摘要:

ObjectiveTo investigate the effect of inspiratory time and inspiratory flow on the respiratory mechanics of intubated and ventilated neonates.DesignPhysiology study.SettingTertiary university neonatal intensive care unit.PatientsNeonates requiring mechanical ventilation with (group 1, n = 9) and without lung disease (group 2, n = 6).InterventionsAll infants were ventilated with a Servo 900C Siemens ventilator in the volume-controlled constant-flow mode. Flow and pressure were measured at the Y-piece, while different inspiratory times (25%, 33%, 50%, and 67% of the respiratory cycle) were applied randomly without changing tidal volume.MeasurementsThe constant flow end-inspiratory airway occlusion technique allowed partitioning of the total respiratory system resistance (Rtot,rs) into a standard intrinsic flow resistance (Rint,rs) and a lung/thorax tissue viscoelastic component (&Dgr;Rrs), and it allowed partitioning of the dynamic respiratory system elastance (Edyn,rs) into a static (Est,rs) and a lung/thorax tissue viscoelastic component (&Dgr;Ers). A two-compartment model of the respiratory system was applied to the experimental data.Main ResultsAll respiratory mechanics components were significantly higher in group 1 compared with group 2. Both groups showed increasing Rint,rswith increasing flow and increasing &Dgr;Rrswith increasing inspiratory time. &Dgr;Rrsrepresented 40% to 75% of Rtot,rswhatever the group. Edyn,rsand Est,rschanged with inspiratory time in the very low (<0.4 secs) and the very long inspiratory time range (>1.0 secs). No change was found when clinically, commonly used inspiratory times were applied (0.4–1.0 secs). &Dgr;Ersrepresented 17% to 19% of Edyn,rs. The relationship between &Dgr;Rrsand increasing inspiratory time fitted the exponential two-compartment model (r = .99,p< .001).ConclusionsTotal respiratory mechanics and its components in ventilated newborns with and without lung disease showed inspiratory time dependence. &Dgr;Rrsincreased with increasing inspiratory time as predicted by the two-compartment lung model, whereas standard Rint,rsand Edyn,rsdecreased.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo compare the percentage of nebulized albuterol delivered with conventional (intermittent mandatory ventilation) vs. synchronous (assist-control and assist-control with flow synchronization) ventilation in a neonatal lung model.DesignProspectivein vitrolaboratory study.SettingResearch laboratory.SubjectNeonatal lung model.InterventionsThe model simulated an intubated neonate with a spontaneous respiratory rate of 40, 60, or 80 breaths per minute and compliance and resistance values of bronchopulmonary dysplasia. A VIP Bird ventilator was used for all ventilator modes. Albuterol 2.5 mg was administered with a T Up-Draft II Neb-U-Mist nebulizer attached to a 12.75-cm (10-mL) reservoir of circuit tubing. Albuterol was collected onto a filter (particle retention ≤0.3 &mgr;m) placed proximal to the test lung. After nebulization, the filter was rinsed with water, and albuterol concentrations were determined by high-performance liquid chromatography. Ten random trials for each mode were completed.Measurements and Main ResultsNo significant differences in percentage albuterol delivered were found among the three modes or the three spontaneous respiratory rates (mean ± sd): intermittent mandatory ventilation, 0.11 ± 0.04%; assist-control, 0.12 ± 0.03%; assist-control with flow synchronization, 0.10 ± 0.04%; 40 breaths per minute, 0.11 ± 0.03%; 60 breaths per minute, 0.11 ± 0.04%; and 80 breaths per minute, 0.11 ± 0.05% (p> .05, two-factor analysis of variance).ConclusionsThe percentage of nebulized albuterol delivered to the end of the endotracheal tube in a mechanically ventilated neonatal model was not affected by mode of ventilation under the conditions studied. Further clinical studies are needed to determine whether lung deposition and distribution or clinical efficacy of albuterol is influenced by synchronous ventilation in this patient population.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesTo review the epidemiology, pathophysiology, therapeutic and preventive strategies of transfusion associated graft versus host disease (TA-GVHD) and relate the findings to the critically ill child.DesignReview article of published medical literature related to TA-GVHD.Data SourcesMedline, bibliography search, published national and institutional guidelines.Study SelectionOriginal publications including prospective studies, case reports, case series, laboratory studies, and animal work.Data ExtractionData were extracted manually after we reviewed selected articles and assessed their contribution to knowledge of TA-GVHD.Data SynthesisNew and significant historic information from the selected publications relating to incidence, therapy, prevention, and complications of preventive therapy of TA-GVHD was incorporated.ConclusionsPediatric critical care practitioners should be aware of this preventable but fatal complication of cellular blood product transfusion. High-risk categories include congenital and acquired immunodeficiency, younger age, transfusion of blood donated by family members, and transfusion with fresh whole blood. Children at risk for the development of TA-GVHD include neonates, infants, and children with congenital heart disease, not restricted to children with “classic” DiGeorge syndrome. At present, risk identification and targeted prevention are the only methods to manage TA-GVHD. Aside from minimizing cellular blood product exposure, blood product irradiation is the only established and widely available method to prevent TA-GVHD. Transfusion guidelines need to reflect a balance between the incidence of TA-GVHD and the costs of instituting irradiation to selected groups or as routine transfusion policy.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Wegener’s granulomatosis is a necrotizing granulomatous vasculitis involving the upper airway, lungs, and kidneys. Diffuse alveolar hemorrhage is a rare and life-threatening presentation of Wegener’s granulomatosis. We report on a previously healthy 13-yr-old boy who presented with fulminant pulmonary hemorrhage leading to acute respiratory distress syndrome and was found to have Wegener’s granulomatosis. The diagnosis was based on clinical, radiologic, serologic, and histologic manifestations. The therapeutic challenges and the modalities of support to sustain life until clinical remission are presented.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

We report hyperkalemic-hypocalcemic cardiac arrest at the initiation of blood-primed continuous venovenous hemofiltration in a 3-wk-old infant. Although hyperkalemia with massive transfusion has been reported and hemodynamic instability is not infrequent at the initiation of continuous venovenous hemofiltration in critically ill children, cardiac arrest in these circumstances is extremely rare at our institution and has not been reported in the literature. We report the case and discuss management strategies for blood-primed extracorporeal circuits.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

PurposeTo evaluate the feasibility of noninvasive ventilation through a nasal mask in the treatment of acute respiratory failure induced by all-trans retinoic acid.DesignObservational, nonrandomized report of two cases.SettingIntensive care unit in a university hospital.PatientsTwo pediatric patients (an 11-yr-old male and a 12-yr-old female) affected by acute promyelocytic leukemia.InterventionsPressure support ventilation was delivered via a nasal mask by means of a bilevel positive pressure ventilator (Respironics, Murrysville, PA).Measurements and Main ResultsWe evaluated the effects of the bilevel positive pressure ventilator on blood gas analysis, respiratory rate, hemodynamics, patient tolerance, complications, and outcome. Patients showed an improvement of blood gas analysis and respiratory rate after 3–6 hrs of noninvasive ventilation. The nasal mask was well tolerated by the two patients. No complications were observed. Patients were discharged from the intensive care unit in stable clinical conditions after 3–4 days.ConclusionsNoninvasive ventilation by a nasal mask can offer effective ventilatory support and improve gas exchange in the treatment of acute respiratory failure in pediatric hematologic patients. In addition, noninvasive ventilation may decrease the risk of life-threatening complications associated with endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesTo describe the toxicokinetics and management of acute pediatric arsenic ingestion.DesignCase report and literature review.SettingTertiary pediatric intensive care unit, St. John’s Children’s Hospital, Springfield, IL.PatientA 22-month-old boy ingested approximately twice the estimated lethal dose of arsenic trioxide (As2O3) ant bait. Only one household arsenical insecticide is available in the United States and is presumed to be shielded from human exposure. He survived without detectable sequelae. Initially, the patient developed signs of acute hemodynamic compromise with tachycardia, hypertension, gastrointestinal symptoms, and poor urine output. He became lethargic with muscle weakness and was somnolent but never developed encephalopathy, seizures, or late onset peripheral neuropathy.InterventionsHe was stabilized with fluid resuscitation, placed on a sodium bicarbonate intravenous drip, and treated with intramuscular dimercaprol (British anti-Lewisite), 5 mg/kg every 6 hrs for 3 days. When the British anti-Lewisite and the sodium bicarbonate drip were discontinued, oral meso 2,3-dimercaptosuccinic acid (Succimer) was administered three times a day for 5 days and thereafter twice daily until the urine arsenic concentration decreased below 50 &mgr;g/L.Measurements and Main ResultsContinuous monitoring in the pediatric intensive care unit included continuous electrocardiogram, arterial blood pressure, urine output, vital signs, arterial blood gases, serum and urine arsenic concentrations, electrolytes, electromyography, and determination of arsenic toxicokinetics. The child’s serum arsenic concentration was the highest ever reported with survival.ConclusionsRecovery from arsenic poisoning was attributable to the restoration and maintenance of adequate cardiac output and renal perfusion in early shock, which allowed depot intramuscular British anti-Lewisite to circulate and eliminate the poison. Although an intravenous antiarsenical chelating agent would be advantageous in treating shock from arsenic poisoning, none is currently available. We urge the immediate use of British anti-Lewisite therapy on patient presentation with suspected toxic arsenic ingestion.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

PurposeThis article describes a neonate with protein S deficiency who presented with life-threatening thrombosis of the aorta. This is the first case report of a neonate with protein S deficiency presenting with aortic thrombosis.Patient and MethodsA 9-day-old boy presented with a history of dark colored urine, vomiting, and apnea. The clinical examination was consistent with a coarctation of the aorta. An echocardiogram showed a normal arch of the aorta. An abdominal ultrasound done revealed an incompletely occluding thrombus in the aorta starting between the celiac axis and superior mesenteric artery to the aortic bifurcation. The patient was started on recombinant tissue plasminogen activator along with heparin and fresh frozen plasma.ResultsWith tissue plasminogen activator, we were able to reestablish flow across the obstruction within a week. The patient had hypertension and renal failure that still requires dialysis.ConclusionProtein S deficiency should be considered in a neonate with aortic thrombosis, and it can be treated successfully with a combination of high-dose tissue plasminogen activator and heparin followed by long-term heparin use.

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1529-7535    

出版商:OVID    

年代:2002

数据来源: OVID