Plasma concentrations of levobupivacaine associated with two different intermittent wound infusion regimens following surgical ductus ligation in preterm infants.

BACKGROUND: Administration of local anesthetics by a surgically placed wound catheter has recently been shown to reduce the need for postoperative morphine administration in extremely preterm infants undergoing ductus ligation. The primary aim of this randomized safety study was to define the plasma levels of levobupivacaine (LB) following two different intermittent infusion regimens. METHODS: Eighteen preterm infants 23-27 gestational weeks, median birthweight 721 g scheduled for ductus ligation were included in the study. All patients were anesthetized according to a standardized protocol based on high-dose fentanyl (25-50 µg·kg(-1) ). Before skin closure, a subcutaneous catheter was inserted into the wound. The patients were randomized to receive one of the two intermittent infusion regimens: Group BII: Initial bolus plus early start of the intermittent infusion or Group DII: No bolus plus delayed start (8 h) of the intermittent infusion. Blood samples for determination of LB plasma concentrations were obtained on six occasions during the 24-h postoperative observation period, as well as hourly postoperative pain assessments using the Echelle Douleur Inconfort Noveau (EDIN) pain scale. RESULTS: Plasma concentrations of LB ranged from 0.094 to 1.682 µg·ml(-1) and 0 to 0.549 µg·ml(-1) in group BII and DII, respectively. Both regimens were associated with low postoperative EDIN pain scores (24 h median of 0 and 1 in group BII and DII, respectively). No signs of systemic local anesthetic toxicity were noted. CONCLUSIONS: The two studied intermittent infusion regimens were associated with plasma levels below potentially toxic levels and were both associated with adequate postoperative pain scores.

Plasma levels of levobupivacaine during continuous infusion via a wound catheter after major surgery in newborn infants: An observational study.

BACKGROUND: Epidurals may be challenging in neonatal patients due to technical difficulties relating to insertion and the risk of local anaesthesia toxicity. The use of wound catheters with an infusion of local anaesthetic has been shown to be well tolerated in adults and older children. There are few data concerning wound catheter techniques in neonatal patients. OBJECTIVES: The primary aim of this study was to analyse plasma levels of levobupivacaine associated with continuous wound infiltration via a catheter following neonatal surgical procedures. Secondary parameters, including the quality of postoperative analgesia and wound healing, were also noted. DESIGN: A prospective, observational study. SETTING: Paediatric ICU at the Karolinska University Hospital, Stockholm, Sweden, from March 2008 to December 2010. PATIENTS: Twenty newborn infants (median weight 3.48 kg) scheduled for major abdominal or thoracic surgery were included. Exclusion criteria were known or suspected hepatic dysfunction. Before skin closure, a subcutaneous catheter was inserted into the wound followed by a 0.5 mg kg(-1) bolus of levobupivacaine (0.125%, 0.4 ml kg(-1)) through the catheter. A continuous infusion was started 20 to 30 min later at a rate of 0.2 mg kg(-1)h(-1) (0.16 ml kg(-1) h(-1)). MAIN OUTCOME MEASURES: Plasma concentrations of levobupivacaine (total and unbound) at 12, 24, 48 and 72 h postoperatively. Morphine consumption, pain scores and wound healing were also analysed. RESULTS: Median concentrations of unbound and total levobupivacaine at 72 h were 0.018 and 1.305 µg ml(-1), respectively. In 18 out of 20 infants [90%; 95% confidence interval (CI) 68.3 to 98.8], the unbound plasma concentration of levobupivacaine remained relatively stable and below 0.05 µg ml(-1) throughout the 72 h observation period. Pain scores and morphine consumption levels were low. All wounds except one healed within 10 days. CONCLUSION: The studied infusion regimen was associated with plasma levels of levobupivacaine well below those associated with toxicity. Adequate wound healing, low pain scores and a reduced need for opioids were also noted.

The natural history of prenatally diagnosed congenital pulmonary airway malformations and bronchopulmonary sequestrations.

BACKGROUND: The natural history of congenital pulmonary airway malformations (CPAM) and bronchopulmonary sequestrations (BPS) is not fully understood, and the management of the newborn with an asymptomatic lesion is a controversial issue. We aimed to study the natural history and outcome of CPAM/BPS at our institution with a policy of watchful waiting, and to investigate if any prognostic factors in the pre- and/or postnatal- period may predict the need for surgery. MATERIAL AND METHODS: A retrospective review study was conducted of children prenatally diagnosed with CPAM and/or BPS during the 18-year period, from 2002 to 2020. Data from the pre and postnatal period was collected and analysed. RESULTS: Sixty- six patients with prenatally observed lung lesions were entered in the study, with an overall survival rate of 94%. Fifty-six percent of the lesions decreased in size during gestation. Thirty-one percent had surgery and 69% could be managed conservatively with a median follow-up of 4 years. Nineteen percent developed symptoms after the neonatal period. Children with a presence of mediastinal shift on postnatal imaging (p = 0.003), with a high CVR (p = 0.005) and a large lesion size during gestation (p = 0.014) were significantly more likely to require surgery. CONCLUSION: Prenatal regression is common among prenatally diagnosed CPAM/BPS and the majority of children that are asymptomatic beyond the neonatal period will remain asymptomatic throughout their childhood. Future analysis with a longer follow-up might give new insights in order to identify children at risk of developing symptoms. LEVEL OF EVIDENCE: III.

Mitral annular disjunction in advanced myxomatous mitral valve disease: echocardiographic detection and surgical correction.

Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus described by pathologists in association with mitral leaflet prolapse and defined as a separation between the atrial wall-mitral valve (MV) junction and the left ventricular attachment allowing for hypermobility of the MV apparatus. The transesophageal echocardiographic characteristics of this abnormality have not been previously described. In patients undergoing MV repair for myxomatous MV degeneration and evaluated using a standardized transesophageal echocardiographic protocol, annular disjunction (mean value 10 +/- 3 mm) was seen at the base of the posterior leaflet in 98% of patients with advanced, and in 9% of patients with mild/moderate MV degeneration. There was a significant correlation between the magnitude of disjunction and the number of segments with prolapse/flail (r = 0.397, P = .001). We found annular disjunction to be a common component of MV apparatus in advanced MV degeneration. Its recognition on transesophageal echocardiography is important to facilitate optimal MV repair. The modification of the repair technique allows surgical correction of the annular disjunction, which seems to optimize long-term results in these challenging cases.

Cardiovascular function during the first 24 hours after off pump coronary artery bypass grafting--a prospective, randomized study.

We hypothesized that cardiovascular performance during the first 24 postoperative hours would be better in patients after off pump coronary artery bypass grafting compared to conventional on pump surgery. Fifty-nine patients were randomized to on or off pump coronary artery bypass grafting. Hemodynamic parameters, including cardiac index and systemic vascular resistance index were measured before and at 1, 4, and 20 h after surgery. Troponin T and creatine kinase-MB (CK-MB) were measured before and at 1, 6, and 20 h after surgery. There was no difference in age, sex, ejection fraction or number of grafts between groups. Cardiac index was higher (p=0.05) and systemic vascular resistance index was lower (p=0.007) in the off pump group 1 h after arrival in the intensive care unit. CK-MB and troponin T were significantly lower in the off pump group after 1 h (CK-MB p<0.001, troponin T p<0.001) and after 6 h (CK-MB p=0.02, troponin T p<0.001). After 24 h there was no difference between the two groups. In conclusion, immediately after surgery there was better cardiovascular performance and less release of markers of myocardial damage after off pump coronary surgery. After 24 h all differences were eliminated.