Introduction

• Multiple organ failure is a syndrome that results from overwhelming systemic inflammatory response Systemic inflammatory response syndrome (SIRS) , disseminated intravascular coagulation Disseminated intravascular coagulation , that leads to organ dysfunction and usually death.
• Numerous inciting causes of systemic inflammation can ultimately lead to MODS.
• Mortality rate in humans with multiorgan failure is 50-80%.
• Similar increased mortality rates are associated with MODS in veterinary patients, particularly due, in some cases, to lack of available technology and staff for intensive monitoring and therapy, lack of client desire to pursue aggressive therapy in veterinary patients, and cost associated with aggressive monitoring and therapy in veterinary patients with MODS.
• The exact incidence of MODS in veterinary patients is unknown.
• Sepsis Shock: septic is a common inciting cause of MODS in veterinary patients, but other causes include:
  • Pyothorax Pyothorax.
  • Peritonitis Peritonitis.
  • Pancreatitis Pancreatitis: acute.
  • Burn injury Skin: burn / scald.
  • Shearing wounds and severe tissue trauma Wound: types - overview.
  • Snakebite Rattlesnake bite Adder bite poisoning.
  • Parvoviral enteritis Parvovirus disease associated with CPV-2.
  • Gastroenteritis Acute hemorrhagic diarrhea syndrome (AHDS).
  • Bacterial Lung: bacterial pneumonia or aspiration pneumonia Lung: aspiration pneumonia.
  • Traumatic pulmonary contusions.
  • Immune mediated hemolytic anemia Anemia: immune mediated hemolytic.
  • Pyelonephritis Kidney: pyelonephritis.
  • Osteomyelitis Osteomyelitis.
  • Pyometra Pyometra.
  • Fungal infection.
• Patients with MODS often require invasive and aggressive monitoring and treatment:
  • Rule of Twenty Kirby's rule of twenty.
  • Fluid therapy Fluid therapy.
  • ECG ECG: overview.
  • Blood pressure Blood pressure: direct measurement.
  • Urinary catheterization Urethral catheterization: female Urethral catheterization: male.
  • Mechanical ventilation Anesthetic ventilators: overview.
  • Pulse oximetry Anesthetic monitoring: pulse oximetry.
  • Arterial blood gases Arterial blood gas sampling.
  • End-tidal CO2.
  • Thoracic radiology/radiography Radiography: thorax.

Pathogenesis

Etiology

• A variety of inciting causes, including viral, fungal, and bacterial infections, envenomation, and inflammatory conditions can all lead to activation of the immune system and the release of proinflammatory cytokines and oxygen-derived free radical species.
• This can be a protective mechanism by which the body overcomes and treats the inciting cause, or the result can be overwhelming inflammation and activation of the coagulation cascade to such an extent that Disseminated Intravascular Coagulation (DIC) Disseminated intravascular coagulation , Acute Respiratory Distress Syndrome (ARDS) Acute Respiratory Distress Syndrome (ARDS) , and end-organ damage occurs to the neurologic, hepatic, coagulation, cardiopulmonary, gastrointestinal, and vascular endothelial systems.

Predisposing factors

General

• Trauma Trauma: overview :
  • Shearing or crush injury.
  • Burn injury.
  • Fractures.
  • Traumatic pulmonary contusions.
  • Traumatic peritonitis.
• Infection:
  • Gram positive and gram negative bacterial sepsis.
    • Pyothorax Pyothorax.
    • Peritonitis Peritonitis.
    • Hepatic abscess.
    • Pyelonephritis Kidney: pyelonephritis.
    • Bacterial pneumonia Lung: bacterial pneumonia.
    • Meningitis Meningitis.
    • Osteomyelitis Osteomyelitis.
  • Fungal infection.
  • Viral infection:
    • Parvoviral enteritis.
  • Iatrogenic from invasive monitoring.
• Heat-induced illness/Heat stroke Heat stroke.
• Burn injury Skin: burn / scald.
• Inflammation:
  • Pancreatitis.
  • Aspiration pneumonitis.
  • Chemical pneumonitis.
  • Immune-mediated hemolytic anemia Anemia: immune mediated hemolytic.
  • Gastric dilatation-volvulus Stomach: gastric dilatation / volvulus (GDV) syndrome.
• Envenomation Venomous animals of Australia Venomous animals of North America :
  • Snakebite Rattlesnake bite.
  • Spider bite Spider bites.
  • Scorpion bite.
• Surgery.

Pathophysiology

• MODS is the end result of systemic inflammation, caused by a variety of conditions.
• Any predisposing factor that can cause systemic inflammation, disseminated intravascular coagulation can ultimately lead to MODS.
• Bacterial endotoxin, severe trauma or tissue injury, and any condition that causes hypotension can cause activation of neutrophils, macrophages and complement.
• The recruitment and activation of neutrophils and macrophages results in the production of pro- and anti-inflammatory cytokines, including interleukin-10 (IL-10), IL-1, Tumor necrosis factor (TNF-a), IL-6, Interferons, Prostaglandins, Leukotrienes, and Platelet activating factor (PAF). The proinflammatory cytokines can perpetuate the inflammatory cascade, and also target end organs including the vascular endothelium, pulmonary vasculature and myocardium, leading to vascular injury, vascular leakiness, and myocardial depression. Additionally, upregulation of inducible nitric oxide synthetase (iNOS), can lead to the production of nitric oxide, a potent vasodilator agent, leading to areas of vasodilation, while other vascular areas become inappropriately vasoconstricted. Activation of neutrophils and complement also can trigger the production of oxygen-derived free radical species that damage the vascular endothelium. Activation of the coagulation cascade, either by tissue factor or complement activation leads to the consumption of platelets and multiple microthrombi forming globally, leading to end-organ thrombosis. The result of hypotension, decreased myocardial contractility, decreased oxygen delivery to tissues, and vascular endothelial damage ultimately leads to tissue hypoxia and end-organ damage that can lead to failure if left untreated.

Timecourse

• The progression of organ failure in patients with MODS usually occurs as follows:
  • Lungs: 24-72 hours.
  • Liver and gastrointestinal tract: 48-72 hours.
  • Acute renal failure: 48-72 hours.
  • Cardiac and brain dysfunction usually >72 hours.

Diagnosis

Treatment

Prevention

Outcomes