSI: chi 2 (4) = 2.852, p greater than 0.50; PRISM: chi 2 (4) = 1.216, p greater than 0.50). Trauma patients are a minority of PICU patients and deaths. Their resource use is proportional to their numbers, although less efficient than for nontrauma patients. PSI and PRISM are accurate mortality risk predictors for trauma patients.

Adverse events during interhospital transport: physiologic deterioration associated with pretransport severity of illness.

The relationship between severity of illness or injury before interhospital transport and the incidence of physiologic deterioration during transport was studied in 117 pediatric patients. Transports were done by referring hospital personnel. Pretransport severity was expressed as the Pediatric Risk of Mortality score for all patients and as the Modified Injury Severity Score for trauma patients. For 71 patients with Pediatric Risk of Mortality scores less than 10, deterioration during transport occurred in 3 (4%) and hospital mortality occurred in 2 (3%). For 10 victims of trauma with Modified Injury Severity Scores less than 10, none had deterioration during transport or hospital mortality. The rare occurrence of serious problems related to transport in low-risk patients indicates that referring hospital personnel are capable of safely transporting such patients. The incidence of physiologic deterioration during transport was significantly greater (P less than .01) with greater pretransport severity of illness or injury. Failure to intubate the trachea was not a major preventable cause of deterioration. The most common preventable problem occurred for 6 of 79 patients with endotracheal tubes that became occluded with secretions, leading to cyanosis in 2 patients. Our data concerning high-risk patients with specified pretransport severity provide a basis for comparison for further evaluation of the benefit of specialized pediatric transport services.