Gad Bar-Joseph

Effectiveness of ketamine in decreasing intracranial pressure in children with intracranial hypertension

OBJECT Deepening sedation is often needed in patients with intracranial hypertension. All widely used sedative and anesthetic agents (opioids, benzodiazepines, propofol, and barbiturates) decrease blood pressure and may therefore decrease cerebral perfusion pressure (CPP). Ketamine is a potent, safe, rapid-onset anesthetic agent that does not decrease blood pressure. However, ketamines use in patients with traumatic brain injury and intracranial hypertension is precluded because it is widely stated that it increases intracranial pressure (ICP). Based on anecdotal clinical experience, the authors hypothesized that ketamine does not increase-but may rather decrease-ICP. METHODS The authors conducted a prospective, controlled, clinical trial of data obtained in a pediatric intensive care unit of a regional trauma center. All patients were sedated and mechanically ventilated prior to inclusion in the study. Children with sustained, elevated ICP (> 18 mm Hg) resistant to first-tier therapies received a single ketamine dose (1-1.5 mg/kg) either to prevent further ICP increase during a potentially distressing intervention (Group 1) or as an additional measure to lower ICP (Group 2). Hemodynamic, ICP, and CPP values were recorded before ketamine administration, and repeated-measures analysis of variance was used to compare these values with those recorded every minute for 10 minutes following ketamine administration. RESULTS The results of 82 ketamine administrations in 30 patients were analyzed. Overall, following ketamine administration, ICP decreased by 30% (from 25.8 +/- 8.4 to 18.0 +/- 8.5 mm Hg) (p < 0.001) and CPP increased from 54.4 +/- 11.7 to 58.3 +/- 13.4 mm Hg (p < 0.005). In Group 1, ICP decreased significantly following ketamine administration and increased by > 2 mm Hg during the distressing intervention in only 1 of 17 events. In Group 2, when ketamine was administered to lower persistent intracranial hypertension, ICP decreased by 33% (from 26.0 +/- 9.1 to 17.5 +/- 9.1 mm Hg) (p < 0.0001) following ketamine administration. CONCLUSIONS In ventilation-treated patients with intracranial hypertension, ketamine effectively decreased ICP and prevented untoward ICP elevations during potentially distressing interventions, without lowering blood pressure and CPP. These results refute the notion that ketamine increases ICP. Ketamine is a safe and effective drug for patients with traumatic brain injury and intracranial hypertension, and it can possibly be used safely in trauma emergency situations.

Abdominal Compartment Syndrome in Children

Objective To investigate the frequency, predisposing factors, clinical presentation, and outcome of abdominal compartment syndrome (ACS) in critically ill pediatric patients. Design A prospective study over a 5-yr period. Setting Pediatric intensive care unit of a tertiary care, university hospital. Patients All patients admitted to the pediatric intensive care unit were screened for the presence of ACS and were treated with a uniform protocol. ACS was defined as abdominal distention with intra-abdominal pressure (IAP) > 15 mm Hg, accompanied by at least two of the following: oliguria or anuria; respiratory decompensation; hypotension or shock; metabolic acidosis. Measurements and Main Results Of 1762 patients admitted over 5 yrs, ten patients (0.6%) had a total of 15 episodes of ACS. Of 406 trauma cases, three had ACS (0.7%). Three of the ten patients had primary abdominal conditions (mesenteric vein thrombosis, intussusception, enterocolitis), three had abdominal surgery (trauma, Kasai operation, esophageal perforation and peritonitis), three had primary central nervous system involvement, and one had meningococcemia. At laparotomy, bowel ischemia or necrosis was found in four episodes of ACS (27%). Mean IAP at diagnosis of ACS was 23.9 ± 3.8 (range 17–31) mm Hg. Physiologic parameters were compared during 4 hrs before the development of ACS, during ACS, and after abdominal decompression. Mean arterial pressure, Pao2, Pao2 /Fio2 ratio, and urinary output decreased significantly, whereas Paco2, peak inspiratory pressures, positive end-expiratory pressures, and base deficit increased significantly after the development of ACS. After decompressive laparotomy, the condition of the patients improved promptly and these variables returned to pre-ACS values. Overall mortality rate in this group was 60%. Conclusions Although relatively infrequent compared with adults, ACS occurs in critically ill children. Timely decompression of the abdomen results in uniform improvement, but overall mortality is still high. In contrast with adults, children with ACS have diverse primary diagnoses, with a significant number of primary extra-abdominal—mainly central nervous system—conditions. Ischemia and reperfusion injury appear to be the major mechanisms for development of ACS in children. Clinical presentation is similar to adults, but children may develop ACS at a lower IAP (as low as 16 mm Hg).

Improved resuscitation outcome in emergency medical systems with increased usage of sodium bicarbonate during cardiopulmonary resuscitation

Background:  The use of sodium bicarbonate (SB) in cardiopulmonary resuscitation (CPR) is controversial. This study analyzes the effects of SB use on CPR outcome in the Brain Resuscitation Clinical Trial III (BRCT III), which was a multicenter randomized trial comparing high‐dose to standard‐dose epinephrine during CPR. Sodium bicarbonate use in BRCT III was optional.

Perforation of the heart by central venous catheters in infants: Guidelines to diagnosis and management

The frequent use of central venous catheters has resulted in improved monitoring and parenteral nutrition. However, these catheters have also been a source of numerous complications, some of them lethal. Two cases of perforation of the heart that resulted in cardiac tamponade and death are reported. Early detection of this complication depends on a high index of suspicion, both clinical and radiographic. Measures such as securing the catheter tip in the superior vena cava can prevent this complication; immediate evacuation of the pericardial fluid by gentle aspiration or pericardiocentesis can prove life-saving.

Comparison of sodium bicarbonate, Carbicarb, and THAM during cardiopulmonary resuscitation in dogs

OBJECTIVES During cardiopulmonary resuscitation (CPR), elimination of CO2 was shown to be limited by low tissue perfusion, especially when very low perfusion pressures were generated. It has therefore been suggested that sodium bicarbonate (NaHCO3), by producing CO2, might aggravate the hypercarbic component of the existing acidosis and thereby worsen CPR outcome. The objectives of this study were to evaluate the effects of CO2 producing and non-CO2 producing buffers in a canine model of prolonged ventricular fibrillation followed by effective CPR. DESIGN Prospective, randomized, controlled, blinded trial. SETTING Experimental animal research laboratory in a university research center. SUBJECTS Thirty-eight adult dogs, weighing 20 to 35 kg. INTERVENTIONS Animals were prepared for study with thiopental followed by halothane, diazepam, and pancuronium. Ventricular fibrillation was electrically induced, and after 10 mins, CPR was initiated, including ventilation with an FIO2 of 1.0, manual chest compressions, administration of epinephrine (0.1 mg/kg every 5 mins), and defibrillation. A dose of buffer, equivalent to 1 mmol/kg of NaHCO3, was administered every 10 mins from start of CPR. Animals were randomized to receive either NaHCO3, Carbicarb, THAM, or 0.9% sodium chloride (NaCl). CPR was continued for up to 40 mins or until return of spontaneous circulation. MEASUREMENTS AND MAIN RESULTS Buffer-treated animals had a higher resuscitability rate compared with NaCl controls. Spontaneous circulation returned earlier and at a significantly higher rate after NaHCO3 (in seven of nine dogs), and after Carbicarb (six of ten dogs) compared with NaCl controls (two of ten dogs). Spontaneous circulation was achieved twice as fast after NaHCO3 compared with NaCl (14.6 vs. 28 mins, respectively). Hydrogen ion (H+) concentration and base excess, obtained 2 mins after the first buffer dose, were the best predictors of resuscitability. Arterial and mixed venous Pco2 did not increase after NaHCO3 or Carbicarb compared with NaCl. CONCLUSIONS Buffer therapy promotes successful resuscitation after prolonged cardiac arrest, regardless of coronary perfusion pressure. NaHCO3, and to a lesser degree, Carbicarb, are beneficial in promoting early return of spontaneous circulation. When epinephrine is used to promote tissue perfusion, there is no evidence for hypercarbic venous acidosis associated with the use of these CO2 generating buffers.

Clostridium septicum infection in children with cyclic neutropenia

Atraumatic Clostridium septicum infection is rare in infancy and childhood and is associated with a high mortality rate. Although in adults it has been reported to occur mainly in patients with gastrointestinal malignancy, pediatric cases were always associated with neutropenia. About 70% of the cases were described in children with neutropenia caused by chemotherapy and 30% were found in children with cyclic neutropenia. No case was described in children with other forms of congenital severe neutropenia. We describe three children with cyclic neutropenia and severe Clostridium septicum infection, discuss the various possibilities of causation, and the need for prompt and aggressive treatment of this serious condition.

Pathophysiologic and therapeutic implications of acid-base changes during CPR

Acid-base changes occurring during cardiac arrest and subsequent CPR are related to a complex low-perfusion state characterized clinically by venous and tissue hypercarbic and metabolic (lactic) acidosis. This low-flow state is a dynamic process dependent on the time intervals between onset of arrest, initiation of CPR, and restoration of adequate spontaneous circulation. Increased release of CO2 from ischemic tissues and reduced CO2 transport from the tissues to the lungs result in profound tissue acidosis. However, recent experimental data suggest that even very low pH is compatible with neurologically intact survival. Thus, the clinical use of buffer agents, and especially of sodium bicarbonate, is currently controversial. Because results of controlled clinical studies are not available, a careful review of well-performed experimental studies is necessary. So far, the use of either CO2-generating or CO2-consuming buffers has not been proved conclusively to increase neurologically intact long-term survival after CPR. More importantly, adequate ventilation and effective chest compressions must be quickly established after cardiac arrest. This will counterbalance the hypercarbic and metabolic acidemia of cardiac arrest by creating concurrent hypocarbic arterial alkalemia during at least the early phase of CPR. Thus, the treatment of the complex acid-base changes associated with CPR is based primarily on the classical maneuvers of A and B (airway and breathing = adequate oxygenation and ventilation), C (chest compressions), and D (early defibrillation for rapid restoration of spontaneous circulation). In cases of prolonged cardiac arrest or preexisting metabolic acidemia, buffer therapy may be indicated.

Brain abscess in children – epidemiology, predisposing factors and management in the modern medicine era

Aims:  Brain abscess is rare in children. Predisposing factors are found in almost 85% of cases. Overall, 25% of brain abscesses develop in children, mostly in the 4–7 years age group. Our study aimed to characterize children with brain abscesses treated in our hospital, identify risk factors, pathogens and short‐term outcome.

A case of H syndrome showing immunophenotye similarities to Rosai-Dorfman disease.

H syndrome (OMIM 612391) is a recently described autosomal recessive genodermatosis characterized by indurated, hyperpigmented, and hypertrichotic skin and systemic manifestations including hepatosplenomegaly, cardiac anomalies, hearing loss, hypogonadism, low height, hypertriglyceridemia, hallux valgus, and flexion contractures. H syndrome results from mutations in the SLC29A3 gene, which encodes the human equilibrative nucleoside transporter hENT3. The cutaneous histopathology is characterized by a striking mononuclear cell infiltrate in the dermis consisting of CD68+ monocyte-derived cells and CD34+ and factor XIIIa+ dendrocytes. We describe a case of H syndrome in which the infiltrating mononuclear cells were CD68+, CD163+, S-100+, and CD1a-, thus simulating the immunophenotype observed in Rosai-Dorfman disease (RDD). The immunostaining for CD21, fascin, and CD34 were negative, and there were also many factor XIIIa+ dendrocytes interspersed within the dense mononuclear cell infiltrate. Recent findings of biallelic mutations in SLC29A3 in 2 families reported to have familial RDD and in a kindred with Faisalabad histiocytosis (OMIM 602782), which is an autosomal inherited form of histiocytosis with similarities to RDD, may explain the RDD-like immunophenotype in our H syndrome case.

Adult Pertussis Is Hazardous for the Newborn

We report 4 cases involving the likely transmission of pertussis from parents to newborns in a hospital setting. The adoption of proper infection control measures and targeted screening of parents may reduce the potential for such transmission.