Shock and blood transfusion
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie in Bailey & Love's Short Practice of Surgery, 2018
In obstructive shock there is a reduction in preload due to mechanical obstruction of cardiac filling. Common causes of obstructive shock include cardiac tamponade, tension pneumothorax, massive pulmonary embolus or air embolus. In each case, there is reduced filling of the left and/or right sides of the heart leading to reduced preload and a fall in cardiac output.
Shock
Ian Greaves, Keith Porter, Chris Wright in Trauma Care Pre-Hospital Manual, 2018
Obstructive shock occurs when there is a physical obstruction to flow into, or out of, the heart. It is characterised by either impairment of diastolic filling (decreased preload) or excessive afterload or both. Impaired diastolic filling can result from direct venous obstruction, increased intrathoracic pressure or decreased cardiac compliance. In the context of the trauma patient, increased intrathoracic pressure can result from tension pneumothorax and pneumomediastinum. It can also result from mechanical ventilation where there is air trapping, excessive inflation pressures or excessive positive end-expiratory pressure. Cardiac tamponade is the commonest cause of restricted cardiac filling (compliance). Excessive afterload is more often associated with pulmonary embolism or aortic dissection. Obstructive shock, as with cardiogenic shock, may easily be missed in the trauma patient if there is co-existing evidence of hypovolaemia.
The patient with acute cardiovascular problems
Peate Ian, Dutton Helen in Acute Nursing Care, 2020
Obstructive shock occurs when there is impedance to the flow of blood through the central circulation. A number of conditions can cause obstructive shock, and treatment is focused on the correction of the disorder causing the obstruction. A large pneumothorax and, as a medical emergency, a tension pneumothorax, obstructs venous return to the heart by increasing intrathoracic pressure. Treatment is with high concentration oxygen and emergency needle decompression, a cannula usually being introduced in the second anterior intercostal space at the mid-clavicular line (Dutton and Finch 2018), quickly followed by chest drain insertion (see also Chapter 5). Cardiac tamponade (see also Chapter 7) occurs when the normal 30–50mL of fluid between the layers of the pericardium increases to such an extent that diastolic filling is impeded due to the pressure exerted on the heart. A rapid accumulation of as little of 50mL can be sufficient to cause cardiac arrest, though a gradual build-up of a pericardial effusion can accommodate up to 1000mL. Immediate medical intervention of pericardiocentesis is required to relieve the pressure so the ventricle can fill, and cardiac output can be maintained.
Alcohol septal ablation to overcome shock
Published in Acta Cardiologica, 2010
Katalien Galle, Johan De Sutter, Kristoff Cornelis
A 69-year-old man, known with hypertrophic obstructive cardiomyopathy (HOCM), was referred to our hospital because of progressive hypoxaemia and sepsis after admission for respiratory infection. Once at the emergency department, cardiopulmonary resuscitation, intubation and mechanical ventilation were necessary. Despite vasopressors and colloids the patient remained haemodynamically unstable. Because of the conviction that the distributive shock, caused by sepsis, was worsened by an associated obstructive shock related to the HOCM, an alcohol septal ablation (ASA) was attempted in these acute circumstances. Immediately after the ASA the gradient over the left ventricular outflow tract disappeared and the mean arterial pressure and oxygenation increased. Despite his cardiovascular recuperation the patient died a couple of days later. Nevertheless we achieved an improvement of the haemodynamic situation of this patient with HOCM by performing an urgent ASA.
Fluid administration limited by lung sonography: the place of lung ultrasound in assessment of acute circulatory failure (the FALLS-protocol)
Published in Expert Review of Respiratory Medicine, 2012
The FALLS-protocol is included in a limited investigation to diagnose the cause of shock. After simple echocardiography has ruled out obstructive shock (tamponade, pulmonary embolism), the lung is investigated. Absence of disseminated lung rockets rules out cardiogenic shock. At this point, hypovolemic and septic shock are differential diagnoses (rarities apart), and the FALLS-protocol provides fluid therapy with constant monitoring of lung artifacts. Hypovolemic shock will eventually improve – septic shock will not, and the slight excess fluid creates an early, silent stage of interstitial edema, demonstrated by B-lines, demanding interruption of fluid therapy. This sequential approach, combined with the usual, clinical, biochemical and echocardiographic parameters, must be evaluated in multicenter studies.
SUDDEN CARDIAC ARREST DURING PREGNANY: A RARE COMPLICATION OF ACQUIRED MATERNAL DIAPHRAGMATIC HERNIA
Published in Acta Clinica Belgica, 2012
R Jacobs, PM Honore, N Hosseinpour, K Nieboer, HD Spapen
Acute cardiac arrest during pregnancy is a rare but devastating event. Major causes are haemorrhagic, septic or anaphylactic shock, trauma, pulmonary or amniotic fluid embolism, and congenital or acquired cardiac disease. We present a case of massive intrathoracic migration of viscera through a left diaphragmatic hernia in a pregnant multipara, causing acute obstructive shock and cardiac arrest. Complications of intrathoracic herniation occur when the intruding viscera cause left lung and cardiac compression or mediastinal “tamponade” with decreased venous return. Intrathoracic strangulation of viscera is also common and may cause ischaemia, gangrene and eventual perforation. Sudden cardiac arrest as first sign of left diaphragmatic rupture during pregnancy, however, has rarely been described. In contrast with our patient, this catastrophic event is mostly seen in nulli-and primipara with a known congenital left diaphragmatic defect. Management of a diaphragmatic hernia depends on the clinical presentation and the period of gestation during which it is detected. Despite prolonged resuscitation with more than 1 hour of chest compressions, our patient recovered completely.
Related Knowledge Centers
- Cardiac Tamponade
- Cardiogenic Shock
- Pulmonary Embolism
- Heart
- Shock
- Great Vessels