Andrés Concha

Cystatin C and beta2-microglobulin: markers of glomerular filtration in critically ill children

IntroductionParameters allowing regular evaluation of renal function in a paediatric intensive care unit (PICU) are not optimal. The aim of the present study was to analyse the utility of serum cystatin C and beta2-microglobulin (B2M) in detecting decreased glomerular filtration rate in critically ill children.MethodsThis was a prospective, observational study set in an eight-bed PICU. Twenty-five children were included. The inverses of serum creatinine, cystatin C, and B2M were correlated with creatinine clearance (CrC) using a 24-hour urine sample and CrC estimation by Schwartz formula (Schwartz). The diagnostic value of serum creatinine, cystatin C, and B2M to identify a glomerular filtration rate under 80 ml/minute per 1.73 m2 was evaluated using receiver operating characteristic (ROC) curve analysis.ResultsMean age was 2.9 years (range, 0.1 to 13.9 years). CrC was less than 80 ml/minute per 1.73 m2 in 14 children, and Schwartz was less than 80 ml/minute per 1.73 m2 in 9 children. Correlations between inverse of B2M and CrC (r = 0.477) and between inverse of B2M and Schwartz (r = 0.697) were better than correlations between inverse of cystatin C and CrC (r = 0.390) or Schwartz (r = 0.586) and better than correlations between inverse of creatinine and CrC (r = 0.104) or Schwartz (r = 0.442). The ability of serum cystatin C and B2M to identify a CrC rate and a Schwartz CrC rate under 80 ml/minute per 1.73 m2 was better than that of creatinine (areas under the ROC curve: 0.851 and 0.792 for cystatin C, 0.802 and 0.799 for B2M, and 0.633 and 0.625 for creatinine).ConclusionSerum cystatin C and B2M were confirmed as easy and useful markers, better than serum creatinine, to detect acute kidney injury in critically ill children.

Non-invasive ventilation in pediatric status asthmaticus: A prospective observational study†‡

Non‐invasive ventilation (NIV) has been shown to be effective in different causes of respiratory failure in both adult and pediatric patients. However, its role in status asthmaticus (SA) remains unclear. We designed a prospective study to assess the feasibility of NIV in children with SA.

Intrathecal vincristine: fatal myeloencephalopathy despite cerebrospinal fluid perfusion.

Background: Vincristine, an antineoplastic agent, must never be injected intrathecally because of its devastating neurotoxic effects, which are usually fatal. We report a case of fatal myeloencephalopathy secondary to inadvertent intrathecal administration of vincristine. Case Report: Intrathecal vincristine was inadvertently injected into a twelve-year-old girl with acute lymphocytic leukemia. The error was immediately recognized and treated with cerebrospinal fluid drainage and cerebrospinal fluid exchange. Clinical evolution during the 83 days until death is described. Multiple samples of cerebrospinal fluid were assayed for vincristine sulfate. Neuropathological post-mortem changes in the brain and spinal cord are reported. Conclusion: We compare our case with other previously reported cases in which patient survival was achieved with the same treatment. We summarize preventive measures to avoid such unfortunate occurrences.

Helmet-delivered continuous positive airway pressure with heliox in respiratory syncytial virus bronchiolitis.

Aim:  The objective of this study was to check the feasibility and efficacy of helmet‐delivered heliox‐continuous positive airway pressure (CPAP) in infants with bronchiolitis.

Non invasive ventilation after extubation in paediatric patients: a preliminary study

BackgroundNon-invasive ventilation (NIV) may be useful after extubation in children. Our objective was to determine postextubation NIV characteristics and to identify risk factors of postextubation NIV failure.MethodsA prospective observational study was conducted in an 8-bed pediatric intensive care unit (PICU). Following PICU protocol, NIV was applied to patients who had been mechanically ventilated for over 12 hours considered at high-risk of extubation failure -elective NIV (eNIV), immediately after extubation- or those who developed respiratory failure within 48 hours after extubation -rescue NIV (rNIV)-. Patients were categorized in subgroups according to their main underlying conditions. NIV was deemed successful when reintubation was avoided. Logistic regression analysis was performed in order to identify predictors of NIV failure.ResultsThere were 41 episodes (rNIV in 20 episodes). Success rate was 50% in rNIV and 81% in eNIV (p = 0.037). We found significant differences in univariate analysis between success and failure groups in respiratory rate (RR) decrease at 6 hours, FiO2 at 1 hour and PO2/FiO2 ratio at 6 hours. Neurologic condition was found to be associated with NIV failure. Multiple logistic regression analysis identified no variable as independent NIV outcome predictor.ConclusionsOur data suggest that postextubation NIV seems to be useful in avoiding reintubation in high-risk children when applied immediately after extubation. NIV was more likely to fail when ARF has already developed (rNIV), when RR at 6 hours did not decrease and if oxygen requirements increased. Neurologic patients seem to be at higher risk of reintubation despite NIV use.

Acute-phase reactants after paediatric cardiac arrest. Procalcitonin as marker of immediate outcome

ObjectiveProcalcitonin (PCT) and C reactive protein (CRP) have been used as infection parameters. PCT increase correlates with the infections severity, course, and mortality. Post-cardiocirculatory arrest syndrome may be related to an early systemic inflammatory response, and may possibly be associated with an endotoxin tolerance. Our objective was to report the time profile of PCT and CRP levels after paediatric cardiac arrest and to assess if they could be use as markers of immediate survival.Materials and methodsA retrospective observational study set in an eight-bed PICU of a university hospital was performed during a period of two years. Eleven children younger than 14 years were admitted in the PICU after a cardiac arrest. PCT and CRP plasma concentrations were measured within the first 12 and 24 hours of admission.ResultsIn survivors, PCT values increased 12 hours after cardiac arrest without further increase between 12 and 24 hours. In non survivors, PCT values increased 12 hours after cardiac arrest with further increase between 12 and 24 hours. Median PCT values (range) at 24 hours after cardiac arrest were 22.7 ng/mL (0.2 – 41.0) in survivors vs. 205.5 ng/mL (116.6 – 600.0) in non survivors (p < 0.05). CRP levels were elevated in all patients, survivors and non-survivors, at 12 and 24 hours without differences between both groups.ConclusionMeasurement of PCT during the first 24 hours after paediatric cardiac arrest could serve as marker of mortality.

Correlation of oxygen saturation as measured by pulse oximetry/fraction of inspired oxygen ratio with Pao2/fraction of inspired oxygen ratio in a heterogeneous sample of critically ill children.

PURPOSE Oxygen saturation as measured by pulse oximetry (Spo2)/fraction of inspired oxygen (Fio2) (SF) ratio has demonstrated to be an adequate marker for lung disease severity in children under mechanical ventilation. We sought to validate the utility of SF ratio in a population of critically ill children under mechanical ventilation, noninvasive ventilation support, and breathing spontaneously. MATERIALS AND METHODS A retrospective database study was conducted in a pediatric intensive care unit of a university hospital. Children with Spo2 less than or equal to 97% and an indwelling arterial catheter were included. Simultaneous blood gas and pulse oximetry were collected in a database. Derivation and validation data sets were generated, and a linear mixed modeling was used to derive predictive equations. Model performance and fit were evaluated using the validation data set. RESULTS Three thousand two hundred forty-eight blood gas and Spo2 values from 298 patients were included. 1/SF ratio had a strong linear association with 1/Pao2/Fio2 (PF) ratio in both derivation and validation data sets, given by the equation 1/SF = 0.00164 + 0.521/PF (derivation). Oxygen saturation as measured by pulse oximetry/Fio2 values for PF criteria of 100, 200, and 300 were 146 (95% confidence interval [CI], 142-150), 236 (95% CI, 228-244), and 296 (95% CI, 285-308). Areas under receiver operating characteristic curves for diagnosis of PF ratio less than 100, 200, and 300 with the SF ratio were 0.978, 0.952, and 0.951, respectively, in the validation data set. CONCLUSIONS Oxygen saturation as measured by pulse oximetry/Fio2 ratio is an adequate noninvasive surrogate marker for PF ratio. Oxygen saturation as measured by pulse oximetry/Fio2 ratio may be an ideal noninvasive marker for patients with acute hypoxemic respiratory failure.

Geochemistry and Geochronology of the Guajira Eclogites, northern Colombia: evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc

The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive islandarc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. 40Ar-39Ar ages of 79.2±1.1Ma and 82.2±2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian

Acute hydrocephalus in carbon monoxide poisoning.

Carbon monoxide (CO) intoxication continues to be one of the most common causes of morbidity due to poisoning. The toxicity is caused by a combination of tissue hypoxia and direct CO‐mediated damage at the cellular level (1). Neurologic consequences of CO poisoning have been most often reported. Loss of consciousness, intermittent convulsions and respiratory failure may appear when carboxyhaemoglobin (COHb) concentrations of 60–80% are reached (2). However, it is important to recognize that COHb levels do not correlate with the severity of symptoms in a substantial number of cases (1). Pathological findings include necrosis and degeneration of the globus pallidus (3) and destructive lesions of the cerebral white matter (4). Computer tomography (CT) commonly shows bilateral low‐density areas in the globus pallidus (2–6) and low‐density lesions in the white matter (4). Magnetic resonance imaging (MRI) is more sensitive in detecting these lesions which appear as hyperintense signals in basal ganglia on T2 weighted images (4, 5). Neuropathological and radiological findings are well correlated (3).

Multiorgan failure due to hemophagocytic syndrome: A case report

IntroductionHemophagocytic syndrome (HFS) is a potentially lethal disorder due to an uncontrolled immune response to a triggering agent. Our objective is to raise the importance of HFS early diagnosis by presenting a representative case.Case presentationA sixteen-year-old girl with Still disease diagnosis developed a progressive multiorgan failure including acute respiratory distress (ARDS), anemia and thrombopenia, elevated liver enzymes, renal failure, coagulopathy with hypofibrinogenemia, and acute phase reactants elevation despite broad-spectrum antibiotics. A bone marrow puncture-biopsy was performed, and hemophagocytosis was found. Prolonged fever, splenomegaly, bicytopenia, hypofibrinogenemia, hyperferritinemia and hypertriglyceridemia confirmed HFS diagnosis. She received intensive care support therapy including mechanical ventilation and specific therapy according to HLH 2004 protocol, with a very good response.ConclusionOur case shows complexity of HFS diagnosis, due to septic shock-like manifestations. Early diagnosis is essential to start appropriate treatment achieving a better outcome.