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, Pao(2), Pao(2)/Fio(2) ratio, and urinary output decreased significantly, whereas Paco(2), 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).

Partial liquid ventilation with perfluorocarbon in acute lung injury: light and transmission electron microscopy studies.

Liquid ventilation using perfluorocarbon has been shown to improve gas exchange in animal models of acute lung injury as well as in children with acute respiratory distress syndrome. This study was designed to define structural features of lung injury following partial liquid ventilation (PLV) using light and transmission electron microscopy in a rabbit model of acute respiratory distress. Animals were treated with either conventional mechanical ventilation (CMV-gas) (n = 6) or PLV (n = 5) for 4 h after the induction of acute lung injury with saline lavage. Control animals were killed after the lung injury. PLV significantly improved alveolar-arterial oxygen tension and the oxygen index compared with CMV (P < 0.05). Morphometric studies using light microscopy show less alveolar hemorrhage, less edema, and fewer hyaline membranes in the PLV group (P < 0.05). Polymorphonuclear leukocyte sequestration in lung capillaries (11.4 +/- 1.5 versus 19.2 +/- 3 x 10(8)/ml, P < 0.05, PLV versus CMV) and migration into airspaces (3.1 +/- 1.2 versus 4.5 +/- 1.1 x 10(8)/ml, P < 0.05, PLV versus CMV) were lower in the gravity-dependent lung regions. There were fewer alveolar macrophages in the PLV group compared with other groups (P < 0.05). Fluorescence microscopy analysis shows fewer type II alveolar epithelial cells in the CMV group and brighter type II cells in the PLV group. Transmission electron microscopy studies show more alveolar wall damage in the CMV group, with type II cells detached from their basement membrane with fewer surfactant-containing lamellar bodies. We conclude that quantitative histologic analysis shows less lung damage and inflammation when perfluorocarbon is combined with CMV in the management of acute respiratory distress syndrome.

The effect of preoperative tranexamic acid on blood loss after cardiac operations in children.

Children undergoing cardiac operations in which cardiopulmonary bypass is used are at risk of significant postoperative blood loss. The acquired coagulopathy is complex but is thought to be due, in part, to excessive fibrinolysis. We examined the possibility of reducing postoperative blood loss in children by using the antifibrinolytic drug tranexamic acid. Using a prospective, randomized, double-blind study design, we administered a single dose of tranexamic acid (50 mg/kg intravenously) or saline placebo, before skin incision, in 88 children undergoing cardiac operations. Post-operative blood loss and fluid replacement were recorded for the next 24 hours. In addition, hemoglobin, platelet counts, and coagulation measures were recorded every 6 hours. When all patients were examined, there was no significant difference in postoperative blood loss between the treated and placebo groups (21.2 +/- 12 ml/kg per 24 hours, tranexamic acid, vs 27.2 +/- 20.3 mls/kg per 24 hours, placebo). However, when the children with cyanosis were analyzed separately, there was a highly significant difference in blood loss between the groups during the first 6 hours (11.2 +/- 3.7 ml/kg per 6 hours, tranexamic acid, vs 27.2 +/- 11.4 mls/kg per 6 hours, placebo; p < 0.002), as well as the overall 24 hour study period (23.7 +/- 7.5 mls/kg per 24 hours, tranexamic acid, vs 48.9 +/- 27.6 mls/kg per 24 hours, placebo; p < 0.02). Also significantly less blood and blood products were administered to the treated cyanosed group. Tranexamic acid produced a significant reduction in postoperative blood loss and blood product requirements in children with cyanosis undergoing heart operations. The drug had no effect in children without cyanosis or those requiring a second thoracotomy.

Salvage of the severely injured limb in children: a multidisciplinary approach.

Massive trauma to a limb, even in young children, may lead to loss of viability and function. A combination of open fracture with vascular, crush, and avulsion injury resulting in acute peripheral ischemia may place the extremity at risk of necrosis and imminent amputation. We suggest a combined, multidisciplinary approach that includes initial vascular repair and fractures fixation, with early institution of hyperbaric oxygen therapy.

The administration of desferrioxamine to paraquat-intoxicated rats.

We investigated the effect of desferrioxamine, an effective iron chelator, on animal survival and on plasma vitamin E levels after administration of paraquat doses close to the LD50. Male Sprague-Dawley rats received 20 mg paraquat/kg followed by 300 mg desferrioxamine/kg/d given ip over 2 d at 3 equal intervals. The results suggested that desferrioxamine prevented the paraquat-induced depletion of vitamin E, but did not improve the mortality due to paraquat. In ancillary in vitro experiments with a paraquat-based free radical system, where glutathione reductase and NADPH were used as sources of enzymic activity for the redox cycling of paraquat, desferrioxamine effectively prevented the formation of hydroxyl radicals, as determined by deoxyribose degradation.

The scale of myocardial involvement in varicella myocarditis.

Two patients with varicella myocarditis are described. An arrhythmia associated with complete recovery occurred in the first patient whereas intractable congestive heart failure complicated by hemiplegia resulted in a fatal outcome in the other case. We stress the extent of myocardial involvement produced by the herpes zoster virus in the setting of varicella.