What is congestion shock?

This is an automatically translated article.

The article is professionally consulted by Master, Doctor Phan Ngoc Toan - Emergency Medicine Doctor - Emergency Department - Vinmec Danang International Hospital.

1. Overview

In 1972, Hinshaw and Cox proposed a classification based on the different hemodynamic phenotypes of the shock state. This classification includes: hypovolemic shock, distributive shock, cardiogenic shock, and obstructive (extracardiac) shock.
Obstructive shock (also called "extracardiac obstructive shock") is a blockage in the great veins, in the heart, pulmonary artery, or aorta to the point that it interferes with blood flow. in the great vessels and is characterized by decreased diastolic filling or afterload overload.
As a consequence, blood flow to or from the heart is obstructed, resulting in decreased cardiac output and therefore inadequate oxygen delivery, presenting the classic clinical signs and symptoms of shock.

2. Causes and treatment

Obstructive shock is less common than other types of shock, in about 2% of ICU patients. The main cause is compression pericardial effusion, pulmonary embolism, or tension pneumothorax.
This is also a rare type of shock in pediatrics, with this group of patients, some other possible causes of this condition are congenital heart diseases characterized by left ventricular outflow tract obstruction ( including severe aortic stenosis, aortic spasm, interrupted aortic arch, and hypoplastic left heart syndrome).
In addition to the general treatment of patients in the setting of shock, the specific treatment according to the cause is summarized below.

Hear distant heart sounds, paradoxical pulse sounds. Metabolic acidosis: rapid breathing, increased lactic acid in the arteries... Cold sweats, pale skin, pale skin. Oliguria or anuria.

2.1 Pressure pneumothorax

A pneumothorax is an accumulation of air in the pleural space (a space made up of the parietal pleura and visceral pleura, which usually contains only a small amount of pleural fluid). It can be idiopathic (common in adolescent males) or secondary to pulmonary disease, such as trauma (both concussion and penetrating), asthma, cystic fibrosis, and pneumonia, or be associated with medical intervention, such as barotrauma during positive pressure ventilation or when central venous catheters are placed...
Tension pneumothorax is when air in the pleural cavity continues to build up with the one-way valve or ball valve effect, i.e. air enters during inhalation, but cannot exit during expiration. Eventually, air accumulates until the thoracic pressure on the affected side is equal to the atmospheric pressure outside. The tension caused by the air will push the mediastinum, compressing and causing collapse of the entire lung and large blood vessels, thereby reducing cardiovascular and respiratory function.
Treatment of emergency tension pneumothorax can be rapid decompression by placing a sterile needle in the second intercostal space along the midclavicular line on the affected side and definitive treatment requires placement of a chest tube.

2.2 Acute cardiac tamponade

The normal pericardium is a fibrous sac containing a thin layer of fluid that surrounds the heart. When the fluid builds up (pericardial effusion) or when the pericardium becomes scarred and no longer elastic, one of three pericardial tamponade syndromes can occur:
Cardiac tamponade - possible acute or subacute, characterized by accumulation of pericardial fluid under pressure.
Constrictive pericarditis - is the result of scarring and consequent loss of elasticity of the pericardium. Pericardial constriction is usually chronic, but can also be subacute, transient.
Constrictive pericarditis + effusion: characterized by the physiology of constriction and coexisting pericardial effusion.
In both tamponade and constrictive pericarditis, cardiac filling is impeded by external forces. The normal pericardium can stretch to accommodate physiological changes in cardiac volume. However, after its reserve volume is exceeded, the pericardium is markedly distended. Pericardial effusion can develop as a result of any type of pericarditis (infectious, cancerous, or idiopathic) or after trauma.
Tamponade is a classic and clinical diagnosis, in which a patient with critical cardiac tamponade presents with Beck's triad (hypotension, ("strangulated") heart murmur and increased jugular venous pressure. Bedside study is an effective tool in diagnosis and treatment
Treatment of acute cardiac tamponade includes:
Pericardial puncture Sometimes pericardial opening or pericardial window Subscapular pericardial puncture Chest compressions are performed in unstable patients when cardiac tamponade is suspected.ECG monitoring during needle insertion for signs of ST-segment elevation (occurs with needle-pericardial contact and requires needle removal). Pericardial puncture is a temporary measure.Removing as little as 10 mL of blood can return blood pressure to normal. are the indicated treatments in patients with a confirmed or highly suspected diagnosis, with well-trained medical personnel, and in critically ill patients who do not respond to detailed measures. In other words, one procedure is performed at the bedside in an emergency. If not, proceed in the operating room as soon as possible.

2.3 Pulmonary embolism

Pulmonary embolism (PE) refers to blockage of the pulmonary artery or one of its branches by material originating elsewhere in the body (eg, a thrombus usually from a large vein of the lower extremities and pelvis, tumor, air or fat).
Risk factors for pulmonary embolism are diseases that reduce the elasticity of the veins, diseases that damage or dysfunction the endothelial vessels, and hypercoagulability.
Pulmonary embolism can be classified according to the following physiological effects: Large: Decreased right ventricular function with hypotension, as defined by systolic blood pressure <90 mmHg or decrease in systolic blood pressure ≥ 40 mm Hg versus baseline BP over a 15-minute period and predicts high mortality within hours or days Moderate: Impaired right ventricular function without hypotension Small: No decrease in RV function and no hypotension When large thrombus occlude major pulmonary arteries, or when multiple small thrombi obstruct > 50% of peripheral vessels, right ventricular pressure increases, which can lead to acute right ventricular failure, shock , or sudden death. The risk of death depends on the degree and rate of elevation of right heart pressure and the patient's underlying cardiopulmonary status. Patients with pre-existing cardiopulmonary disease have a higher risk of death, but young and/or otherwise healthy patients can survive even with pulmonary embolism with >50% occlusion of the pulmonary artery.
Clinical symptoms: The most common signs of PE are Tachycardia Tachypnea Tachycardia Signs of right ventricular failure in chronic cases Fever, if present, usually low grade unless caused by underlying medical condition Infarction Pulmonaryngeal disease is usually characterized by chest pain (primarily pleural) and occasionally acute hemoptysis may also present with symptoms of deep vein thrombosis (ie, pain, swelling, and/or rash). redness of the leg or arm). Large PE may present with hypotension, tachycardia, headache/fatigue, syncope, or cardiac arrest. Diagnostic aid: When approaching a patient with suspected acute pulmonary embolism. The most useful tests for diagnosing or ruling out PE are the D-dimer Test, Computed tomography Angiography, Ventilation-Perfusion Scan, Duplex Ultrasound, Treatment: Adjunctive therapy Anticoagulation, Static membrane filtration Lower aorta Rapid reduction of blood clot Anticoagulation is the mainstay of treatment for pulmonary embolism, rapidly reducing the effects of blood clots through thrombolytic therapy or thrombectomy is indicated for patients with hypotension pressure and in some patients with impaired right ventricular function. Consider placing a percutaneous inferior vena cava filter (IVCF) for patients with contraindications to anticoagulation or who have recurrent pulmonary embolism despite anticoagulation.
Initial anticoagulation options for acute pulmonary embolism include
Intravenous unfractionated heparin Subcutaneous low molecular weight Heparin Subcutaneous Fondaparinux Factor Xa inhibitors (apixaban and rivaroxaban) Intravenous infusion Intravenous argatroban for patients with heparin-induced thrombocytopenic purpura In severe pulmonary embolism, rapid thrombolytic therapy requires more complex treatment, including:
Total thrombolytic therapy Drug-friendly (alteplase, urokinase...) Pulmonary infarction therapy with catheter thrombolysis (fibrinolysis, thrombectomy with spiral catheter), placement of pulmonary arteries to disrupt and/or to dissolve blood clots, commonly used to treat large pulmonary infarctions. Thrombectomy, reserved for patients with pulmonary infarction who are hypotensive despite supportive measures (continuous systolic BP 90 mmHg after fluid and oxygen therapy or if treatment is required) with vasopressors) or is about to have cardiac or respiratory arrest. Regardless of the cause of shock, there is a high risk of death if not detected and treated promptly. Therefore, family members need to pay attention to the symptoms and take the patient to the emergency room as quickly as possible if they see the typical signs of obstructive shock as above. Currently, Vinmec International General Hospital is one of the leading prestigious hospitals in the country, trusted by a large number of patients for medical examination and treatment. Not only the physical system, modern equipment: 6 ultrasound rooms, 4 DR X-ray rooms (1 full-axis machine, 1 light machine, 1 general machine and 1 mammography machine) , 2 DR portable X-ray machines, 2 multi-row CT scanner rooms (1 128 rows and 1 16 arrays), 2 Magnetic resonance imaging rooms (1 3 Tesla and 1 1.5 Tesla), 1 room for 2 levels of interventional angiography and 1 room to measure bone mineral density.... Vinmec is also the place to gather a team of experienced doctors and nurses who will greatly assist in diagnosis and detection. early signs of abnormality in the patient's body. In particular, with a space designed according to 5-star hotel standards, Vinmec ensures to bring the patient the most comfort, friendliness and peace of mind.

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