Update on Perioperative Pediatric Pulmonary Hypertension Management.

Pediatric pulmonary hypertension is a disease that has many etiologies and can present anytime during childhood. Its newly revised hemodynamic definition follows that of adult pulmonary hypertension: a mean pulmonary artery pressure >20 mmHg. However, the pediatric definition stipulates that the elevated pressure must be present after the age of three months. The definition encompasses many different etiologies, and diagnosis often involves a combination of noninvasive and invasive testing. Treatment often is extrapolated from adult studies or based on expert opinion. Moreover, although general anesthesia may be required for pediatric patients with pulmonary hypertension, it poses certain risks. A thoughtful, multidisciplinary approach is needed to deliver excellent perioperative care.

Flecainide Toxicity Secondary to Accidental Overdose: A Pediatric Case Report of Two Brothers.

Flecainide is a class 1C antiarrhythmic with a narrow therapeutic window and thereby a high-risk medication for causing acute toxicity. Dysrhythmias secondary to flecainide ingestion are often refractory to antiarrhythmics and cardioversion, and patients commonly require extracorporeal support. We review the successful resuscitation of two brothers aged 2 and 4 who presented two years apart with unstable wide-complex tachyarrhythmia suspicious for severe flecainide toxicity. Each patient received sodium bicarbonate and 20% intravenous lipid emulsion with a full recovery. While extracorporeal support is often required following flecainide ingestion, we present two cases where it was avoided due to aggressive multimodal management with sodium bicarbonate, electrolyte repletion, and 20% intravenous lipid emulsion. In addition, avoidance of agitation-induced tachycardia may be beneficial.

Perioperative management and considerations in pediatric patients with connective tissue disorders undergoing cardiac surgery.

BACKGROUND: Marfan syndrome and Loeys-Dietz syndrome are connective tissue disorders associated with cardiac and vascular disease. Patients often require surgical repair, but limited data exist to describe their perioperative management. AIMS: Our goals were to review the perioperative features of patients with Marfan and Loeys-Dietz syndrome that may affect anesthesia care and to describe the differences in preoperative clinical characteristics and intra-operative anesthetic management. METHODS: We conducted a retrospective cohort study of patients with Marfan and Loeys-Dietz syndrome who underwent cardiac surgery at a single institution. We collected demographic and perioperative data from the electronic medical record and performed descriptive statistics to characterize the patient populations and describe their anesthetic management. RESULTS: In 71 patients (40 Marfan, 31 Loeys-Dietz), we found significant differences between the Marfan and Loeys-Dietz patients in airway difficulty, preoperative weight, blood utilization, valvular disease, and age at first cardiac surgery. Patients with Loeys-Dietz syndrome had higher preoperative rates of severe noncardiac comorbidities, including gastroesophageal reflux and asthma that required chronic medical therapy. CONCLUSIONS: Despite undergoing similar surgical procedures, patients with Marfan and Loeys-Dietz syndrome have different intrinsic patient characteristics and comorbidities that may affect their perioperative care. This retrospective cohort study identified some factors, but additional collection and reporting of patient data based on multicenter experience are essential for the ongoing optimization of perioperative care in these patient populations.

Age-Related Changes in Upper Airway Anatomy Via Ultrasonography in Pediatric Patients.

PURPOSE: Ultrasonography is a portable, noninvasive tool that may be used to evaluate the upper airway. The purpose of our study was to present a systematic approach to identify salient features of the pediatric airway and determine whether ultrasonography can identify anatomical changes that occur with growth and development. METHODS: We present a prospective, observational trial where patients included were between 1 day and 10 years of age presenting for elective surgery who had no known history of unfavorable airway pathology. We sequentially obtained 5 ultrasound views under anesthesia: (1) sagittal sternal notch view of the trachea, (2) sagittal longitudinal view of trachea (LT), (3) axial view at the level of the vocal cords (AVC), (4) axial view at the level of the cricoid membrane (AC), and (5) sagittal longitudinal submental space view (SM). A broadband linear array transducer was used to identify airway structures and perform measurements. RESULTS: Eighty-four percent of enrolled patients underwent airway imaging and were analyzed using multiple regression and Spearman correlation (ρ). In view 1, tracheal diameter via sagittal sternal notch view was immeasurable because of air disturbance. In the LT view, the distance from the skin to the cricothyroid membrane (LT1) did not statistically increase with age in days (P = 0.06); however, the distance from the cricoid to thyroid cartilage (LT2) did correlate to age (P < 0.001; 99% confidence interval [CI], 1.8 × 10-5, 7.7 × 10-5; ρ = 0.77, P = 0.001). We found a statistically significant relationship between age and the distance between the anterior and posterior commissures (AVC2; P < 0.001; 99% CI, 1.0 × 10-4, 1.7 × 10-4; ρ = 0.80, P < 0.001), the distance from the skin to the posterior commissure (AVC3; P < 0.001; 99% CI, 9.6 × 10-5, 2.0 × 10-4; ρ = 0.73, P < 0.001), the distance to the cricoid cartilage (AC; P < 0.001; 99% CI, 2.0 × 10-5, 7.7 × 10-5; ρ = 0.66, P < 0.001), and the distance from the tongue base to the soft palate (SM2; P < 0.001; 9% CI, 1.8 × 10-4, 3.9 × 10-4; ρ = 0.85, P < 0.001). There were no significant relationships between age and AVC1 (P = 0.16) and SM1 (P = 0.44). CONCLUSIONS: Airway ultrasound is a feasible tool to evaluate the pediatric airway in children younger than 10 years; however, the detection of age-related changes of certain structures is limited to select measurements.

The Use of Bivalirudin in Pediatric Cardiac Surgery and in the Interventional Cardiology Suite.

Anticoagulation is an essential component for patients undergoing cardiopulmonary bypass or extracorporeal membrane oxygenation and for those with ventricular assist devices. However, thrombosis and bleeding are common complications. Heparin continues to be the agent of choice for most patients, likely owing to practitioners' comfort and experience and the ease with which the drug's effects can be reversed. However, especially in pediatric cardiac surgery, there is increasing interest in using bivalirudin as the primary anticoagulant. This drug circumvents certain problems with heparin administration, such as heparin resistance and heparin-induced thrombocytopenia, but it comes with additional challenges. In this manuscript, the authors review the literature on the emerging role of bivalirudin in pediatric cardiac surgery, including its use with cardiopulmonary bypass surgery, extracorporeal membrane oxygenation, ventricular assist devices, and interventional cardiology. Moreover, they provide an overview of bivalirudin's pharmacodynamics and monitoring methods.

Trends and Updates on Cardiopulmonary Bypass Setup in Pediatric Cardiac Surgery.

Perfusion strategies for cardiopulmonary bypass have direct consequences on pediatric cardiac surgery outcomes. However, inconsistent study results and a lack of uniform evidence-based guidelines for pediatric cardiopulmonary bypass management have led to considerable variability in perfusion practices among, and even within, institutions. Important aspects of cardiopulmonary bypass that can be optimized to improve clinical outcomes of pediatric patients undergoing cardiac surgery include extracorporeal circuit components, priming solutions, and additives. This review summarizes the current literature on circuit components and priming solution composition with an emphasis on crystalloid, colloid, and blood-based primes, as well as mannitol, bicarbonate, and calcium.

HeartWare Ventricular Assist Device Implantation for Pediatric Heart Failure-A Single Center Approach.

While pediatric HeartWare HVAD application has increased, determining candidacy and timing for initiation of pediatric VAD support has remained a challenge. We present our experience with a systematic approach to HVAD implantation as a bridge to pediatric heart transplantation. We performed a retrospective, single center review of pediatric patients (n = 11) who underwent HVAD implantation between September 2014 and January 2018. Primary endpoints evaluated were survival to heart transplantation, need for right ventricular assist device (RVAD) at any point, ongoing HVAD support, or death. Median patient age was 11 years (range: 3-16). Median BSA was 1.25 m2 (range: 0.56-2.1). Heart failure etiologies requiring support were dilated cardiomyopathy (n = 8), myocarditis (n = 1), congenital mitral valve disease (n = 1), and single ventricle heart failure (n = 1). Median time from cardiac ICU admission for heart failure to HVAD placement was 15 days (range 3-55), based on standardized VAD implantation criteria involving imaging assessment and noncardiac organ evaluation. The majority of patients (91%) were INTERMACS Level 2 at time of implant. Three patients (27%) had CentriMag RVAD placement at time of HVAD implantation. Two of these three patients had successful RVAD explanation within 2 weeks. Median length of HVAD support was 60 days (range 6-405 days). Among the 11 patients, survival during HVAD therapy to date is 91% (10/11) with 9 (82%) bridged to heart transplantation and one (9%) continuing to receive support. Posttransplant survival has been 100%, with median follow-up of 573 days (range 152-1126). A systematic approach to HVAD implantation can provide excellent results in pediatric heart failure management for a variety of etiologies and broad BSA range.

A Review of Goal-Directed Cardiopulmonary Bypass Management in Pediatric Cardiac Surgery.

Cardiopulmonary bypass perfusion management significantly affects postoperative outcomes. In recent years, the principles of goal-directed therapy have been applied to the field of cardiothoracic surgery to improve patient outcomes. Goal-directed therapy involves continuous peri- and postoperative monitoring of vital clinical parameters to tailor perfusion to each patient's specific needs. Closely measured parameters include fibrinogen, platelet count, lactate, venous oxygen saturation, central venous oxygen saturation, mean arterial pressure, perfusion flow rate, and perfusion pulsatility. These parameters have been shown to influence postoperative fresh frozen plasma transfusion rate, coagulation state, end-organ perfusion, and mortality. In this review, we discuss the recent paradigm shift in pediatric perfusion management toward goal-directed perfusion.

Membrane Oxygenator Use With Biventricular Assist Device: Facilitation of Support and Lung Recovery.

We present the use of a low-resistance membrane oxygenator (Quadrox D, Maquet) in series with a pulsatile right ventricular assist device (Berlin Heart EXCOR, Berlin Heart) in a patient with biventricular support who required high-frequency oscillatory ventilation (HFOV), due to refractory acute respiratory distress syndrome associated with Cytomegalovirus pneumonia. The high mean airway pressure associated with the use of HFOV resulted in a significant negative impact on left ventricular assist device (LVAD) filling that led to a combined respiratory and metabolic acidosis and the need for vasopressor support. Oxygenator placement enabled transition to conventional ventilation and the discontinuation of vasopressor support. This case demonstrates the feasibility and safety of the use of this lung support system in patients requiring ventricular assist device (VAD) support.

Acute Renal and Hepatic Failure in an Adolescent: An Unusual Presentation of Multiple Aortic Aneurysms.

Aortic dissection secondary to thoracoabdominal aortic aneurysms is very uncommon in children, and this life-threatening diagnosis requires a high clinical index of suspicion. Unlike adults, in whom atherosclerosis, inflammation, and advanced age are typically contributing factors, aortic dissection in children is usually due to nonatherosclerotic causes.Aortic aneurysms can be asymptomatic when small but, when significantly enlarged, can compromise organ function and dissect, resulting in high mortality rates. It is therefore critical that children with this uncommon condition be identified early when medical or surgical management can potentially improve outcome. We describe a 15-year-old patient with multiple aortic aneurysms with dissection whose presentation includes chronic anemia, acute-on-chronic renal failure with hyperkalemia, and liver injury.