Acquired carnitine abnormalities in critically ill children

In order to characterize the role of carnitine during metabolic stress, we prospectively determined carnitine profiles in plasma and urine on admission, days 2, 5, 10 and 15, among 28 critically ill children free of any known conditions associated with secondary carnitine deficiency. More than 25% of plasma and 50% of urinary carnitine measurements were abnormal; 96% (27/28) of patients displayed on at least one occasion an abnormal [< -2 SD or > +2 SD] carnitine value in plasma. Three children had extremely low [< 10 micromol/l] free carnitine (FC) levels in plasma. Plasma esterified and FC levels on admission were not related to the risk of mortality [PRISM score], to muscle lysis [CK values], and to the caloric intake. Levels of FC and esterified carnitine in plasma were unrelated to those measured in urine. Conclusion: Abnormal plasma and urine carnitine measurements are frequently found in critically ill children; the biological significance of these perturbations remains unclear. Caution must be exercised before concluding that an abnormal carnitine value is indicative of an underlying hereditary metabolic disorder in this population.     

Ionized magnesium concentrations in critically ill children

OBJECTIVE: To test the hypothesis that many critically ill children exhibit ionized hypomagnesemia despite having normal total magnesium (TMg) concentrations. DESIGN: A prospective, observational study with convenience sampling. SETTING: Pediatric and cardiovascular intensive care units of a large children's hospital. PATIENTS: Patients aged 1 day to 21 yrs admitted from January 1 to October 31, 1996. Patients with chronic renal failure or weight <3 kg were excluded. A group of healthy children involved in a school-based nutritional assessment study were also studied. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Sixty-seven patients (5.4+/-5.7 [SD] yrs) and 24 healthy children (10.84+/-0.93 yrs, p< .001) were studied. Plasma was assayed for ionized magnesium (IMg) using a blood analyzer. Forty (59%)/67 critically ill subjects had IMg concentrations <0.40 mmol/L, the lowest published normal value and the lowest value observed in our group of healthy children. Of these, 24 (60%)/40 had normal TMg concentrations. IMg was significantly (p=.00) lower in critically ill subjects than in the group of healthy children (0.37+/-0.10 mmol/L vs. 0.46+/-0.03 mmol/L). IMg did not correlate strongly with ionized calcium (r2=0.49), albumin (r2=0.09), or pH (r2=0.18). CONCLUSION: Many critically ill children exhibit ionized hypomagnesemia with normal TMg concentrations. These children would not be recognized as magnesium-deficient based on routine TMg testing. Critically ill children exhibited significantly lower concentrations of IMg than a group of healthy children.     

Femoral vascular catheterization in critically ill infants and children

The success rate and complications from femoral arterial and venous catheterization in infants and children in a university affiliate pediatric intensive care unit were determined prospectively over a 2-year period. We also performed a meta-analysis from published literature to determine the combined estimates of noninfectious and infectious complications (with 95% confidence limits) using the inverse variance-weighted method. Success rates were 94.5% and 94.4% for femoral arterial (n=110) and venous (n=89) catheterizations, respectively, and were related to operator expertise, age, and hemodynamic status. Median age was 2.4 years and 1.1 year for arterial and venous catheterizations, respectively. Immediate complications were hematoma (10.9% arterial, 16.8% venous) and minor bleeding (13.6% arterial, 13.5% venous). Decreased pulses occurred with 7.7% of arterial catheterizations, and lower limb swelling occurred in 9.5% of venous catheterizations. Vascular complications occurred only in infants and resolved within 7-14 days. Catheter-related infections occurred in 1.9% of arterial and 3.6% of venous catheterizations. The mean duration of catheterization was 5.3 days and 6.3 days with femoral arterial and venous catheterizations, respectively. Meta-analysis of published studies shows that the estimates for noninfectious complications were 5.0%, 10.1%, 1.1%, and 1.8% for femoral arterial, femoral venous, axillary arterial, and nonfemoral venous catheters, respectively. The estimates for catheter-related infection were 2.5%, 3.7%, and 3.0% for femoral arterial, femoral venous, and nonfemoral venous catheters, respectively. The meta-analytic estimates for complication rates from published literature are not significantly different from the rates observed in our study. Femoral arterial and venous catheterization in infants and children are safe with an expected high success rate and acceptably low complication rates.     

Anthropometric nutritional assessment of critically ill hospitalized children

In a prospective study, the nutritional status was evaluated in 46 consecutive admissions to a Pediatric Intensive Care Unit, using anthropometric parameters. About 65% of the patients presented malnutrition on admission, with predominance of the chronic form. The mortality rate was greater in the malnourished (20 versus 12.5%) and chronic malnutrition was associated with a higher incidence of infection (42%). There was a fall in channel of percentile for weight-for-height in 36% of the patients evaluated at the final follow up. These results suggest that a significant number of patients are at nutritional risk at the time of hospital admission, and there is an association between nutritional status and hospital course. The anthropometric nutritional evaluation is a simple an reproducible method, and a valuable parameter for an objective nutritional assessment of the critically ill child. Therefore, it should be performed on admission and follow up of hospitalized children.     

Low-dose theophylline increases urine output in diuretic-dependent critically ill children

BACKGROUND: The pathogenesis of unstable angina involves the presence of intracoronary thrombus which may have potential bearing on the therapeutic efficacy of intracoronary stenting to reduce acute complications and restenosis rate. METHODS: In order to evaluate in-hospital and long-term outcome of coronary stenting in patients with unstable angina, we retrospectively examined our experience in 311 consecutive patients. Braunwald class III angina (B or C) was present in 35% of the cases. Three hundred seventy one stents were implanted in 315 lesions, most of them (62.4%) with complex morphology. Angiography identified an intraluminal thrombus in 22 target sites. Stent indication was elective in 146 cases (46.9%), for suboptimal results in 149 (47.9%) and for bail-out in 16 (5%). RESULTS: Procedural success was obtained in 96.3% of the study population. Major complications occurred in 12 (3.7%) patients: myocardial infarction in 6 (1.9%) cases, emergency bypass surgery in 3 (0.9%) and death in 3 (0.9%), none of them related to acute stent thrombosis. Vascular complications occurred in 5 patients (1.6%). The mean hospital stay after stenting was 2.8 +/- 1.6 days. Subacute stent thrombosis occurred in one patient and led to a Q-wave anterior myocardial infarction. Follow-up (9 +/- 5 months) status was ascertained in 216 patients and revealed an overall clinical success rate of 87.3%. Restenosis occurred in 23.5% of 157 patients who underwent angiographic follow-up. Late events included 3 non-fatal myocardial infarction, 6 new PTCA, 3 elective bypass surgery and 1 cardiac death. CONCLUSIONS: Intracoronary stenting appears safe and effective in patients with unstable angina, despite the presence of a thrombogenic milieu. Optimal immediate angiographic results, related to the mechanical properties of stents, together with a vigorous antithrombotic regimen, contributes to the favorable outcomes in this adverse setting.     

Reversing oliguria in critically ill patients

Oliguria is a common occurrence in the ICU setting. In patients with preserved renal function, fluid challenges or low doses of diuretics are generally successful. In patients with oliguric renal failure, it is still essential to ensure adequate intravascular fluid volume, especially in critically ill patients. Loop diuretics remain the mainstay of treatment. When diuretic resistance is encountered, physicians should consider further optimization of hemodynamics, alternative loop diuretics, and combined drug therapy. In some cases, continuous renal replacement therapy can be very effective. Yet, while these interventions can help reduce the morbidity of severe volume overload, they have not been shown to improve mortality rates.     

Usefulness of gastric intramucosal pH for monitoring hemodynamic complications in critically ill children

OBJECTIVE: To assess the efficacy of gastric intramucosal pH for the evaluation of tissue perfusion and prediction of hemodynamic complications in critically ill children. DESIGN: Open prospective study without controls. SETTING: Pediatric intensive care unit (ICU) of a tertiary care university pediatric hospital. PATIENTS: Thirty critically ill children (16 boys and 14 girls), age range: 3 months-12 years. MEASUREMENTS AND RESULTS: A tonometry catheter was placed in the stomach of all patients on admission to the pediatric ICU. Simultaneous tonometry and arterial gas measurements were made on admittance and every 6-12 h throughout the study; a total of 202 measurements were made. The catheter was removed after extubation and/or when the patient was hemodynamically stable. Intramucosal pH was calculated using the Henderson-Hasselbalch equation based on the pCO2 of the tonometer and arterial bicarbonate. Intramucosal pH values between 7.30 and 7.45 were considered to be normal. The patient's condition was analyzed using the Pediatric Risk Mortality Score (PRISM). The relations between intramucosal pH and the presence of major hemodynamic complications (cardiopulmonary arrest, shock), minor hemodynamic complications (hypotension, hypovolemia or arrhythmia), death, PRISM score and the duration of the stay in the pediatric ICU were analyzed. Intramucosal pH on admission was 7.48 +/- 0.15 on average (range 7.04-7.68). Five patients (16%) had an intramucosal pH lower than 7.30 on admission; these patients did not have a higher incidence of hemodynamic complications. The 16 patients (53%) who had an intramucosal pH of less than 7.30 at some time during the course of their disease had more hemodynamic complications than the patients who did not have pH lower than 7.30 (p < 0.0001). Every case of cardiopulmonary arrest and shock was related to intramucosal pH of less than 7.30. Patients with major complications (cardiopulmonary arrest and shock) had lower intramucosal pHs than those with minor hemodynamic complications (p = 0.03); similarly, they had low intramucosal pH readings more often than those with minor complications (p = 0.0032). Intramucosal pH values less than 7.30 had a sensitivity of 90% and a specificity of 98% as a predictor of hemodynamic complications. There was no relation between intramucosal pH lower than 7.30 and either PRISM or the duration of the stay in the pediatric ICU. Patients with intramucosal pH less than 7.20 had a higher PRISM than the patients who did not have pH lower than 7.20 (p < 0.05). A patient who died during the study due to cardiopulmonary arrest had prior intramucosal pH measurements of 7.23 and 7.10, and three patients died of late complications after the end of the study. Hemodynamic complications were not detected with arterial pH. Gap pH (arterial pH-intramucosal pH) and standard pH measurements yielded the same results as gastric intramucosal pH. CONCLUSION: Intramucosal pH could provide a useful early indication of hemodynamic complications in critically ill children.     

The care of critically ill children in adult ICUs: the way forward

It is unlikely that in the short or medium term the PIC service can be restructured to such an extent that no children would need to be admitted to an adult ICU. Until this is the case the contribution of adult ICUs to the provision of PIC should be acknowledged and formally recognised as part of the service. Furthermore, there should be active support for these units from major/regional centres. There are clearly only a few adult ICUs which admit significant numbers of children. However, a more detailed analysis of adult ICUs is required to identify units which have available the full range of facilities, support services and appropriate staff to care for critically ill children. It is likely that only a few adult ICUs could meet the recommendations above, and it is in these units where efforts need to be concentrated. It is imperative that any nationally agreed standards or guidelines for PIC must apply equally to both adult ICU and paediatric ICU.     

Endocrine disorders and osteoporosis

INTRODUCTION: The use of computers has yielded new diagnostic techniques (US, CT, MRI and computed radiography) that can successfully replace conventional film in data acquisition, image display and image interpretation. Thanks to the Picture Archiving and Communication System (PACS), we can now manage the whole of diagnostic data because the images are acquired, coupled to the patient data stored in the Radiology Information System (RIS), sent to display workstations and finally sent to the archives. PURPOSE: To present the configuration and functions of a new PACS used in radiology and nuclear medicine departments and to evaluate its efficacy one year after implementation. Particular attention is paid to the objective difficulties radiologists found in approaching the system. RESULTS: Secretarial work reduction and a more rational archiving organization are two of the advantages of automation. PACS permits rapid image display, retrieval nd archiving for both scientific and statistical purposes; however, its correct use is hindered by a series of problems, namely: a) reluctance to use PACS by many members of the medical staff, due to the complexity of its procedures; b) lack of panoramicity on the display monitor in multi-image examinations and c) underuse of viewing workstations in several wards of our institution due to lack of know-how. CONCLUSIONS: Although the use of PACS has improved the workload management in our departments, the system still needs to be customized to the radiologist to optimize its use. Workstations must be user-friendly, with simultaneous display of more images. On the other hand, radiologists need to expand their knowledge of new techniques, thus modifying obsolete working procedures.     

Nutritional support of critically ill patients

Severe depletion of body protein stores can result from prolonged starvation or from hormonal and cytokine-mediated effects during critical illness. Recent advances in the understanding of cytokine actions have substantially refined the interpretation of the nutritional assessment of critically ill patients. In addition, the design of nutritional programs for hospitalized patients has changed considerably during the past decade. Although nutritional support of critically ill patients will not lead to positive nitrogen balance, nutrition can increase protein synthesis, enhance immune function, and beneficially modify the body's response to an illness.