Outcome of renal transplants from pediatric donors <5 yr of age

AIM: Outcomes of single renal transplants from donors <5 yr old have traditionally been inferior to those from older donors. We retrospectively studied our experience with patients who received renal transplants, either individually or en bloc, from young donors (<5 yr of age) to determine the utility of these organs. We also compared the outcomes of these transplant patients maintained on either cyclosporine- (CyA) or tacrolimus-based (TRL) immunosuppression regimens. PATIENTS: Ninety-eight patients received transplants at our center from donors <5 yr of age between August 1993 and August 2003. They were followed-up from 12 months to 11 yr. Patients were divided into four groups based on whether they received single or en bloc transplants, and whether CyA or TRL was the base immunosuppressive agent. Patients in group I (n = 13) received single pediatric kidneys and were treated with CyA regimens; group II patients (n = 26) also received single pediatric kidneys, but were treated with TRL regimens; group III patients (n = 31) were transplanted en bloc and were treated with CyA; and group IV patients (n = 28) received en bloc transplants and were treated with TRL. RESULTS: One-year patient and death-censored graft survival was not significantly different between recipients of en bloc vs. single grafts (i.e. 88 and 85% vs. 90 and 87%, respectively), or between the four treatment groups (group I: 85 and 85%, group II: 92 and 88%, group III: 87 and 84%, and group IV: 89 and 86%, respectively). The overall 1-yr rejection rate was 30% (29 of 98), which was significantly higher in the CyA-treated patients 19 of 44; i.e. 43%, than in TRL-treated patients 10 of 54, i.e. 19%, p = 0.03). In the en bloc recipients, seven grafts (12%) were lost as a result of vascular thrombosis. Notably, none of the single kidneys were lost because of vascular thrombosis. At the end of follow-up the creatinine levels of both groups were comparable. CONCLUSIONS: Pediatric donor kidneys transplanted individually provide for equal patient and graft survival when compared with en bloc transplants. TRL can be used reduce the detrimental effect of acute rejection on graft growth and function when compared with CyA. Single use of such kidneys can safely and efficaciously be transplanted into adult recipients, greatly expanding the donor pool.     

Perioperative N-acetylcysteine to prevent renal dysfunction in high-risk patients undergoing cabg surgery: a randomized controlled trial

Context  Renal dysfunction is a complication of coronary artery bypass graft (CABG) surgery performed with cardiopulmonary bypass (CPB) that is associated with increased morbidity and mortality. N-acetylcysteine, an antioxidant and vasodilator, counteracts renal ischemia and hypoxia. Objective  To determine whether perioperative intravenous (IV) N-acetylcysteine preserves renal function in high-risk patients undergoing CABG surgery with CPB compared with placebo. Design, Setting, and Patients  Randomized, quadruple blind, placebo-controlled trial (October 2003-September 2004) in operating rooms and general intensive care units (ICUs) of 2 Ontario tertiary care centers. The 295 patients required elective or urgent CABG and had at least 1 of the following: preexisting renal dysfunction, at least 70 years old, diabetes mellitus, impaired left ventricular function, or undergoing concomitant valve or redo surgery. Interventions  Patients received 4 (2 intraoperative and 2 postoperative) doses of IV N-acetylcysteine (600 mg) (n = 148) or placebo (n = 147) over 24 hours. Main Outcome Measures  The primary outcome was the proportion of patients developing postoperative renal dysfunction, defined by an increase in serum creatinine level greater than 0.5 mg/dL (44 µmol/L) or a 25% increase from baseline within the first 5 postoperative days. Secondary outcomes included postoperative interventions and complications, the requirement for renal replacement therapy (RRT), adverse events, hospital mortality, and ICU and hospital length of stay. Results  There was no difference in the proportion of patients with postoperative renal dysfunction (29.7% vs 29.0%, P = .89; relative risk [RR], 1.03 [95% confidence interval {CI}, 0.72-1.46]) in the N-acetylcysteine and placebo groups, respectively. We noted nonsignificant differences in postoperative interventions and complications, the need for RRT (0.7% vs 2.1%; P = .37), total (6.1% vs 9.6%; P = .26) and serious adverse events, hospital mortality (3.4% vs 2.7%; P>.99), and ICU and hospital length of stay between the N-acetylcysteine and placebo groups. A post hoc subgroup analysis of patients (baseline creatinine level >1.4 mg/dL [120 µmol/L]) showed a nonsignificant trend toward fewer patients experiencing postoperative renal dysfunction in the N-acetylcysteine group compared with the placebo group (25.0% vs 37.1%; P = .29). Conclusions  N-acetylcysteine did not prevent postoperative renal dysfunction, interventions, complications, or mortality in high-risk patients undergoing CABG surgery with CPB. Further research is required to identify CABG patients at risk for postoperative renal events, valid markers of renal dysfunction, and to establish renal thresholds associated with important clinical outcomes.      

An exploration into the most effective way to teach drug calculation skills to nursing students

Drug calculations are an essential skill for nurses. Nurses need to be able to perform them accurately to calculate correct dosages of drugs to administer to patients. Incorrect calculations can cause drug errors and potential harm to patients (; ). For student nurses therefore learning how to calculate drug dosages is an important skill that they need to be taught during their nurse training. This paper describes an action research project undertaken to explore the most effective way of teaching drug calculations to a group if 2nd year diploma and degree pre registration nurses. The evaluation of this project has demonstrated that a three stage approach to drug calculation appears to be an effective teaching strategy. These stages involve addressing mathematical concepts, teaching drug calculation formulae and then practising these skills in a clinical setting.     

Dexmedetomidine pharmacodynamics: part I: crossover comparison of the respiratory effects of dexmedetomidine and remifentanil in healthy volunteers

BACKGROUND: Dexmedetomidine, a highly selective alpha2-adrenoceptor agonist used for short-term sedation of mechanically ventilated patients, has minimal effect on ventilation. METHODS: This study compared the respiratory effect of dexmedetomidine to that of remifentanil. The authors measured and compared respiratory responses of six healthy male volunteers during (1) a stepwise target-controlled infusion of remifentanil, (2) a stepwise target-controlled infusion of dexmedetomidine, and (3) a pseudonatural sleep session. RESULTS: Compared with baseline, remifentanil infusions resulted in respiratory depression as evidenced by a decrease in respiratory rate and minute ventilation, respiratory acidosis, and apnea episodes resulting in desaturations. Remifentanil disturbed the natural pattern of breathing and flattened the distribution of ventilatory timing (inspiratory time/ventilatory cycle time). The respiratory effects of dexmedetomidine markedly contrasted with those of remifentanil. When compared with baseline, during dexmedetomidine infusions, the respiratory rate significantly increased, and the overall apnea/hypopnea index significantly decreased. The distribution of inspiratory time/ventilatory cycle time showed an increased peak. In addition, dexmedetomidine seemed to mimic some aspect of natural sleep. While the subjects were breathing a 5% CO2 mixture, hypercapnic arousal phenomena (documented by the Bispectral Index, the electroencephalogram, and sudden increase in the minute ventilation) were observed during dexmedetomidine infusions. Similar phenomena during natural sleep have been reported in the literature. CONCLUSIONS: In comparison with remifentanil, dexmedetomidine infusions (1) did not result in clinically significant respiratory depression, (2) decreased rather than increased the apnea/hypopnea index, and (3) exhibited some similarity with natural sleep.     

An effective pyloromyotomy length in infants undergoing laparoscopic pyloromyotomy

BACKGROUND: Traditional management of pyloric stenosis has consisted of open pyloromyotomy during which the surgeon is able to palpate and determine whether the hypertrophied pylorus has been completely divided. During the last decade, laparoscopic pyloromyotomy has become an increasingly popular approach for this condition. The purpose of this study was to determine whether there is an effective pyloromyotomy length that will allow the surgeon to feel confident that a complete pyloromyotomy was performed with the laparoscopic approach. METHODS: All infants undergoing laparoscopic pyloromyotomy from October 1999 through October 2003 at a single institution were retrospectively studied. Clinical variables collected included the patient's age, gender, electrolyte status on admission, the elapsed time from admission to operation, ultrasonographic dimensions of the hypertrophied pylorus, operative time, the length of the pyloromyotomy performed, the time to initial and to full feedings, and the duration of the postoperative hospitalization. RESULTS: One hundred seventy-one patients comprised the study group. The age (mean +/- standard deviation) at the time of operation was 5.2 +/- 2.8 weeks. The mean preoperative ultrasonic measurements for both pyloric thickness and pyloric length were 4.3 +/- 0.7 mm and 19.5 +/- 2.8 mm, respectively. The average pyloromyotomy incision length for this entire group was 1.9 +/- 0.21 cm. The mean operative time was 23.5 +/- 8.3 minutes. There were no mucosal perforations, no conversions to an open procedure, and no evidence for an incomplete pyloromyotomy. CONCLUSIONS: Laparoscopic pyloromyotomy is a safe and effective technique for infants with pyloric stenosis. A pyloromyotomy incision length of approximately 2 cm appears to be an effective measure of a complete pyloromyotomy.     

Comparison of heparin administration using the Rapidpoint Coag and Hepcon HMS

A retrospective chart review was conducted of patients who underwent cardiopulmonary bypass (CPB) to compare the quantities of heparin administered, postoperative blood loss, and homologous blood products transfused during their procedure and subsequent stay in the intensive care unit. The primary purpose of this review was to determine if any difference in heparin administration resulted when two different devices were used for dosing and monitoring heparin. Postoperative blood loss and amount of blood products transfused were also quantified, as any differences would potentially be a result of a difference in administration of heparin. The first group (n = 341) underwent CPB using the Hepcon HMS, Medtronic Inc., Minneapolis, MN, for heparin dosing and monitoring. The Rapid Point Coag, Bayer Healthcare LLC, Tarrytown, NY was used for the second group (n = 345). The two populations were compared for similarity on: age, body surface area (BSA), CPB time (minutes), aortic-cross clamp time (minutes), baseline activated clotting time, and baseline hematocrit. No significant difference was found between the two groups. The second group, using the Rapidpoint Coag, received less heparin during CPB than the group using the Hepcon HMS. In addition, there were decreases in amounts of some blood products transfused as well as mediastinal drainage from the Hepcon HMS to the Rapidpoint Coag group. A summary of the findings can be found in Table 1. A secondary purpose of this study was to determine the influence of hemodilution on the Heparin Management Test (HMT). Citrated whole blood was diluted to varying degrees at various concentrations to determine whether hemodilution with crystalloid would alter the HMT measurements. At all heparin levels and degrees of dilution, the HMT remained stable, with coefficients of variation (CV) of less than 5% at all heparin levels even while incorporating excessive crystalloid dilution (up to 75%).     

Etoricoxib

Etoricoxib (Arcoxia, Merck & Co., Inc.) is a selective inhibitor of cyclooxygenase-2 (COX-2), an enzyme involved in pain and inflammation. It is a member of the COX-2-selective (coxib) class of nonsteroidal antiinflammatory drugs (NSAIDs). Extensive clinical trials have confirmed its analgesic and antiinflammatory efficacy to be at least as good as and in some cases superior to nonselective NSAIDs in a number of disease and patient treatment settings. Etoricoxib displays improved gastrointestinal safety compared with nonselective NSAIDs and has a favorable overall safety and tolerability profile. It is rapidly and completely absorbed following oral administration providing a rapid onset of action. Its long plasma half-life allows for once-daily dosing. Etoricoxib is currently approved in a number of countries for various indications including the treatment of acute pain, acute gouty arthritis, chronic low back pain, primary dysmenorrhea, and chronic treatment for the signs and symptoms of osteoarthritis and rheumatoid arthritis. In countries where it is approved, the highest recommended daily dose for chronic use is 90 mg for rheumatoid arthritis and 60 mg for osteoarthritis and chronic low back pain. The recommended daily dose for acute pain relief treatment from primary dysmenorrhea and acute gouty arthritis is 120 mg. This review summarizes the published preclinical and clinical data relevant to the use of etoricoxib in clinical practice.     

Repositioning accuracy of a commercially available double-vacuum whole body immobilization system for stereotactic body radiation therapy

We evaluated the repositioning accuracy of a commercially available stereotactic whole body immobilization system (BodyFIX, Medical Intelligence, Schwabmuenchen, Germany) in 36 patients treated by hypofractionated stereotactic body radiation therapy. CT data were acquired for positional control of patient and tumor before each fraction of the treatment course. Those control CT datasets were compared with the original treatment planning CT simulation and analyzed with respect to positional misalignment of bony patient anatomy, and the respective position of the treated small lung or liver lesions. We assessed the stereotactic coordinates of distinct bony anatomical landmarks in the original CT and each control dataset. In addition, the target isocenter was recorded in the planning CT simulation dataset. An iterative optimization algorithm was implemented, utilizing a root mean square scoring function to determine the best-fit orientation of subsequent sets of anatomical landmark measurements relative to the original treatment planning CT data set. This allowed for the calculation of the x, y and z-components of translation of the patient's body and the target's center-of-mass for each control CT study, as well as rotation about the principal room axes in the respective CT data sets. In addition to absolute patient/target translation, the total magnitude vector of patient and target misalignment was calculated. A clinical assessment determined whether or not the assigned planning target volume safety margins would have provided the desired target coverage. To this end, each control CT study was co-registered with the original treatment planning study using immobilization system related fiducial markers, and the computed isodose calculation was superimposed. In 109 control setup CT scans available for comparison with their respective treatment planning CT simulation study (2-5 per patient, median 3), anatomical landmark analysis revealed a mean bony landmark translation of -0.4 +/- 3.9 (mean +/- SD), -0.1 +/- 1.6 and 0.3 +/- 3.6 mm in x, y and z-directions, respectively. Bony landmark setup deviations along one or more principal axis larger than 5 mm were observed in 32 control CT studies (29.4%). Body rotations about the x-, y- and z-axis were 0.9 +/- 0.7, 0.8 +/- 0.7 and 1.8 +/- 1.6 degrees, respectively. Assuming a rigid body relationship of target and bony anatomy, the mean computed absolute target translation was 2.9 +/- 3.3, 2.3 +/- 2.5 and 3.2 +/- 2.7 mm in x, y and z-directions, respectively. The median and mean magnitude vector of target isocenter displacement was computed to be 4.9 mm, and 5.7 +/- 3.7 mm. Clinical assessment of PTV/target volume coverage revealed 72 (66.1%), 23 (21.1%), and 14 (12.8%), of excellent (100% isodose coverage), good (>90% isodose coverage), and poor GTV/isodose alignment quality (less than 90% isodose coverage to some aspect of the GTV), respectively. Loss of target volume dose coverage was correlated with translations >5 mm along one or more axes (p<0.0001), rotations >3 degrees about the z-axis (p=0.0007) and body mass index >30 (p<0.0001). The analyzed BodyFIX whole body immobilization system performed favorably compared with other stereotactic body immobilization systems for which peer-reviewed repositioning data exist. While the measured variability in patient and target setup provided clinically acceptable setup accuracy in the vast majority of cases, larger setup deviations were occasional observed. Such deviations constitute a potential for partial target underdosing warranting, in our opinion, a pre-delivery positional assessment procedure (e.g., pre-treatment control CT scan).