Makindo Medical Notes.com

Related Subjects: Atropine |Acute Anaphylaxis |Basic Life Support |Advanced Life Support |Adrenaline/Epinephrine |Acute Hypotension |Cardiogenic shock |Distributive Shock |Circulatory Shock |Obstructive Shock |Septic Shock and Sepsis |Shock (General Assessment) |Toxic Shock Syndrome |Upper Gastrointestinal Bleed |Non invasive ventilation (NIV) |Intubation and Mechanical Ventilation |Critical illness neuromuscular weakness |Multiple Organ Dysfunction Syndrome

About

• Loss of circulating blood volume either through haemorrhage or loss of fluid or burns
• Haemorrhage: Bleeding. Fluid loss: Diarrhoea, Sweating, Polyuria DKA/HHS.
• Ultimately there is tissue hypoperfusion and hypooxygenation

A metabolic acidosis with base deficit > 5 mmol/L often indicates increased lactic acid production in poorly perfused, hypoxic tissues. Serial lactate measurements may help in monitoring response to treatment

Causes

• Haemorrhage
  • GI Tract: Haematemesis, Melena, High Urea
  • Retroperitoneal space: Trauma or Anticoagulant, Pancreatitis
  • AAA leaking needs urgent CT and surgery
  • Trauma into Chest cavity, pelvis, long bone fractures or pelvis
  • Penetrating Arterial or Venous puncture +/=- Coagulopathy
  • Penetrating Cardiac damage +/=- Coagulopathy
• Fluid loss
  • Massive diarrhoea e.g. cholera or other bowel fluid losses
  • Renal losses: Massive polyuria with DKA, Diabetes insipidus
  • Insensible: Sweating or Dehydrated with no oral or IV intake
  • Burns and transdermal losses

Clinical

• Low BP, lying to sitting BP drop, thready pulse, tachycardia
• Poor capillary return, cold, obtunded, comatose
• Oliguria, concentrated urine (except DKA/DI)
• Grey turners/Cullens signs for retroperitoneal bleeding
• PR blood/melena suggets UGI Bleed, Pulsatile aneurysm

Investigations

• FBC - low Hb or normal acutely even with acute bleed. May be high if haemoconcentrated
• U&E - raised urea in AKI or GI bleed
• Raised lactate > 2 mmol/L in sepsis or tissue hypoperfusion
• Group and hold in case blood needed
• Imaging CT abdomen/pelvis

Management

• ABCs, Oxygen, Get Good IV access x 2 quickly. Commence IV Crystalloids
• Close monitoring of haemodynamics, ABGs, H⁺, base deficit, lactate
• Group and cross match 4-6 units if felt to bleeding. Transfuse as needed - Massive transfusion protocol. Even if not bleeding Optimise Hb concentration: 70–90 g/L; 100 g/L if ischaemic heart disease. Red cells as required
• Consider CVP line and correct coagulopathy. Optimise volume status: fluid challenge(s)
  • CVP < 6 mmHg: 250 mL 0.9% saline or colloid
  • CVP > 6 mmHg or poor ventricular function suspected: 100 mL boluses
  • Consider pulmonary artery catheter or oesophageal Doppler
• Consider Mechanical Ventilation
  • Intractable hypoxaemia/Respiratory distress
  • Hypercapnia: PaCO₂ > 6.7 kPa (50 mmHg)
  • Impaired conscious level and unsafe airway
• Achieve target BP once hypovolaemic managed
  • Vasopressor: Noradrenaline
  • Inotrope: Dobutamine
• Further Management depends on likely cause found by initial assessments
• Endoscopy (Upper GI endoscopy, colonoscopy/mesenteric angiography) for GI bleeding
• CT scan for leaking AAA and retroperitoneal bleed and urgent surgery
• IV fluid and electrolyte replacement and treating medical causes