Multi- organ dysfunction syndrome

Question 1

Define multi-organ dysfunction syndrome. (MODS)

Answer 1

Altered organ function in an acutely ill patient so that homeostasis cannot be maintained without intervention.

Diagnostic criteria - Present if SIRS is associated with organ dysfunction (e.g., oliguria, hypoxia)

Question 2

What is the definition of SIRS (systemic inflammatory response syndrome)?

Answer 2

Present if two or more of the following are present:

1. Temp >38°C or <36°C
2. HR >90 bpm
3. Resp rate >20 breaths/min or PaCO2 <4.3 kPa
4. WCC >12,000 or <4000 cells/mm3 or more than 10% immature forms
5. Serum lactate >4 mmol/L

Question 3

What is the pathophysiology of MODS?

Answer 3

Mediators - mainly cytokines including TNF-a, IL1,2,6, and platelet activating factor.

Mechanisms causing distant organ failure:

1. Inducing excessive release of cytokines
2. Disrupting oxygen delivery
3. Impairing intestinal barrier function –> translocation of intestinal bacteria and endotoxin to the portal and systemic circulations
4. Damaging the reticulo-endothelial system

Question 4

What are the causes of MODS?

Answer 4

Causes include:

• infection - especially gram -ve bacteria –> release of inflammatory cytokines
• endotoxaemia (gram -ve sepsis) - e.g. breached intestinal barrier
• retained necrotic tissue - e.g. gangrenous leg
• shock

Question 5

What is the difference between MODS and sepsis?

Answer 5

Sepsis if when infection if the initiating factor of MODS.

Question 6

What is the pattern of organ failure in MODS?

Answer 6

1. Pulmonary first
2. Hepatic
3. Intestinal
4. Renal
5. Cerebral
6. Cardiac last

Question 7

How might you investigate organ dysfunction in MODS?

Answer 7

Can assess them in order of failure from pulonary to cardiac

1. Pulmonary first - ?ARDS
2. Hepatic - rising bilirubin, impaired clotting (rising PT), low albumin, thrombocytopenia, rising ALT and LDH
3. Intestinal - stress bleeding requiring transfusion
4. Renal - rising plasma creatinine and low urine output
5. Cerebral - confusion
6. Cardiac last - low CO and hypotension

Question 8

What are the sepsis six?

Answer 8

All within 1 hour:

1. Give high-flow oxygen via non-rebreathe bag
2. Take blood cultures and consider source control
3. Give IV antibiotics according to local protocol
4. Start IV fluid resuscitation with Hartmann or equivalent
5. Check lactate
6. Monitor hourly urine output; consider catheterisation