Pathology Notes

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...

Anaphylaxis and anaphylactic shock   Updated: 06/20/22 © Jun Wang, MD, PhD Definition Anaphylaxis : Severe, generalized or systemic, rapid onset, life threatening allergic reaction Uniphasic anaphylaxis: most common type, usually peaks within an hour after symptoms appears and resolved either spontaneously or after treatment within an hour Biphasic anaphylaxis: a uniphasic anaphylaxis, followed by an asymptomatic period and a second reappearance of presentations of anaphylaxis without additional exposure to allergen Protracted anaphylaxis: anaphylactic reaction lasting hours or days without complete resolving of presentations Anaphylactic shock : Anaphylaxis with life-threatening hypotension, a type of distributive shock Common triggers Medication: beta-lactam antibiotics, radiocontrast, etc Blood products: esp for patients with Isolated IgA deficiency Food: nuts, milk, certain sea food Insect sting: wasp, honeybees, fire ants, etc Pathophysiology Key wo...