2 Anatomy and Physiology of Cardiovascular System CO = SV * HR (Normal = l/min)MAP = Dist. Pressure + 1/3 Pulse Pressure (Normal = mmHg)Preload (volume)After load (SVR)Contractility
3 ShockIt is a state of generalized cellular hypoperfusion in which delivery of oxygen at the cellular level is inadequate to meet metabolic needs.
4 Signs and Symptoms of Shock Decreased LOC, anxiety, disorientation.Tachycardia, decreased SBP and pulse pressureRapid shallow breathingCold, pale, clammy, diaphoretic, cyanotic skin, decreased capillary refill time.Decreased urine output
5 Classification of Shock Hypovolemic shock (blood)Distributive shock (vasogenic)Cardiogenic (heart)
6 Severity of ShockCompensated shock: patient is developing shock but body still able to maintain perfusion.Decompensated shock: patient developed shock but body no longer can compensate.Irreversible shock: patient developed shock but body is unable to maintain perfusion to organs.
7 Hypovolemic ShockIt is the most common cause of shock in trauma patients.Causes:External: bleeding (trauma), GI bleeding, ruptured aneurysms, hemorrhagic pancreatitis. vomiting or diarrhea, adrenal insufficiency, diabetes insipidus, dehydrationInternal: third spacing: intestinal obstruction, pancreatitis, cirrhosis
8 Hypovolemic Shock Markers: UOP,CVP, BP, HR, Hct, CO Treatment: ABCs, IVF (crystalloid), Blood Transfusion.Patients on β-blockers, or with spinal shock & athletes may not be presented with tachycardia.
9 Categories of Hemorrhagic Shock Class IClass IIClass IIIClass IVBlood Loss %< 750 ml< 15 %ml (15-30 %)ml(30-40 %)> 2000 ml> 40 %HR (b/min)Normal or minimally ↑> 100> 120> 140Ventilatory R. (breath/min)Normal20 – 3030 – 40> 35SBPDecreasedGreatly DecreasedUrine Output(ml/hr)5 – 15Minimal
10 Distributive (Vasogenic) Shock It occurs when vascular container enlarges without a proportional increase in fluid volume.Septic ShockNeurogenic ShockPsychogenic (vasovagal) Shock
11 Septic ShockCaused by cytokines release in response to infection, sepsis: G(-/+ ) septicemia, e.g. pneumonia, peritonitis, etc.S & S: cool, clammy, pale, mottled skin, BP drop, altered LOC, slowed capillary refill.Markers: Temp, WBC count, …Rx: ABCs, IVF, Drainage (ie abscess).
12 Neurogenic ShockIt occurs when injury interrupts the spinal cord sympathetic nervous system pathway.S & S: warm, dry, pink skin, bradycardia, BP drop, lucid LOC, normal capillary refill.Rx: IVF, vasoactive medications if refractory
13 Psychogenic ShockIt is mediated through parasympathetic nervous system. (stimulation of vagal nerve)It is temporary state lasts for few minutes.
14 Cardiogenic Shock Failure of the heart’s pumping activity. Intrinsic Causes:Heart muscle damageDysrhythmiaValvular disruptionExtrinsic Causes:Cardiac tamponadeTension pneumothorax
19 ColloidsHigh molecular weight substances so do not cross capillary membranes.Used as volume or plasma expandersThey include:AlbuminHetastarchDextran
20 BloodIt is given as packed RBCs, which should be cross-matched, but in an urgent situation, 1 to 2 units of type O Rh-negative blood are an acceptable alternative.When > 1 to 2 units are transfused (eg, in major trauma), blood is warmed to 37° C.Patients receiving > 8 to 10 units may require replacement of clotting factors with infusion of fresh frozen plasma or cryoprecipitate and platelet transfusion.