[Severe acute kidney injury in critically ill children: Epidemiology and prognostic factors]

INTRODUCTION

Acute kidney injury (AKI) is a severe complication in critically ill children. The aim of the study was to describe the characteristics of AKI, as well as to analyse the prognostic factors for mortality and renal replacement therapy (RRT) in children admitted to Paediatric Intensive Care Units (PICUs) in Spain.

PATIENTS AND METHODS

Prospective observational multicentre study including children from 7 days to 16 years old who were admitted to a PICU. A univariate and multivariate logistic regression analysis of the risk factors for mortality and renal replacement therapy at PICU discharge were performed.

RESULTS

A total of 139 cases of AKI were analysed. RRT was necessary in 60.1% of cases. Mortality rate was 32.6%. At PICU discharge RRT was necessary in 15% of survivors. Thrombopenia and low creatinine clearance values were prognostic markers of RRT at PICU discharge. High values of platelets, serum creatinine and weight were associated with higher survival.

CONCLUSIONS

Critically ill children with AKI had a high mortality and morbidity rate. Platelet values and creatinine clearance are markers of RRT at PICU discharge, whereas number of platelets, serum creatinine and weight were associated with mortality.

[Prediction of PaO₂/FiO₂ ratio from SpO₂/FiO₂ ratio adjusted by transcutaneous CO₂ measurement in critically ill children]

OBJECTIVE

To evaluate if the inclusion of the transcutaneous CO(2) tension measurement (PtcCO(2)) can improve partial pressure of oxygen/ fraction of inspired oxygen ratio [PaO(2)/FiO(2) (P/F)] prediction from pulse oximetry saturation/FiO(2) ratio [SpO(2)/FiO(2) (S/F)].

METHODS

Retrospective analysis of blood gas data from critically ill children. PaO(2), SpO(2), FiO(2) and PtcCO(2) from 40 samples in 8 patients were analysed. A multiple linear regression model was performed to predict P/F ratio from S/F ratio and PtcCO(2). Using the equation obtained, S/F ratio values were calculated for P/F ratios of 200 and 300 and different levels of PtcCO2. Receiver Operator Characteristic (ROC) curves were made to analyse the diagnostic values of P/F ratio (200 and 300).

RESULTS

The linear regression model was: P/F=37.277+(1.072×S/F) - (1.567×PtcCO2); P<.0001; R(2)=0.469. Using the equation, for a PtcCO(2) value of 40 mmHg, P/F ratios of 200 and 300 corresponded to S/F ratios of 295.1 and 426.5, respectively. Computed P/F ratio less than 256.7 had 84.6% sensitivity and 85.2% specificity for the diagnosis of P/F ratio less than 200. Computed P/F ratio less than 297.6 had 89.7% sensitivity and 82% specificity for the diagnosis of P/F ratio less than 300.

CONCLUSION

PtcCO(2) has a significant influence on the prediction of P/F ratio from S/F ratio. Prospective studies with more patients are needed to validate these results.

[Prognostic indexes of mortality in pediatric intensive care units]

OBJECTIVE

To assess the validity of the Pediatric Risk of Mortality score (PRISM), the Pediatric Index of Mortality (PIM) and the PIM 2 in two Spanish pediatric intensive care units.

PATIENTS AND METHODS

We prospectively studied 241 critically ill children consecutively admitted over a 6-month period. The overall performance of the scoring systems was assessed by the Standardized Mortality Ratio (SMR), comparing observed deaths with expected deaths by each index. Discrimination (the ability of the model to distinguish between patients who live and those who die) was quantified by calculating the area under the receiver operating characteristic (ROC) curve. Calibration (the accuracy of mortality risk predictions) was calculated with the Hosmer-Lemeshow goodness-of-fit test, in which statistical calibration is evidenced by p > 0.05.

RESULTS

The mortality rate was 4.1 %. PRISM overestimated mortality (SMR = 0.44). Discrimination was better for PRISM and PIM 2 than for PIM (areas under ROC curves: 0.883, 0.871, and 0.800 respectively), with no significant differences. Finally, calibration was acceptable for PIM 2 (x2 (8) = 4.8730, p 0.8461) and for PIM (x2 (8) = 8.0876, p 0.5174), but no statistical calibration was found for PRISM (x2 (8) = 15.0281, p 0.0133).

CONCLUSIONS

PIM and PIM 2 showed better discrimination and calibration than PRISM in a heterogeneous group of children in Spanish critical care units. However, these results should be confirmed in a larger study.

Asistencia al paciente politraumatizado. Realidad actual desde la perspectiva de las unidades de cuidados intensivos

OBJECTIVE

To study the epidemiology and management of pediatric trauma patients as well as the organizational, human and technical resources dedicated to these children from the perspective of the pediatric intensive care unit (PICU).

MATERIAL AND METHODS

A standardized data collection form was sent to 43 PICUs in Spain. Items inquired about the existence of training courses, trauma clinical practice guidelines and trauma registers, and which physician was in charge of trauma patients. Data on casuistics, the age of trauma patients, and the availability of human and technical resources, were also recorded.

RESULTS

Twenty-four PICUs completed the questionnaire. The PICU physician was responsible for trauma patient care in 66% of the hospitals. No training courses were available in 59% of the hospitals. No trauma register was available in 62% of the hospitals. Trauma patients represented 11% of PICU admissions, and most patients were aged up to 14 years old. An anesthetist was always at the hospital in 100% of the hospitals. A radiologist and traumatologist were always at the hospital in 91%, a neurosurgeon in 66% and a pediatric surgeon in 50%. The remaining surgical and medical specialties were on call. Continuous intracranial pressure monitoring was available in 87% of the PICUs, jugular venous saturation monitoring in 54% and continuous electroencephalogram and transcranial Doppler ultrasound in 50%. Computed tomography and ultrasound were available at all times in all hospitals. Magnetic nuclear resonance and echocardiography were available at all times in 44% of the hospitals, and arteriography in 42%.

CONCLUSION

In Spain, the organization of pediatric trauma management is based on pediatric teams under the supervision of a PICU physician. Some hospitals show a lack of technical and human resources. Therefore, the minimum criteria required to consider a hospital as a pediatric trauma center should be established. Trauma training courses are required.

Ética y reanimación cardiopulmonar pediátrica

Cardiopulmonary resuscitation (CPR) is a medical activity that involves major ethical issues. As in other areas of clinical ethics, CPR decisions must be based on the principles of autonomy, beneficence, nonmaleficence, and justice. The decision-making process is more difficult in emergency situations, and when the patient is a minor, the parents and the child's best interests must be taken into consideration. There are specific situations in which starting CPR is clearly indicated and others in which ceasing resuscitation maneuvers is justified. Do not attempt resuscitation orders must be respected by health staff. Other ethical issues involved in CPR include resuscitation of potential organ donors, learning CPR procedures, research in CPR, and the information given to the parents of children with cardiorespiratory arrest.

Reanimación cardiopulmonar avanzada en pediatría

Advanced life support (ALS) includes all the procedures and maneuvers used to restore spontaneous circulation and breathing, thus minimizing brain injury. The fundamental steps of ALS are airway control with adjuncts, ventilation with 100% oxygen, vascular access and fluid and drug administration, and monitoring to diagnose and treat arrhythmias. Airway control can be achieved by means of oropharyngeal airway, endotracheal intubation, and alternative methods (laryngeal mask and cricothyroidotomy). Vascular access can be achieved by the peripheral venous, intraosseous, central venous, and tracheal routes. The most frequent rhythms found in children with cardiorespiratory arrest are nonshockable (asystole, severe bradycardia, pulseless electrical activity, and complete atrioventricular block). In these cases, adrenaline continues to be the essential drug. Currently, low adrenaline doses (0.01 mg/kg IV and 0.1 mg/kg intratracheal administration) are recommended throughout the resuscitation period. Amiodarone (5 mg/kg) is the drug of choice in cases of ventricular fibrillation refractory to electric shock. The treatment sequence for shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia) is one 4 J/kg electric shock, followed by cardiopulmonary resuscitation (chest compressions and ventilation) for 2 minutes with subsequent reassessment of the electrocardiographic rhythm. Adrenaline must be administered immediately before the third electric shock and subsequently every 3-5 minutes. Amiodarone must be administered immediately before the fourth shock.

[Noninvasive ventilation in a pediatric intensive care unit]

OBJECTIVE

To describe our experience of noninvasive positive-pressure ventilation (NIPPV).

PATIENTS AND METHODS

We performed a retrospective study of all patients who underwent NIPPV in our unit over an 18-month period. To assess the effectiveness of NIPPV, respiratory rate, heart rate, inspired oxygen, and arterial blood gases PaO2 and PaCO2 were evaluated before and 2 hours after initiating NIPPV.

RESULTS

Twenty-three patients with a mean age of 36.7 months underwent a total of 24 NIPPV trials. Indications for NIPPV were: hypoxemic acute respiratory failure (14 trials), hypercapnic acute respiratory failure (four trials), and postextubation respiratory failure (six trials). Conventional ventilators were used in 10 trials and specific noninvasive ventilators were used in 14. The main interfaces used were buconasal mask in patients older than 1 year, and pharyngeal prong in infants aged less than 1 year. In all groups, significant decreases in respiratory distress, defined as a reduction in tachypnea (45 +/- 16 breaths/min pre-treatment vs. 34 +/- 12 breaths/min post-treatment; p = 0.001), and tachycardia (148 +/- 27 beats/min pre-treatment vs. 122 +/- 22 beats/min (after or post) post-treatment; p < 0.001) were observed after initiation of NIPPV. The oxygenation index PaO2/FiO2 also improved (190 +/- 109 pre-treatment vs. 260 +/- 118 post-treatment; p = 0.010). Five patients (20.8 %) required intubation and conventional mechanical ventilation after NIPPV, of which three were aged less than 6 months.

CONCLUSIONS

NIPPV should be considered as a ventilatory support option in the treatment of acute respiratory failure in selected children.

[Acute renal failure in critically-ill children. A preliminary study]

OBJECTIVE

To analyze the characteristics of acute renal failure (ARF) in critically-ill children and develop a protocol for a multicenter study.

METHODS

A prospective, descriptive study was performed in four pediatric intensive care units (PICU) over 5 months. Epidemiological, clinical and laboratory data from children aged between 7 days and 16 years with ARF were analyzed. Premature neonates were excluded.

RESULTS

There were 16 episodes of ARF in 14 patients and 62.5 % were male (mean 6 SD age: 50 +/- 49 months). The incidence of ARF was 2.5 % of PICU patients. The most frequent primary diseases were nephro-urological (50 %) and heart disease (31 %). The main risk factors for ARF were hypovolemia (44 %) and hypotension (37 %). Six patients (37.5 %) developed ARF following surgery (cardiac surgery in four, kidney transplantation in one and urological surgery in one). Furosemide was used in 13 patients (as continuous perfusion in nine), inotropes in nine and renal replacement therapy in 12. Medical complications were found in 94 % and some organic dysfunction was found in 81 %. The length of stay in the PICU was 21 +/- 21 days. The probability of death according to the Pediatric Risk of Mortality was 14 +/- 8 %. Five patients died (36 % of the patients and 31.2 % of ARF episodes).

CONCLUSIONS

The incidence of ARF in critically-ill children is low but remains a cause of high mortality and prolonged stay in the PICU. Mortality was caused not by renal failure but by multiple organ failure.

[Importance of initial management in severe pediatric trauma]

INTRODUCTION

Trauma is the most frequent cause of mortality in childhood and adolescence and causes almost 25% of admissions in Pediatric Intensive Care Units (PICU). We have evaluated the initial assesment of the severely injured children admitted in our PICU (pre-hospital care).

MATERIAL AND METHODS

We reviewed the children younger than 16 years admitted in our PICU between January 1996 and December 2002. Prehospital caretakers, transportation after initial evaluation and therapeutic management were analized, using Pediatric Trauma Score (PTS) and Pediatric Risk of Mortality Score (PRISM) as predictors of injury severity and mortality, respectively.

RESULTS

We treated 152 traumatized children in this period, 106 males and 46 females, with a mean age of 7.5 +/- 4.3 years. 116 patients received inmediate medical care with a mean PTS significatively greater than non-medical group (12 children). Non-medical caretakers treated 8.1% of severe trauma (PTS<8). Specialized transporter was inadequated in 7.1% of severe traumatized children. Gastric and vesical tube and spinal inmobilization were accomplished in 50%, specially in children with low PTS and high PRISM. We found a great variability in fluid and drugs administration.

CONCLUSIONS

Although there has been a good evolution in treatment of pediatric trauma, in order to diminish morbidity and mortality it is necessary to identify and correct deficiencies in management, specially during the "golden hour", and train pre-hospital caretakers in pediatric trauma management.

[Ventilation in special situations. Mechanical ventilation during transportation of pediatric patients]

Most severe pediatric injuries occur far from regional centres specialized in the definitive care of the critically-ill child. Adequate initial stabilization and an appropriate transport system significantly decrease morbidity and mortality in these patients. In the last few years, technological developments have improved the quality of medical transportation. Mechanical ventilation is one of the elements that has been affected by these advances with portable ventilators and monitoring systems that are increasingly similar to those used in pediatric intensive care units. To prevent complications from developing during transportation, adequate preparation is required consisting of (i) prior stabilization of the patient, (ii) assessment of potential risks and specific needs, (iii) monitoring, (iv) transport preparation, and (v) assessment of vital signs and patient management. Portable ventilators are designed to be used for short periods under difficult conditions (temperature changes, altitude, rain, knocks, etc.). Consequently they should have specific common characteristics: portability, resistance, ease of handling, low electricity and gas consumption, and safety. They should also be easy to set up. Their programming is generally similar to that of conventional ventilators and should be based on the physiologic characteristics of the child according to age and underlying process.

Muerte encefálica y donación en población infantil

BACKGROUND

Brain death is the irreversible cessation of intracranial neurologic function and is considered as the person's death. The objective of this study was to describe the characteristics of pediatric donors in the Hospital Central de Asturias from October 1995 to October 2002.

METHODS

We performed a retrospective and descriptive study of the dead children who were potential donors in the pediatric intensive care unit (PICU).

RESULTS

Of 43 dead children, 15 (34.9 %) were diagnosed with brain death. In four patients (family refusal in one, sepsis in two and brain tumor in one) there was no donation. In all patients, the diagnosis of brain death was based on clinical examination and electroencephalogram. Doppler ultrasonography and technetium-99m hexamethylpropyleneamineoxamine (Tc-99-HMPAO) scanning was also performed in three and nine patients respectively. The mean age of the donors was 8.1 years (range: 13 months-15 years). The male/female ratio was 3/1. The cause of death was multiple trauma in six children, brain hemorrhage in three, cardiac arrhythmias in three, lightning strike in one, diabetic ketoacidosis in one, septic shock in one and hypovolemic shock in one. The median interval between admission and brain death was 1.4 days (range: 3 hours-12 days). The time of organ support between brain death and donation was 8.4 hours (range: 6-13 hours). The most frequent complications after brain death were central diabetes insipidus in 90.9 % of the patients, hyperglycemia in 54.5 % and hypokalemia in 45.4 %. During support 72.7 % of the patients required inotropic aid.

CONCLUSIONS

In our PICU more than one-third of the dead children suffered brain death, and most became donors. The most frequent cause of brain death was multiple trauma. Coordination with the transplant team and the training of medical staff are important to achieve a high percentage of donations.

[Estimation of creatinine clearance by the height/plasma creatinine formula in critically-ill children]

INTRODUCTION

Critically-ill children frequently show impaired renal function, necessitating adjustment of drug dosages. Our objectives were to study estimated creatinine clearance through the correlation between the height/plasma creatinine formula (CrClest) and measured creatinine clearance (CrClms) and to examine whether CrClest over- or underestimates CrClms by analyzing the influence of diagnosis, severity, and the practical consequences.

PATIENTS AND METHODS

Seventy-seven patients admitted to the pediatric intensive care unit were included. CrClms was calculated using serum creatinine and creatinine in urine collected over 24 hours. CrClest was estimated using serum creatinine, height, and a constant. The difference between CrClms and CrClest was expressed as a percentage: (CrClms CrClest) x 100/CrClms. Differences of greater than 15 % were considered poor estimates. ResultsThe mean percentage difference was 29.2 (standard error: 39.9). There were no differences among diagnoses in the distribution of significant bias, although the frequency of metabolic diagnoses was high. Incorrect evaluation of CrClest would result in a therapeutic error in 11.69 % of the cases, with overdosage in 10.39 %. The Pediatric Risk of Mortality (PRISM) score was higher (p < 0.05) in patients at risk for overdosage.

CONCLUSIONS

CrClest estimation using the height/plasma creatinine formula was not an accurate method in critically ill children. In 10.39 % of patients with more severe illness, the dosage of renally excreted drugs would be too high. The highest risk was found in patients with metabolic and neurological diagnoses.

Ventilación mecánica en el síndrome de dificultad respiratoria aguda/lesión pulmonar aguda

Acute respiratory distress syndrome (ARDS), which was first described by Ashbaugh in 1967, consists of acute hypoxemic respiratory failure (PaO2/FiO2< or =200) associated with bilateral infiltrates on the chest radiograph caused by noncardiac diffuse pulmonary edema. Although ARDS is of multiple etiology, pulmonary or extrapulmonary injury can produce systemic inflammatory response that perpetuates lung disturbances once the initial cause has been eliminated. Most patients with ARDS require mechanical ventilation. Currently, the old standard is conventional ventilation optimized to protect against ventilator-associated lung injury. Other mechanical ventilation strategies such as high-frequency oscillatory ventilation, which is also based on alveolar recruitment and adequate lung volume, can be useful alternatives. In this review, the level of evidence for other therapies, such as prone positioning, nitric oxide and prostacyclin inhalation, exogenous surfactant, and extracorporeal vital support techniques are also analyzed.

[Use of peripherally inserted multilumen catheters as an alternative to central venous access]

BACKGROUND

In the last decade alternatives to central venous lines in critically ill children have been developed. Multilumen catheters have classically been used through central venous access but there are no reports on their use as peripherally inserted central lines.

PATIENTS AND METHODS

We performed a retrospective study of patients admitted to the pediatric intensive care unit in the previous 3 years who underwent catheterization with peripherally inserted central venous lines. The catheters were four French, double-lumen and 30-cm long.

RESULTS

Twenty-two catheters were used in 22 children (mean age: 8.3 years; range 1.7-13.8). The catheters remained in place for a mean of 7.2 days. Ninety percent of the catheters were placed in antecubital veins. The catheters were used to administer antibiotics (59 %), other drugs (81 %), total parenteral nutrition (50 %) and blood (9 %). Central venous pressure monitoring was performed in eight patients. Complications were found in five patients (22 %): three cases of phlebitis, one catheter occlusion and one infection at the site of insertion. No significant differences were found in the complication rate between peripherally inserted catheters and 298 central venous catheters inserted in our unit in the same time period.

CONCLUSIONS

Peripherally inserted multilumen catheters may be an alternative in the management of critically-ill pediatric patients.

[Care of critically-ill children in Asturias (Spain): characteristics and effectiveness]

OBJECTIVE

To describe the work performed in the Pediatric Intensive Care Unit of the Hospital Central de Asturias (Spain) in its first 5 years and to assess the effectiveness of the care provided.

METHODS

A prospective study of the characteristics of critically-ill children admitted from 1996 to 2000 was performed. Effectiveness was defined as the ratio of observed to expected mortality, determined by pediatric risk of mortality (PRISM) score calculated 24 hours after admission.

RESULTS

The median age of critically-ill children was 38 months and the mean length of stay was 6.8 days. Forty percent of the patients were transferred from other hospitals in Asturias and Leon. The most frequent causes of admission were respiratory, neurological and infectious diseases, and trauma. Overall mortality was 4.3 %. Over the years the severity of the patients increased with a consequent rise in mean length of stay, use of central venous access and mechanical ventilation. Forty-two percent of deaths were expected. The effectiveness of care was high among high-risk patients, among those with respiratory and metabolic diseases and in the postoperative period but was low among patients with hematologic and gastrointestinal diseases. Effectiveness increased over time.

CONCLUSIONS

Studies analyzing pediatric intensive care units are useful for assessing and improving the effectiveness of care in these centers.

[Uric acid as a prognostic marker in critically ill patients]

BACKGROUND

Elevated uric acid concentrations reflect adenosine triphosphate degradation and suggest poor prognosis since they indicate a cellular bioenergetic crisis.

OBJECTIVE

To study uric acid concentrations as a prognostic marker of disease severity in critically ill children.

PATIENTS AND METHODS

Seventy-eight patients admitted to our pediatric intensive care unit with different diseases were prospectively studied. Thirty-five patients with meningococcal infection were retrospectively studied. Data on uric acid concentrations, diagnosis, length of stay, age, weight, the therapeutic intervention scoring system (TISS) and the pediatric risk of mortality score (PRISM) were collected. In patients with meningococcal infection severity was evaluated by studying evolution (death and the presence of sequelae or otherwise).

RESULTS

Uric acid concentrations on admission were significantly correlated with TISS on the first day (r 0.260; p 0.023) and with PRISM during the first 24 hours (r 0.277; p 0.015). In patients without craniocerebral trauma, correlations between uric acid concentrations and PRISM during the first 24 hours (r 0.524; p < 0.001) and correlations between uric acid concentrations with TISS on day 1 (r 0.483; p < 0.001) and day 2 (r 0.373; p 0.014) improved. In patients with craniocerebral trauma no significant correlations were found between uric acid and any of the other variables. In patients with meningococcal infection, uric acid concentrations on admission were closely related to evolution (uric acid concentrations were 13.20 8.2 mg/dl in patients who died, 8.01 1.77 mg/dl in those with sequelae and 4.72 1.84 mg/dl in in those without sequelae; p < 0.003).

CONCLUSIONS

Serum uric acid concentrations can be considered as a marker of severity in critically ill patients without craniocerebral trauma and especially in patients with meningococcal infection.

[Risk factors associated with nosocomial bacteremia in low birth weight neonates. Grady Memorial Hospital, Atlanta]

BACKGROUND

Nosocomial bloodstream infections occur frequently in Neonatal Intensive Care Units and are associated with recognized and unrecognized risk factors. Little has been published regarding risk factors for bloodstream infections in low birth weight neonates.

OBJECTIVE

To investigate risk factors for bloodstream infection in neonates < 1,500 g admitted at a Neonatal Intensive Care Unit.

METHODS

A prospective study was undertaken in low birth weight neonates (< 1,500g) during a 22 months period. Bivariant, and logistic regresion (stepwise procedure) analysis was used to determine the significance association of bloodstream infection and perinatal and nosocomial risk factors.

RESULTS

A total of 72 patiens with nosocomial bacteriemia and 147 non bacteriemic patients were studied. Independent risk factors associated with bloodstream infection were birth weight, persistence of umbilical catheter > 7 days and persistence of peripheral arterial catheter > 1 day.

CONCLUSIONS

The uses of umbilical catheter > 7 days, peripheral arterial catheter > 1 day and birth weight < 1,500 g were significant determinants of nosocomial bloodstream infection risk. Because of the importance of invasive procedures as a source of nosocomial bloodstream infections, the lines duration needs to be reviewed with the aim of reducing the incidence of blood stream infection.

[Blood pressure in childhood and adolescence. Its relationship with growth and maturation variables]

AIM

To analyze the relationship between blood pressure in childhood and adolescence and different variables including gender, age, weight, height, body mass index and sexual maturation.

METHODS

Cross-sectional study conducted in 1278 boys and girls aged 6 to 18 years old. Two blood pressure measurements were obtained. Mean value in the two measurements was obtained for each of the pressures: systolic (SBP), diastolic IV (DBPIV) and diastolic V (DBPV). Simple and multiple regression analysis were done to evaluate association between variables.

RESULTS

14 years 0.33; SBP boys > 14 years 0.34; DBPIV 0.25; DBPV 0.24) and height (SBP 6-13 years 0.33; SBP girls > 14 years 0.23; SBP boys > 14 years 0.29; DBPIV 0.25; DBPV 0.24) than for age (SBP 6-13 years 0.27; SBP girls > 14 years 0.17; SBP boys > 14 years 0.15; DBPIV 0.23; DBPV 0.22) for each of the blood pressures. Multiple regression analysis demonstrated a significant association between body mass index, height and SBP in the group of boys and girls aged 6-13 years old. No other significant associations were obtained.

CONCLUSIONS

Blood pressure values in childhood and adolescence show a positive association with growth and maturation variables. It's of capital importance to considerate not only age, but also height, weight and body mass index when evaluating the blood pressure value of a child.

[Hyperamylasemia after cardiac surgery in children]

OBJECTIVE

To analyze the incidence of hyperamylasemia after cardiac surgery in children, the pathogenic mechanisms and the relationship with morbidity and mortality.

PATIENTS AND METHODS

A prospective open study was made in the Intensive Care Unit of a tertiary care pediatric hospital. One hundred thirty-one patients (75 boys and 56 girls), between 7 days and 16 years of age, were studied after cardiac surgery between 1992 and 1994. We determined serum amylase on their admission, at 24 hours, between the 2nd and 5th days, and thereafter according to the clinical evolution. We considered a serum amylase higher than 250 UI/L as hyperamylasemia. We also determined liver enzyme levels (AST, ALT, Gamma-glutamyl transpeptidase, alkaline phosphatase, and direct and total bilirubin) and renal function (urea and creatinine). We studied the relationship between hyperamylasemia and the type of surgery, shock, renal insufficiency, hepatic alterations and mortality.

RESULTS

Fourteen patients (10%) showed hyperamylasemia. Mean serum amylase in these patients was 534 +/- 332.6 UI/L (range 252-1426 UI/L). Of the patients were cardiopulmonary bypass was performed, 11.4% presented hyperamylasemia, and 8.5% of the patients without a cardiopulmonary bypass surgery (non-significant difference). Of the children with hyperamylasemia, 42.8% suffered shock during the postoperative period after cardiac surgery and only 15.2% of the rest of the patients (p < 0.05). There were no differences in the incidence of renal insufficiency and liver alterations between children with hyperamylasemia and the rest of the patients. There was no significant difference between the mortality of children with hyperamylasemia (7.1%) and the rest of the children (4.7%; p > 0.05).

CONCLUSIONS

Hyperamylasemia is frequent after cardiac surgery in children. Hyperamylasemia is related to shock and the ischemia is probably the most pathogenic factor.

[Urinary concentration capacity in neonatal hydronephrosis]

In order to determine the renal concentration capacity in neonatal hydronephrosis, 10 micrograms of DDAVP were administered intranasally to 18 infants with hydronephrosis. Fluid intake was restricted to 50% of normal for 3 hours before and 6 hours after the administration of DDAVP. Maximal urine osmolality (mean +/- SD) was 348 +/- 180 mOsm/kg in 7 newborns younger than 21 days and 420 +/- mOsm/kg in 11 neonates between 22-50 days of age. Both osmolarities were inferior to the standard response to DDAVP reported in normal neonates. After 24 hours of clinical observation, we did not notice any secondary effects caused by this test.