Ashok P. Sarnaik

Management of hyponatremic seizures in children with hypertonic saline: a safe and effective strategy.

ObjectiveTo study efficacy and safety of hypertonic saline administration in the management of hyponatremic seizures. DesignRetrospective, observational, cross-sectional study with factorial design. SettingIn-patient population in a university hospital. PatientsAll children admitted with serum sodium concentrations <125 mmol/L. Sixty-nine episodes of severe hyponatremia in 60 children were reviewed. Forty-one of these children presented with seizures. InterventionsTwenty-five of 41 seizure patients received an iv bolus of 4 to 6 mL/kg body weight of 3% saline. Twenty-eight patients were treated with a benzodiazepine and/or phenobarbital with or without the subsequent administration of hypertonic saline. Measurements and Main ResultsThirteen treatment failures and ten instances of apnea occurred among the 28 patients treated with benzodiazepine/phenobarbital. Administration of hypertonic saline resulted in resolution of seizures and apnea in all cases. Those patients receiving 3% saline had a higher serum sodium increase rate from 0 to 4 hrs than the remaining patients (3.1 ± 1.3 vs. 1.7 ± 1.2 mmol/L-hr, p < .01). None developed subsequent neurologic deterioration or clinical manifestations of osmotic demyelination syndrome. ConclusionTreatment of hyponatremic seizures with routine anticonvulsants may be ineffective and is associated with a considerable incidence of apnea. A rapid increase in the serum sodium concentration by 3 to 5 mmol/L with the use of hypertonic saline is safe and efficacious in managing acute symptomatic hyponatremia. (Crit Care Med 1991;19:758)

Dexamethasone for the prevention of postextubation airway obstruction: a prospective, randomized, double-blind, placebo-controlled trial.

OBJECTIVE To determine whether dexamethasone prevents postextubation airway obstruction in young children. DESIGN Prospective, randomized, double-blind, placebo-controlled study. SETTING Pediatric intensive care unit of a university teaching hospital. PATIENTS Sixty-six children, < 5 yrs of age, intubated and mechanically ventilated for > 48 hrs. INTERVENTIONS Patients were randomized to receive intravenous dexamethasone (0.5 mg/kg, maximum dose 10 mg) or saline, every 6 hrs for six doses, beginning 6 to 12 hrs before elective extubation. MEASUREMENTS AND MAIN RESULTS Dependent variables included the presence of stridor, Croup Score, and pulsus paradoxus at 10 mins, 6, 12, and 24 hrs after extubation; need for aerosolized racemic epinephrine and reintubation. The dexamethasone and placebo groups were similar in age (median 3 months [range 1 to 57] vs. 4 months [range 1 to 59], p = .6), frequency of underlying airway anomalies (3/33 vs. 3/33, p = 1.0), and duration of mechanical ventilation (median 3.3 days [range 2.1 to 39] vs. 3.5 days [range 2.1 to 15], p = .7). The dexamethasone group had a lower frequency of stridor, Croup Score, and pulsus paradoxus measurement at 10 mins and at 6 and 12 hrs after extubation. Fewer dexamethasone-treated patients required epinephrine aerosol (4/31 vs. 22/32, p < .0001) and reintubation (0/31 vs. 7/32, p < .01). Three patients exited the study early-one patient in the dexamethasone group had occult gastrointestinal hemorrhage and one patient in each group had hypertension. CONCLUSION Pretreatment with dexamethasone decreases the frequency of postextubation airway obstruction in children.

Limitations of the Glasgow Coma Scale in predicting outcome in children with traumatic brain injury

OBJECTIVE To study the hypothesis that, in the absence of an ischemic-hypoxic state, children with severe traumatic brain injury and with unfavorable Glasgow Coma Scale scores may have good recovery. DESIGN Retrospective, observational, cross-sectional study with factorial design. SETTING Inpatient population in a university hospital. PATIENTS Seventy-nine children with traumatic brain injury admitted to the intensive care unit. INTERVENTIONS All patients received close monitoring and strict control of intracranial pressure (less than 20 mm Hg) and cerebral perfusion pressure (greater than 60 mm Hg). MEASUREMENTS AND RESULTS Admission Glasgow Coma Scale score, survival, need for cardiopulmonary resuscitation, presence of shock, peak intracranial pressure, duration of coma, Glasgow Outcome Scale score, and the results of neuropsychologic tests were analyzed. Of 79 children, 70 (89%) survived. Although the mortality rate was higher among patients with Glasgow Coma Scale scores of 3 to 5, 14 (64%) of 22 of these children survived. Nonsurvivors had a significantly higher incidence of shock and need for cardiopulmonary resuscitation. Except for two patients who had prolonged hypoxemia, all children, including those with Glasgow Coma Scale scores of 3 to 5, had a satisfactory outcome (Glasgow Outcome Scale scores of 4 or 5). Neuropsychologic outcome was not significantly different in the survivors with Glasgow Coma Scale scores of 3 to 5 and those with Glasgow Coma Scale scores of 6 or more. CONCLUSIONS A low Glasgow Coma Scale score does not always accurately predict the outcome of severe traumatic brain injury; in the absence of hypoxic-ischemic injury, children with traumatic brain injury and Glasgow Coma Scale scores of 3 to 5 can recover independent function.

Does prematurity alter the course of respiratory syncytial virus infection

We compared previously healthy prematurely born infants with full-term infants hospitalized with respiratory syncytial virus (RSV) infection to evaluate the role of prematurity on the clinical course of the illness. During a 5-yr period (1984 to 1989), 484 previously healthy patients were admitted to the hospital with RSV infection. No differences were found in the presenting symptoms of respiratory distress, cough, fever or shock, although the premature group was more likely to present with apnea (p < .001). Chest roentgenograms revealed that premature infants had a higher incidence of atelectasis/infiltrate and hyperinflation (p < .05). Premature infants had longer hospital stays as well as a higher Physiologic Stability Index and Therapeutic Intervention Score (p < .001). They were also more likely to receive supplemental oxygen, ICU admission, mechanical ventilation, and nothing by mouth status (p < .001). We conclude that premature birth increases the risk of more severe and prolonged RSV disease.

Predicting outcome in children with severe acute respiratory failure treated with high-frequency ventilation

OBJECTIVES a) To demonstrate the effect of high-frequency ventilation on gas exchange in children with severe acute respiratory failure unresponsive to conventional ventilation; b) to identify patients at high risk of death early after institution of high-frequency ventilation. SETTING Tertiary care pediatric intensive care unit in a university hospital. DESIGN A cross-sectional, observational study with factorial design. PATIENTS Thirty-one patients with severe acute respiratory failure defined as a Pao2/F1o2 of < 150 torr (< 20 kPa) with a positive end-expiratory pressure of > or = 8 cm H2O and/or Paco2 of > 60 torr (> 8 kPa) with an arterial pH < 7.25. INTERVENTIONS Patients received either high-frequency oscillation or jet ventilation if respiratory failure was unresponsive to conventional ventilation and if the underlying disease process was deemed reversible. MEASUREMENTS AND MAIN RESULTS Thirty-one children were managed with high-frequency ventilation, 11 children with jet and 20 children with oscillator. Arterial blood gases and level of ventilatory support were recorded before and at 6, 24, 48, 72, and 96 hrs after institution of high-frequency ventilation. There was an improvement in an arterial pH, Paco2, Pao2, and Pao2/FID2 6 hrs after institution of high-frequency ventilation (p < .01). This improvement, along with decreased need for oxygen, was sustained through the subsequent course. Twenty-three (74%) of 31 children treated with high-frequency ventilation survived. Survivors showed an increase in an arterial pH, Pao2, Pao2/FIO2, and a decrease in Paco2 within 6 hrs, whereas nonsurvivors did not. Oxygenation index was the best predictor of outcome. A combination of an initial oxygenation index of > 20 and failure to decrease the oxygenation index by > 20% by 6 hrs after initiation of high-frequency ventilation predicted death with 88% (7/8) sensitivity and 83% (19/23) specificity, with an odds ratio of 33 (p = .0036, 95% confidence interval 3-365). CONCLUSIONS In patients with potentially reversible underlying diseases resulting in severe acute respiratory failure that is unresponsive to conventional ventilation, high-frequency ventilation improves gas exchange in a rapid and sustained fashion. The magnitude of impaired oxygenation and its improvement after high-frequency ventilation can predict outcome within 6 hrs.

Oxygen consumption, energy expenditure, and substrate utilization after cardiac surgery in children

ObjectiveTo determine the oxygen consumption (Vo2), resting energy expenditure, and substrate utilization after cardiac surgery in children. DesignProspective, observational, cross-sectional study with factorial design. SettingPediatric ICU at a university hospital. PatientsTwenty-six consecutive children during the first 3 days after open-heart surgery. InterventionsPatients were mechanically ventilated and received routine therapeutic interventions. Measurements and Main ResultsVo2, resting energy expenditure, and substrate utilization were determined by indirect calorimetry. Cardiac index was calculated using the Fick equation from the measured Vo2 and the arterial-mixed venous oxygen content difference, and this cardiac index value was compared with a simultaneous cardiac index value that was measured by thermodilution whenever possible. There were excellent correlation and agreement between cardiac index measurements by Fick equation and thermodilution, indicating accurate Vo2 measurements. Vo2 was consistent with predicted values in healthy resting children. Resting energy expenditure was consistent with the predicted basal metabolic rate. The mean caloric intake was 19% of the mean energy expenditure. The respiratory quotient was 0.74 ± 0.05. The substrate utilization showed a shift toward fat oxidation and either gluconeogenesis or impaired carbohydrate utilization. ConclusionsCardiovascular surgery in children does not significantly alter resting energy expenditure but influences the substrate utilization. Perioperative hormonal stress responses and therapeutically administered catecholamines may explain the shift toward fat oxidation.

Intracranial pressure and cerebral perfusion pressure in near-drowning

Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were strictly controlled in 11 pediatric victims of near-drowning. Three outcome groups were defined: complete recovery, persistent vegetative state, and death. In the early postimmersion phase (first 72 h), CPP was consistently above 50 mm Hg in all patients. There were occasional, nonrepetitive, and easily controllable ICP spikes above 15 mm Hg in three patients from each group. Repeated ICP spikes above 15 mm Hg were observed in some patients with adverse outcome only after 72 h. Successful control of ICP and CPP did not ensure intact survival, and sustained late intracranial hypertension is more likely a sign of pro-found neurologic insult rather than its cause.

Syndrome of inappropriate antidiuretic hormone secretion in children following spinal fusion

OBJECTIVES a) To determine if antidiuretic hormone (ADH) is elevated in patients undergoing spinal fusion, especially in those who have clinical evidence of syndrome of inappropriate antidiuretic hormone (SIADH); b) to evaluate the relationship between ADH secretion and the secretion of atrial natriuretic peptide (ANP). SETTING Tertiary care pediatric intensive care unit (ICU) in a university hospital. DESIGN A prospective cross-sectional, observational study with factorial design. PATIENTS Thirty patients > or = 10 yrs of age undergoing spinal fusion admitted to the ICU for postoperative care. INTERVENTIONS Patients underwent anterior, posterior, or both anterior/posterior spinal fusion. Blood was collected for serial measurements of ADH, ANP and serum electrolyte levels. Heart rate, blood pressure and central venous pressure were measured. MEASUREMENTS AND MAIN RESULTS Thirty children were studied. Nineteen had idiopathic scoliosis, nine had neuromuscular scoliosis, one had Marfans disease, and one had congenital scoliosis. Ten (33%) children met clinical criteria of SIADH. There was no difference in duration of surgery, blood loss, volume of iv fluid administration pre- and intraoperatively, or type of scoliosis between those who developed SIADH and those who did not. Hemodynamic variables were similar in both groups. ADH levels increased in both groups immediately postoperatively and at 6 hrs after surgery, but were much more elevated in those patients with SIADH. Patients with SIADH also had significantly higher ADH levels preoperatively. In relation to serum osmolality, ADH was considerably higher in those with SIADH compared with those who did not. Although ANP values tended to be higher in the group with SIADH, this did not reach statistical significance. CONCLUSION SIADH occurs in a subset of children who undergo spinal fusion. The diagnosis of SIADH can be made easily using clinical parameters which are well-defined. In the face of SIADH, continued volume expansion may be harmful, and should therefore be avoided.

Hyponatremia: pathophysiology and treatment, a pediatric perspective

Hyponatremia is the most commonly observed electrolyte abnormality in hospitalized children. The most serious consequences of hyponatremia and its treatment involve the central nervous system (CNS). Important factors determining the development of clinical symptomatology include: the rate of fall in serum sodium, and the severity and duration of hyponatremia. Acute hyponatremia is associated with increased brain water resulting in varying grades of encephalopathy whereas the osmoregulatory mechanism allows normalization of CNS water content in chronic hyponatremia. It is recommended that the therapy for hyponatremia be initiated on the basis of the presence or absence of symptoms. An increase of 4–6 mmol/l in serum sodium over 10–15 min is recommended in symptomatic patients. Rapid correction of chronic hyponatremia may result in osmotic dehydration syndrome and therefore should be avoided.

Role of aggressive intracranial pressure control in management of pediatric craniocerebral gunshot wounds with unfavorable features.

During a 6-year period, 14 consecutive children with penetrating craniocerebral gunshot wounds (GSW) were studied. Eleven patients were comatose on admission. Five had an admission Glasgow Coma Scale (GCS) score of 4 or less and developed clinical signs of brain death within 12 hours despite maximum therapeutic efforts. The remaining six patients, all of whom had three or more of the previously described unfavorable prognostic features, were aggressively managed with prophylaxis and treatment of intracranial hypertension. Intracranial pressure (ICP) was controlled with mechanical hyperventilation, mannitol osmotherapy, pentobarbital, and surgical decompression. Substantial intracranial hypertension occurred for up to 10 days after admission. There were four survivors. Neurobehavioral and intellectual functions were evaluated over a period of 1 to 2 years. Although serious cognitive deficits were noted, all survivors had sufficient functional recovery to warrant aggressive cardiopulmonary resuscitation and measures to control ICP in the management of comatose victims of craniocerebral GSW.