摘要:

ObjectiveTo describe changes in creatinine clearance (CrCl) in a small group of neonates who underwent surgery for repair of transposition of the great arteries or palliation of hypoplastic left heart syndrome. To determine whether serum creatinine, urine output, or the Schwartz formula accurately predict measured CrCl in these patients.DesignProspective, randomized controlled trial with subsequent extraction of information regarding renal function from the database.SettingA 14-bed pediatric intensive care unit in a children’s hospital.PatientsA total of 14 neonates (hypoplastic left heart syndrome, 6; transposition of the great arteries, 8).MeasurementsDemographic information, urine output, serum creatinine, and 24-hr CrCl preoperatively and postoperatively on days 1 and 2.Main ResultsWeight, age, and body surface area were 3.3 ± 0.6 kg, 8.2 ± 6.9 days, and 0.2 ± 0.02 m2, respectively. Urine output increased from 1.8 ± 0.5 mL·kg−1·hr−1preoperatively to 2.4 ± 0.8 mL·kg−1·hr−1on postoperative day 1 (p= .02) and 2.8 ± 1.1 mL·kg−1·hr−1on postoperative day 2 (p= .007). Serum creatinine changed from 0.64 ± 0.15 mg/dL preoperatively to 0.72 ± 0.40 mg/dL on postoperative day 1 (p= .4, not significant) to 0.78 ± 0.41mg/dL on postoperative day 2 (p= .17, not significant). Measured CrCl changed from 22.8 ± 9.4 mL·min−1·1.73 m−2preoperatively to 25.1 ± 31 mL·min−1·1.73 m−2on postoperative day 1 (p= .77, not significant) and 24.9 ± 19.9 on postoperative day 2 (p= .69, not significant). No difference in measured CrCl was noted based on hypoplastic left heart syndrome vs. transposition of the great arteries. Median overestimation of CrCl by the Schwartz equation was 58% preoperatively, 78% on postoperative day 1, and 53% on postoperative day 2. Clinically significant correlations were not noted between measured CrCl and serum creatinine or urine production preoperatively, on postoperative day 1, or on postoperative day 2. Bland-Altman plot demonstrated that the Schwartz equation was a biased and imprecise estimate of CrCl at all three time points.ConclusionsPerioperative CrCl is unpredictable in neonates with transposition of the great arteries and hypoplastic left heart syndrome. Serum creatinine, urine output, and the Schwartz formula do not accurately predict CrCl. Reliance on estimates of CrCl could result in toxic concentrations of drugs eliminated by the kidneys.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo compare the Bispectral Index with clinical sedation assessment using the Ramsay score in normal sedated and paralyzed critically ill children.DesignProspective observational study.SettingMultidisciplinary 18-bed pediatric intensive care unit at a university-affiliated children’s hospital.PatientsA total of 48 pediatric intensive care unit patients requiring mechanical ventilation and sedation. Of these, 24 patients were not paralyzed.Measurements and Main ResultsTwenty-four pediatric intensive care unit children with normal mentation who were sedated and being ventilated in the intensive care unit were included in the study. The Ramsay score as assessed by the nurses was compared with the blinded Bispectral Index score. The regression coefficient between the Bispectral Index score and Ramsay score was 0.77 (p< 0.0001). The second group of patients included normal children similar to the previous group but paralyzed. The Ramsay score, as expected, was a poor tool for sedation assessment in a paralyzed patient. The nurse assessment only detected 8% of those patients at risk for awareness and recall (Bispectral Index score, ≥80). Nurse assessment for oversedation (Bispectral Index score, <40) was better with a sensitivity of 89.7% but a poor specificity of 38.6%.ConclusionsThe Bispectral Index correlates well with the Ramsay score in the normal sedated child. The Ramsay score and bedside nurse assessment are inadequate for monitoring the depth of sedation in paralyzed children. The Bispectral Index is a useful adjunct in assessing sedation in a paralyzed patient.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTransfusion of packed red blood cells containing high concentrations of potassium have been associated with fetal and neonatal arrhythmia and hyperkalemic cardiac arrest. This study sought to determine the biochemical and associated clinical effects of packed red blood cells transfusion in critically ill children.DesignProspective case series.SettingTertiary multidisciplinary university hospital pediatric intensive care unit.PatientsConsecutive sample of 28 children 2.7–27 kg (1 wk to 12 yrs old) receiving a packed red blood cell transfusion.InterventionsNone.Measurements and Main ResultsPotassium concentration was prospectively measured from packed red blood cell transfusions. Adverse events were recorded during and for 4 hrs following transfusion including hyperkalemia, therapy for hyperkalemia, arrhythmia, cardiac arrest, and death. There were 54 packed red blood cell transfusions (mean volume of 11.8 ± 2.8 mL/kg). The measured packed red blood cell potassium concentration was >25 mmol/L in 16, 15–25 mmol/L in 11, and < 15 mmol/L in 25. The mean patient potassium concentrations before (3.85 ± 0.55, range 2.7–5.2 mmol/L) and after transfusion (3.94 ± 0.62, range 2.8–5.7 mmol/L) were not significantly different. There was no therapy required for hyperkalemia, no new arrhythmia, no cardiopulmonary arrest, and no deaths during and up to 4 hrs following transfusion. Of the six children given a bolus of packed red blood cells (≥5 mL/kg over <10 mins), the maximum increase in patient potassium concentration was 0.8 mmol/L, in a child who had an initial potassium concentration of 2.7 mmol/L. No patient’s potassium concentration was >5 mmol/L following rapid transfusion.ConclusionsThis prospective study found no significant change in patient potassium concentration and no acute adverse events related to transfusion in critically ill children, including those receiving packed red blood cells by bolus. Larger prospective studies are required to evaluate the acute effects of rapid and central venous transfusion in critically ill children.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveDisconnecting the endotracheal tube from the ventilator causes significant loss in lung volume, which is further exacerbated by suctioning. In-line catheter suction systems have putative benefits over open catheter suction by maintaining positive pressure, thereby minimizing hypoxemia and hemodynamic instability. However, there is a theoretical risk of generating large negative airway pressures and auto-cycling of the ventilator with in-line catheter suction systems. We studied the effects on lung volume with both these techniques.DesignOpen, randomized, crossover, clinical trial.SettingPediatric critical care unit.PatientsFourteen paralyzed patients, age 6 days to 13 yrs.InterventionsEach patient, acting as his or her own control, was suctioned with an in-line catheter suction system and open catheter suction. Each suction maneuver was standardized. Changes in lung volume were measured by inductance plethysmography. Heart rate, blood pressure, and oxygen saturation were continuously monitored.Measurements and Main ResultsTotal lung volume loss was greater with open catheter suction compared with in-line catheter suction systems (p= .008). The most significant amount of lung volume loss associated with open catheter suction appears to be related to ventilator disconnection, rather than actual suctioning. Patients with decreased pulmonary compliance (<0.8 mL/cm H2O/kg) demonstrated a greater loss in lung volume, both absolute and relative, as a result of ventilator disconnection (p= .038 and .006, respectively). Patients suctioned with open catheter suction desaturated to a greater extent than patients suctioned with in-line catheter suction (p= .026). There was evidence of ventilator triggering during the actual suction maneuver in all patients during in-line catheter suctions.ConclusionsThe most significant loss in lung volume during suctioning occurs primarily during ventilator disconnection. Hence, open catheter suction results in greater lung volume loss when compared with in-line catheter suction. We suggest that in-line catheter suction is preferable, especially in patients with significant lung disease and who require high positive end-expiratory pressures, to avoid alveolar derecruitment and exacerbating hypoxemia during endotracheal tube suctioning.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo define nosocomial urinary tract infection (NUTI) rates in a pediatric intensive care unit, and determine whether practice recommendations have been sustained after 10 yrs.DesignRetrospective, descriptive observational study followed by point prevalence audits of duration of urinary tract catheterization.SettingA 32-bed pediatric intensive care unit in a multidisciplinary, 300-bed, university-affiliated tertiary care hospital.SubjectsThe retrospective review included patients admitted to the pediatric intensive care unit between December 1997 and July 1999 who developed a NUTI. The audits of duration of urinary tract catheterization were performed in December 2001.InterventionsNone.Measurements and Main ResultsThe primary outcome measure was the development of NUTI. Out of 2,832 consecutive admissions, 25 patients developed 27 episodes of NUTI (rate, 0.95/100 admissions). Previous surgery for congenital heart disease was the primary risk factor for NUTI. All 18 patients for whom the duration of catheterization was available had been catheterized for at least 3 days. Gram-negative bacilli and yeast accounted for 82% of NUTI pathogens. Twenty percent of bacterial pathogens were antibiotic resistant. Audits of the duration of urinary tract catheterization done on five separate occasions revealed that the mean duration of catheterization ranged from 3.5 to 4.7 days, with a peak absolute value of 16 days.ConclusionsNUTIs in children in our pediatric intensive care unit were associated with previous cardiovascular surgery and with urinary tract catheterization of at least 3 days. The need for careful fluid monitoring by catheterization must be balanced against the increased risk of catheter-related urinary tract infection. Removal of urinary catheters at the earliest opportunity will prevent many infections. Ongoing education or innovative strategies will be required to sustain optimal practice.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo compare the effects of administering propofol as a continuous infusion vs. bolus dosing in children undergoing ambulatory oncologic procedures in the pediatric intensive care unit (PICU).DesignProspective, randomized study.SettingTertiary PICU in a university hospital.PatientsAmbulatory oncology patients scheduled for diagnostic or therapeutic procedures with propofol anesthesia in the PICU were eligible for enrollment.InterventionsPatients were randomly assigned to receive either continuous infusion or bolus administration of propofol in a protocol-driven manner. All patients received an initial bolus of 1.5 mg/kg, with additional 0.5 mg/kg doses until complete induction. Continuous infusions were started at 0.1 mg/kg/min and, if needed, increased 20% after a bolus of 0.5 mg/kg. Bolus group patients were given doses of 0.5 mg/kg if needed. Ramsay scores of <5 were used as criteria for additional dosing.Measurements and Main ResultsEighteen patients undergoing 40 separate procedures were enrolled during the study period. Twenty procedures each were performed with continuous or bolus administration of propofol. No differences were present between groups in demographic characteristics, induction dose and time, procedure and recovery times, or adverse events. All patients had adequate anesthesia and favorable satisfaction scores. More boluses were needed in the bolus group (8.5 ± 4.6 vs. 5.4 ± 2.9;p< .05). Average systolic blood pressure decreased more in the continuous infusion group (26.4% ± 12 vs. 19.3% ± 10;p< .05). Total propofol dose was higher in the continuous infusion group (8.0 mg/kg ± 3.8 vs. 5.7 mg/kg ± 2.4;p< .05).ConclusionBoth continuous and bolus administration of propofol provided conditions for conducting oncologic procedures that were satisfying to patients, their families, and physicians. Continuous infusions were associated with a larger total dose and greater decreases in systolic blood pressure. Physician preference is likely to dictate which method is used.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveWe investigated the time course of intracellular adhesion molecule-1 messenger RNA induction following cardiopulmonary bypass with hypothermic circulatory arrest.DesignAnimal case study.SettingAn animal research laboratory and molecular biology laboratory at a university children’s hospital.SubjectsNeonatal lambs.InterventionsNeonatal lambs were cooled on cardiopulmonary bypass for 30 mins, followed by hypothermic circulatory arrest at 15°C for 120 mins and warming on cardiopulmonary bypass for 30 mins. Animals were killed after 0, 3, or 6 hrs of reperfusion. Control animals had sternotomy only. To generate a species-specific probe, ovine intracellular adhesion molecule-1 complementary DNA was cloned and sequenced. By using a ribonuclease protection assay, we measured intracellular adhesion molecule-1 messenger RNA in lung, cardiac ventricle, and brain, with nonmuscle actin as an internal control. Data were quantitated by PhosphorImager.Measurements and Main ResultsIn lung, intracellular adhesion molecule-1 messenger RNA was induced immediately following cardiopulmonary bypass/hypothermic circulatory arrest with no reperfusion (mean increase of 1.7-fold vs. control). The highest intracellular adhesion molecule-1 messenger RNA levels were found at 3 hrs reperfusion (mean increase of 2.8-fold vs. control), but the levels remained significantly elevated at 6 hrs reperfusion (mean increase of two-fold vs. control). Although not statistically significant, cardiac ventricle showed the highest intracellular adhesion molecule-1 messenger RNA levels at 6 hrs reperfusion. The brain had lower levels of intracellular adhesion molecule-1 messenger RNA than lung or ventricle and did not demonstrate induction.ConclusionsWe found an earlier peak induction of intracellular adhesion molecule-1 messenger RNA in lung compared with ventricle. This may represent both local ischemic injury and filtering of bypass-related inflammatory mediators in the pulmonary capillary bed. Early intracellular adhesion molecule-1 messenger RNA induction may reflect its role in neutrophil-mediated, ischemia-reperfusion injury.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectivesTo evaluate carbon dioxide clearance in normal rabbits during high-frequency oscillatory ventilation with helium-oxygen mixtures by using a low bias flow oscillation (LBFO) system designed to conserve expensive gas.DesignA prospective, paired-controlled, interventional,in vivoanimal laboratory study.SettingAnimal laboratory of a health science university.SubjectsTwelve New Zealand White rabbits.InterventionsJuvenile rabbits were anesthetized, paralyzed, and ventilated through a tracheostomy. LBFO was performed with a modified high-frequency oscillatory ventilation circuit that uses low bias flow (100 mL/kg) and a soda lime cartridge to clear carbon dioxide. LBFO-heliox trials were performed with 20%, 40%, 50%, 60%, and 70% helium (balanced with oxygen) for 30 mins. Each heliox trial was preceded by a paired control trial with 40% oxygen and 60% nitrogen for 30 mins. Ventilator settings in control and heliox trials were identical. During the second part of the study, four rabbits were made hypercapnic by decreasing the power (amplitude), and LBFO was performed with 70% helium against paired-control trials of 40% oxygen and 60% nitrogen. Arterial blood gases were measured at 15-min intervals and airway pressure amplitude was recorded. Paco2of control and heliox trials, alveolar Po2-Pao2gradient of control, and 60% helium trials were compared by paired Student’st-test.Measurements and Main ResultsAt constant power, amplitude was unaffected by helium. Helium concentrations of 40%, 50%, 60%, and 70% decreased Paco2by 12%, 33%, 36%, and 46%, respectively. Alveolar Po2-Pao2gradient was decreased by 40% during ventilation with 60% helium. Under hypercapnic conditions, 70% helium decreased Paco2by 20%.ConclusionHelium concentrations ≥40% facilitate carbon dioxide clearance from lungs of normal rabbits during LBFO. This could be accomplished inexpensively with LBFO due to preservation of heliox when using this device.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model.DesignProspective intervention study in animals.SettingAnimal research laboratory of a university medical center.SubjectsSix anesthetized newborn lambs with patent ductus arteriosus and left-to-right shunt, installed on venoarterial extracorporeal membrane oxygenation.InterventionsSix lambs of 140 days gestational age were prepared to keep the ductus arteriosus open by infiltration of the vessel wall with formaline 10%. The animals were installed on standard venoarterial extracorporeal membrane oxygenation. With a mechanical occluder, the ductus was closed.Measurements and Main ResultsChanges of mean arterial blood pressure and carotid artery blood flow were measured simultaneously. Using near infrared spectrophotometry, we calculated changes in cerebral concentration of oxyhemoglobin and deoxyhemoglobin (reflecting changes in cerebral oxygen supply) and total hemoglobin (reflecting changes in cerebral blood volume). Also, cerebral oxygen delivery before and after ductus closure was calculated. Before ductus closure there was a left-to-right shunt with a mean ± sem of 41 ± 20% of total body blood flow. Closure of the ductus resulted in an immediate increase in mean arterial blood pressure and carotid artery blood flow. The concentration of oxyhemoglobin increased and the concentration of deoxyhemoglobin decreased, representing increased cerebral oxygen supply. The concentration of total hemoglobin was unchanged, representing unchanged cerebral blood volume. There was an increase in cerebral oxygen delivery.ConclusionsIn this lamb model, a considerable left-to-right shunt over the ductus during venoarterial extracorporeal membrane oxygenation reduced cerebral circulation and oxygenation.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo report an 11-yr-old boy with acute status asthmaticus being managed with permissive hypercapnia who developed a subarachnoid hemorrhage during the course of his illness.SettingAn eight-bed pediatric intensive care unit in a community hospital.InterventionsThe patient was intubated for respiratory failure and managed with permissive hypercapnia. After the development of changes in his pupillary exam, computerized tomography of the brain revealed diffuse subarachnoid hemorrhage. Carotid angiography was performed to rule out the possibility of underlying vascular malformation.ResultsAggressive investigation including a normal carotid angiogram failed to reveal underlying pathology that may have put the patient at risk for the event.ConclusionsWe conclude that this patient suffered subarachnoid hemorrhage in association with the use of permissive hypercapnia in the setting of severe asthma.

ISSN:1529-7535    

出版商:OVID    

年代:2003

数据来源: OVID