Preoperative management of hypoplastic left heart syndrome (Views : 615 times)
Sandro Dessardo, Vladimir Ahel
Abstract
Pediatricians are frequently involved in the care of cyanotic newborns in the labor and delivery room, as well as in the well baby nursery. Causes of hypoxia and cyanosis in the term newborn can be found within all physiological systems. Congenital heart structural diseases account for the largest diagnostic category. There have been significant advances during the past years in the diagnosis and treatment of neonates with critical congenital heart disease, especially in the field of pre- and post-operative intensive care.
The term hypoplastic left heart syndrome (HLHS) describes a spectrum of cardiac structural abnormalities characterized by marked hypoplasia of the left ventricle and ascending aorta. Prenatal diagnosis, initial resuscitation and optimal preoperative management are key elements that allow the best opportunity for low mortality and normal neurodevelopment in affected newborns. Preoperatively, the goal is to achieve adequate systemic oxygen delivery. Patency of the ductus arteriosus (DA) is critical for survival until surgery. Blood flow to the pulmonary and systemic circulations should be nearly balanced (goal Qp/Qs ratio of 1). The immediate therapy for all infants with HLHS is an intravenous infusion of prostaglandin E1 (PGE1) in order to manipulate the DA and maintain ductal patency. Oxygen saturations of 75% to 85% by pulse oximetry suggest an adequate balance between systemic and pulmonary blood flow. Judicious use of inotropic support is initiated if evidence of low cardiac output is detected. Diuretics may be necessary to help alleviate the increased volume load on the right ventricle. The goal of respiratory management is to increase pulmonary vascular resistance and decrease systemic vascular resistance. Infants with HLHS who are born with a severely restricted or no inter-atrial communication, a rare occurrence, have profound hypoxemia. The severe restriction of blood flow across the atrial septum results in a life-threatening situation and these patients, which present with severe cyanosis and hemodynamic instability, require urgent postnatal cardiac catheterization to relieve the septal obstruction and improve oxygenation. Special attention should be paid to the prevention of brain injury and poor neurodevelopmental outcome.
Care for infants with HLHS is complex, and often multiple specialists are involved. Despite an increase in the number of newborns with complex congenital heart disease and a growing percentage of patients with single-ventricle physiology, it is possible to care for this particular group of patients and achieve acceptable mortality risks, even in centres with no pediatric cardiac surgery facilities, if good preoperative management protocols are followed.
Key words: congenital heart disease, newborn, intensive care, hemodynamics, PGE1, ductus arteriosus
Transfusion related acute lung injury (TRALI) (Views : 1330 times)
Tajana Zah, Jasna Mesarić, Višnja Majerić-Kogler
Abstract
Transfusion-related acute lung injury (TRALI) is a complication following transfusion of blood products and is potentially a life-threatening adverse event of transfusion. The first case of fatal pulmonary edema following transfusion was reported in the 1950s. In recent time, TRALI has developed from an almost unknown transfusion reaction to the most common cause of transfusion related major morbidities and fatalities. A clinical definition of TRALI was established in 2004, based on acute respiratory distress which has temporal association with transfusion of blood components. In 2008 a distinction between classic and delayed syndrome was proposed. However, pathophysiology of TRALI still remains controversial. A number of different models were proposed to explain the pathogenesis. The two, presently most accepted models, are not mutually exclusive. The first is the antibody mediated model and the second is the two-event model.
In this review article the definition of TRALI, patient predisposition, treatment, prevention and reporting guidelines are examined. The current knowledge on the topic TRALI is summarized.
Key words: transfusion, acute lung injury
The addition of enteral to parenteral antimicrobials may prolong antibiotic era (Views : 965 times)
Hendrik K.F. Van Saene, Nia Taylor, Smilja Kalenić, Mladen Perić, Miguel Angel de la Cal
Abstract
Resistance to parenteral antimicrobials generally occurs within two years after introduction into general use. The site where de novo resistance develops has been acknowledged to be the gut. Overgrowth of abnormal flora, defined as 105 potential pathogens per g of faeces is a risk factor for resistance following increased spontaneous mutation leading to polyclonality and antimicrobial resistance. As parenteral antimicrobials generally fail to eradicate the abnormal carrier state in overgrowth concentrations due to sub-lethal concentrations in bile and mucus the enteral antimicrobials polymyxin/tobramycin aiming at converting the abnormal carrier state into normal carriage, are the essential component of selective decontamination of the digestive tract (SDD), because they eradicate carriage and overgrowth including resistant mutants, maintaining the usefulness of parenteral antimicrobials.
Keywords: normal carriage, abnormal carriage, overgrowth, mutation, polyclonality, resistance, selective decontamination of the digestive tract, parenteral antimicrobials, enteral antimicrobials
Advantage of spontaneous breathing in patients with respiratory failure (Views : 1612 times)
Abstract
The fact that different modalities of mechanical ventilation are associated with a number of serious side effects and risks and can influence the clinical outcome of patients, the various modes of mechanical ventilation have, over the past ten years, been the subject of a wide variety of scientific studies. Many of these modalities are designed for partial ventilatory support, which might reflect the complexity of the issue of patient's ventilator interactions when spontaneous breathing activity is present, compared to controlled mechanical ventilation. Spontaneous breathing modes during mechanical ventilation may integrate intrinsic feedback mechanisms that should help prevent ventilator- induced lung injury and improve synchrony between the ventilator and the patient's demand. The improvements in pulmonary gas exchange, systemic blood flow, and oxygen supply to the tissue that have been observed when spontaneous breathing has been maintained during mechanical ventilation are reflected in the clinical improvement in the patient' s condition. It is the aim of this article to review the effects of preserved spontaneous breathing activity during mechanical ventilation in patients with acute respiratory failure.
Key words: mechanical ventilation, acute respiratory distress syndrome, ventilation mode, spontaneous breathing
Human protein C concentrates in adult septic patients (Views : 1139 times)
Giovanni Landoni, Martina Crivellari, Giacomo Monti, Chiara Gerli, Paolo Silvani, Alberto Zangrillo
Abstract
Some case reports and case series suggest that protein C concentrates may improve the outcome in patients with congenital or acquired protein C deficiency (not only in those with sepsis induced purpura fulminans). We reviewed the published literature on the use of protein C concentrates in adult septic patients and found that it is limited to less than 70 patients reported in observational studies with a 70% survival, and added our personal experience (two adult patients with sepsis and contraindications to recombinant activated protein C).
Key words: sepsis, protein C, cardiac surgery
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