A performance comparison of the most commonly used minimally invasive monitors of cardiac output.

BACKGROUND: Shock is common in critically ill and injured patients. Survival during shock is highly dependent on rapid restoration of tissue oxygenation with therapeutic goals based on cardiac output (CO) optimization. Despite the clinical availability of numerous minimally invasive monitors of CO, limited supporting performance data are available. METHODS: Following approval of the University of Saskatchewan Animal Research Ethics Board, we assessed the performance and trending ability of PiCCOplus™, FloTrac™, and CardioQ-ODM™ across a range of CO states in pigs. In addition, we assessed the ability of invasive mean arterial blood pressure (iMAP) to follow changes in CO using a periaortic transit-time flow probe as the reference method. Statistical analysis was performed with function-fail, bias and precision, percent error, and linear regression at all flow, low-flow (> 1 standard deviation [SD] below the mean), and high-flow (> 1 SD above the mean) CO conditions. RESULTS: We made a total of 116,957 paired CO measurements. The non-invasive CO monitors often failed to provide a CO value (CardioQ-ODM: 40.6% failed measurements; 99% confidence interval [CI], 38.5 to 42.6; FloTrac: 9.6% failed measurements; 99% CI, 8.7 to 10.5; PiCCOplus: 4.7% failed measurements; 99% CI, 4.5 to 4.9; all comparisons, P < 0.001). The invasive mean arterial pressure provided zero failures, failing less often than any of the tested CO monitors (all comparisons, P < 0.001). The PiCCOplus was most interchangeable with the flow probe at all flow states: PiCCOplus (20% error; 99% CI, 19 to 22), CardioQ-ODM (25% error; 99% CI, 23 to 27), FloTrac (34% error; 99% CI, 32 to 38) (all comparisons, P < 0.001). At low-flow states, CardioQ-ODM (43% error; 99% CI, 32 to 63) and Flotrac (45% error; 99% CI, 33 to 70) had similar interchangeability (P = 0.07), both superior to PiCCOplus (48% error; 99% CI, 42 to 60) (P < 0.001). Regarding CO trending, the CardioQ-ODM (correlation coefficient, 0.82; 99% CI, 0.81 to 0.83) was statistically superior to other monitors including iMAP, but at low flows iMAP (correlation coefficient, 0.58; 99% CI, 0.58 to 0.60) was superior to all minimally invasive CO monitors (all comparisons P < 0.001). CONCLUSIONS: None of the minimally invasive monitors of CO performed well at all tested flows. Invasive mean arterial blood pressure most closely tracked CO change at critical flow states.

RéSUMé: CONTEXTE: L'état de choc est fréquent chez les patients blessés et en urgence absolue. La survie pendant le choc dépend fortement de la restauration rapide de l'oxygénation tissulaire avec des objectifs thérapeutiques basés sur l'optimisation du débit cardiaque (DC). Malgré la disponibilité clinique de nombreux moniteurs minimalement invasifs du DC, il n'existe que des données limitées sur leur performance pour appuyer leur utilisation. MéTHODE: À la suite de l'approbation du comité d'éthique de la recherche animale de l'Université de la Saskatchewan, nous avons évalué la performance et la capacité de suivi des tendances des appareils PiCCOplus™, FloTrac™ et CardioQ-ODM™ sur une vaste gamme d'état de DC chez des cochons. Nous avons également évalué la capacité de la tension artérielle moyenne invasive (iMAP) à suivre les changements de DC en utilisant une sonde périaortique de débit basée sur le temps de transit comme méthode de référence. L'analyse statistique a été réalisée avec fonction-échec, biais et précision, pourcentage d'erreur et régression linéaire à des conditions de DC de tous les débits, de faible débit (> 1 écart-type [ET] au-dessous de la moyenne) et de débit élevé (> 1 ET au-dessus de la moyenne). RéSULTATS: Nous avons effectué un total de 116 957 mesures de DC appariées. Les moniteurs non invasifs de la DC n'ont souvent pas réussi à fournir une valeur de DC (CardioQ-ODM : 40,6% de mesures échouées; intervalle de confiance [IC] de 99 %, 38,5 à 42,6; FloTrac : 9,6 % de mesures échouées; IC 99 %, 8,7 à 10,5; PiCCOplus : 4,7 % de mesures échouées; IC 99 %, 4,5 à 4,9; toutes les comparaisons, P < 0,001). La tension artérielle moyenne invasive n'a fourni aucun échec plus souvent que n'importe lequel des moniteurs de DC testés (toutes les comparaisons, P < 0,001). Le PiCCOplus était le plus interchangeable avec la sonde de débit à tous les états de débit : PiCCOplus (erreur de 20 %; IC 99 %, 19 à 22), CardioQ-ODM (erreur de 25 %; IC 99 %, 23 à 27), FloTrac (erreur de 34 %; IC 99 %, 32 à 38) (toutes les comparaisons, P < 0,001). Aux états de débit faible, les moniteurs CardioQ-ODM (erreur de 43 %; IC 99 %, 32 à 63) et FloTrac (erreur de 45 %; IC 99 %, 33 à 70) présentaient une interchangeabilité similaire (P = 0,07), tous deux supérieurs au PiCCOplus (erreur de 48 %; IC 99 %, 42 à 60) (P < 0,001). En ce qui concerne le suivi des tendances de DC, le CardioQ-ODM (coefficient de corrélation, 0,82; IC 99 %, 0,81 à 0,83) était statistiquement supérieur aux autres moniteurs, y compris au iMAP, mais à faibles débits, l'iMAP (coefficient de corrélation, 0,58; IC 99 %, 0,58 à 0,60) était supérieure à tous les moniteurs de DC minimalement invasifs (toutes les comparaisons, P < 0,001). CONCLUSION: Aucun des moniteurs de DC minimalement invasif n'a donné de bons résultats à tous les débits testés. La tension artérielle moyenne invasive était le moniteur qui a suivi de plus près les changements de DC dans des états critiques de débit.

Intravenous dextrose versus ondansetron for prevention of postoperative vomiting in children: a randomized non-inferiority trial.

BACKGROUND: Postoperative vomiting (POV) in children is frequent. Dextrose-containing intravenous fluids in the perioperative period have shown improvement of POV in adults. Similar studies have not been done in children. AIM: The primary purpose was to study the efficacy of intraoperative intravenous dextrose for antiemetic prophylaxis in children undergoing ambulatory surgery. METHODS: A non-inferiority randomized clinical trial of healthy children (three to nine years old) undergoing ambulatory dental surgery was conducted. The control group received dexamethasone (0.15 mg·kg-1 iv) and ondansetron (0.05 mg·kg-1 iv); the intervention group received dexamethasone (0.15 mg·kg-1 iv) and intravenous 5% dextrose in 0.9% normal saline according to a weight-based maintenance rate. The primary outcome was POV in the postanesthetic care unit (PACU) within two hr after surgery. Secondary outcomes included POV within 24 hr from discharge and unplanned hospital admission. A non-inferiority analysis was conducted on the primary outcome using an absolute risk difference of 7.5% as the non-inferiority margin. RESULTS: Data from 290 patients were analyzed. Demographics and intraoperative anesthetic management were similar between groups. Vomiting in the PACU occurred in 7.6% and 3.5% of the dextrose and ondansetron groups, respectively, with a risk difference of 4.2% (95% confidence interval [CI], -1.0 to 9.5). Given that the upper limit of the 95% CI exceeded our non-inferiority margin, non-inferiority of dextrose compared with ondansetron was not shown. CONCLUSION: These results do not support the use of intravenous dextrose as a satisfactory alternative to ondansetron to prevent POV in ambulatory pediatric dental surgery patients. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01912807); registered 18 July 2013.

RéSUMé: CONTEXTE: Les vomissements postopératoires (VPO) sont fréquents chez l'enfant. Il a été démontré qu'en période périopératoire, les solutés intraveineux contenant du dextrose entraînaient une diminution des VPO chez l'adulte, mais des études similaires n'ont pas été réalisées auprès de populations pédiatriques. OBJECTIF: L'objectif principal était d'évaluer l'efficacité du dextrose intraveineux peropératoire en tant que prophylaxie antiémétique chez les enfants subissant une chirurgie ambulatoire. MéTHODE: Une étude clinique randomisée de non-infériorité a été réalisée auprès d'enfants en bonne santé (de trois à neuf ans) devant subir une chirurgie dentaire en ambulatoire. Le groupe témoin a reçu de la dexaméthasone (0,15 mg·kg−1 iv) et de l'ondansétron (0,05 mg·kg−1 iv); le groupe intervention a reçu de la dexaméthasone (0,15 mg·kg−1 iv) et du dextrose intraveineux 5 % dans une solution de normal salin 0,9 % selon une échelle basée sur le poids. Le critère d'évaluation principal était la présence de VPO en salle de réveil au cours des deux heures suivant la chirurgie. Les critères d'évaluation secondaires comprenaient les VPO au cours des 24 h suivant le congé et une admission non planifiée à l'hôpital. L'analyse de non-infériorité a été réalisée pour le critère d'évaluation primaire en se fondant sur une différence de risque absolu de 7,5 % comme marge de non-infériorité. RéSULTATS: Les données de 290 patients ont été analysées. Les données démographiques et de prise en charge anesthésique peropératoire étaient semblables entre les deux groupes. Des vomissements sont survenus en salle de réveil chez 7,6 % et 3,5 % des groupes dextrose et ondansétron, respectivement, avec une différence de risque de 4,2 % (intervalle de confiance [IC] 95 %, -1,0 à 9,5). Étant donné que la limite supérieure de l'IC 95 % excédait notre marge de non-infériorité, la non-infériorité du dextrose comparativement à l'ondansétron n'a pas été démontrée. CONCLUSION: Ces résultats n'appuient pas l'utilisation de dextrose intraveineux en tant qu'alternative à l'ondansétron afin de prévenir les VPO chez les patients pédiatriques de chirurgie dentaire ambulatoire. ENREGISTREMENT DE L'éTUDE: www. CLINICALTRIALS: gov (NCT01912807); enregistrée le 18 juillet 2013.

Aluminum Exposure from Parenteral Nutrition: Early Bile Canaliculus Changes of the Hepatocyte.

Background: Neonates on long-term parenteral nutrition (PN) may develop parenteral nutrition-associated liver disease (PNALD). Aluminum (Al) is a known contaminant of infant PN, and we hypothesize that it substantially contributes to PNALD. In this study, we aim to assess the impact of Al on hepatocytes in a piglet model. Methods: We conducted a randomized control trial using a Yucatan piglet PN model. Piglets, aged 3⁻6 days, were placed into two groups. The high Al group (n = 8) received PN with 63 µg/kg/day of Al, while the low Al group (n = 7) received PN with 24 µg/kg/day of Al. Serum samples for total bile acids (TBA) were collected over two weeks, and liver tissue was obtained at the end of the experiment. Bile canaliculus morphometry were studied by transmission electron microscopy (TEM) and ImageJ software analysis. Results: The canalicular space was smaller and the microvilli were shorter in the high Al group than in the low Al group. There was no difference in the TBA between the groups. Conclusions: Al causes structural changes in the hepatocytes despite unaltered serum bile acids. High Al in PN is associated with short microvilli, which could decrease the functional excretion area of the hepatocytes and impair bile flow.

Infant Parenteral Nutrition Remains a Significant Source for Aluminum Toxicity.

BACKGROUND: Aluminum toxicity is associated with anemia, impaired bone metabolism, neurologic defects, and parenteral nutrition (PN)-associated liver disease. This element is a ubiquitous contaminant of PN components, especially in infant formulations. We assessed the current levels of aluminum contamination in infant PN at a level III neonatal intensive care unit. MATERIALS AND METHODS: Thirty samples of PN prepared in the same hospital for infants aged <30 days (mean [SD] weight, 1.54 [0.71] kg) were collected from discarded solution. Each sample was analyzed for aluminum content via inductively coupled plasma mass spectrometry. The components of PN (from label) and measured aluminum content were then compared using linear regression and 1-way analysis of variance. RESULTS: The mean (SD) aluminum contamination of infant PN was 14.02 (6.51) mcg/kg/d. Only 3 samples were <5 mcg/kg/d. Aluminum levels and infant weight were not associated. Linear regression revealed a significant correlation between aluminum and both calcium gluconate ( P < .0001) and phosphate ( P = .05), with a trend between aluminum and potassium ( P = .07). CONCLUSIONS: Aluminum contamination in infant PN remains almost 3 times higher than the advised maximum exposure (<5 mcg/kg/d, Food and Drug Administration 2004). Unexpectedly, an association between infant weight and aluminum exposure was not apparent, likely due to the homogeneity of our population. Isolating the source of aluminum contamination is difficult, as multiple components appear to be involved. Calcium gluconate is likely still a major contributor, but further investigations into individual components are warranted to promote the reduction of aluminum in infant PN.

Outcomes following neonatal patent ductus arteriosus ligation done by pediatric surgeons: a retrospective cohort analysis.

PURPOSE: Patent Ductus Arteriosus (PDA) ligation in premature infants is an urgent procedure performed by some but not all pediatric surgeons. Proficiency in PDA ligation is not a requirement of Canadian pediatric surgery training. Our purpose was to determine the outcomes of neonatal PDA ligation done by pediatric surgeons. METHODS: We performed a retrospective review of premature infants who underwent PDA ligation by pediatric surgeons in 3 Canadian centers from 2005 to 2009. Outcomes were compared to published controls. RESULTS: The review identified 98 patients with a mean corrected GA and weight at repair of 29 weeks and 1122 g, respectively. There were no intraoperative deaths. The 30-day and inhospital mortality rates were 1% and 5%. Mortality and morbidity were comparable to the published outcomes. CONCLUSIONS: This study documents that a significant number of preterm infant PDA ligations are safely done by pediatric surgeons. To meet the Canadian needs for this service by pediatric surgeons, proficiency in PDA ligation should be considered important in pediatric surgery training programs.

Reduced aluminum contamination decreases parenteral nutrition associated liver injury.

PURPOSE: Parenteral nutrition-associated cholestasis remains a significant problem, especially for the surgical neonates. Aluminum is a toxic element known to contaminate parenteral nutrition. We hypothesize that parenterally administered aluminum causes liver injury similar to that seen in parenteral nutrition-associated cholestasis. METHODS: Twenty 3- to 6-day-old domestic pigs were divided into 5 equal groups. A control group received daily intravenous 0.9% NaCl. Each subject in experimental groups received intravenous aluminum chloride at 1500 µg kg(-1) d(-1) for 1, 2, 3, or 4 weeks. At the end of the study, blood was sampled for direct bilirubin and total bile acid levels. Liver, bile, and urine were sampled for aluminum content. Liver tissue was imaged by transmission electron microscopy for ultrastructural changes. RESULTS: Transmission electron microscopy revealed marked blunting of bile canaliculi microvilli in all experimental subjects but not the controls. Serum total bile acids correlated with the duration of aluminum exposure. The hepatic aluminum concentration correlated with the duration of aluminum exposure. CONCLUSIONS: Parenterally infused aluminum resulted in liver injury as demonstrated by elevated bile acids and by blunting of the bile canaliculi microvilli. These findings are similar to those reported in early parenteral nutrition-associated liver disease.

Parenteral aluminum induces liver injury in a newborn piglet model.

PURPOSE: Parenteral nutrition-associated cholestasis remains a significant problem, especially for the surgical neonate. Aluminum is a toxic element known to contaminate parenteral nutrition. We hypothesize that parenterally administered aluminum causes liver injury similar to that seen in parenteral nutrition-associated cholestasis. METHODS: Twenty 3- to 6-day-old domestic pigs were divided into 5 equal groups. A control group received daily intravenous 0.9% sodium chloride. Each subject in experimental groups received intravenous aluminum chloride at 1500 µg/kg per day for 1, 2, 3, or 4 weeks. At the end of the study, blood was sampled for direct bilirubin and total bile acid levels. Liver, bile, and urine were sampled for aluminum content. Liver tissue was imaged by transmission electron microscopy for ultrastructural changes. RESULTS: Transmission electron microscopy revealed marked blunting of bile canaliculi microvilli in all experimental subjects but not the controls. Serum total bile acids correlated with the duration of aluminum exposure. The hepatic aluminum concentration correlated with the duration of aluminum exposure. CONCLUSIONS: Parenterally infused aluminum resulted in liver injury as demonstrated by elevated bile acids and by blunting of the bile canaliculi microvilli. These findings are similar to those reported in early parenteral nutrition-associated liver disease.

Waiting for an operation: parents' perspectives.

OBJECTIVE: To determine parents' attitudes toward and acceptance of waiting times for their child's operation. DESIGN: Waiting times were measured by a cross-sectional method. A descriptive survey was conducted of families with a child waiting for a non-urgent operation. SETTING: A university teaching hospital. SUBJECTS: Parents of children (age < 20 yr) waiting for non-urgent pediatric general-surgery operations. MAIN OUTCOME MEASURES: Parents' concerns and attitudes about waiting for their child's operation, how it was affecting the child and family, how urgent they felt the need for surgery was, and what they thought was a reasonable maximum waiting period. RESULTS: Of 89 patients waiting for non-urgent pediatric general-surgery operations at the time of the survey, 61% had been waiting > 6 months and 30% > 12 months. Of the 57 families (64%) who returned completed surveys, 94% reported the wait to be emotionally stressful for the family; 81.5% expected their child's quality of life would improve after the operation. As for length of wait, 83% felt that > 3 months was unacceptable, and 98% > 6 months. CONCLUSIONS: Parents of children waiting for pediatric general surgery operations thought that the need for the operation was significantly more urgent then their classification of elective. They felt that waiting periods should not exceed 3 months. Long waiting periods are stressful for both family and child. Parental perceptions are important when considering strategies for wait-list management.

Parenteral nutrition-associated cholestasis in neonates: the role of aluminum.

Parenteral nutrition (PN) is an essential component in the care of premature and ill infants. The incidence of parenteral nutrition-associated cholestasis (PNAC) ranges from 7.4 to 84%. One substance in PN solutions that has been implicated in PNAC is aluminum. Aluminum loading in animals and humans causes hepatic accumulation and damage. The degree of aluminum contamination of PN solutions has decreased over time, but contamination still significantly exceeds levels that are safe for human neonates. Further study into the relationship between aluminum contamination in neonatal PN solutions and the development of PNAC is necessary.

Zygomycotic infection of the neonatal upper extremity.

Zygomycosis is a rare fungal infection that may present as a necrotizing soft tissue infection in the neonate. This report illustrates the typical presentation of a premature, infant with a rapidly progressive soft tissue necrotizing infection of his upper extremity at an intravenous site. Early diagnosis with tissue biopsy confirmed the diagnosis of Zygomycosis. Successful treatment required systemic amphotercin B and aggressive debridement requiring through-the-elbow amputation for survival.

Routine pathological evaluation of tissue from inguinal hernias in children is unnecessary.

INTRODUCTION: Because unexpected disease is rare in a child's inguinal hernia sac we decided to investigate the cost of routine pathological evaluation of inguinal hernial sacs in children and the incidence of clinically significant pathological findings. METHODS: We searched the health records at the University Hospital, Saskatoon, for patients under 20 years of age who had inguinal hernia repair between 1988 and 1997. For records noting pathology findings of duct-like structures, the operative reports and histology slides were reviewed. Specimens were immunostained for muscle-specific actin. The cost of pathological evaluation was estimated using a provincial physician-billing schedule. RESULTS: During the study period, there were 488 inguinal hernia repairs in 371 patients under 20 years of age. Of these, 456 (93.4%) specimens were evaluated microscopically. There were 4 (0.88%) cases with unexpected findings diagnosed as epididymis at a cost of Can dollar 6988/case. CONCLUSION: The routine histologic evaluation of inguinal hernia sacs in children is an unnecessary expense and should be reserved for select cases at the discretion of the surgeon.

Telehealth provides effective pediatric surgery care to remote locations.

PURPOSE: The aim of this study was to document the experience and patient satisfaction with providing pediatric surgery consultations and follow-up appointments to remote locations via audiovisual telecommunications technology. METHODS: From January 2000 to April 2001, 16 consecutive pediatric general surgery clinics were reviewed for the type of patient (new or review), the diagnosis, the adequacy and accuracy of the evaluation, and the ability to formulate a plan. In the first year, first-time users were requested to complete a satisfaction survey of 15 questions. Responses to 13 questions were recorded on a 4-point Likert scale, and 2 questions required a "yes" or "no" response. RESULTS: One hundred eighteen appointments were scheduled. Twenty patients did not show up or cancelled. There were 45 new patient consultations. Thirty-three patients were scheduled for surgery, of which, 21 are completed, and 12 are pending. There were no errors in diagnosis or changes in planned procedures. There were 42 patients seen in 53 follow-up sessions. Thirty-six surveys of a possible 53 were available for analysis. The mean rating of overall treatment experience at Telehealth was 3.47 (95% confidence interval 0.17). One hundred percent responded they would use Telehealth again and would recommend it to another person. CONCLUSION: Telehealth is an effective and acceptable way to provide pediatric general surgery clinics to remote locations.