Francesca Iodice

Cryoablation of Typical Atrioventricular Nodal Reentrant Tachycardia in Children: Six Years’ Experience and Follow‐Up in a Single Center

Background: Cryoablation is an effective and safe treatment for children with supraventricular tachycardias when the reentry circuit is located near the atrioventricular (AV) junction. We retrospectively reviewed consecutive cryoablation procedures for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in children and young adults in a single pediatric center.

Comparative evaluation of high-flow nasal cannula and conventional oxygen therapy in paediatric cardiac surgical patients: a randomized controlled trial

OBJECTIVES The aim of this study was to compare high-flow nasal cannula (HFNC) and conventional O2 therapy (OT) in paediatric cardiac surgical patients; the primary objective of the study was to evaluate whether HFNC was able to improve PaCO2 elimination in the first 48 h after extubation postoperatively. METHODS We conducted a randomized, controlled trial in pediatric cardiac surgical patients under 18 months of age. At the beginning of the weaning of ventilation, patients were randomly assigned to either of the following groups: OT or HFNC. Arterial blood samples were collected before and after extubation at the following time points: 1, 6, 12, 24 and 48 h. The primary outcome was comparison of arterial PaCO2 postextubation; secondary outcomes were PaO2 and PaO2/fractional inspired oxygen (FiO2) ratio, rate of treatment failure and need of respiratory support, rate of extubation failure, rate of atelectasis, simply to complications and the length of paediatric cardiac intensive care unit stay. RESULTS Demographic and clinical variables were comparable in the two groups. Analysis of variance for repeated measures showed that PaCO2 was not significantly different between the HFNC and OT groups (P = 0.5), whereas PaO2 and PaO2/FiO2 were significantly improved in the HFNC group (P = 0.01 and P = 0.001). The rate of reintubation was not different in the two groups (P = 1.0), whereas the need for noninvasive respiratory support was 15% in the OT group and none in the HFNC group (P = 0.008). CONCLUSIONS HFNC had no impact on PaCO2 values. The use of HFNC appeared to be safe and improved PaO2 in paediatric cardiac surgical patients.

Cobalamin c defect presenting with isolated pulmonary hypertension

Cobalamin C (cblC) defect is the most common inborn error of vitamin B12 metabolism. Clinical features vary as does the severity of the disease. In most cases, the clinical symptoms of cblC defect tend to appear during infancy or early childhood as a multisystem disease with severe neurologic, ocular, hematologic, renal, and gastrointestinal signs. The neurologic findings are common and include hypotonia, developmental delay, microcephaly, seizures hydrocephalus, and brain MRI abnormalities. We report a case of a young boy with cblC defect, who did not undergo newborn screening, presenting at the age of 2 years with isolated pulmonary hypertension as the leading symptom. This novel way of presentation of cblC defect enlarges the spectrum of inherited diseases that must be considered in the differential diagnosis of pulmonary hypertension.

Paroxysmal reciprocating supraventricular tachycardia in infants: electrophysiologically guided medical treatment and long-term evolution of the re-entry circuit

AIMS The aim of this study is to evaluate the long-term prognosis in infants affected by paroxysmal reciprocating supraventricular tachycardia (SVT), to identify predictors of SVT disappearance, and to assess the efficacy of electrophysiologically guided drug therapy in preventing recurrences. METHODS AND RESULTS A six step regimen of oral therapy was used in 55 infants with SVT: (i) propafenone (P); (ii) flecainide (F); (iii) flecainide plus propranolol (FP); (iv) amiodarone (A); (v) amiodarone plus propranolol (AP); (vi) amiodarone plus flecainide plus propranolol (AFP). If one step was not successful, the patient was passed on to the next treatment step and so on. Transesophageal atrial pacing (TAP) was used to evaluate treatment efficacy and the evolution of SVT at the end of the first, second, and third year. Propafenone was successful in 32.7% of the patients, F in 14.5%, FP in 23.6%, A alone in 5.4%, and AP in 18.1%; only 7.2% reached step 6. At month 12, after therapy wash out, SVT recurred spontaneously in 2 patients (3.6%) and remained inducible in 25 (45.5%). Inducibility was significantly higher in patients treated with A. At 24 months, SVT was inducible or spontaneous in 86% of the cases and at 36 months in 87%. There were no recurrences using the treatment confirmed by TAP. No further predictor of SVT inducibility was identified. CONCLUSION Supraventricular tachycardia disappeared in approximately 50% of the patients during the first year of life and in another 20% thereafter. The necessity for A treatment is the only predictor of persistence of the re-entry circuit during the first year of life. Transesophageal atrial pacing is useful in guiding the medical treatment.

High levels of free haemoglobin in neonates and infants undergoing surgery on cardiopulmonary bypass

OBJECTIVES Haemolysis is known to occur during surgery on cardiopulmonary bypass (CPB) and to be responsible for kidney injury. The aim of this study was to assess, in a cohort of infants, the reference levels of free haemoglobin (fHb) and their change over time postoperatively; the predicting variables of haemolysis in the intraoperative phase; and the association between fHb and renal function. METHODS A retrospective analysis in infants undergoing surgery on CPB was conducted. Children with preoperative renal dysfunction and need for extracorporeal membrane oxygenation support were excluded. fHb was sampled before and after CPB and on the first 2 postoperative days (POD). RESULTS Twenty-two patients with a median (interquartile) age of 111 (63-184) days and Aristotle score of 8 (6.4-9) were enrolled. fHb had a baseline value of 29 (24-41) mg/dl, peaked to 75 (65-109) mg/dl at CPB weaning and returned to 35 (30-55) mg/dl on POD 2 (P <0.0001). The median normalized index of haemolysis was 0.15 (0.09-0.19) g of fHb per 100 l of pumped blood. A multivariable regression model showed that, at CPB weaning, fHb levels were independently associated with left atrial venting flow (P = 0.02), and that CPB time remained the only independent variable (P = 0.034), when left atrial venting was excluded from the analysis. Acute kidney injury (AKI) occurred in 10 patients (45%). fHb levels in the 48 post-CPB hours were not significantly different between AKI and non-AKI patients: However, a significant correlation was present between creatinine on POD1 and CPBw-fHb (r = 0.48; P = 0.045); and between cystatin C on POD1 and CPBw-fHb (r = 0.58; P = 0.02). CONCLUSIONS A high rate of fHb is released during paediatric surgery with CPB in infants. fHb mainly depends on the left atrial venting flow rate and CPB duration. However, such peaks of fHb levels were not associated with renal dysfunction.

Inappropriate use of neurally adjusted ventilator assist

Neurally adjusted ventilator assist (NAVA) is a ventilator mode based on providing assistance to the patient in proportion to the electrical activity of the diaphragm. NAVA may improve patient–ventilator interactions. We describe a very complex case of a child with a permanent ventricular assist device where we attempted to use NAVA during the weaning process and then realised that it was impossible to use.

PAIN RELIEF IN PATIENTS UNDERGOING TONSILLECTOMY

Dear Editor, It is with great interest that I read the research article by Dr. Mogadam and colleagues: Comparison of Analgesic Effect between Gabapentin and Diclofenac on Post-Operative Pain in Patients Undergoing Tonsillectomy (1). This randomized controlled trial of 90 patients undergoing tonsillectomy attempts to underline the importance of preemptive analgesia. This involves the beginning of an analgesic regimen before the onset of a noxious stimulus to prevent central sensitization and limit the subsequent pain experience (2). Preemptive analgesia is a treatment that initiated before a surgical procedure reduces the physiological consequences of nociceptive transmission provoked by the nociceptive stimuli. Owing to this ‘protective’ effect on the nociceptive pathways, preemptive analgesia has the potential to be more effective than a similar analgesic treatment initiated after surgery. Consequently, immediate postoperative pain may be reduced and the development of chronic pain may be prevented (3). Pain relief was administered 1 hour before surgery in both the diclofenac and gabapentin groups. As predicted pain scores were lower among the pain relief groups compared with the study group, the authors may have considered comparing a third analgesic regimen, for example paracetamol, rather than a control group (without analgesia). This is more appropriate from an ethical point of view. The author’s choice of gabapentin appears to be adequate, since an increasing number of trials have shown its efficacy as a postoperative analgesic (4). Jeon et al. published an interesting study evaluating the effectiveness of premedication using gabapentin on postoperative pain control in patients undergoing tonsillectomy (5). This randomized trial was performed in adults who were randomly assigned to a control, placebo group and a gabapentin group. Pain assessment was performed using a visual analog scale during resting periods (rVAS) and during swallowing (sVAS) for a period of 9 days after the operation. The number of diclofenac sodium injections and the total amount of fentanyl injected decreased significantly in the gabapentin group (P < 0.01). The sVAS of the gabapentin group was also significantly lower than that of the control group at 2 and 4 h after surgery, but there were no significant differences in the sVAS observed between the two groups for the remainder of the postoperative period. In this study, premedication with gabapentin decreased post-tonsillectomy pain. The authors used only VAS scores to evaluate pain. It should be emphasized that VAS scores and other measures of pain may be influenced by side effects and other confounding variables, and may not be reliable as the sole measure in the evaluation of efficacy of pain medication. In addition, the use of VAS is an assessment that is highly subjective, these scales are of most value when looking at change within individuals, and are of less value for comparing across a group of individuals at one time point.

Evolution of Biventricular Loading Condition in Pediatric LVAD Patient: A Prospective and Observational Study

The aim of this study was to describe the echocardiographic trend of left ventricular (LV) and right ventricular (RV) function after implantation of a pulsatile flow left ventricular assist device (LVAD) in children. From 2013 to 2016, we prospectively evaluated 13 consecutive pediatric Berlin Heart EXCOR LVAD patients. Clinical and echocardiographic data were collected at baseline, within 24 h after implantation and monthly until LVAD explant. Median age and weight at the implantation was 8 (4-23) months and 5 (4.6-8.3) kg at the time of implantation, respectively. All were affected by dilated cardiomyopathy. Average LVAD support time was 226.2 ± 121.2 days. Nine (70%) were transplanted, 4 (30%) died. LV end-systolic and end-diastolic volumes were reduced until the follow up of two months (P = 0.019 and P = 0.001). A progressive increase in RV dimensions was observed. After 4 months of follow up, RV fractional area change worsening was statistically related with the deterioration of LV unloading (P = 0.0036). Four patients needed prolonged inotropic support for RV failure. Pulsatile LVAD in pediatrics is followed by an early and mid-term LV unloading, as expressed by a decrease in LV volumes and diameters at echocardiogram. The effects of unloading do not remain stable at long term follow up. RV function improved in the acute phase, but a progressive dilatation of RV was noted over time. In some patients, RV failure might lead to the need of an increase of inotropic support at long term follow up.