Shock: Difference between revisions

Latest revision as of 11:07, 29 July 2020

Background

Inadequate tissue perfusion and oxygenation leading to multiorgan dysfunction

Shock Index

Heart Rate / Systolic Blood Pressure
Usual range 0.5 to 0.7
If over 0.9, suggests impaired cardiac function and predicts mortality

Clinical Manifestations

Hypoperfusion
- Low BP (SBP < 90, MAP < 65, decrease in SBP by 40+)
- BP unresponsive to fluid challenge
- Long cap refill
End-organ dysfunction
- Lightheadedness
- Confusion
- Diaphoresis
- Decreased urine output
- Increased creatinine
- Chest pain
- Other ischemic pain

Severity of hypovolemic shock

	Class I	Class II	Class III	Class IV
Blood loss (mL)	<750	750-1500	1500-200	>2000
Blood loss (%)	<15%	15-30%	30-40%	>40%
HR	<100	>100	>120	>140
BP	Normal	Normal	Low	Low
Pulse pressure	Normal	Low	Low	Low
RR	14-20	20-30	30-40	>40
Urine output mL/h	>30	20-30	5-15	anuria
Mental status	anxious	anxious	confused	lethargic

Differential Diagnosis

Cardiogenic shock
Obstructive shock
- Massive pulmonary embolism
- Tension pneumothorax
- Cardiac tamponade
- Right ventricular infarction
Hypovolemic shock
Distributive shock
- Sepsis
- Anaphylaxis
- Systemic inflammatory response
- Mitochondrial dysfunction
  - Cyanide toxicity
- Adrenal crisis
- Myxedema coma
- Neurogenic shock

Management

Approach to diagnosis

Remember that BP = CO x SVR
Cold and clammy suggests low cardiac output (CO)
- High JVP: cardiogenic shock or obstructive shock
- Low JVP: hypovolemic shock
Warm with bounding pulses suggests low systemic vascular resistance (SVR)
- Distributive shock

@@ Line 1: / Line 1: @@
-== Definition ==
+==Background==
-* Inadequate tissue perfusion and oxygenation leading to multiorgan dysfunction
+*Inadequate tissue perfusion and oxygenation leading to multiorgan dysfunction
-== Shock Index ==
+===Shock Index===
-* Heart Rate / Systolic Blood Pressure
+*Heart Rate / Systolic Blood Pressure
-* Usual range 0.5 to 0.7
+*Usual range 0.5 to 0.7
-* If over 0.9, suggests impaired cardiac function and predicts mortality
+*If over 0.9, suggests impaired cardiac function and predicts mortality
+==Clinical Manifestations==
-== Approach ==
+*Hypoperfusion
-<pre class="mermaid">graph TB
+**Low BP (SBP &lt; 90, MAP &lt; 65, decrease in SBP by 40+)
+**BP unresponsive to fluid challenge
+**Long cap refill
+*End-organ dysfunction
+**Lightheadedness
+**Confusion
+**Diaphoresis
+**Decreased urine output
+**Increased creatinine
+**Chest pain
+**Other ischemic pain
+===Severity of hypovolemic shock===
-Start[&quot;BP = CO x SVR&quot;] --&gt; LowCO[&quot;Low cardiac output (CO)&quot;]
-Start --&gt; LowSVR[&quot;Low systemic vascular resistance (SVR)&quot;]
+{| class="wikitable"
-LowCO --&gt; CNC[&quot;Cold and clammy&quot;]
-CNC --&gt; HighJVP[&quot;High JVP&quot;]
-CNC --&gt; LowJVP[&quot;Low JVP&quot;]
-HighJVP --&gt; Cardio[&quot;Cardiogenic shock&quot;]
-HighJVP --&gt; Obstruct[&quot;Obstructive shock&quot;]
-LowJVP --&gt; Hypo[&quot;Hypovolemic shock&quot;]
-LowSVR --&gt; WNB[&quot;Warm and bounding pulse&quot;]
-WNB --&gt; Distro[&quot;Distributive shock&quot;]
-</pre>
-== Differential Diagnosis ==
-* [[Cardiogenic shock]]
-* Obstructive shock
-** Massive pulmonary embolism
-** Tension pneumothorax
-** Cardiac tamponade
-** Right ventricular infarction
-* Hypovolemic shock
-* Distributive shock
-** [[Sepsis]]
-** [[Anaphylaxis]]
-** [[Systemic inflammatory response]]
-** Mitochondrial dysfunction
-*** Cyanide poisoning
-** Adrenal crisis
-** Myxedema coma
-** Neurogenic
-== Clinical Presentation ==
-* Hypoperfusion
-** Low BP (SBP &lt; 90, MAP &lt; 65, decrease in SBP by 40+)
-** BP unresponsive to fluid challenge
-** Long cap refill
-* End-organ dysfunction
-** Lightheadedness
-** Confusion
-** Diaphoresis
-** Decreased urine output
-** Increased creatinine
-** Chest pain
-** Other ischemic pain
-=== Classes of shock ===
-{|
 !
-! Class I
+!Class I
-! Class II
+!Class II
-! Class III
+!Class III
-! Class IV
+!Class IV
 |-
-| Blood loss (mL)
+|Blood loss (mL)
-| &lt;750
+|&lt;750
-| 750-1500
+|750-1500
-| 1500-200
+|1500-200
-| &gt;2000
+|&gt;2000
 |-
-| Blood loss (%)
+|Blood loss (%)
-| &lt;15%
+|&lt;15%
-| 15-30%
+|15-30%
-| 30-40%
+|30-40%
-| &gt;40%
+|&gt;40%
 |-
-| HR
+|HR
-| &lt;100
+|&lt;100
-| &gt;100
+|&gt;100
-| &gt;120
+|&gt;120
-| &gt;140
+|&gt;140
 |-
-| BP
+|BP
-| Normal
+|Normal
-| Normal
+|Normal
-| Low
+|Low
-| Low
+|Low
 |-
-| Pulse pressure
+|Pulse pressure
-| Normal
+|Normal
-| Low
+|Low
-| Low
+|Low
-| Low
+|Low
 |-
-| RR
+|RR
-| 14-20
+|14-20
-| 20-30
+|20-30
-| 30-40
+|30-40
-| &gt;40
+|&gt;40
 |-
-| Urine output mL/h
+|Urine output mL/h
-| &gt;30
+|&gt;30
-| 20-30
+|20-30
-| 5-15
+|5-15
-| anuria
+|anuria
 |-
-| Mental status
+|Mental status
-| anxious
+|anxious
-| anxious
+|anxious
-| confused
+|confused
-| lethargic
+|lethargic
 |}
+== Differential Diagnosis ==
+*[[Cardiogenic shock]]
+*[[Obstructive shock]]
+**Massive [[pulmonary embolism]]
+**[[Tension pneumothorax]]
+**[[Cardiac tamponade]]
+**Right ventricular infarction
+*[[Hypovolemic shock]]
+*[[Distributive shock]]
+**[[Sepsis]]
+**[[Anaphylaxis]]
+**[[Systemic inflammatory response]]
+**Mitochondrial dysfunction
+***[[Cyanide toxicity]]
+**[[Adrenal crisis]]
+**[[Myxedema coma]]
+**[[Neurogenic shock]]
+== Management ==
+=== Approach to diagnosis ===
+* Remember that BP = CO x SVR
+* Cold and clammy suggests low cardiac output (CO)
+** High JVP: [[cardiogenic shock]] or [[obstructive shock]]
+** Low JVP: [[hypovolemic shock]]
+* Warm with bounding pulses suggests low systemic vascular resistance (SVR)
+** [[Distributive shock]]
 [[Category:Critical care]]