The pathophysiology of atypical tamponade in infants undergoing cardiac surgery

Abstract

A small solid state transducer was used to measure pericardial pressure (PP) in 13 pediatric patients (mean age 18 months) at hourly intervals for 24 h following cardiac surgery. The mean PP following closed cardiac surgery via a left thoracotomy (group 1: 5 patients) was 2.7 +/- 1.4 mmHg and did not change with time. Maximum PP occurred during isovolumic relaxation of the ventricle rising to a peak at the onset of the 'a' wave of the central venous pressure (CVP). PP was strongly correlated with CVP (r = 0.58, P less than 0.001) but not with airways pressure (r = 0.27, P less than 0.2). Mean PP in the 3 patients undergoing transatrial surgery (group 2) was 4.5 +/- 2.7 mmHg (group 1 vs group 2, P less than 0.001). PP was significantly raised in the 2 patients undergoing transventricular correction of Fallot's tetralogy (group 3, PP = 10.2 +/- 3.2 mmHg; group 3 vs group 2, P less than 0.001) and in the 3 patients undergoing homograft conduit reconstruction of the right ventricular outflow tract for truncus arteriosus (group 4, PP = 9.3 +/- 2.6 mmHg; group 4 vs group 2, P less than 0.001). The results confirm that PP is a mathematical function of the expansile forces of the heart and the restricting forces of the pericardium and mediastinum. Patients with pulmonary regurgitation or pulmonary hypertensive crisis leading to increased right ventricular end diastolic dimension or a space occupying conduit have a high PP and are therefore at risk of atypical tamponade. In this situation splinting open the chest may reduce PP and break the cycle of falling cardiac output.

Center variation and outcomes associated with delayed sternal closure after stage 1 palliation for hypoplastic left heart syndrome

“…In our analysis, we did not find a significant relationship between in-hospital mortality and DSC. Despite potential alterations in hemodynamic status associated with primary sternal closure, and hypothesized benefits of DSC, a survival benefit was not evident in our analysis (2, 3). …”

“…Capillary leak syndrome is common after cardiopulmonary bypass and is characterized by increased vascular permeability, generalized edema, impaired pulmonary function, coagulopathy, and cardiac dysfunction (1). Sternal closure immediately after surgery can be associated with cardiac compression, decreased ventricular compliance, and reduced cardiac output, further compromising hemodynamic and respiratory status (2, 3). Thus, the aim of DSC is to minimize post-operative hemodynamic and respiratory instability, and to provide ready access to sites of persistent bleeding.…”

Right atrial pressure as a measure of ventricular constraint arising from positive end-expiratory pressure during mechanical ventilation of the neonatal lamb

“…Our study also has implications for the assessment of cardiac function in newborns after surgery for congenital heart disease in which pericardial effusions and tamponade (29,47), increased tissue pressure caused by lung edema (47)(48)(49)(50)(51)(52), lower thoracic compliance (5), and PEEP (3)(4)(5)53) all increase ventricular constraint and consequently may alter the LV diastolic pressure-volume relation (54,55). As a result, assessment of Plved as a measure of ventricular preload as has occurred during cardiothoracic surgery, may be misleading and inaccurate (29,47) because transmural pressure may be substantially less than ventricular intracavitary pressure (29,47,56).…”

Delayed sternal closure in newborns after surgery for congenital heart defect

“…Podle zahraničních studií spočívá negativní hemodynamický dopad, způsobený uzávěrem hrudníku u dětí, ve významném vzestupu perikardiálního tlaku s odpovídajícím zvýšením tlaku v pravé a levé síni a následnou redukcí end-diastolického objemu. (7,8) Ačkoli se větší podíl na nízkém srdečním výdeji připisuje horšímu plnění srdce v diastole, ze studií u dospělých pacientů víme, že je dalším negativním jevem i snížení kontraktility v průběhu isovolumické kontrakce a redukce koronárního průtoku jako následek snížené srdeční compliance. (9) Nepříznivým faktorem po operaci v mimotělním oběhu je vyjádřený syndrom kapilárního úniku, který souvisí s délkou samotného mimotělního oběhu a má vliv na primární uzávěr operační rány.…”