General Surgery Sheet #1 By Muna Sawwan

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General Surgery Sheet #1 By Muna Sawwan

Post by Sura on 17/2/2012, 9:38 pm



Last edited by Sura on 30/3/2012, 3:26 am; edited 1 time in total
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Re: General Surgery Sheet #1 By Muna Sawwan

Post by Shadi Jarrar on 11/3/2012, 12:27 pm

7th Feb. 2012
1st General Surgery lec.
Dr.Firas Obiedat
By: Muna Sawwan
Shock
1st you should know what does shock mean 
Lectures outlines:
Types of shock.
Management.
And manifestations of shock.
General principles  :
You know the Heart, vessels (veins "preload" and arteries that are responsible for the peripheral vascular system). ,,,, In normal people, heart generates its power that is sufficient to give adequate blood supply and oxygen to the tissues and organs, and to remove waste products from tissues by venous system (again this is in normal people).
But,,, failure of the heart to generate this power will be responsible for the shock state.
Shock is a pathophysiological condition known as inadequate tissue perfusion; this inadequate perfusion will lead to anaerobic metabolism (metabolic acidosis).
Now in any shock state (or preshock) the body will try to compensate by distribution of the blood to the vital organs, f the body fails to redistribute the blood to the vital organs this will lead o irreversible state which is MOF (multi-organs failure) and when the number of organs increase (3 or 4 organs) this will increase the mortality up to 90%.
Let's repeat circulatory Homeostasis again: 
Preload ( IVC "inferior vena cava " , SVC "superior vena cava" that bring blood to the heart) so the production of the power of the heart will be assessed by the blood reaches the heart which is called END DIASTOLIC VOLUME and that will determine the C.O "cardiac output".
After load: peripheral vascular system "Arteries" and the major component "Blood pressure".
For any patient, when you suspect shock. You have to check A,B,C,D and E.
A>> airway,,, check patency, no foreign body inside that obstruct airway, or saliva.
B>> breathing, like tension pneuomothorax when fluid or air present in pleural cavity.
C>> circulation, check his blood pressure ….. Any pt comes to ER,, the baseline is to provide breathing , IV fluids cannula. You have to get an access either peripheral or central, but if he is hypotensive, never try to put central access, because veins are collapsed and you will face difficulties and increase mortality
D> deficits, motor function in the limbs.
E> exposure, to expose and check the whole body specially after trauma ( that is called secondary survey, and A, B, C and D are primary survey).
So in E you have to check for missing injury like anal injury or back injury.
Stages of shock:
1st stage: compensative , or warm shock, or pre-shock state:
Loss of intravascular volume of blood is not more than 10% ( no change of blood pressure or perfusion in normal healthy people).
How does the body compensate? The heart will try to induce more C.O so a stage of tachycardia occurs, but if you measure his blood pressure it will be normal.
2nd stage: obvious shock state, loss of blood more than 20-25%, signs and symptoms of organs disfunction and the body can't compensate for this loss.
If we don't manage the patient properly at this stage he will ends up with MOF

Tissue perfusion is determined by : C.O and peripheral vascular resistance.
CO= heart rate * stroke volume " SV which is the amount of blood pumped each beat and depends on the preload and afterload".
Types of shock:
"most common type of shock in dentistry is Septic shock and Anaphylactic shock"
a. hypovolemic shock : decrease in preload, so decrease EDV "end diastolic volume" and CO.
causes:
dehydration (i.e in children caused by diarrhea ) or burn.
Hemorrhage and bleeding (specially G.I bleeding).
Sepsis.
b. cardiogenic shock: the failure is in the pump itself not the preload. ( ischemic heart disease , MI ,angina. Ischemia. Valvular disruption, myocardial rupture.
c. obstruction or mechanical type of shock , obstruction to the inflow or outflow .
again !!!
inflow=preload. If preload is good but cant reach the heart due to obstruction (e.g stab wound in thorax > tension pneumothorax will compress the vessel and prevent the blood from reaching the heart.
Outflow , in patient with cardiac temponade " like in pt with heart failure or malignancies" they may accumulate fluid around the heart so compressing it and affects inflow and outflow.
Or in pt with pulmonary embolism, the blood will be prevented from reaching the lungs from rt ventricle.
d. vasodilatory (distributive type of shocks ): the problem is in peripheral vascular system.
Flaccid and dilatation to the vascular system peripherally occur. Like ( neurogenic shock, septic, anaphylactic and .. sorry cant hear it well !!!)we will talk about them later in the lecture.
Common features for all types of shock:
Hypotensive.
Cool skin "except pt with septic shock they are usually warm in the early state"
Cool skin because the body will try to compensate and the skin can tolerate less perfusion(can tolerate ischemia)so vasospasm occur to redistribute blood to the vital organs , so skin become cool clammy .
Oliguria, also because the body will try to compensate and deliver blood to the vital organs. Kidney try to avoid excretion and so preserve water and sodium (retention) " protective mechanism"
Alter mental state
Metabolic acidosis due to anaerobic metabolism because of oxygen lacking.
Now in hospital or ER ,,, history is very important (bleeding disorder, hypovolemia, allergy, history of MI or cardiogenic shock). And you have to examine heart, lung and skin and to do a proper investigation according to the case ( i.e if you suspect hypovolemic shock ou have to administer i.v fluids ,,, BUT IN CASE OF CARDIOGENIC SHOCK ( and ONLY in cardiogenic shock) you shouldn’t give him fluids because you will induce the load on the heart since already 3ndo failure in pump. So in pt with ischemic heart disease or MI you must be very cautious when giving i.v fluids.
Management of shock
These pt you have to keep them on a good perfusion in ICU and –at the same time- to treat the underlying cause. ( if you suspect sepsis give i.v fluids but at the same time you have to look for the sepsis >> culture >> proper antibiotic…… if pt had MI you have to try to optimize the function of the heart ,,, if he is hypovolemic pt you have to replace intravascular volume.
Main goal for the management of shock is to restore the perfusion and oxygenation, so you have to keep him on oxygen.
There is many scaling system depends on many things such as : eye movement, verbal commands, ( if it was <8 ,, then these pt must be intubated.) fe scoring system btkwwn mn 14 ( ??? ).
Another goal is to optimize the hemodynamic status
Third is to treat the underlying cause (i.e sepsis >> antibiotic).
Final goal is to prevent MOF ,, because these pt if they don’t receive a proper care they will die.
How do we treat pt ?
inpatient with hypovolemic shock : access and i.v fluids.
Septic shock: they are hypovolemic because of vasodilatation, pooling of intravascular volume into periphery soooo I have to try to give a fluid ( so fluid is very imp. In sepsis) and also antibiotics.
Neurogenic shock: you have to keep the patient in Trendelberg position, to give more blood to the brain.
Cardiogenic shock: again, be careful from i.v fluid , don’t give that much, try to optimize the function of the heart and give diuretics ( if MI or heart failure pt , he will accumulate fluids in the lungs >> pulmonary edema ,, so you give them diuretics).
Again ,, the main goal is to increase perfusion and also to reduce demands on heart.
الدكتور حكى : (يعني انا اوكي بعطي سوائل بس بنفس الوقت ما بدي اتعب القلب ،، يعني بجوز واحد healthy ,, he will compensate !!
يعني المقصود فيها ، نعطي proper fluids بس بنفس الوقت to optimize the fun. Of the heart
مش وحدة من التنتين ،، اذا بقدر اعملهم التنتين ، لانو القلب ممكن بعد شو يتعب، اذا المريض عنده risk factors or atherosclerosis
He might develop MI during resuscitation so).
لذلك ما تخلي المسؤولية الكبرى عالقلب انو يوصل دم لل vital organ
AGAIN AND AGAIN :
Hypovolemic shock : is the most common type , cause : reduction in the pre-load that is caused by: massive blood loss, plasma loss ( burn : destruction in vascular system> extravasations to the plasma) or extracellular fluids ( third space loss " sorry im not sure " )
متل المرضى اللي عندهم انسدادات بالامعاء they may present with hypovolemic shock due to third space loss.
Compensatory mechanisms :
These will prevent the manifestation of shock specially in small amount loss like with 10% loss in healthy pt :
Increase in catecholamine, inc. in cortisol, body will try to prevent excretion of water and sodium, inc. capillary hydrostatic pressure, so shifting of fluids from outside to the inside of vessels. Mthln inc. 2,3 dpg !!!!!!! " sorry bs shofooha m elhandout " will inc. the release of oxygen from blood to the peripheral cells.
Again : vascular access is very imp. Any hypotensive pt you have to give them challenge you give them 20 cc/ kg or roughly 500 cc crystalloids ( running) 1 in each arm. If pt health improves then its fine if not give another 500 cc ( he might had massive loss or internal bleeding)
If he is well now,, I can give him central access l2eennoh el veins are not collapsed now , so you can give more fluids.
What are the fluids to be given in a hypovolemic shock??
We like Crystalloids. Like normal saline or ringer lactate ,,,,, if you think that the pt lost 500 cc you give him *3 >>> so you give him 1500 cc because crystalloids ( 2/3 of it will be transudated outside the vessels.
It has very little side effects, inexpensive and available every where.
Also we can use Colloids ( natural or synthetic)
Natural like the blood, plasma
Synthetic like Dextran and many others.
But in a state of shock , they are not preferable as a 1st line of management . so 1st line is the crystalloids. But if pt health doesn’t improve I give him colloids ( volume by volume) if he lost 500 cc I give him 500 cc,,,, their problem ,specially the synthetics that they interfere with coagulation and may lead to bleeding disorder and they could face allergic rxn,so we are afraid of giving blood specially in emergency, except if we have a frank evidence that there is on going active bleeding,,, plus blood transfusion is expensive.
Now of the pt is in need , sure, we have to give him blood , it must be cross-matched, but in case we don’t have, we give him O –ve blood.
Any patient, even after surgery, if he has a Hb >7 , we don’t give him blood, except if he has ischemic heart disease, you have to keep his Hb above 10 ,,, because if he is left he might has attacks of ischemia.
When to give vasopressors?
If pt is hypovolemic, and I gave him good amount of fluids, but he is not getting well , then o give him vasopressors to increase vessels tone. " remember : fluids is the first line of treatment".
Compression shock: may be a compression of the heart due to pericardium infusion or affects arteries or veins , and lead to decrease cardiac output and ventricular production.
Causes of compression shock:
Tension pneumothorax,pericardium temponade, patient on a ventilater with a positive end expiratory pressure ( that will prevent pre-load and may cause hypertension) , abdominal injury with migration of intra-abdominal organs to thoracic cavity.
Cardiogenic shock:
Most common type of shock in medical people !!
Ischemic heart disease is the most common, also arrhythmia of the heart may cause this shock, congestive heart failure, ischemic heart disease, valvular heart disease, stenosis.
Again : you don’t give significant fluids, you have to optimize the function of the heart,anf as we said , we give them antidiuretics like Nitrates that make vasodilatation in venous system, so more blood will occupy venou system, then decreasinf blood returning to the heart, then you might give him Ionotropes that will help heart to beat effectively (I,e instead of 90 beats !! heart will beat 70 times but effectively).
Neurogenic shock:
Caused by denervation of the vessels, so flaccid vascularity.
Examples: patient had regional anesthesia ( pt with an Elbow fracture, they anesthetized him , Brachial plexus) so pooling of the blood in that limb occurred.
Also general and spinal anesthesia may cause vascular denervation.
Keep them in Trendelberg position in order to help blood reaching brain and heart.
AGAINnnnnN,,,
Hypovolemic shock : 1) fluids 2)vasoconstrictors.
Cardiogenic shock : NO fluids ,,, but Diuretics.
Neurogenic shock : vasoconstrictors " because the problem is not I the volume but in the vessels , we are trying to get the normal tone if the vessels. "
Septic shock: infection >>> bacteremia >> sepsis >> septic shock.
SIRS : Systemic Inflammatory Response Syndrome ,,, now , if patient has 2 or more from the following , we say that he has SIRS :
High temperature , high respiratory rate ,
Now ,,, SIRS and infection ,, then its sepsis.
Example : pt with high blood count and high respiratory rate and I documented that he has bacteria in blood then its sepsis.
Severe sepsis : he had manifestation of organ dysfunction. " hypovolemia, hypertension , oligurea" .
Septic shock : means that in spite of resuscitation there is no alteration in organ dysfunction.
Early state : Now in all types of shock , the first is vasoconstriction sooo cool skin, EXCEPT IN SEPTIC SHOCK dilatation of the vessels occur " but its not due to dennervation of the vessels like in neurogenic shock but due to inflammatory mediators" so warm skin at the beginning but cool clammy skin later on.
Give them i.v fluids and antibiotics,, documentation of the site of infection by urine, sputum and blood culture. If he has abscess you have to drain it ….
Soooo finally :
We talked about the following:
Shock is a poor tissue perfusion.
4 types.
Common signs and symptoms.
Aggressive resuscitation except in cardiogenic shock.


 good luck 








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Shadi Jarrar
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