Shock Flashcards
Shock
Lack of perfusion to the body, commonly due to blood loss, vomiting, dehydration -> hypovolemic shock, cardiogenic shock (low cardiac output), Obstructive shock (obstruction in blood flow such as Pulmonary embolism ), Distributive shock (fluid accumulates between cells / organs and blood vessels due to swelling and inflammation -> tissues can’t get oxygen due to fluid )
Shock - oxygen delivery and metabolism
Cardiogenic / Hypovolemic shock (extraction oxygen increases, demand increases, oxygen return to heart decreases )
Distributive shock ( extraction oxygen decreases, demand increases, oxygen return to heart to heart increases).
Mixed venous oxygen (Smvo2, if decreased in RA then there is increase in extraction oxygen, if increased in RA then there is decrease in extraction oxygen )
Shock diagnosis and treatment
Low blood pressure, echocardiogram, pulmonary capillary wedge pressure (pressure in LA ), central venous pressure (pressure in RA), pulmonary artery catheter (used to measure pulmonary capillary wedge pressure, central venous pressure, if its a cardiogenic shock PCWP will be high, if its a hypovolemic shock PCWp will be low), pulse oximetry, ABG (atrial blood gas : test for oxygen, carbon dioxide and pH), pulmonary artery catheter can also test for Scvo2 (Central venous O2 stat, extraction o2 increased ->Scvo2 decreased, extraction decreased -. Scvo2 increased), accumulation of lactic acid (happens in presence of anaerobic metabolism by cells ).
Treatment - fluids are pumped in body, vasoconstriction (pressors)
Cardiogenic shock
Causes - valvular problems, Arrythmias, heart attack, CHF, heart failure, fluid overload
Symptoms - pulmonary congestion, cough, increased jugular vein destention, chest pain / angina, cool skin
Diagnosis - serum lactate , ABG, Troponin, CXR, EKG, Echocardiogram, PCWP (>18 mmHg), CO/Cardiac Index (CO (cardiac output) // BSA (Body Surface Area) , CI <2.2)
Treatment - O2, CV support ( increasing SVR (Vasopressors ) , increasing contractility , repair heart problems.
Sepsis (systemic inflammatory response syndrome, SIRS) to Multiple organ dysfunction syndrome (MODS)
SIRS - temperature > 100.5 For <96.8 F, HR>90, RR> 20, PaCO2 <32, WBC > 12000 or <4000, >10 % band cells (young immature white cells )
Sepsis : SIRS + confirmed infection (organ damage )
Septic shock - sepsis + Hypotension (fluid is given : 30 ml/Kg x pt’s wt and the blood pressure still doesn’t go up ),
MODS : severe septic shock leading to organ failure which is beyond recovery
Septic shock - pathophysiology and symptoms
The infective agent is present in he interstitial space and when the WBCs detect it, they further recruit more WBC to the site. When they are present in blood stream and are trying to get to the interstitial space they release Nitric Oxide which causes vasodilation, this also makes blood vessels ,more permeable. The BP lowers because the SVR decreases, fluid leaves the vessels and accumulates into interstitial space, WBC release reactive oxidative species (ROS) and lyric enzyme to destroy infective agent which causes damage to the blood vessels.
Now the coagulation factors jump into the repair of blood vessels which leads to clot formation that will eventually result in lack of clotting factors resulting in blood leak into interstitial space. Sepsis can cause DIC (Desseminated Intravascular Coagulation : clot formation in vessels every where), ARDS (Acute respiratory distress syndrome (blood vessels damaged in lungs -> No oxygen absorption in blood), cardiac output increase is attempted by heart to compensate but eventually damage occurs to healt resulting in depressed CO, CO decreases -> BP decrease.
Symptoms - warm skin -> cool skin (upon sepsis progression), Altered mental status, Respiratory distress, Low Urinalysis output).
Septic shock
Diagnoses and treatment
Diagnosis - lab testing : blood culture, Lactate, ABG, BUN, Creatinine (for kidney function)
Treatment - Broad spectrum antibiotic, after blood culture is back -> tailored antibiotic therapy is given, IV fluids (to restore BP), Pressors(vasoconstriction)
Progress monitoring - CRP (C-reactive proteins _ and ESR (Erythrocyte sedimentation rate), labs to track inflammation, initially theCRP _> <1 mg/dl, ESR -> <20-25 mm/hr, but later the values would lower if the treatment is effective.
Hypovolemic shock
Low blood in the system, preload decreases, afterload decreases -> SV decreases -> CO decreases -> HR increases (compensation effort for decreased CO) -> RA ( to increase preload ).
Causes : blood loss, fluid loss all through bleeding, diarrhea, vomiting, excessive urination, sweating.
Symptoms : increased HR, decreased BP, increased RR ( cool, clammy skin), dryness, pale )
Diagnoses : lab testing (CBC, ABG, serum lactate, Hematocrit, Hemoglobin)
Treatment ( IV fluids, pressors, blood transfusion, Platelets, Coagulation factors (FFP -> Fresh Frozen Plasma), Albumin (to keep blood volume / fluid in blood vessels instead of interstitial space).
Neurogenic Shock
Nervous system provides tone to blood vessels and heart. Nervous system provides vascular tone to the blood vessel and if that is missing then the vessels loose resistance and would extensively widen, blood won’t move forward in vessels resulting in shock -> CO x SVR deceased -> BP decreases -> SV decreases -> CO decreases -> HR decreases -> Co further decreases -> oxygen decreases.
Symptoms : altered mental status, poor urine output, bradycardia (due to lack of input from nervous system), warm skin (due to dilation / widening of vessels )
Medication : Pressors, IV fluids, Atropine ( block parasympathetic system and raises sympathetic nervous system -> HR increases )
Obstructive shock
Pulmonary edema, jugular vein destention, cardio eagle, Anasarca (whole body swelling), Cardiogenic shock. HR increases BP decreases, o2 decreases.
4 types (Cardiac Tamponade : pressure created on heart due to fluid build up in Pericardial sac -> pericardial effusion, constrictive pericarditis : Pericardium becomes rigid), (Tension Pneumothorax: Air leaks into pleural cavity ), pulmonary embolism : blood clot obstructs blood flow in Pulmonary artery ), Aortic stenosis : Narrowing of AOrtic valve)
diagnoses : labs - serum lactate, ABG, Echocardiogram / X-ray (to detect obstruction)
Treatment : Needle Thoracostomy - hollow tube is inserted in chest which releases air and relieves tension -> Tension Pneumothorax, Valvuloplasty - to fix aortic stenosis, Dissolving - removing emboli ->Pulmonary embolism, Thoracentesis - Needle is inserted to remove all the fluid -> cardiac Tamponade.
Anaphylactic shock
2 types anaphylaxis (immunologic or non immunologic )
Immunologic : infective agent enter the body-> B cells create antibodies (I’ve) -> Mast cells (each IgE docks on to one mast cell ) _> sensitization (happens upon first time exposure to a antigen), second time exposure will result in a much quicker response where the allergen will dock to the mast cells + IgE antibody complexes -> mast cells activating cytokines (used for cellular communication ) -> mast cells can communicate with WBCs -> WBCs recruit to the site -> more WBCs recruit to the site -> releases Histamine (vasodilator )-> BP decreases -> blood vessels become leaky , fluid accumulates in interstitial space -> preventing o2 delivery to cells -> also cases swelling everywhere )
Non immunologic response is are as immunologic response but with different pathology
Symptoms : BP decreases, flushing skin, swelling, itching, runny nose, bronchospasm (caused by histamines), swelling in throat (narrows passage ).
Treatment : ABC, Epinephrine (strong vasoconstrictor and causes bronchodilator , IV fluids, anti-histamines
Dissociative shock
Hemoglobin molecule holds 4 iron atoms and fe2+ has affinity for o2, but when o2 doesn’t dissociate, leads to dissociative shock.
Two main causes (Methemoglobin: Methemoglobin in blood (Methemoglobinemia), a form of hemoglobin where the ferric form of iron (when the Fe is oxidized to the three plus state -> Fe 3+, it will not bind to the o2 readily), Fe 3+ cannot bind o2, Fe2+ increases binding of oxygen, decreased perfusion to tissues, caused by nitrates, nitrates are found in medications (antibiotics : Trimethoprim, TMP and sulfamethoxazole, SMX, Dapsone, some anesthetic, Benzocaine)
Symptoms : headaches, dizziness, fatigue, confusion, LOC, Dyspnnea
Treatment : IV Mehtylene blue (Fe3+ -> Fe2+) especially dangerous for new borne, cytochrome B5 Reductase (adults have, coverts Fe3+ to Fe2+, new horns don’t have enough of this enzyme until four years old)
Carbon monoxide poisoning (carbon monoxide binds to HB and prevents o2 binding resulting in lack of o2 perfusion. Causes : fires(wood stove, house fires)
Symptoms : headache, dizziness, fatigue, confusion, LOC, dyspnea,
Treatment : 100 % O2 administration
