Capnographic monitoring of ventilatory status during moderate (conscious) sedation.

BACKGROUND: Moderate (conscious) sedation is required to perform endoscopic procedures. Capnography provides a means for continuous, real-time monitoring of ventilation and may also decrease the incidence of oversedation. METHODS: A retrospective examination of all endoscopic procedures performed from January through December 2001 at our institution was undertaken to determine the potential benefits of capnographic monitoring. RESULTS: In 4,846 endoscopic procedures performed without capnography, adverse outcomes related to moderate sedation were noted in 14 cases (0.29%). A subset of patients at higher risk for moderate sedation was identified. There were no cases of oversedation in 600 cases monitored with capnography. The complication rates were not significantly different for the two groups ( p = 0.30, NS). CONCLUSION: The addition of capnography during moderate sedation endoscopy does not appear to significantly lower anesthesia-related morbidity. However, in cases requiring moderate sedation for prolonged procedures, in older patients with comorbidities, or in instances where respiratory excursion of the patient is obscured from view, practitioners should nonetheless consider capnography.

Dynamic retention: a technique for closure of the complex abdomen in critically ill patients.

Management of the open abdomen in the setting of massive visceral swelling or extensive intra-abdominal abscess may pose an extremely difficult surgical scenario. We herein describe the technique and results of dynamic-retention sutures used in 13 patients with abdominal catastrophes after trauma, vascular reconstruction, tumor extirpation, and intra-abdominal infection. Three of these patients died during their acute care hospitalization. The remaining 10 patients were discharged to home with no resultant fistulas and 1 recurrent hernia (10%). Dynamic-retention sutures provide a useful technique for the closure of the complex surgical abdomen. We observed a low complication rate. In properly selected patients, this technique avoids the use of mesh or additional surgical procedures such as skin grafting or plastic surgical reconstruction of the abdominal wall.

Gastric trichobezoar: case report and literature review.

Bezoars are conglomerates of food or fiber in the alimentary tract of humans and certain animals, mainly ruminants. In adults, bezoars are most frequently encountered after a gastric operation, but in children, bezoars are associated with pica, mental retardation, and coexistent psychiatric pathologic disorders. We describe a 4-year-old girl with trichotillomania in whom a gastric trichobezoar resulted in failure to gain weight, iron deficiency anemia, and a painless epigastric mass. The causes of gastric bezoars are discussed, with emphasis on diagnostic considerations, treatment options, and preventive measures.

Vena caval impalement: an unusual lawn mower injury in a child.

Penetrating injury to the vena cava is a potentially life threatening condition that necessitates prompt recognition and immediate treatment. Herein we describe a unique lawn mower-related injury in a 4-year-old boy, resulting in the impalement of the inferior vena cava by a foreign body projectile. Relevant concepts in the management of children with lawn mower injuries are discussed, with emphasis on penetrating injury to the inferior vena cava.

Nonoperative management of solid organ injuries in children. Is it safe?

OBJECTIVE: The authors reviewed their experience with life-threatening blunt injuries in approximately 2900 children (0-14 years) admitted to the designated state pediatric shock trauma unit between 1990 and 1993. METHODS: During this time, the authors treated all severely injured children with a prospective, nonoperative protocol if they were hemodynamically stable after less than 40 mL/kg fluid replacement, had proven evidence of solid organ injuries and remained stable in the pediatric intensive care unit under surgical management. RESULTS: Twenty-eight children had computed tomography (CT) or operatively proven lacerations of the spleen, 25 had lacerations of the liver, 18 had lacerations of the kidney, 7 had lacerations of the pancreas, and 11 had two or more solid organ injuries. Three of the 28 children with injured spleens required laparotomy (two splenectomy, one splenorrhaphy). Two of the 25 children with liver injuries required laparotomy (one suturing, one partial resection). One of the 18 children with kidney injuries required laparotomy (nephrectomy), and 3 of the 7 children with pancreas injuries required laparotomy (two resection, one pseudocyst). There were three deaths after laparotomy (two head, one chest/abdominal). There were no deaths in the children managed nonoperatively, and there were no immediate or long-range complications. CONCLUSIONS: Comparison of the authors' data with the National Pediatric Trauma Registry shows similar results. The authors believe that nonoperative management of solid organ injuries under careful surgical observation in a pediatric intensive care unit is safe and appropriate.

Maturational differences in hepatic microhemodynamics in rats.

Age-related changes in the hepatic microcirculation may contribute to the increased susceptibility of the immature liver to microvascular injury. We quantified sinusoidal and acinar diameters, sinusoidal red cell velocities (VRBC), and sinusoidal volume flows to characterize microhemodynamics of weanling and adult rat livers with and without hepatic artery (HA) ligation using intravital fluorescence videomicroscopy. Despite a 20% faster heart rate and a nearly 20% lower mean arterial and portal vein pressure in weanling rats relative to those in the adults, weanling periportal and pericentral sinusoidal velocities were approximately 30 and 25% faster, respectively, than those in adults. Furthermore, the HA was found to contribute more to maintenance of sinusoidal VRBC in the immature liver as demonstrated by a significant decrease in both periportal and pericentral VRBC following HA ligation. HA ligation had no effect on VRBC of either zone in adults. Zonal volume flow (HA intact), however, was maintained independent of age. These results suggest a lower extrasinusoidal resistance in the weanling. The 25% shorter acinar diameter that we found in weanling livers likely contributes to a lower extrasinusoidal resistance by allowing a higher ratio of inflow vessels to volume of tissue. Shorter sinusoidal pathways in weanling livers also decreases sinusoidal resistance 1.3-fold relative to that in the adult, countering the approximately 1.5 times increase in resistance due to the smaller caliber of sinusoidal vessels so that overall sinusoidal resistance is not age-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrahepatic hepatocyte transplantation following subtotal hepatectomy in the recipient: a possible model in the treatment of hepatic enzyme deficiency.

Orthotopic liver transplantation as treatment for hereditary enzyme deficiencies in the absence of cirrhosis suffers from significant operative risks, complications, and donor shortages. Transplantation of isolated hepatocytes (HTX) may offer opportunities for the treatment of these diseases and retain the recipient liver. Hepatocytes transplanted into the portal vein, spleen, or omentum lack an ideal growing environment for cell proliferation and maintenance. Therefore, we investigated a method combining 75% recipient hepatectomy with direct injection of hepatocytes into the remaining 25% of liver parenchyma to provide proliferative stimuli and a stable environment during and following liver regeneration. Recipient Gunn rats (glucuronyltransferase deficiency and hyperbilirubinemia) underwent hepatectomy before HTX by direct injection of 10(7) isolated hepatocytes into the remaining parenchyma. Inbred male Wistar and Gunn rats were used as normal and control hepatocyte donors and saline injection served as a sham transplant control. Isolation of donor hepatocytes was performed with a two-step collagenase digestive method (Seglen) with cell viability of 85% to 95%. Liver regeneration was complete by 2 weeks posttransplant. Four weeks following HTX, total serum bilirubin and qualitative bile analysis were performed. A significant decrease in total serum bilirubin levels was observed in Gunn rats receiving Wistar hepatocytes compared with those receiving Gunn hepatocytes and saline control. Bile analysis from HTX rats demonstrated a normal pattern containing bilirubin monoglucuronides and diglucuronides (conjugated bilirubin) in the rats receiving Wistar hepatocytes, whereas the control group receiving Gunn hepatocytes or saline injection demonstrated only unconjugated bilirubin. No differences in histological appearance were noted between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal villus microcirculatory response to hemorrhage in adult and immature rats.

The response of the villus microcirculation to moderate hemorrhage was compared in adult and immature rats. As an estimate of villus blood flow, flux of red blood cells through the terminal arteriole loop at the villus tip was quantified in vivo using fluorescence epilumination videomicroscopy. Baseline red blood cell flux and mean arterial pressure (MAP) of immature rats (973 cells/s, 84 mm Hg) were significantly less than that of adults (1,435 cells/s, 131 mm Hg). Following hemorrhage of 30% of estimated blood volume, MAP of immature rats was still 24% less than that of adults; however, villus flux was not significantly different (578 cells/s immature, 640 cells/s adult; P = .63). Thus, as indicated by changes in villus flux, immature rats do not appear to be more susceptible to acute intestinal blood flow reduction induced by a single moderate hemorrhage. Immaturity of villus microvascular anatomy and of intestinal vasoregulatory mechanisms may account for the differential response.

Conjugated desferoxamine attenuates hepatic microvascular injury following ischemia/reperfusion.

Iron-dependent oxy radicals have been implicated in reperfusion injury. Although the iron chelator desferoxamine (DFO) is beneficial, its hemodynamic effects and short vascular retention limit its use in vivo. We tested whether DFO conjugated to a high-molecular-weight starch might ameliorate in vivo hepatic microvascular injury without adverse side effects following 120 min of ischemia. Prior to reperfusion, conjugated DFO (100 mg/kg), vehicle (Veh), or saline (I/R) was administered. After 90 min of reperfusion, blood was collected for serum transaminase determination (ALT; U/liter), and fluorescein-albumin was injected to label perfused microvessels, which were quantified in frozen sections by a point-count technique. Tissue edema was estimated by wet to dry weight ratios (W/D). Reperfusion results in hepatocyte injury (rise in ALT and W/D) and a 30% loss of perfused microvessels. Intravenous administration of conjugated DFO produces no significant change in systemic hemodynamics, whereas both ALT and tissue edema were decreased by approximately 50%. Moreover, perfused microvessels were restored virtually to nonischemic control levels. Enhanced perfusion and attenuated cell injury with DFO suggest that microvascular failure and resultant cell death are mediated, at least in part, by iron-dependent mechanisms in reperfusion.

Post-necrotizing enterocolitis strictures presenting with sepsis or perforation: risk of clinical observation.

Intestinal stenosis or stricture occurs in approximately one third of medically treated infants surviving the acute phase of necrotizing enterocolitis (NEC). Identification of these lesions by the use of routine contrast enemas has been advocated as a means of decreasing potential morbidity from delayed diagnosis. However, the significant incidence of spontaneous resolution and reluctance to submit asymptomatic infants to contrast enema have led recent researchers to reserve these studies for patients developing symptoms of obstruction during a period of close observation. From July 1984 to July 1986, symptomatic strictures developed in five infants (15%) responding to medical management at our institution. Contrast enemas were not routinely performed and four (80%) of these patients presented with life-threatening sepsis or perforation associated with intestinal obstruction. Two infants developed complete colonic obstruction 4 and 6 weeks after discharge from the Intensive Care Nursery, having initially tolerated oral feedings. Both infants were critically ill due to perforation or sepsis and underwent emergency colostomy at community hospitals. Two other infants developed abdominal distension with sepsis and cardiopulmonary decompensation while remaining hospitalized for prematurity and pulmonary insufficiency. These patients became symptomatic 5 and 7 weeks after cautious refeeding while closely monitored in the Intensive Care Nursery. The occurrence of such life-threatening complications suggests that clinical observation alone is not adequate in the management of many of these infants. Contrast enemas should be performed to identify those patients at risk of such potential morbidity or mortality, especially those infants not residing near pediatric surgical facilities.