Peter R. Holbrook

Validation of a Physiologic Stability Index for Use in Critically Ill Infants and Children

Summary: We developed a physiology-based scoring system, the Physiologic Stability Index (PSI) to assess severity of acute illness in the total population of pediatric Intensive Care Unit (ICU) patients. Thirty-four variables from seven physiologic systems were chosen, and the degree of abnormality of each variable was assigned a score reflecting the clinical importance of the derangements. Validity was demonstrated by comparing PSI to hospital mortality and to two other methods that reflect severity of illness, the Clinical Classification System (CCS) and the Therapeutic Intervention Scoring System (TISS). Four hundred and twenty three consecutive admissions to a multidisciplinary ICU were followed daily. Patients classified into higher CCS classes had significantly higher PSI scores (P < 0.001), and there was a highly significant correlation (P < 0.001) between PSI and TISS scores. The linear-logistic regression of observed mortality versus PSI was highly significant (P < 0.0001) and provided an excellent fit. Highly significant differences between survivors and nonsurvivors were observed for PSI scores (P < 0.001), as well as for composite slopes of the regression of PSI scores versus days of care (P < 0.001). These data demonstrate validity of the PSI scoring system.

Aspiration of activated charcoal and gastric contents

A case of aspiration of activated charcoal and gastric contents is reported. The patient developed immediate airway obstruction treated by endotracheal intubation and suctioning. Protracted respiratory insufficiency characterized by severe bronchospasm developed after airway obstruction was alleviated.

Malnutrition in Critically III Infants and Children

The prevalences of acute and chronic protein-energy malnutrition (PEM) and deficiencies in stores of fat and somatic protein have not been previously examined in a pediatric intensive care unit. One hundred eight nutritional assessments were performed using anthropometric techniques on infants and children in a multidisciplinary intensive care unit. Overall, the prevalence of acute PEM was 19% and chronic PEM was 18%. The prevalence of fat store depletion was 14% and somatic protein store depletion was 21%. In general, children <2 years had poorer nutritional status compared to children ≥2 years. There was not a statistically significant difference between medical and surgical patients. It is concluded that PEM and deficiencies in the macronutrient stores of fat and somatic protein are common in critically ill infants and children.

Early nutritional depletion in critically ill children.

&NA; Nutritional status was evaluated in 50 medical admissions to a pediatric ICU. All patients were evaluated within 48 h of admission; none had chronic organ failure or malignancies. Nutritional assessment included weight/50th percentile weight for length, length/50th percentile length for age, triceps skinfold thickness, and midarm muscle circumference. Acute protein‐energy malnutrition (PEM) occurred in 16% of all children. Chronic PEM also occurred in 16%. The nutrient stores of fat and somatic protein were deficient in 18 and 20% of all children. Acute PEM and deficient somatic protein stores were more frequent in children < 2 years ( p < 0.05). These findings indicate that malnutrition and nutrient store deficiencies are common early in the course of critical illnesses in children, especially in those < 2 years of age. However, the findings do not indicate if the severity of illness was the cause or effect of poor nutritional status.

Assessment of pediatric intensive care--application of the Therapeutic Intervention Scoring System.

There are few reports analyzing the results of intensive care for children. We evaluated quantitatively the amount of care required in our multidisciplinary pediatric ICU using the Therapeutic Intervention Scoring System (TISS) and assessed qualitatively the severity of illness using the Clinical Classification System (CCS). Over a 6-month period, there were 323 patients (99 CCS Class II, 83 Class III, 141 Class IV) whose overall mortality at 1-month follow-up was 10% (Class II, 0%; Class III 2%; Class IV, 23%). A strong association was obtained between CCS and TISS admission scores (Class II-TISS, 11 +/- 0.6; Class III-TISS, 20 +/- 0.8; Class IV-TISS, 38 +/- 1.0). Class IV patients had a highly significant difference between survivors (S) and nonsurvivors (NS) for admission TISS (S = 36, NS = 47, p less than 0.001) and highest TISS (S = 38, NS = 54, p less than 0.001), as well as slopes of the regression of TISS points versus days of care (S = -4.2 vs. NS = +2.3). The mortality of our Class IV patients was lower than a comparable adult population with similar TISS scores; however, the TISS regression slopes for Class IV patients were similar. We conclude that CCS and TISS are both useful for describing the pediatric intensive care patient population. TISS is particularly helpful in assessing the amount of care received as well as providing a means of evaluating severity of illness.

Evaluation of pediatric intensive care.

A total of 294 Clinical Classification System (CCS) Classes III and IV patients in a pediatric ICU (PICU) were evaluated in terms of severity of illness and quantity of care. The group was comprised of patients from 3 services: medicine, cardiovascular surgery, and other surgery. Severity of illness was measured by the Physiologic Stability Index (PSI) and quantity of care was measured by the Therapeutic Intervention Scoring System (TISS). Comparisons were made between survivors and nonsurvivors and among the 3 services. Nonsurvivors had significantly higher (p < .01) PSI and TISS scores than survivors. Medical patients had the highest PSI scores while cardiovascular surgery patients had the highest TISS scores. Analysis of 7-day regression slopes for all survivor groups and medicine and other surgery nonsurvivor groups demonstrated slopes consistent with the expected clinical course. Cardiovascular surgery nonsurvivor slopes were unique and demonstrated increasing stability with stable amounts of care. The PSI/TISS ratio was used to relate levels of physiologic instability to the amount of therapy. Medical patients had the highest ratios and cardiovascular surgery patients had the lowest ratios. Comparisons of survivors and nonsurvivors for the PSI/TISS ratios and regression slopes demonstrated differences that were not evident through comparison of PSI and TISS scores alone.

Immune dysfunction in children after corrective surgery for congenital heart disease

ObjectiveTo study the effect of open- and closed-heart surgery on the immune status of infants and children. DesignProspective study. Data collected before anesthesia and surgery and 2 and 24 hrs after surgery. SettingOperating room and pediatric ICU in a childrens hospital. PatientsChildren undergoing surgery for correction of congenital heart disease (age 3 months to 12 yrs). A total of 31 patients were studied (open-heart surgery, n = 25; closed-heart surgery, n = 6). Measurements and Main ResultsIncreased neutrophil counts and lymphopenia were observed after both open- and closed-heart surgery. Serum levels of the complement components C3 and C4 were depressed after open-heart surgery, but not after closed procedures. The percentage of T3+ and T4+ lymphocytes, proliferative responses of the lymphocytes and serum immunoglobulin (Ig)G and IgM were decreased from preoperative levels after open-heart surgery. The percentage of T8+ lymphocytes and serum IgA levels did not change. Intraoperative variables and postoperative severity of illness (Pediatric Risk of Mortality score) did not correlate with immune suppression. ConclusionsThe immune system is affected after pediatric cardiac surgery, particularly after open-heart surgery. (Crit Care Med 1991; 19:874)

Pneumothorax and pneumomediastinum during pediatric mechanical ventilation.

The incidence of pulmonary barotrauma during mechanical ventilation in children beyond the neonatal age group was studied in two groups of patients. In the first group, 179 cases of pediatric mechanical ventilation for over 12 hours were retrospectively analyzed for the occurrence of pneumothorax and pneumomediastrinum. Eleven percent (6 of 57) of young infants (0--6 months) without hyaline membrane disease and 3% (4 of 122) of older infants and children (over 6 months) developed these complications. Pulmonary barotrauma in young infants occurred only after cardiothoracic surgery and involved the same site as the intraoperative repair in all cases. Pulmonary barotrauma in older infants and children occurred in patients with severe respiratory disease requiring high peak airway pressures, PEEP, and respiratory rates. In the second group, the incidence of pulmonary barotrauma during ventilation with PEEP greater than or equal to 15 cm H2O was analyzed in 14 patients including 4 patients from the previous group. Overall, 64% (9 of 14) of this group developed pulmonary barotrauma and 43% (6 of 14) developed pneumothorax. Of 9 patients receiving PEEP greater than or equal to 15 cm H2O for longer than 24 hours, 6 developed pulmonary barotrauma after the first 24 hours. The incidence of pneumothorax and pneumomediastinum in ventilated infants without hyaline membrane disease and children is comparable to adult series.

Prehospital care of critically ill children

Care of the critically ill child before he enters the environment where he can receive definitive care is still a neglected area. Largely, this is because the magnitude of this problem was not perceived. Now that EMS systems are maturing, it is imperative that attention be paid to the needs of the child. In the 1980s, an appropriate legacy of the International Year of the Child would be the development of optimal EMS care for children.

Prospective evaluation of a nonradiographic device for determination of endotracheal tube position in children.

A new noninvasive, nonradiographic endotracheal tube (ETT) position detection system (ETT-PDS) for guidance of ETT positioning was evaluated in pediatric ICU patients. The system includes an ETT with a metallic element embedded at a defined distance from the ETT tip, and a portable locator instrument which detects transcutaneously the position of the metallic element. The contribution of ETT-PDS to accuracy of ETT positioning after intubation and before chest radiographs was evaluated in 92 critically ill children. The ETT malposition rates observed on the postintubation chest radiographs were 39.1% after positioning guided by clinical assessment alone, and 19.6% after positioning guided by clinical assessment plus the ETT-PDS (p less than 0.5). This reduction in malnutrition rate could not be demonstrated when the ETT-PDS was used to guide routine ETT positioning performed before morning chest radiographs.