Why shock is a major topic in surgery

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I finished the hardest shift I have ever been on. One week where you could be called to handle a case that the general practitioner (another doctor) thinks is related to your team at any moment in the night or day. As the house officer in the team, I am supposed to see the patients first.

I am glad I had the chance of learning under the resident doctors I was under. Ideally, there are supposed to be more house officers than residents in a team so that more cases will be handled and also some more experienced house officers (with about 6 months experience) would be teaching those with less experience, But in this center, I had to pick up skills as quickly as possible because if I didn't I'd be screwed in the next unit.

The senior registrar in the unit was a really chill guy who is cool to hang out with. Then the other registers were a guy and a catholic church sister who to me were like experienced house officers except they weren't.

They had different methods of teaching, one would prefer to do it in front of you till you learned it...that's the guy. His method had the flaw of not realizing when I was not learning...but gave me a visual goal to climb to.

The sister was more of the kind that would do it once and hope you picked up everything and built intuition for yourself. It led oftentimes to her expecting a lot from me and sometimes getting disappointed. Which meant I was disappointed in myself and also needed to step up.

All in all the two put together made for the perfect learning environment. Check here to know more about the training program.

On this occasion, we were preparing a patient for surgery and me and the guy register were going through every patient trying to make sure they were prepared for the surgery.

We were setting IV cannulas and giving them prescriptions for things they needed to buy before the surgery. He was handling some in one ward and I was handling the others in another ward.

I got a call from him that he needed my help urgently. When I got there I met a semiconscious man who was throwing up and his eyes were turning upwards. He found it hard to sit and he was for all purposes of description going lifeless.

I'm sure the registrar had checked his pulse, and if he did at that time his pulse rate would have been very hard to detect and very fast. Check here for signs and symptoms of shock.

That was last week Tuesday when the surgery was scheduled but had to be moved because he was not hemodynamically stable.

The days that followed had me thinking about how we were taught shock in surgery intensively. We also learned a lot about fluid and electrolytes in surgery and I'm guessing for the same reason.

I also wanted to be able to explain a lot of concepts simply so my readers here would enjoy reading about them.


The patient was going through a type of shock known as hypovolemic shock. He had not been receiving enough fluids over time and was supposed to be on intravenous fluids.

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We were going from one patient to another setting IV cannulas on each of them so they would be on intravenous fluids by the time we got to his bedside he had already been too dehydrated.


what is shock?

A patient goes into shock when their blood pressure drops suddenly. Blood pressure is the force exerted by the content of the blood on the walls of the blood vessels.

When we check a patient's blood pressure we use an inflatable cuff to try to occlude the vessel. The vessel in question is usually the brachial artery that supplies the upper limbs.

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The cuff is also attached to a one-way valve that carries air into it but can not take the air out until it is released. There is another tube attached to the cuff that transmits air to the mercury manometer that measures the pressure in the cuff as it tries to occlude the vessel.

So when we measure blood pressure we press down on the brachial artery with a cuff while checking for a pulse on the forearm (on the radial artery-a branch of the brachial artery). At the exact moment, we can't feel the pulse on the artery, we note that as the systolic blood pressure.

We usually confirm this with a stethoscope placed on the elbow to listen to the blood as it smashes against the brachial artery as it gets occluded...that is the diastolic blood pressure. At the same time, we confirm the systolic blood pressure which is when we can no longer hear the blood smashing against the blood vessel.


When We met the patient I mention his heart was racing and we had to start instituting management immediately so he wouldn't go unconscious.

There was no time to confirm that his blood pressure was low. IF we had to tie a cuff on his arm and inflate and note his systolic and diastolic pressure, we would be losing valuable time.

We immediately set two wide bore cannulas on both his arms. When the first cannula was set, I placed the fluid as high as I could so the fluid would run as fast as possible. When the next cannula was placed it was also running as fast as possible.

We rushed 2 liters of normal saline as quickly as possible (within an hour).


What are the signs and symptoms of shock?

When we got there he was unarousable and was vomiting. He was having a fast pulse that was almost undetectable because of the low volume in the peripheral blood vessels.

Other signs that people show when they are going into shock are:

A pale look, cold extremities, shallow rapid difficult breathing, anxiety, fast pulse rate. Heartbeat will be irregular and the patient may have palpitations (feeling one's heartbeat). The mouth of the patient could be dry and the patient could be thirsty. If the patient is on a Urinary catheter and has a urine bag on them you might notice that their urine is dark-colored. They could be nauseous, vomiting, and be lightheaded, or dizzy.

Sometimes they may be confused or even unconscious.


The patient was on Nil per Oral. What that means is that he was not taking water or food through the oral route.

We do this in patients that are supposed to be under anesthesia and sedated so that they do not vomit fluid from their stomach to their lungs (aspirate) and drown on their own gastric content.

We also put sedated patients on a Nasogastric tube for the same reason. Read about NG tubes [here](https://peakd.com/hive-196387/@ebingo/case-review-and-discussion-of-intestinal-obstruction.


What are the causes of shock?

Shock can be caused by a few conditions. Let's start with the patient we managed.

The patient saw us in the clinic and was booked for a colostomy reversal.


A colostomy is when a surgical opening is made for the content of the bowels to be removed through the abdominal wall. So when the indication for the surgery has resolved, a reversal is usually done.


There 4 major types of shock, Obstructive, Cardiogenic, Distributive, and Hypovolemic.

Our patient had hypovolemic shock and was having the symptoms I already described.


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Hypovolemic shock
This is due to a reduced blood volume as the name implies, hypo is greek for beneath of less than and volemic basically means volume. and sometimes we use it to describe the condition by simply just saying hypovolemia.

Although the main cause of this type of shock is usually blood loss caused by injuries that cause a lot of blood loss, in our patient he didn't have that feature. He was however very dehydrated because he had not been having any water or food.


A little fun fact, most of what we know about managing shock is from world war II. As reasonable as it would seem now to stop the bleeding before transfusing a patient it doesn't change the fact that it was not common practice before that time. Read that here.


For a patient like the one, we had the solution is to rehydrate the patient as soon as possible. That is what we did and within a few minutes, he was more arousable and was even talking!!


Obstructive shock
This arises when blood flow is hindered and so blood can not get to where it is supposed to get to.

In pulmonary embolism, a particle that is not soluble in blood travels from whatever source and gets lodged in the blood vessels of the lungs.

This leads to the signs of shock we discussed earlier, particularly those that have to do with the respiratory system such as shallow rapid difficult breathing.

In Aortic stenosis, a major blood vessel as it makes its way from the heart is constricted and leads to difficult blood flow.


Cardiogenic shock
The abnormal blood flow is due to the heart's inability to pump blood properly. Many conditions that lead to weak heart musculature or abnormal electrical conduction in the heart can lead to this type of shock.

Myocardial Infarction or heart attack arises when the heart musculature dies due to lack of blood supply. It usually has the classical symptoms of chest tightness, pain in the chest, jaw, back, or other parts of the upper body. The pain typically comes and goes. The other symptoms are what you would normally find in a person who is in shock.


Distributive Shock
TO understand distributive shock it is important to note that our body is constantly trying to neutralize toxins that exist in our bloodstream. One of the ways the body does this is by causing more blood to flow to such areas where toxins exist.

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When the blood vessels sense that there are toxins through a myriad of complex mechanisms (check here and here) there is vasodilation. The way I like to think of it is that our body tries to pour water (by expanding the blood vessels to accommodate more blood) on the fire (whatever toxin is in the blood...including carbon dioxide).

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In Allergic Reactions the body in an attempt to fight off what it perceives as a problem pools blood to areas that are affected by an insect bite, or certain types of food or medication. The average population of humans do not have these responses.

When these processes take place, the symptoms we typically see in movies start happening: flushing on the skin, difficult breathing, and the rest.

Septic shock is a type of distributive shock and is also due to the mechanisms I just described where there is the pooling of the blood to the area of a toxin. Sepsis is a general term for the infection of the blood. This happens when microbes start living in the blood.

What leads to shock is that as they live in the blood they start producing toxins and these toxins lead the vasodilation and similar presentation like when a person has allergies.

Spinal cord injury can also cause a type of distributive shock known as Neurogenic shock. The skin is warm and flushed as a result of the damage to the spinal cord...a similar presentation to all the other types of distributive shock. This is because damage to the spinal cord has a system of control (sympathetic nervous system) over the blood vessel tonicity.


The patient was later not properly prepared for the surgery after the anesthetic team evaluated him. He still had irregular pulses after in the morning and so we could not operate on him.

Conclusion

To tie up everything into surgery... Hypovolemic shock appears to be the main type of shock that typically needs a surgeon's attention. This is because even if it is a sudden cause like a road traffic accident or in the case of preoperative optimization then a surgeon will need to have a grasp of shock and its presentation. That said, every field of health care can benefit from the broad and specific knowledge of shock.

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7 comments
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Interesting and informative !discovery 20

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The patient was later not properly prepared for the surgery after the anesthetic team evaluated him. He still had irregular pulses after in the morning and so we could not operate on him.

In such a case, does he get sent home or does he just stay there another day to be rechecked?

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Painfully, he had to go home. We have theatre days only once in the week.

I'm no longer in the unit, but I think today he is to be operated on.

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So he had to wait another week to get the operation? Sounds tough. But now I have another question, what happens if someone needs to have an operation performed on an emergency basis (in other words, they have a life-threatening situation), if the theatre days are only once per week?

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The on call doctors handle it. We are usually in call on alternate weeks around here.

Nigeria's poor system of healthcare is not without its quirks. Some cases that could be save elsewhere die around here.

But that's the protocol...there are always doctors on call.

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