Pathology Notes

Obstructive shock Updated: 06/30/2022 © Jun Wang, MD, PhD General features Reduced cardiac output due to obstruction of large vessels or heart Similar symptoms to cardiogenic shock , but different treatment Usually clinical diagnosis, based on history and clinical presentations Etiology Pulmonary vascular Pulmonary embolism Severe pulmonary hypertension Pulmonary or tricuspid stenosis, acute obstruction Mechanical Tension pneumothorax Pericardial tamponade Constrictive pericarditis Restrictive cardiomyopathy High-PEEP ventilation Vena Cava compression syndrome Cardiac mass   Increased afterload Aortic dissection Aortic valve stenosis Pathophysiology Obstruction of large vessels or heart Impaired diastolic filling Reduced cardiac preload Increased cardiac afterload Clinical presentations Non specific Presentation associated with underlying cause: cardiac mass , pneumothorax, etc Presentations of hypoperfusion: Tachycardia Hypo

Cardiogenic shock Updated: 06/23/2022 © Jun Wang, MD, PhD General features Reduced cardiac output due to severe ventricular dysfunction Adequate circulating volume Tissue hypoxia due to hypoperfusion Etiology Acute myocardial infarction: most common cause Multivessel coronary artery disease Arrhythmia Mechanic defects: septal defect, papillary muscle rupture, etc Key risk factors Older age Anterior myocardial infarction History of hypertension, diabetes mellitus, multivessel coronary artery disease, myocardial infarction Systolic BP< 120 mmHg Heart rate > 90 beats per minute Heart failure at admission EKG findings of ST-elevation and left bundle branch block Clinical presentations Presentation associated with underlying cause: acute myocardial infarction, etc Chest pain Difficulty in breathing Symptoms of shock : Tachycardia Hypotension Tachypnea Physical examination findings Distended jugular vain Coolness of skin Gallo

Hypovolemic shock Updated: 02/05/2024 © Jun Wang, MD, PhD General features Associated with rapid fluid loss Hemorrhagic or extracellular fluid loss Most common type of shock in children, usually associated with diarrhea in developing countries Markedly reduced circulating volume Inadequate tissue perfusion Etiology Bleeding: solid organ injury, aortic aneurysm rupture, GI bleeding, bleeding due to ectopic pregnancy, surgery, etc Extracellular fluid loss GI: Retractable vomiting, diarrhea especially profuse diarrhea such as cholera , external drainage via stoma or fistulas Urinary: diuretic therapy, osmotic diuresis , salt wasting nephropathy, etc Skin: sweating in hot and dry climate, esp with interrupted skin barrier Third space sequestration: intestinal obstruction, pancreatitis , crush injuries, peritonitis, major vein obstruction Pathogenesis Clinical presentations History of blood and/or extracellular fluid loss Symptoms Symptoms ass