Martine Leblanc

Early Disruptive Behavior, Poor School Achievement, Delinquent Behavior, and Delinquent Personality: Longitudinal Analyses.

Three alternative models concerning the causal links between early disruptive behavior, poor school achievement, and delinquent behavior or antisocial personality were tested with linear structural equation modeling. Subjects were boys and girls followed from first grade to age 14. Disruptive behavior was assessed in Grade 1; school achievement was assessed in Grades 1 and 4; delinquent behavior and antisocial personality were assessed at age 14. With regard to self-reported delinquent behavior at age 14, results indicate that the best model for boys was a direct causal link between Grade 1 disruptive behavior and delinquent behavior. Poor school achievement was not a necessary causal factor. For girls, none of the tested models were a good fit to the delinquent behavior data. As for delinquent personality, results indicate that, for both boys and girls, poor school achievement was a necessary component of the causal path between Grade 1 disruptive behavior and age 14 delinquent personality.

Impact of Emergency Colectomy on Survival of Patients With Fulminant Clostridium difficile Colitis During an Epidemic Caused by a Hypervirulent Strain

Objectives:To determine whether emergency colectomy reduces mortality in patients with fulminant Clostridium difficile-associated disease (CDAD), and to identify subgroups of patients more likely to benefit from the procedure. Summary Background Data:Many hospitals in Quebec, Canada, have noted since 2003 a dramatic increase in CDAD incidence and in the proportion of cases severe enough to require intensive care unit (ICU) admission. The decision to perform an emergency colectomy remains largely empirical. Methods:Retrospective observational cohort study of 165 cases of CDAD that required ICU admission or prolongation of ICU stay between January 2003 and June 2005 in 2 tertiary care hospitals of Quebec. Multivariate analysis was performed through logistic regression; adjusted odds ratios (AOR) and their 95% confidence intervals (CI) were calculated. The primary outcome was mortality within 30 days of ICU admission. Results:Eighty-seven (53%) cases resulted in death within 30 days of ICU admission, almost half (38 of 87, 44%) within 48 hours of ICU admission. The independent predictors of 30-day mortality were: leukocytosis ≥50 × 109/L (AOR, 18.6; 95% CI, 3.7–94.7), lactate ≥5 mmol/L (AOR, 12.4; 95% CI, 2.4–63.7), age ≥75 years (AOR, 6.5; 95% CI, 1.7–24.3), immunosuppression (AOR, 7.9; 95% CI, 2.3–27.2) and shock requiring vasopressors (AOR, 3.4; 95% CI, 1.3–8.7). After adjustment for these confounders, patients who had an emergency colectomy were less likely to die (AOR, 0.22; 95% CI, 0.07–0.67, P = 0.008) than those treated medically. Colectomy seemed more beneficial in patients aged 65 years or more, in those immunocompetent, those with a leukocytosis ≥20 × 109/L or lactate between 2.2 and 4.9 mmol/L. Conclusion:Emergency colectomy reduces mortality in some patients with fulminant CDAD.

Establishing a dialysis therapy/patient outcome link in intensive care unit acute dialysis for patients with acute renal failure

Abstract The aim of this study was to describe a relationship between intensive care unit (ICU) patient acuity, delivered dialysis dosing, and patient mortality from newly acquired acute renal failure (ARF) requiring dialytic support. A prospectively collected ICU ARF registry formed the basis for data comparison. All data was verified. Eight hundred forty-four ICU patients were identified who met biochemical or clinical criteria of ARF and required first-time dialytic support. An acute dialysis scoring system was established using 23 independent variables identified with univariant analysis, and reduced to eight variables with multiple regression analysis in 512 patients. These eight variables were assigned a weighted score derived from their odds ratio, and the scoring system was than validated prospectively to either registry data not involved in the generation of the system (n = 148), or double-blinded score assignment at time of first dialysis (n = 130). Several established scoring systems were also appliedto the database for external comparison. Dialysis dosing was analyzed using either direct dialysate quantification or blood side urea kinetics once appropriate formulae were identified from paired blood/dialysate results. Using our database and four published ARF acuity/predictive models (Lohr, Cioffi, Bullock, Acute Physiology and Chronic Health Evaluation [APACHEii]), outcome predictions were grossly inaccurate. Application of the Cleveland Clinic Foundation (CCF) ARF acuity score showed highly predictable outcomes when compared using the Lemeshow, Hosmer goodness-of-fit statistics, and highly reproducible results in both the prospective database and double-blinded prospective clinical trials. When comparing dialytic support techniques received (intermittent dialysis v continuous therapies), the CCF scoring system remained highly predictive of mortality. When one compares dose of delivered dialysis to patients with ARF in the ICU setting, there seems to be no effect on outcome at the two ends of the scoring system. Those with very low ( 15) CCF scores had survivals of 78% and 0%, respectively, regardless of the dose of dialysis. Patients with intermediate scores seemed to be the most effected by dialysis dose delivery, with higher delivery (>58% urea reduction ratio for intermittent hemodialysis; UREA ) for continuous renal replacement therapy [CRRT]) associated with a significant reduction in mortality when compared with the same CCF scoring quartile with low-dialysis dose delivery. While underlying patient comorbidity has a significant effect on survival in ARF, the dose of delivered dialysis also seems to play a major role in patients with moderated levels of severity. Methods that allow a higher delivered dialysis dose to this group of patients will be rewarded with improved patient outcome.

Protocolized intensive care unit management of analgesia, sedation, and delirium improves analgesia and subsyndromal delirium rates.

BACKGROUND: Sedatives and analgesics, in doses that alter consciousness in the intensive care unit (ICU), contribute to delirium and mortality. Pain, agitation, and delirium can be monitored in ICU patients. These symptoms were noted before (PRE) and after (POST) a protocol to alleviate undesirable symptoms. Analgesia and sedation levels, the incidence of coma, delirium, length of stay (LOS), discharge location, and mortality were then compared. We hypothesized that the likely reduction in iatrogenic coma would result in less delirium, because these 2 morbid conditions seem to be linked. METHODS: All patients were consecutively admitted to an ICU PRE-protocol (August 2003 to February 2004, 610 patients) and POST-protocol (April 2005 to November 2005, 604 patients). Between February 2004 and April 2005, we piloted and taught individualized nonpharmacologic strategies and titration of analgesics, sedatives, and antipsychotics based on sedation, analgesia, and delirium scores. We measured the following outcomes: coma, delirium, LOS, mortality, and discharge location. RESULTS: The POST group benefited from better analgesia, received less opiates (90.72 ± 207.45 vs 22.93 ± 40.36 morphine equivalents/d, P = <0.0001), and, despite comparable sedation, had shorter duration of mechanical ventilation. Medication-induced coma rates (18.1%vs 7.2%, P < 0.0001), ICU and hospital LOS, and dependency at discharge were lower in the POST-protocol group. Subsyndromal delirium was significantly reduced; delirium was similar. The 30-day mortality risk in the PRE cohort was 29.4% vs 22.9% in the POST cohort (log-rank test, P = 0.009). CONCLUSION: Educational initiatives incorporating systematic management protocols with nonpharmacologic measures and individualized titration of sedation, analgesia, and delirium therapies are associated with better outcomes.

Dialysate Leaks in Peritoneal Dialysis

Dialysate leakage represents a major noninfectious complication of peritoneal dialysis (PD). An exit‐site leak refers to the appearance of any moisture around the PD catheter identified as dialysate; however, the spectrum of dialysate leaks also includes any dialysate loss from the peritoneal cavity other than via the lumen of the catheter. The incidence of dialysate leakage is somewhat more than 5% in continuous ambulatory peritoneal dialysis (CAPD) patients, but this percentage probably underestimates the number of early leaks. The incidence of hydrothorax or pleural leak as a complication of PD remains unclear. Factors identified as potentially related to dialysate leakage are those related to the technique of PD catheter insertion, the way PD is initiated, and weakness of the abdominal wall. The pediatric literature tends to favor Tenckhoff catheters over other catheters as being superior with respect to dialysate leakage, but no consensus on catheter choice exists for adults in this regard. An association has been found between early leaks (≤30 days) and immediate CAPD initiation and perhaps median catheter insertion. Risk factors contributing to abdominal weakness appear to predispose mostly to late leaks; one or more of them can generally be identified in the majority of patients. Early leakage most often manifests as a pericatheter leak. Late leaks may present more subtly with subcutaneous swelling and edema, weight gain, peripheral or genital edema, and apparent ultrafiltration failure. Dyspnea is the first clinical clue to the diagnosis of a pleural leak. Late leaks tend to develop during the first year of CAPD. The most widely used approach to determine the exact site of the leakage is with computed tomography after infusion of 2 L of dialysis fluid containing radiocontrast material. Treatments for dialysate leaks include surgical repair, temporary transfer to hemodialysis, lower dialysate volumes, and PD with a cycler. Recent recommendation propose a standard approach to the treatment of early and late dialysate leaks: 1–2 weeks of rest from CAPD, and surgery if recurrence. Surgical repair has been strongly suggested for leakage causing genital swelling. Delaying CAPD for 14 days after catheter insertion may prevent early leakage. Initiating CAPD with low dialysate volume has also been recommended as a good practice measure.

Prevention of Dialysis Catheter Malfunction with Recombinant Tissue Plasminogen Activator

BACKGROUND The effectiveness of various solutions instilled into the central venous catheter lumens after each hemodialysis session (catheter locking solutions) to decrease the risk of catheter malfunction and bacteremia in patients undergoing hemodialysis is unknown. METHODS We randomly assigned 225 patients undergoing long-term hemodialysis in whom a central venous catheter had been newly inserted to a catheter-locking regimen of heparin (5000 U per milliliter) three times per week or recombinant tissue plasminogen activator (rt-PA) (1 mg in each lumen) substituted for heparin at the midweek session (with heparin used in the other two sessions). The primary outcome was catheter malfunction, and the secondary outcome was catheter-related bacteremia. The treatment period was 6 months; treatment assignments were concealed from the patients, investigators, and trial personnel. RESULTS A catheter malfunction occurred in 40 of the 115 patients assigned to heparin only (34.8%) and 22 of the 110 patients assigned to rt-PA (20.0%)--an increase in the risk of catheter malfunction by a factor of almost 2 among patients treated with heparin only as compared with those treated with rt-PA once weekly (hazard ratio, 1.91; 95% confidence interval [CI], 1.13 to 3.22; P = 0.02). Catheter-related bacteremia occurred in 15 patients (13.0%) assigned to heparin only, as compared with 5 (4.5%) assigned to rt-PA (corresponding to 1.37 and 0.40 episodes per 1000 patient-days in the heparin and rt-PA groups, respectively; P = 0.02). The risk of bacteremia from any cause was higher in the heparin group than in the rt-PA group by a factor of 3 (hazard ratio, 3.30; 95% CI, 1.18 to 9.22; P = 0.02). The risk of adverse events, including bleeding, was similar in the two groups. CONCLUSIONS The use of rt-PA instead of heparin once weekly, as compared with the use of heparin three times a week, as a locking solution for central venous catheters significantly reduced the incidence of catheter malfunction and bacteremia. (Current Controlled Trials number, ISRCTN35253449.).

Risk factors for acute renal failure: inherent and modifiable risks

Purpose of reviewOur purpose is to discuss established risk factors in the development of acute renal failure and briefly overview clinical markers and preventive measures. Recent findingsFindings from the literature support the role of older age, diabetes, underlying renal insufficiency, and heart failure as predisposing factors for acute renal failure. Diabetics with baseline renal insufficiency represent the highest risk subgroup. An association between sepsis, hypovolemia, and acute renal failure is clear. Liver failure, rhabdomyolysis, and open-heart surgery (especially valve replacement) are clinical conditions potentially leading to acute renal failure. Increasing evidence shows that intraabdominal hypertension may contribute to the development of acute renal failure. Radiocontrast and antimicrobial agents are the most common causes of nephrotoxic acute renal failure. In terms of prevention, avoiding nephrotoxins when possible is certainly desirable; fluid therapy is an effective prevention measure in certain clinical circumstances. Supporting cardiac output, mean arterial pressure, and renal perfusion pressure are indicated to reduce the risk for acute renal failure. Nonionic, isoosmolar intravenous contrast should be used in high-risk patients. Although urine output and serum creatinine lack sensitivity and specificity in acute renal failure, they remain the most used parameters in clinical practice. SummaryThere are identified risk factors of acute renal failure. Because acute renal failure is associated with a worsening outcome, particularly if occurring in critical illness and if severe enough to require renal replacement therapy, preventive measures should be part of appropriate management.

Renal Replacement in End-Stage Renal Disease Patients over 75 Years Old

Background: Over the last decade, the age of dialysis patients has been increasing steadily in several units in Canada. Our main objective was to assess prevalence, co-morbidity and outcome of ESRD patients over 75 years old at the beginning of dialysis treatment in our center. As a group, they were compared to younger dialysis patients treated simultaneously. Methods: In the last 5 years, all cases beginning dialysis in our institution who were above 75 years of age were reviewed, as well as cases aged between 50 and 60 years who started dialysis during the same period. Between January 1996 and December 2000, among a total of 429 new chronic dialysis patients, 67 ESRD patients over 75 years (15.6%) and 66 patients between 50 and 60 years (15.4%) began dialysis treatment. Results – Primary and Secondary: Diabetes was present in 37% of elderly and in 56% of the younger patients. Younger patients had been referred earlier to our nephrologists than the older ones (42 vs. 27%). Elderly were more frequently treated by hemodialysis than peritoneal dialysis (81 vs. 19%) when compared to their younger counterparts (65 vs. 35%). Long-term catheters for hemodialysis were used more often in elderly patients. No renal transplantation were performed in older patients while 7 younger patients received a renal graft. Survival rates after 1 and 3 years were, respectively, 93 and 74% for patients between 50 and 60 years, whereas it decreased to 80 and 45% for those over 75 years (p = 0.002). More than 50% of patients older than 75 years died within 2 years after starting dialysis; their mean survival was 31 months; patients starting dialysis between 50 and 60 years survived on the average 44 months during the study period. According to the multivariate logistic regression model, risk factors for increased mortality in the older group were: number of hospitalization days during the past 3 months (OR 34.8, 95% CI 8.3–145.7, p < 0.001) and lower weight (OR 16.6, 95% CI 2.0–139.0, p = 0.001). Conclusion: We may conclude that, in our hands, life expectancy of patients who began dialysis above 75 years is significantly shorter than for patients for whom dialysis is initiated between age 50 and 60 years, especially if they have a low weight, lose weight and/or require hospitalization.

Lithium poisoning treated by high-performance continuous arteriovenous and venovenous hemodiafiltration

Intermittent hemodialysis is considered the modality of choice when enhanced lithium removal is indicated. However, postdialysis rebound in serum lithium concentration is frequently observed after the dialysis sessions and results from incomplete intracellular removal. Continuous renal replacement therapy could provide a more gradual and complete lithium removal since it is performed over longer time periods, thus avoiding rebound following therapy. Seven patients presenting with symptomatic lithium intoxication were treated by continuous renal replacement therapy (continuous arteriovenous and venovenous hemodiafiltration [CAVHDF and CVVHDF]). For CAVHDF, the dialysate flow rate was increased to 4 L/hr to optimize solute clearances. Five intoxicated patients (four acute and one chronic) were treated by high dialysate flow rate (HDFR) (4 L/hr) CAVHDF and two patients with chronic poisoning were treated by CVVHDF, one with a dialysate flow rate of 1 L/hr and one with a dialysate flow rate of 2 L/hr. Serum lithium concentrations for the four acute poisoning cases were 4.0, 4.6, 4.4, and 3.2 mEq/L, at initiation of HDFR CAVHDF, and decreased respectively to 1.2, 0.8, 1.2, and 1.1 mEq/L after 15, 19, 35, and 21 hours of treatment. No lithium rebound was observed over 24 to 36 hours following CAVHDF. For the three chronic intoxication cases, serum lithium concentrations dropped from 1.7, 2.2, and 3.8 mEq/L to 0.7, 0.17, and 0.4 mEq/L, respectively, after 18, 42, and 44 hours of HDFR CAVHDF or CVVHDF. The chronic case treated for only 18 hours presented a slight rebound in lithium level (0.3 mEq/L), whereas no significant rebound was observed for the two other cases treated for longer periods. Mean +/- SEM dialyser urea, lithium, and creatinine clearance during HDFR CAVHDF were 50.5 +/- 5.0, 41.4 +/- 4.6, and 37.6 +/- 3.7 mL/min, respectively (number of measurements = 41). Dialyser lithium clearance during CVVHDF was 48.4 +/- 1.4 mL/min (n = 10) and 61.9 +/- 2.3 mL/min (n = 7), with dialysate flow rates of 1 and 2 L/hr, respectively. Mean dialyzer lithium removal for the seven cases was 106.4 mEq, while mean renal lithium removal was 21.5 mEq during the same period. We conclude that HDFR CAVHDF and CVVHDF are effective alternatives to intermittent hemodialysis for treatment of lithium poisoning. They provide excellent lithium clearances (60 to 85 L/d); in addition, because of their continuous nature, they prevent posttherapy lithium rebound by allowing a more gradual and complete removal from intracellular compartments, and they may be particularly useful in chronic poisoning in which intracellular lithium accumulation is more extensive.

What Dialysis Dose Should Be Provided in Acute Renal Failure? A Review

Increased dialysis dose has been shown to improve morbidity and survival in chronic hemodialysis patients. Despite improvement in care and technological aspects of renal replacement therapy, mortality rates of acute renal failure (ARF) have remained essentially unchanged for over two decades, exceeding 50% in most studies. The occurrence of ARF in older patients with more complicated medical and surgical conditions has contributed to this lack of outcome amelioration, and death of ARF patients is now more frequently caused by underlying disease than ARF itself. A recent prospective survey at this institution found a mortality rate of 79.1% among a total of 363 ARF medical and surgical intensive care unit patients, with a mean age near 60 years and a mean admission APACHE II score of over 20, who were treated by intermittent hemodialysis and continuous renal replacement therapy (CRRT). Nonsurvivors had a mean of over four failed systems, in addition to the renal failure, compared with survivors who had less than four. The standards for dialysis adequacy in ARF are not currently defined. Increased catabolism seen in ARF patients in the intensive care unit may justify large dialysis dose delivery. An apparent influence of delivered dialysis dose on the outcome of ARF intensive care unit patients has been recently observed at our institution. Compared with nonsurvivors, survivors had received significantly higher dialysis dose, as assessed by Kt/V and urea reduction ratio. In ARF patients, the discrepancy between delivered versus prescribed dialysis dose may be particularly important and contributed to by the following: reduced blood flow rate and dialysis time consequent to patient intolerance; lower dialyzer in vivo clearances, particularly in heparin-free dialysis; blood recirculation when using temporary vascular access; and postdialysis urea rebound. Prolonging the course of renal failure is one of the risks attributed to frequent dialysis; hypotension and ultrafiltration combined with a deficient renal autoregulation can result in further renal damage. The detrimental effects of bioincompatible membranes have been demonstrated with an induced-delay of renal function recovery. A recent study has reported benefits of biocompatible membranes in terms of potential for renal recovery and maintenance of urine output during dialytic support when compared with bioincompatible membranes. CRRT offers many advantages over intermittent hemodialysis for ARF intensive care unit patients: better hemodynamic tolerance, avoidance of solute rebound, and removal of serum sepsis mediators. However, CRRT have not yet been firmly shown to improve survival rates. Recently, urea kinetics have been used to estimate dialysis dose provided by CRRT.(ABSTRACT TRUNCATED AT 400 WORDS)