Forced-Air Warming During Pediatric Surgery: A Randomized Comparison of a Compressible with a Noncompressible Warming System.

BACKGROUND: Perioperative hypothermia is a common problem, challenging the anesthesiologist and influencing patient outcome. Efficient and safe perioperative active warming is therefore paramount; yet, it can be particularly challenging in pediatric patients. Forced-air warming technology is the most widespread patient-warming option, with most forced-air warming systems consisting of a forced-air blower connected to a compressible, double layer plastic and/or a paper blanket with air holes on the patient side. We compared an alternative, forced-air, noncompressible, under-body patient-warming mattress (Baby/Kleinkinddecke of MoeckWarmingSystems, Moeck und Moeck GmbH; group MM) with a standard, compressible warming mattress system (Pediatric Underbody, Bair Hugger, 3M; group BH). METHODS: The study included 80 patients aged <2 years, scheduled for elective surgery. After a preoperative core temperature measurement, the patients were placed on the randomized mattress in the operation theater and 4 temperature probes were applied rectally and to the patients' skin. The warming devices were turned on as soon as possible to the level for pediatric patients as recommended by the manufacturer (MM = 40°C, BH = 43°C). RESULTS: There was a distinct difference of temperature slope between the 2 groups: core temperatures of patients in the group MM remained stable and mean of the core temperature of patients in the group BH increased significantly (difference: +1.48°C/h; 95% confidence interval, 0.82-2.15°C/h; P = 0.0001). The need for temperature downregulation occurred more often in the BH group, with 22 vs 7 incidences (RR, 3.14; 95% confidence interval, 1.52-6.52; P = 0.0006). Skin temperatures were all lower in the MM group. Perioperatively, no side effects related to a warming device were observed in any group. CONCLUSIONS: Both devices are feasible choices for active pediatric patient warming, with the compressible mattress system being better suited to increase core temperature. The use of lower pediatric forced-air temperature settings, as recommended by the manufacturer, in the noncompressible mattress group resulted in more stable core temperature conditions, with fewer forced-air temperature adjustments necessary to avoid hyperthermia.

Feasibility and pharmacokinetics of caudal blockade in children and adolescents with 30-50 kg of body weight.

BACKGROUND: Caudal blockade, although an important technique of pediatric regional anesthesia, is rarely used in children heavier than 30 kg. This reservation is due to anatomical concerns and lack of pharmacokinetic data. We therefore set out to evaluate, in pediatric patients weighing 30-50 kg, the feasibility of ultrasound-guided caudal blockade and the pharmacokinetics of caudally administered ropivacaine. METHODS: Twenty consecutive children were included. General anesthesia was used to ensure a secured airway. For the caudal punctures, we applied the same clinical standards as in smaller children, administering ropivacaine 3.1 mg·ml-1 for a volume of 1 ml·kg-1 via ultrasound guidance. Pharmacokinetic analysis was based on total plasma ropivacaine levels and included maximum concentration (Cmax ), time to Cmax (tmax ), terminal elimination half-life, area under the concentration-time curve for the 4-h sampling period, apparent total body clearance, and apparent volume of distribution. RESULTS: In all 19 cases of successful puncture, we identified the relevant anatomical structures (sacral cornua, sacral hiatus, dura mater) and verified correct administration of the local anesthetic by visualizing its cranial spread. Surgical blockade was successful in 18 of 20 cases (90%; one puncture was technically not possible and one child received intraoperatively 50 µg fentanyl). The pharmacokinetic profile of the administered ropivacaine 3.1 mg·ml-1 indicated plasma levels within safe ranges in pediatric patients weighing 30-50 kg. CONCLUSIONS: Based on our pharmacodynamic and pharmacokinetic results, we suggest that the body weight of 50 kg it is feasible to perform effective and safe caudal blockade in children up to 50 kg body weight.

Awake caudals and epidurals should be used more frequently in neonates and infants.

The current literature provides fundamental insights regarding the neurotoxic potency of various general anesthetic drugs in neonates and small infants. Therefore, considerations to minimize the use of general anesthetic drugs in this age group are required. The use of caudal and epidural anesthesia under sedation is one possibility to minimize the use of general anesthetic drugs. A large number of surgical procedures can be managed with this anesthetic concept. Training, practical hand skills, good infrastructure, a well-defined indication, and a team approach including the entire operation room staff are the major prerequisites to implement these techniques in the daily clinical practice. This review article discusses all present aspects and possible future evolutions of caudal and epidural anesthesia under sedation.

A pharmacodynamic evaluation of dexmedetomidine as an additive drug to ropivacaine for peripheral nerve blockade: A randomised, triple-blind, controlled study in volunteers.

BACKGROUND: Previous data have indicated the efficacy of dexmedetomidine as an additive to peripheral regional anaesthesia. There are no pharmacodynamic data regarding the addition of dexmedetomidine to local anaesthetics for perineural administration. OBJECTIVE: The objective of this study is to assess the dose-dependency of dexmedetomidine when injected with ropivacaine for peripheral nerve blockade. DESIGN: A randomised, triple-blind, controlled study in volunteers. SETTING: Department of Clinical Pharmacology, Medical University of Vienna. PARTICIPANTS: Twenty-four volunteers. INTERVENTIONS: All volunteers received an ulnar nerve block with 22.5 mg ropivacaine alone (R), or mixed with 50 (RD50), 100 (RD100) or 150 µg (RD150) dexmedetomidine. MAIN OUTCOME MEASURES: The primary outcome was the duration of complete sensory block to pinprick and time to complete recovery of pinprick. Secondary outcomes included block success and onset time, motor block, haemodynamic parameters and sedation level. RESULTS: There was a significant dose-dependent (P < 0.0001) increase in the mean duration (SD) of sensory block with dexmedetomidine: R: 8.7 (1.5) h, RD50: 16.4 (4.0) h, RD100: 20.4 (2.8) h and group RD150: 21.2 (1.7) h. Sedation was also enhanced in a dose-dependent (P < 0.001) manner. Two volunteers each receiving 150 µg dexmedetomidine had postblock paraesthesia for 72 h. CONCLUSION: Dexmedetomidine mixed with ropivacaine produces a dose-dependent prolongation of sensory block and clinically relevant dose-dependent sedation. Dexmedetomidine 100 µg may represent a balance between efficacy and sedation.

Lung transplantation in children and young adults: a 20-year single-centre experience.

Lung transplantation in adults is an accepted therapeutic option, whereas there is ongoing debate on its positive impact on survival in children. We report our experience of the first 20 yrs of paediatric lung transplantation at a single centre in Austria. Patient survival, organ survival and freedom from bronchiolitis obliterans were estimated by Kaplan-Meier curves. Pre- and post-transplant parameters were assessed and their influence on patient and organ survival evaluated by univariate tests and stepwise multivariate analyses. A total of 55 transplantations were performed in 43 patients. 1- and 5-yr patient survival rates were 72.1% and 60.6%, respectively, and 52.6% of patients were found to be free from bronchiolitis obliterans syndrome at 5 yrs post-transplant. Analysing different eras of transplantation suggests an improvement over the years with a 5-yr survival rate of 70.6% in the second decade. A positive effect of pre-transplant diabetes mellitus and immunosuppression was found with the newer drug tacrolimus, and a negative effect of pre-transplant in-hospital admission was reported. A high rate of successful re-transplantation prolonged total patient survival.

A randomized trial comparing the Ambu® Aura-i™ and the Ambu® Aura Gain™ laryngeal mask as conduit for tracheal intubation in children.

BACKGROUND: The Ambu Aura Gain is a newer second-generation supraglottic airway device designed for fibreoptic bronchoscopy (FOB)-guided tracheal intubation. METHODS: 57 patients between 18 months and six years of age were randomized to receive either the Ambu Aura-I (N.=29) or the Ambu Aura Gain (N.=28). Primary endpoint was the time for intubation. Secondary endpoints were the time and number of attempts for device insertion, the feasibility of FOB-guided intubation, the oropharyngeal leak pressure (OLP) the fibreoptic grade of laryngeal view and possible complications. RESULTS: No difference was found in the time for intubation, the time for device insertion or the fibreoptic grade of laryngeal view. First-attempt device insertion was successful in all (N.=28) patients with Aura Gain (100%) and in 27 (97%) with Aura-i. In the Aura-i group one insertion failed. A significant difference in successful intubation was seen between the Aura-i and the Aura Gain (79% vs. 100%, respectively, P=0.0011). Also found was a significant difference in the mean OLP (SD) between the Ambu Aura-i and the Ambu Aura Gain (18 [3] vs. 20 [3] cmH2O, respectively; mean difference [MD] 2 cmH2O; P=0.005). CONCLUSIONS: The Ambu Aura Gain served as a reliable device for FOB-guided tracheal intubation. Even if the time for intubation, when intubation was possible did not differ, the Aura-i showed only 79% intubation success, making it a doubtful device for FOB-guided tracheal intubation in cases of emergency and severe hypoxemia in small children.

A prospective interventional study on the use of extracorporeal photopheresis in patients with bronchiolitis obliterans syndrome after lung transplantation.

BACKGROUND: The aim of this prospective study was to evaluate the efficacy and safety of extracorporeal photopheresis (ECP) in patients with bronchiolitis obliterans syndrome (BOS) after lung transplantation and to identify factors predicting treatment response. METHODS: The study was performed at a single center and consisted of a cohort of 1,012 lung transplant recipients (November 1989-June 2010). A total of 194 patients developed BOS after a mean of 1,293 ± 1,008 days (range, 99-4,949 days) and received established treatment, and 51 patients received additional ECP. RESULTS: Thirty-one (61%) of the ECP-treated patients responded to the therapy and showed sustained stabilization (forced expiratory volume in 1 second range, -5% to 5% vs baseline at start of ECP) of lung function over 6 months. Responders to ECP showed significantly greater survival and less need for retransplantation (p = 0.001) than non-responders. Factors associated with an inferior treatment response were cystic fibrosis as underlying lung disease and a longer time between transplantation and development of BOS. No side effects were observed after ECP. Compared with BOS patients not treated with ECP, the ECP responders showed an improved graft survival (p = 0.05). CONCLUSIONS: These results confirm and suggest that early use of ECP could be an effective adjunct treatment for patients who develop BOS after lung transplantation.

Cytomegalovirus prevention in high-risk lung transplant recipients: comparison of 3- vs 12-month valganciclovir therapy.

BACKGROUND: Cytomegalovirus (CMV) infections are common after lung transplantation (LuTx) and have an influence on acute rejection rates and chronic organ dysfunction. The objective of this study was to determine the incidence of CMV infections by comparing a prolonged valganciclovir prophylaxis with a standard regimen in high-risk LuTx recipients. METHODS: A retrospective, single-center study was performed comparing two different CMV prophylactic regimens in high-risk LuTx recipients (D(+)/R(-)). The study population received either 3 months (Group A, 15 patients) or 12 months (Group B, 17 patients) of oral valganciclovir 900 mg/day in combination with CMV hyperimmune globulin in four doses (Days 1, 7, 14 and 21 post-transplant). RESULTS: CMV viremia was noted in 11 of 15 patients in Group A (75%) and 5 of 17 in Group B (33%) (p < 0.05) at 6 months after valganciclovir cessation. The incidence of symptomatic CMV disease/syndrome was 6 of 15 (44%) in Group A and 2 of 17 in Group B (13%) (p < 0.05). Histologically proven acute rejection episodes of ISHLT Grade > or =A2 were found in 4 patients in Group A and in 1 patient in Group B within the first year (p = 0.14). CONCLUSIONS: A 12-month CMV prophylaxis with oral valganciclovir is effective in significantly reducing CMV viremia and CMV disease/syndrome in high-risk lung transplant recipients. In addition, a reduction in acute and recurrent rejection episodes was observed, possibly due to less CMV viremia and subsequent immunomodulatory effects.