Alternative anticoagulation during cardiovascular procedures in pediatric patients with heparin-induced thrombocytopenia.

Patients with heparin-induced thrombocytopenia (HIT) that require anticoagulation for cardiovascular procedures represent a challenging and high-risk group. Bivalirudin and argatroban have been successfully used as alternative anticoagulants in adult patients with HIT. There have been few experiences published involving the pediatric population and controversy exists regarding the properties and optimal dosing of these drugs. This report describes the experience of managing two pediatric patients with HIT that underwent cardiovascular procedures requiring anticoagulation. Bivalirudin was used in both cases for anticoagulation during cardiopulmonary bypass, while argatroban was used without complications during cardiac catheterization. A description of perfusion and anticoagulation protocols is included.

Continuous incisional infusion of local anesthetic in pediatric patients following open heart surgery.

AIM: To determine the efficacy and safety of a continuous subcutaneous local anesthetic (LA) infusion in pediatric patients following open heart surgery. BACKGROUND: The use of a continuous LA infusion has been shown to be beneficial following adult cardiac surgery. To date there are no studies in the pediatric population. METHODS/MATERIALS: Using a prospective, randomized, and double blind design, we compared LA, either 0.25% levobupivacaine or bupivacaine (Treatment Group) to saline (Placebo Group) delivered subcutaneously via a continuous infusion for 72 h after open heart surgery in 72 patients. Requirements for postoperative analgesics and pain scores were recorded for 72 h and plasma levels of local anesthetic were measured. Secondary outcomes measures included time to first oral intake, time to first bowel movement, time to urinary catheter removal, length of stay, requirements for antiemetics and additional sedation. RESULTS: Total morphine requirements over the first 24 h were less in the Treatment Group than the Placebo Group (0.05 mg x kg(-1) vs 0.2 mg x kg(-1), P = 0.007); this was true for all patient groups except those patients weighing less than 6.3 kg. The number of patients requiring no morphine was greater in the Treatment Group (7/35 vs 1/37, P = 0.02). The Treatment Group also received less midazolam, lorazepam, and ketorolac than the Placebo Group over 72 h due to the reduced clinical need for these agents in patients weighing less than 31 kg. There were no differences in secondary outcomes. CONCLUSIONS: A continuous incisional infusion of LA reduced postoperative analgesic requirement and sedative use in pediatric patients undergoing a median sternotomy incision. Dosed at a maximum rate of 0.4 mg x kg(-1) x h(-1), a continuous incisional infusion of LA is effective and safe for up to 72 h, with plasma levels of local anesthetic well below the toxic threshold.

Perioperative hyperglycemia: effect on outcome after infant congenital heart surgery.

BACKGROUND: Studies demonstrate that cardiopulmonary bypass (CPB) causes intraoperative and postoperative hyperglycemia. Hyperglycemia has been associated with morbidity and mortality after infant cardiac surgery. We studied the effects on early postoperative outcomes of glucose (GLU) changes during and after pediatric cardiac surgery. METHODS: The records of 144 infants less than 10 kg who underwent CPB for a variety of congenital cardiac procedures were reviewed. The GLU values (at multiple intervals during and after surgery), age, weight, CPB time, ultrafiltration volume, and risk adjustment for congenital heart surgery (RACHS-1) score were recorded. Univariate and multivariate linear and binary logistic regression were used to examine the dependence of the composite outcome mortality or postoperative infection, the mechanical ventilation time (VENT time), and the length of stay (LOS), on these variables. RESULTS: The RACHS-1 score was the only significant predictor of the composite variable "mortality or infection" (p = 0.008). Glucose at any time was not a significant factor predicting this outcome. Lower pre-CPB GLU, younger age, and higher RACHS-1 score were significant predictors of greater LOS and VENT time. CONCLUSIONS: In this study, post-CPB and postoperative hyperglycemia were not risk factors for postoperative morbidity and mortality after infant cardiac surgery.

Dexmedetomidine/ketamine for diagnostic cardiac catheterization in a child with idiopathic pulmonary hypertension.

The use of a combination of dexmedetomidine and ketamine to provide procedural sedation in a 12-year old boy with a diagnosis of idopathic pulmonary hypertension and a behavioral disorder, undergoing diagnostic cardiac catheterization, is presented. Following a loading dose of ketamine one mg/kg and dexmedetomidine one mcg/kg, an infusion of dexmedetomidine at one mcg/kg/hr was used with the patient breathing spontaneously. Stable hemodynamics were observed throughout the procedure and pulmonary vascular resistance was measured under three conditions. The dexmedetomidine infusion was continued for two hours post-catheterization, facilitating a smooth emergence.

Initial experience with dexmedetomidine for diagnostic and interventional cardiac catheterization in children.

BACKGROUND: Children undergoing diagnostic and interventional cardiac catheterization require deep sedation or general anesthesia (GA). Dexmedetomidine, a selective alpha-2 adrenergic agonist, has sedative, analgesic and anxiolytic properties without respiratory depression. These characteristics make it potentially suitable as a sedative agent during diagnostic procedures in children. We report our experience using dexmedetomidine in 20 children aged 3 months to 10 years undergoing cardiac catheterization. METHODS: Following a midazolam premedication, intravenous access was secured facilitated by the inhalation of sevoflurane in oxygen. A loading dose of 1 microg x kg(-1) dexmedetomidine was administered over 10 min followed by an initial infusion rate of 1 microg x kg(-1) x h(-1). Nasal cannulae were applied, allowing endtidal CO2 monitoring with the patients breathing spontaneously. Hemodynamic parameters, Bispectral Index Score (BIS) and sedation score were measured every 5 min. Patient movement or evidence of inadequate sedation were treated with propofol (1 mg x kg(-1)). The dexmedetomidine infusion rate was titrated to the level of sedation to a maximum of 2 microg x kg(-1) x h(-1) to maintain a sedation score of 4-5 and a BIS value <80. RESULTS: Five patients (25%) had some movement on local infiltration or groin vessel access. This did not necessitate restraint or result in difficulty securing vascular access. No patients failed sedation that required the addition of another sedative agent or conversion to GA; eight patients were sedated with dexmedetomidine alone; however, 12 (60%) patients did receive a propofol bolus at some time during the procedure due to movement, increasing BIS value or in anticipation of stimulation. There were no incidences of airway obstruction or respiratory depression. In all cases the heart rate and blood pressure remained within 20% of baseline. No patient required treatment for profound bradycardia or hypotension. The average infusion rate for dexmedetomidine following the loading dose was 1.15 (+/-0.29)microg x kg(-1) x h(-1) (range 0.6-2.0 microg x kg(-1) x h(-1)). CONCLUSIONS: This initial experience showed dexmedetomidine, with or without the addition of propofol, may be a suitable alternative for sedation in spontaneously breathing patients undergoing cardiac catheterization.