David S. Jardine

Practice of pediatric critical care medicine: results of the Future of Pediatric Education II survey of sections project.

Objective To summarize the demographics and practice patterns of the current pediatric critical care workforce and to identify the key workforce issues that may affect the delivery of pediatric critical care services in the future. Design A questionnaire designed to analyze current pediatric critical care workforce demographics and future workforce trends. Subjects Pediatric critical care physicians from the United States were identified from the American Academy of Pediatrics Critical Care Section, from a list of physicians certified in pediatric critical care medicine (PCCM) by the American Board of Pediatrics, and from a list of pediatrician members of the Society for Critical Care Medicine. Interventions None. Measurements PCCM physicians were polled regarding board certification, practice characteristics, professional activities, referral patterns, patient profiles, competition, job satisfaction, and projected retirement age. Main Results A total of 805 PCCM physicians completed the survey. When grouped by age, 40% of the responding PCCM physicians were younger than 40 yrs, 49% were 40 to 49 yrs old, and only 11% were 50 yrs of age or older. The younger group had a higher percentage of female pediatricians than the older groups. For all age groups, the largest proportion of time was devoted to direct patient care time in pediatric critical care. This was especially true for the youngest age group that had the largest amount of patient care time devoted to critical care (43%). Time devoted to research was also significantly higher for the younger age group, although very few respondents reported that they have >50% of their time protected for research. For all age groups, those reporting increases in referral volume and referral complexity over the previous 12 months far outnumbered those reporting decreases. The majority of respondents reported being satisfied with their career choice. In general, respondents were more likely to report that too many rather than too few PCCM physicians were currently being trained. Approximately one third of respondents (34%) planned on leaving the field of critical care medicine before retiring from medicine completely. Conclusions PCCM physicians were increasingly women and working for >65 hrs/wk, with a good level of job satisfaction. Competition from a variety of sources seems to affect the work of PCCM physicians. The relatively small percentage of time devoted to research, however, is a finding of great concern.

Oxymetazoline and hypertensive crisis in a child: can we prevent it?

Oxymetazoline nasal spray is not FDA approved for use in children less than 6 years; however, its safety and efficacy are widely accepted, and it is in widespread use in children prior to procedures that may lead to epistaxis. We report a case of intraoperative oxymetazoline toxicity in a 4‐year‐old boy that led to a hypertensive crisis. While examining the possible causes for this problem, we became aware that the method of drug delivery led to an unanticipated overdose. The position in which the bottle is held causes pronounced variation in the quantity of oxymetazoline dispensed.

A Single Nucleotide Polymorphism in the Corticotropin Receptor Gene Is Associated With a Blunted Cortisol Response During Pediatric Critical Illness

Objectives: The cortisol response during critical illness varies widely among patients. Our objective was to examine single nucleotide polymorphisms in candidate genes regulating cortisol synthesis, metabolism, and activity to determine if genetic differences were associated with variability in the cortisol response among critically ill children. Design: This was a prospective observational study employing tag single nucleotide polymorphism methodology to examine genetic contributions to the variability of the cortisol response in critical illness. Thirty-one candidate genes and 31 ancestry markers were examined. Setting: Patients were enrolled from seven pediatric critical care units that constitute the Eunice Kennedy Shriver Collaborative Pediatric Critical Care Research Network. Subjects: Critically ill children (n = 92), age 40 weeks gestation to 18 years old, were enrolled. Interventions: Blood samples were obtained from all patients for serum cortisol measurements and DNA isolation. Demographic and illness severity data were collected. Measurements and Main Results: Single nucleotide polymorphisms were tested for association with serum free cortisol concentrations in context of higher illness severity as quantified by Pediatric Risk of Mortality III score greater than 7. A single nucleotide polymorphism (rs1941088) in the MC2R gene was strongly associated (p = 0.0005) with a low free cortisol response to critical illness. Patients with the AA genotype were over seven times more likely to have a low free cortisol response to critical illness than those with a GG genotype. Patients with the GA genotype exhibited an intermediate free cortisol response to critical illness. Conclusions: The A allele at rs1941088 in the MC2R gene, which encodes the adrenocorticotropic hormone (corticotropin, ACTH) receptor, is associated with a low cortisol response in critically ill children. These data provide evidence for a genetic basis for a portion of the variability in cortisol production during critical illness. Independent replication of these findings will be important and could facilitate development of personalized treatment for patients with a low cortisol response to severe illness.

Gene expression analysis characterizes antemortem stress and has implications for establishing cause of death

Within the field of forensic pathology, determination of the cause of death depends upon identifying physical changes in the corpse or finding diagnostic laboratory abnormalities. When such perturbations are absent, definitive assignment of a cause of death may be difficult or impossible. An example of such a problem is sudden infant death syndrome (SIDS), a common cause of neonatal mortality that does not produce physical findings or laboratory abnormalities. Although respiratory failure as a cause of SIDS represents the most widely held hypothesis, sudden cardiac death and hyperthermia have also been advanced as possible causes. We hypothesize that each of these physiological stresses would produce a different pattern of premortem gene expression and that these patterns of gene expression would remain evident in tissues collected postmortem. If these patterns were sufficiently distinctive, they could be used to identify the cause of death. Using an infant mouse model, we compared gene expression patterns in liver tissue after sudden death, lethal hyperthermia, and lethal hypoxia. Each of these conditions produced readily distinguishable differences in gene expression patterns. With the K-nearest neighbor classification algorithm, only 10 genes are necessary to correctly classify samples. If the liver tissue was not harvested immediately after death, additional alteration in gene expression patterns resulted; however, these alterations did not affect the group of genes used to classify the samples. Our findings suggest that gene expression analysis from tissues collected postmortem may provide useful clues about certain physiologic stresses that may precede death.

Specific Diseases of the Respiratory System

Pearls • Diseases leading to compromise of the airway are the most frequent cause of cardiac arrest in pediatric patients. A small reduction in the caliber of the child’s airway may lead to a life-threatening reduction of airflow.• Laryngomalacia is the most common congenital anomaly of the larynx. Infants tend to outgrow this problem during the first year of life; however, the condition may be of sufficient severity in some infants that activities such as feeding are compromised.• The trachea may be compressed by the presence of an abnormal vascular structure. Children affected by this problem may have such diverse symptoms as stridor, wheezing, lobar atelectasis, or recurrent pulmonary infections.• The practice of treating laryngotracheobronchitis with corticosteroids is standard of care, especially for hospitalized patients. A meta-analysis in which the efficacy of corticosteroids was evaluated suggests that corticosteroids may reduce the need for endotracheal intubation and hasten improvement when given in the first 24 hours of illness.• Epiglottitis, a bacterial infection of the supraglottic tissues historically caused by Haemophilus influenzae type B, is now most frequently caused by group A β-hemolytic streptococcus.• Patients with bacterial tracheitis usually do not respond to inhaled racemic epinephrine, have a high fever, and appear very ill.

Negative pressure ventilation for infants with respiratory failure after cardiac surgery

We report our experience using negative pressure ventilation (NPV) to support 40 infants who required prolonged positive pressure ventilation after cardiac surgery (average duration of post‐operative positive pressure ventilation was 9.2 days). NPV was used for an average of 2.4 days, during which 20 patients were weaned to spontaneous unsupported ventilation, and 20 patients required reintubation. Progressive tachypnoea during NPV was a reliable sign of respiratory insufficiency and preceded failure of NPV.