摘要:

ObjectivesWe sought to test the assumption that the measured concentrations of medication infusions are within pharmaceutical standards (±10% of intended concentrations) and whether, at the time the infusion was mixed, the professional background of persons preparing the infusion or the unit for which the infusion was prepared were related to the observed variation.Design, Setting, and ParticipantsThis prospective, observational study was conducted in the neonatal and pediatric intensive care units of a university-affiliated tertiary pediatric center. Morphine infusions prepared for clinical use were randomly sampled over a 7-month period. Those with no error between labeled and ordered concentration were further analyzed. High-performance liquid chromatography was used to determine the concentration of morphine infusions. The primary outcome was a difference of >10% between ordered and measured concentrations.Measurements and Main ResultsThe measured concentration of 65% of the 232 infusions was >10% different from the ordered concentration (95% confidence interval, 58–71%). The concentrations of 6% of infusions represented two-fold errors (95% confidence interval, 3–9%). The difference was normally distributed around zero, suggesting a cumulative effect of random errors, rather than a systematic bias. The time that the infusion was prepared, the professional background of the persons preparing the infusion, and the unit for which the infusion was mixed were not significant predictors of discrepancy (p= .74, analysis of variance).ConclusionsThe concentration of two thirds of infusions prepared for clinical use was outside accepted industry standards. These findings are likely to be broadly representative of intravenous drug administration in hospitalized children and pediatric pharmacokinetic studies. Further study of the causes and clinical impact is required.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine the percentage of time that intensive care unit (ICU) nurses spend on documentation and other nursing activities before and after installation of a third-generation ICU information system.DesignProspective data collection using real-time time-motion analysis, before and after installation of the ICU information system.SettingA ten-bed surgical ICU at a Veterans Affairs medical center.SubjectsICU nurses.InterventionsInstallation of a third-generation ICU information system.Measurements and Main ResultsTen ICU nurses were studied before and after installation of the ICU information system. Each ICU nurse’s activities and tasks, during 4-hr observation periods, were categorized in real-time by a nurse observer and recorded in a laptop computer. Each recorded task was automatically time-stamped and logged into a data file. The percentage of time spent on documentation decreased from 35.1 ± 8.3% to 24.2 ± 7.6% (p= .025) after the ICU information system was installed. The percentage of time providing direct patient care increased from 31.3 ± 9.2% to 40.1 ± 11.7% (p= .085). The percentage of time doing patient assessment, a direct patient care task, increased from 4.0 ± 4.7% to 9.4 ± 4.4% (p= .001).ConclusionsInstallation of a third-generation ICU information system decreased the percentage of time ICU nurses spent on documentation by >30%. Almost half of the time saved on documentation was spent on patient assessment, a direct patient care task.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo examine the effects of hypertonic/hyperoncotic treatment on physiologic variables and regional cerebral blood flow and to test its neuroprotective efficiency in a model of permanent venous ischemia.DesignRandomized prospective study.SettingUniversity research institute.SubjectsAdult male Wistar rats, weighing 359 ± 54 g (n = 38).InterventionsRats were subjected to photochemical occlusion of two adjacent cortical veins. A randomized infusion with vehicle (0.9% NaCl), 10% hydroxyethyl starch 200000 (HES), or 7.5% saline plus 10% hydroxyethyl starch 200000 (HHES) was started 30 mins after two-vein occlusion. Effects on physiologic variables and regional cerebral blood flow (assessed by laser Doppler flowmetry) were studied up to 120 mins after two-vein occlusion. Two days after occlusion, the brains were removed for histologic evaluation.Measurements and Main ResultsAfter occlusion, regional cerebral blood flow decreased by 50%, significantly in all groups (from 47.3 ± 3 to 22.2 ± 2.2 laser Doppler units). In the vehicle and HES groups, regional cerebral blood flow further decreased to 12.9 ± 1.9 and 17.8 ± 2.3 laser Doppler units, respectively. HHES improved regional cerebral blood flow significantly to 27.3 ± 3.5 laser Doppler units, particularly by reducing no-flow/low-flow areas and reducing infarct size.ConclusionWe found that HHES reduced infarct size as a consequence of an improved regional cerebral blood flow and reduced no-flow/low-flow areas in the tissue at risk in the two-vein occlusion model.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine the effectiveness of nasopharyngeal cooling for selective brain cooling and neuroprotection from ischemia.DesignProspective animal study.SettingExperimental laboratory in a university hospital.SubjectsMale Wistar rats (n = 28).InterventionsIn study 1, hippocampal temperature was decreased to 31°C under spontaneous circulation. In the nasopharyngeal cooling group, physiologic saline (5°C) was infused to the bilateral nasal cavities at the rate of 100 mL·min−1·kg weight−1. In the whole body cooling group, a fan and a water blanket (5°C) were used. In study 2, ischemia and resuscitation were performed in normothermic and nasopharyngeal cooling (initiated with resuscitation after 5 mins of ischemia and continued for 20 mins) groups.Measurements and Main ResultsThe hippocampal temperature was decreased to 31°C in 7 ± 2 mins without any change in the rectal temperature in the nasopharyngeal cooling group, whereas a decrease in hippocampal temperature to 31°C took 33 ± 1 mins in the whole body cooling group. Although skull base region was cooled by nasopharyngeal cooling, the epidural temperature of the parietal region was lower than the hippocampal temperature, indicating that brain temperature was hematogeneously lowered. There was no difference between changes in cerebral blood flow or between the ratios of oxygen extraction from arterial blood in the head region in the nasopharyngeal cooling and whole body cooling groups. In the second study, all animals were successfully resuscitated, and the times required for recovery of mean arterial blood pressure (60 mm Hg) after resuscitation in the nasopharyngeal cooling and normothermic groups were the same. The histologic damage was significantly attenuated in the nasopharyngeal cooling group (33 ± 21% cell death in the hippocampus) compared with that in the normothermic group (73 ± 11%).ConclusionsNasopharyngeal cooling enables rapid and selective reductions in cortical and subcortical temperatures without disturbing the recovery of systemic circulation after resuscitation.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectivesTo measure changes in medullary and cortical renal blood flow during experimental hyperdynamic sepsis and the effect of subsequent norepinephrine infusion on such flows.DesignExperimental animal study.SettingAnimal laboratory of university-affiliated physiology institute.SubjectsEighteen anesthetized merino sheep.InterventionsA transit-time flow probe was placed around the left renal artery. Laser Doppler flow probes were inserted in the left renal medulla and cortex by micromanipulation to measure changes in regional intrarenal blood flow.Measurements and Main ResultsSystemic pressures, cardiac output, renal, and intrarenal blood flows were measured continuously. A bolus ofEscherichia coli(7.5 × 109colony forming units) was given intravenously to induce hyperdynamic sepsis. After the onset of hyperdynamic sepsis, all animals were randomly allocated to either norepinephrine (0.4 &mgr;g·kg−1·min−1for 30 mins) or observation for 30 mins in random order.E. coliinjection induced a significant decrease in mean arterial pressure (102.2 ± 15.2 mm Hg to 74.3 ± 16.1 mm Hg,p< .05) and an increase in mean cardiac output (4.60 ± 1.62 L/min to 5.93 ± 1.18 L/min,p< .05). However, renal blood flow did not change significantly (326.4 ± 139.4 mL/min to 293.1 ± 117.5 mL/min, not significant) despite a 30% increase in renal conductance (3.27 ± 1.52 to 4.13 ± 2.01 mL·min−1·mm Hg−1,p< .05). Cortical blood flow decreased by 15% (not significant) and medullary flow by 5% (not significant) during sepsis, but individual changes were unpredictable. On the other hand, norepinephrine infusion caused a significant improvement in mean arterial pressure (74.3 ± 16.1 to 105.7 ± 17.7 mm Hg,p< .05) and a further increase in cardiac output (5.93 ± 1.18 to 7.13 ± 1.52 L/min,p< .05). Mean renal blood flow also increased (293.1 ± 117.5 to 384.5 ± 168.1 mL/min,p< .05) despite decreased renal conductance (4.13 ± 2.01 to 3.73 ± 1.91 mL·min−1·mm Hg−1,p< .05). Infusion of norepinephrine significantly increased medullary blood flow by 35% compared with baseline (p< .05) and by 54% compared with untreated sepsis (p< .05), whereas the increases in cortical blood flow (16 and 53%, respectively) were not significant.ConclusionsHyperdynamic sepsis caused renal vasodilation but had limited effects on regional intrarenal blood flow. Norepinephrine infusion (0.4 &mgr;g·kg−1·min−1) during sepsis significantly increased global and medullary renal blood flow and restored renal vascular tone toward but not above normal.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo evaluate a new technique for pressure-volume curve tracing.DesignProspective experimental study.SettingAnimal research laboratory.SubjectsSix anesthetized rats.InterventionsTwo pressure-volume curves were obtained by means of the super-syringe method (gold standard) and the continuous positive airway pressure (CPAP) method. For the CPAP method, the ventilator was switched to CPAP and the pressure level was raised from 0 to 50 cm H2O in 5 cm H2O steps and then decreased, while we measured lung volume using respiratory inductive plethysmography. Thereafter, lung injury was induced using very high-volume ventilation. Following injury, two further pressure-volume curves were traced. Pressure-volume pairs were fitted to a mathematical model.Measurements and Main ResultsPressure-volume curves were equivalent for each method, with intraclass correlation coefficients being higher than .75 for each pressure level measured. Bias and precision for volume values were 0.46 ± 0.875 mL in basal measurements and 0.31 ± 0.67 mL in postinjury conditions. Lower and upper inflection points on the inspiratory limb and maximum curvature point on the deflation limb obtained using both methods and measured by regression analysis also were correlated, with intraclass correlation coefficients (95% confidence interval) being .97 (.58, .99), .85 (.55, .95), and .94 (.81, .98) (p< .001 for each one). When inflection points were estimated by observers, the correlation coefficient between methods was .90 (.67, .98) for lower inflection points (p< .001). However, estimations for upper inflection points and maximum curvature point were significantly different.ConclusionsThe CPAP method for tracing pressure-volume curves is equivalent to the super-syringe method. It is easily applicable at the bedside, avoids disconnection from the ventilator, and can be used to obtain both the inspiratory and the deflation limbs of the pressure-volume curve. Use of regression techniques improves determination of inflection points.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo evaluate the effects of high-frequency oscillation on the response to exogenous surfactant in lung-injured adult sheep.DesignA prospective, controlled,in vivo, animal laboratory study.SettingAnimal research facility of a health sciences university.SubjectsTwenty-eight adult sheep.InterventionsAnimals were anesthetized and instrumented with a tracheostomy and vascular catheters. Following whole lung saline lavage, animals were randomized to one of four groups: Group S-CMV received surfactant and was ventilated for 4 hrs using a conventional mechanical ventilation strategy, group S-HFOV/CMV received surfactant and was ventilated with a high-frequency oscillation technique for 2 hrs and a conventional mechanical strategy for 2 hrs, group HFOV/CMV underwent the latter ventilatory strategies without receiving surfactant, and group HFOV was ventilated with high-frequency oscillation only for 4 hrs. At the end of the ventilatory period, the distributions of ventilation and surfactant were evaluated in animals that received surfactant.Measurements and Main ResultsAnimals in the S-CMV group had a significantly greater mean Pao2value at the end of the experimental period than animals in the S-HFOV/CMV or HFOV/CMV groups. Evaluation of the distribution of ventilation relative to surfactant demonstrated that animals ventilated with high-frequency oscillation followed by conventional mechanical ventilation had a significantly greater disproportionate distribution of ventilation relative to surfactant compared with the CMV-only group.ConclusionsA period of high-frequency oscillation, as used in this study, immediately following exogenous surfactant administration mitigates the host’s response to surfactant when subsequently switched to conventional mechanical ventilation.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveThe aim of the present study was to determine the underlying cellular mechanisms in the pancreas after acute pancreatitis and to study the pathogenesis of pancreatitis-associated lung injury. We applied a differential display analysis to normal pancreas and to the pancreas with acute pancreatitis in rats, and we examined the expression of the identified gene in the lung as well as the pancreas after acute pancreatitis.DesignControlled animal study.SettingResearch laboratory of an academic institution.SubjectsNinety male Wistar rats.InvestigationsPancreatitis was induced by retrograde intraductal infusion of 4% sodium taurocholate (100 &mgr;L/100 g of body weight). Data were compared with data from controls (sham).Measurements and Main ResultsWe cloned some expressed sequence tags and identified one complementary DNA fragment. The deduced protein was a polypeptide of 218 amino acids, which was almost identical to human 19-kD interacting protein-3-like (NIP3L) protein. The expression of rat NIP3L identified in this study increased slightly in the pancreas after induction of acute pancreatitis but showed a marked increase in the lung by both Northern and Western blot analysis. NIP3L immunoreactivity was noted in alveolar and epithelial cells of the control (sham) lung, and the immunoreactivity in these cells was elevated after induction of acute pancreatitis. Moreover, acute pancreatitis increased terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive alveolar and bronchiolar cells in the lung.ConclusionNIP3L may be involved in lung injury, which is one of the major causes of death in cases of severe acute pancreatitis.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo assess the effect on outcome (1 yr) of decompressive craniectomy performed within or after the first 24 hrs posttrauma in severely head-injured trauma patients with intractable cerebral hypertension.DesignRetrospective cohort study.SettingsIntensive care unit of a university hospital.PatientsAmong 816 patients with severe head trauma (Glasgow Coma Scale ≤8), 40 underwent decompressive craniectomy. After data collection, patients were divided into two groups: early and late decompressive craniectomy. An early decompressive craniectomy was performed within the first 24 hrs in patients according to the following criteria: a Glasgow Coma Scale score <6 and the existence of clinical signs of cerebral herniation (absence of pupillary reflexes), correlated with abnormalities in computed tomography scan including hematoma, appearance of diffuse or unilateral brain swelling, and/or cerebral herniation. The intracranial pressure in these patients was not measured before the decompressive craniectomy was performed. A late decompressive craniectomy (>24 hrs) was performed according to following criteria: an intractable intracranial hypertension with intracranial pressure >35 mm Hg, a unilateral or bilateral absence of pupillary reflexes, and the same abnormalities in computed tomography scan as previously described.InterventionTwenty-seven patients with signs of cerebral herniation required the procedure at the time of initial evacuation of a mass lesion. In 13 patients, decompressive craniectomy was performed because of elevated intracranial pressure refractory to medical treatment consisting of cerebrospinal fluid derivation, deep sedation, osmotherapy, hyperventilation, and nesdonal or propofol.Measurements and Main ResultsFive patients (19%) in whom an early decompressive craniectomy was performed had good recoveries (social rehabilitation), eight patients (30%) remained in a persistent vegetative state or with a severe disability, and 14 died (52%). On the other hand, the performance of late decompressive craniectomy in case of medical treatment failure was followed by social rehabilitation in five patients (38%) and death in three patients (23%). A persistent vegetative state or a severe disability was observed in five patients (38%). Meningitis or cerebral abscess occurred in six patients after decompressive craniectomy and were easily cured by antibiotic treatment.ConclusionsIn 40 patients with intractable intracranial hypertension and at very high risk of brain death, decompressive craniectomy allowed 25% of patients to attain social rehabilitation at 1 yr.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

ObjectiveTo determine the utility of continuous noninvasive capnometry for monitoring pediatric patients with diabetic ketoacidosis as assessed by the agreement between end-tidal carbon dioxide (Petco2) and Pco2.DesignClinical, prospective, observational study.SettingUniversity affiliated children’s hospital.InterventionsPatients with diabetic ketoacidosis were monitored with an oral/nasal carbon dioxide (CO2) sampling cannula while in the emergency department. Laboratory studies were ordered per protocol. Petco2values were correlated with respiratory rate, Pco2, and pH.Measurements and Main ResultsOne hundred twenty-one patients were monitored for 5.9 ± 0.32 hrs. The average (mean ± sd) initial values for pH were 7.08 ± 0.18; respiratory rate, 35.1 ± 9.1 breaths/min; Petco2, 18.6 ± 10.8 torr; and venous Pco2, 20.2 ± 10.6 torr. At the conclusion of the observation period, averages were pH, 7.29 ± 0.05; respiratory rate, 22.4 ± 3.7 breaths/min; Petco2, 35.3 ± 5.8 torr; and venous Pco2, 36.8 ± 5.3 torr. For all 592 observations, the correlations between Petco2and venous Pco2(r = .92,p= .0001), Petco2and pH (r = .88,p= .0001), Petco2and respiratory rate (r = −.79,p= .0001), and respiratory rate and pH (r = −.80,p= .0001) were statistically significant and the correlations with respiratory rate were inversely related to pH and Petco2. The difference scores were not related to the average scores for initial readings (r = −.073,p= .43), final readings (r = −.124,p= .18), and overall readings (r = .057,p= .17). Limits of agreement between the two methods were established with Petco2lower than venous Pco2with 95% limits of agreement 0.8 ± 8.3 (2 sd) torr.ConclusionsPetco2monitoring of patients with diabetic ketoacidosis provides an accurate estimate of Pco2. Noninvasive Petco2sampling may be useful in patients with diabetic ketoacidosis to allow for continuous monitoring of patients.

ISSN:0090-3493    

出版商:OVID    

年代:2003

数据来源: OVID