Shock ManagementShock Management

Dr.Jason WaechterDr.Jason WaechterJan/04Jan/04

But first!But first!

A little refresher from a previous A little refresher from a previous presentation …presentation …

What is the Ddx of an anion What is the Ddx of an anion gap metabolic acidosis?gap metabolic acidosis?

“KUSMAL breathing is a memory helper”“KUSMAL breathing is a memory helper”

K ketonesK ketonesU uremiaU uremiaS salycilatesS salycilatesM methanolM methanolA alcoholA alcoholL lactateL lactate

What is Shock?What is Shock?

Is a condition where the perfusion of organs is Is a condition where the perfusion of organs is too low to meet the metabolic demands and too low to meet the metabolic demands and leads to anaerobic metabolism.leads to anaerobic metabolism.

In other words, blood flow (pressure) and In other words, blood flow (pressure) and oxygen delivery to the body is too lowoxygen delivery to the body is too low

An Approach to ShockAn Approach to Shock

BP = CO x SVRBP = CO x SVR

BP = blood pressureBP = blood pressureCO = cardiac outputCO = cardiac output

SVR = systemic vascular resistanceSVR = systemic vascular resistance

An Approach to ShockAn Approach to Shock

If the blood pressure is low, then either the:If the blood pressure is low, then either the:

CO is lowCO is low oror

the SVR is lowthe SVR is low

Low SVRLow SVR

There are only a few causes of low SVR.There are only a few causes of low SVR.They ALL cause vasodilation:They ALL cause vasodilation:

•sepsis•acute spinal cord injury (spinal,

epidural)•vasodilators (NTG, anesthetics)•anaphylaxis

How do you assess SVR?How do you assess SVR?

Look at and feel the patient!Look at and feel the patient!

Low SVR has the features:Low SVR has the features:• warm !!!warm !!!• pink (maybe also a rash)pink (maybe also a rash)• hyperdynamic heart (fast and hyperdynamic heart (fast and

pounding)pounding)

What if the SVR is high?What if the SVR is high?

• patient will have cool or cold arms/legspatient will have cool or cold arms/legs• patient will NOT look pinkpatient will NOT look pink

Cause of shock or low BP is then:Cause of shock or low BP is then:

low COlow CO

What are factors of CO?What are factors of CO?

CO = HR x SVCO = HR x SV

CO = cardiac outputCO = cardiac outputHR = heart rateHR = heart rate

SV = stroke volumeSV = stroke volume

HR ProblemsHR Problems

• HR problems are easy to diagnoseHR problems are easy to diagnose

• bradycardia and tachycardia will be covered bradycardia and tachycardia will be covered in my “arrhythmia” talk laterin my “arrhythmia” talk later

Low SV (stroke volume)Low SV (stroke volume)

Most common cause of shockMost common cause of shock

butbutMost difficult to diagnose and manageMost difficult to diagnose and manage

Factors of SVFactors of SV

Preload:Preload: is the ventricle full?is the ventricle full?Contractility:Contractility: how well does the ventricle contracthow well does the ventricle contractValve function:Valve function: normal?normal?

regurgitation?regurgitation?stenosis?stenosis?

Stroke VolumeStroke Volume

Which factors can we influence?Which factors can we influence?• Preload and contractilityPreload and contractility

We cannot change valve functionWe cannot change valve function

SummarySummary

BP = CO x SVRBP = CO x SVR

CO = HR x SVCO = HR x SVSV =SV = preloadpreload

contractilitycontractilityvalvesvalves

Perfusion (blood pressure) depends on:Perfusion (blood pressure) depends on:

Your patient has BP of 60/20Your patient has BP of 60/20

BP 60/20 BP 60/20

What do you think of?What do you think of?

CO and SVRCO and SVRHR and SVHR and SVpreload, contractility, valvespreload, contractility, valves

Case 1: BP 60/20Case 1: BP 60/20

• 25 yr old healthy man25 yr old healthy man• after induction, HR to 180 over 2 minutesafter induction, HR to 180 over 2 minutes• JVP flatJVP flat• arms and hands flushed and warmarms and hands flushed and warm• Diagnosis?Diagnosis?

Case 1Case 1

Possibilities:Possibilities:• anaphylaxisanaphylaxis• anesthetic overdoseanesthetic overdose• severe volume depletionsevere volume depletion

Case 2: BP 60/20Case 2: BP 60/20(real case at Jichi)(real case at Jichi)

• Emergency case of abdominal sepsisEmergency case of abdominal sepsis• dx. of perf. intestinedx. of perf. intestine• 4 days post axillo-fem bypass, on warfarin4 days post axillo-fem bypass, on warfarin• HR 130, JVP flat, extremities very coldHR 130, JVP flat, extremities very cold• subacute course of < 12hourssubacute course of < 12hours• no previous cardiac diseaseno previous cardiac disease

What are your thoughts?What are your thoughts?

Case 2: BP 60/20Case 2: BP 60/20

What is the SVR in this patient?What is the SVR in this patient?High (cold arms and legs)High (cold arms and legs)What is the SVR in early sepsis?What is the SVR in early sepsis?Low (warm, flushed)Low (warm, flushed)This patient did not have a fever.This patient did not have a fever.

Is this septic shock?Is this septic shock?

Case 2: BP 60/20Case 2: BP 60/20

If SVR is high, then CO is low!If SVR is high, then CO is low!Next, we have to think about:Next, we have to think about:Preload … contractility … valvesPreload … contractility … valvesJVP is flat … therefore this is NOT:JVP is flat … therefore this is NOT:• PE, tension pneumothorax, tamponadePE, tension pneumothorax, tamponade• acute heart failureacute heart failure

Case 2: BP 60/20Case 2: BP 60/20

• Why is the JVP flat?Why is the JVP flat?• Volume depletionVolume depletion• Why is the patient volume depleted?Why is the patient volume depleted?• Had an IV for maintenanceHad an IV for maintenance• Why did the patient crash over 12 hours?Why did the patient crash over 12 hours?

Case 2: BP 60/20Case 2: BP 60/20

• 15 minutes into the laparotomy, the blood 15 minutes into the laparotomy, the blood results became availableresults became available

• the Hb was 50the Hb was 50• the the pre-oppre-op CT scan showed a CT scan showed a

retroperitoneal hematomaretroperitoneal hematomaThe laparotomy was completely unnecessaryThe laparotomy was completely unnecessary

The patient was in shock because of acute The patient was in shock because of acute bleeding and not because of sepsisbleeding and not because of sepsis

Case 3: BP 60/20Case 3: BP 60/20

• trauma car accidenttrauma car accident• HR 130, JVP full, extremities coldHR 130, JVP full, extremities cold

Thoughts?Thoughts?

Case 3: BP 60/20Case 3: BP 60/20

Does a full JVP mean that preload is adequate?Does a full JVP mean that preload is adequate?• nonoWhat are 4 causes of decreased preload with a full What are 4 causes of decreased preload with a full

JVP?JVP?• pulmonary embolismpulmonary embolism• tension pneumothoraxtension pneumothorax• pericardial tamponadepericardial tamponade• RV infarctionRV infarction

Case 3: BP 60/20Case 3: BP 60/20

In a In a trauma settingtrauma setting, think about:, think about:• tension pneumothoraxtension pneumothorax• pericardial tamponadepericardial tamponade

… … as causes of inadequate preloadas causes of inadequate preload

SummarySummary

Managing shock is THE SAME as managing Managing shock is THE SAME as managing low blood pressurelow blood pressure

Requires analysis of all factors of BP:Requires analysis of all factors of BP:SVR, CO, HR, preload, contrqctility, valvesSVR, CO, HR, preload, contrqctility, valves