Surgery 2.1 (3-6) - Sheet1 Flashcards
What are the different forms of shock?
Hypovolemic Shock (Hemorrhagic)
Cardiogenic Shock
Vasodilatory Shock (Septic)
Neurogenic Shock
When does Hypovolemic/Hemorrhagic Shock occur?
It is present when marked reduction in oxygen delivery results from diminished cardiac output secondary to inadequate to vascular volume.
Hypovolemic/Hemorrhagic Shock is the most common cause of…
Shock in the surgical or trauma patient.
Which type of shock is most common in regards to external loses?
Hemorrhagic is the most common (external loses)
Why is there a marked reduction in oxygen delivery?
This results from diminished cardiac output secondary to inadequate vascular volume.
What can cause a decrease in effective circulating volume?
Internal redistribution of extracellular fluid from intravascular to extravascular space (3rd space)
Is shock still considered to be a medical diagnosis?
Shock remains a clinical diagnosis despite technological advances.
What are some clinical signs of Hypovolemic/Hemorrhagic Shock?
Some signs are an agitated patient pallor, cold clammy extremities, tachycardia, weak or absent peripheral pulse and hypotension.
How much blood loss is associated with Hypovolemic/Hemorrhagic Shock?
Clinical sign are apparent at least 25-30% blood loss.
What is considered to not be accurate in regards to measuring one’s index of shock?
BP is not an accurate index of shock
What are some signs of Hypovolemic/Hemorrhagic Shock?
Initially, the patient is anxious, appears tired and depending on the degree of shock, can be extremely restless or frankly comatose.
How much blood loss is needed to produce little in regards to obvious symptoms?
15% blood loss (700-750mL for 70kg pt) may produce little in terms of obvious symptoms.
How much blood loss would be required for mild tachycardia, tachypnea and anxiety?
30% blood loss (1.5L)
How much blood loss results in hypotension, marked tachycardia, confusion?
> 30% blood loss
How much blood loss is needed for it to be considered life threatening and generally requires operative control of bleeding?
40% blood loss
What is ABG?
Metabolic acidosis (lactic academia)
How are the serum electrolytes?
Nearly always normal
Why is serum creatinine important?
useful for evaluation of renal function
When is hematocrit most likely to occur?
Normal within few hours of trauma
How could one check for Hypovolemic/Hemorrhagic Shock?
Ultrasound or diagnostic peritoneal lavage.
Thoracentesis or abdominal tip.
What are the appropriate priorities in regards to dealing with Hypovolemic/Hemorrhagic Shock?
Secure the airway
Control the source of bleeding
Intravenous volume resuscitation
What are other forms of treatment?
Identify the body cavity harboring active hemorrhage.
Blood transfusion, O2 inhalation
Early intra operative intervention to correct intraabdominal or intrathoracic blood loss.
What is cardiogenic shock?
Cardiogenic shock is circulatory pump failure.
What can cardiogenic shock lead to?
It can lead to diminished forward flow and subsequent tissue hypoxia.
What is the name of the criteria for “cardiogenic shock”?
It is called “Hemodynamics criteria”.
List the three components of hemodynamics criteria.
- ) Sustained hypotension (i.e. SBP <90mmHg for at least 30 mins).
- ) Reduced cardiac index, (,2.2 L/min per square meter).
- ) Elevated pulmonary artery wedge pressure (>15mmHg).
What happens to the Myocardial diastolic function when cardiogenic shock occurs?
The Myocardial diastolic function becomes impaired.
What is the mortality rate of cardiogenic shock?
50% - 80%
What is the most common cause of cardiogenic shock?
Acute, extensive MI is the most common cause of cardiogenic shock.
When cardiogenic shock occurs, it causes significant damage to which part of the heart?
It causes damage to the Left ventricle in 40% of cases.
In what percentage of cases is damage found to the Left ventricle when a patient dies from cardiogenic shock?
In 40% of cases, patients dying from cardiogenic shock has found damage to the Left ventricle.
Cardiogenic shock complicates what percentage of acute MI’s?
It complicated 5-10; most common cause of death in patient hospitalized with acute MI).
What is mandatory to minimize mortality?
Acute MI, expeditious restoration of cardiac output.
What happens with increased time to restoration of coronary blood flow?
The extent of myocardial salvage possibly decreases exponentially.
What happens to the degree of coronary flow after percutaneous transluminal coronary angioplasty?
It correlates within hospital mortality.
What are some examples of the degree of coronary flow after percutaneous transluminal coronary angioplasty correlating within hospital mortality?
33% mortality with complete reperfusion; 50% mortality with incomplete reperfusion; and 85% mortality with absent reperfusion.
What is cardiogenic shock caused by?
Myocardial ischemia that causes myocardial dysfunction.
What causes the stroke volume to decrease?
When sufficient mass of the left ventricular wall is necrotic or ischemic and fails to pump.
What happens when sufficient mass of the left ventricular wall is necrotic or ischemic and fails to pump?
It causes the stroke volume to decrease.
What disease do most cardiogenic shock patients have?
A majority have multivessel disease with limited vasodilator reserve and pressure dependent coronary flow in multiple areas of heart.
During cardiogenic shock, what happens to myocardial diastolic function?
Myocardial diastolic function is impaired.
What is one result from myocardial ischemia?
Decreased compliance results form myocardial ischemia.
What are the causes of cardiogenic shock?
- ) Acute MI - Pump Failure, Mechanical Complications (acute mitral regurgitation, acute ventricular septal defect [VSD], free wall rupture, pericardial tamponade).
- ) Arrhythmia, End-stage cardiomyopathy, Myocarditis, Severe myocardial contusion.
- ) Left ventricular outflow obstruction - Mitral stenosis, Left atrial myxoma.
- ) Acute mitral regurgitation, Acute aortic insufficiency, Metabolic causes, Drug reactions
Why is it important to have rapid identification of the Px with pump failure and an institution of corrective action?
They are both essential, including history and PE (for the Px with pump failure) in preventing the ongoing spiral of decreased cardiac output from injury causing increased myocardial O2 needs that cannot be met.