05.02 Nursing Care and Pathophysiology for Hypovolemic Shock
Pathophysiology: There is low blood flow either from hemorrhage, traumatic injury, dehydration, or burns. There is a loss of the circulating volume so there isn’t enough blood to enter the heart (preload), which decreases stroke volume and low cardiac output. The body will vasoconstrict to compensate. The body will shunt blood away from nonvital organs to vital organs.
- Hypovolemic Shock – loss of blood volume leading to decreased oxygenation of vital organs
- Body’s compensatory mechanisms fail and organs begin to shut down.
- Stages of Hypovolemia
- Stage I – 500-750 mL Loss
- Stage II – 750 – 1500 mL Loss
- Stage III – 1500 – 2000 mL Loss
- Stage IV – > 2000 mL Loss
- Stage I – compensation
- May be asymptomatic
- Mild weakness
- Maybe pale
- Stage II – over compensation
- HR >100
- UOP < 30mL/hr
- Stage III – failing compensation
- HR > 120
- ↓ BP
- ↓ LOC
- Pale, cool, clammy
- UOP <20 mL/hr
- Stage IV – failed compensation
- HR > 140
- SBP < 90
- RR > 30
- ↓ LOC → coma
- Weak pulse
- VERY pale, cool, diaphoretic
- No UOP
- Stage I – compensation
- Identify Cause
- Vomiting / diarrhea x days
- Severe burns
- Traumatic injury
- Hemorrhage (surgical, obstetric)
- Treat Cause
- OR for repair
- Meds for vomiting / diarrhea
- Replace Volume
- Crystalloid – LR, NS
- Colloid – Blood Products
- Rapid Infuser
- Support Perfusion
- Hemodynamic Monitoring
- Life Support
- Decreased LOC = may need airway protection & ventilation
- Fluid & Electrolytes
- 2 Large-bore IV’s
- Replace Volume IV
- RAPID IV Bolus
- Monitor VS
- Hemodynamic Monitoring
- Central Line
- Titrate Vasopressors
- Monitor airway/breathing
- Monitor SpO2 and LOC
- Give O2 as needed
- Prep for Life Support
- Reason for IV fluids
- Keep informed during treatment
- Possible informed consent for OR
- Blood transfusions
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Okay guys, we’re gonna talk specifically about hypovolemic shock.
In hypovolemic shock, the initial insult, or the reason the organs aren’t receiving oxygen, is low blood volume. This could be because of a traumatic injury or hemorrhage, severe dehydration, or even burns can cause significant loss of circulating volume. If you guys can get the patho behind this, it will be easy to understand the symptoms. So if this is our circulatory system and this tank is our total blood volume, you can see here that the tank is low. So what happens is the blood that enters and fills the heart is decreased. Remember that’s called our preload. When our preload decreases, cardiac output also decreases and our body has mechanisms it uses to try to compensate. So you’ll see a lot of vasoconstriction in the body because it’s trying to push the blood back toward the heart – that means the pressure our heart has to pump against is increased – that’s our afterload. But it also means blood flow has shunted away from the non-vital organs like the skin – that’s why they get pale and cold. And then the heart rate will also increase to compensate for the lower stroke volume. After a while, we’ll begin to see our Blood pressure decrease because the body can only compensate for so long. Ultimately, there’s just not enough circulating blood volume to serve the whole system, and it will start to shut down.
So in our patients, the severity of the symptoms we see depends entirely on the amount of volume they’ve lost. In the first couple stages, they’ve lost a good bit of volume, but not so much that the body can’t compensate. You may not see any symptoms, but if you do they’re minor. You might see an elevated heart rate, they might be a little pale or cold, and you may start to see a decreased urine output because the kidneys are working to compensate by retaining fluid.
In stage III, this is where shock is kicking in. These compensatory mechanisms are failing and the patient is definitely in trouble. You’ll see their blood pressure decrease, their heart rate increases, and their urine output will be low for sure. They’ll be pale, clammy, and weak and will likely have a decreased level of consciousness because of the lack of oxygen to the brain. So we’re seeing this lack of perfusion to the kidneys and lack of perfusion to the brain – that’s shock. This patient needs intervention as soon as possible.
Stage IV is a dire life-threatening condition for the patient. Their blood pressure will be significantly low, their heart rate and respiratory rate will be significantly high. Their level of consciousness will be decreased – possibly to the point of them being unresponsive. Pulses may be thready, they will be very pale, cool, and clammy. And they will likely have little to no urine output at this point because of the lack of kidney flow. Now, you’ll notice that stage IV is a fluid loss of more than 2 L. The body only holds about 5 L of blood, so this person has lost 40% of their circulating volume! If we don’t restore the flow of oxygenated blood, this patient’s not gonna make it.
You know, sometimes you’ll see these things and you won’t know what’s really going on because there’s no obvious sign of bleeding or anything. This actually happened to me once in a post-op patient. They seemed fine, vitals were stable. They were complaining of being weak and they were a little pale, but I thought it was the anesthesia. They started to get anxious and their heart rate went up a little – but they were also in pain, so I just gave them some morphine. Next thing I knew, their heart rate was in the 120s, their blood pressure had dropped, and they were super confused. They had already pushed into Stage III and were showing signs of shock because their brain wasn’t getting enough oxygen. I called the surgeon and within 30 minutes my patient was back in the OR repairing a bleed. So it’s so important that you know when your patient is at risk and recognize these early signs for what they are! We want you to catch it sooner rather than later!
So what’s the treatment plan for a patient in hypovolemic shock? Well we ALWAYS want to treat the cause, whatever it was. But either way, we need to replace the volume they lost. This may be crystalloids or colloids, depending on the problem. Now, sometimes we just can’t replace fluids fast enough to support their blood pressure, so we may give things like vasopressors while we work on replacing volume. But it’s so important to remember that squeezing the tank does nothing if it’s empty. So always start filling the tank first. Also since these patients are at risk for a decreased LOC, they may actually need to be put on life support to protect their airway, depending on their situation.
When it comes to nursing care, there are a lot of priorities for this patient – one of which being that they need to be in an ICU. But we’re gonna focus on the top 3 concepts here. If you check out the outline and the care plan attached to this lesson, you’ll see a ton of details about specific interventions. The first concept is fluid & electrolytes because the #1 priority here is going to be to replace the volume they lost as fast as possible! When it comes to perfusion, we need to work to monitor and maintain their blood pressure. Then finally, these patients are definitely at risk for airway and breathing issues, so we need to monitor their oxygen status and intervene if needed.
So remember in hypovolemic shock, the initial insult is low blood volume – that causes a decrease in the oxygen being provided to the tissues. After a large amount of volume loss, the body loses its ability to compensate, hence the progression into shock. We want to treat the cause and we want to replace the volume they’ve lost (and then some). We will need to support their perfusion during this process so we’ll monitor them closely and possibly start vasopressors if necessary – just remember to fill the tank first! Keep your priority nursing concepts in mind and intervene as needed. And of course remember that this is an emergency. Recognize it and act quickly!
We want you guys to have peace of mind and be confident knowing that you can recognize this and even save a life! We love you guys, go out and be your best self today! And, as always, Happy Nursing!