Hypotension Post Cardiac Surgery

OVERVIEW

  • Think PROVED?: pump, rhythm, obstruction, volume, (endocrine), distributive, ? = artefactual

MANAGEMENT

Errors and artifacts

  • examine the patient for pulses and check for symmetry
  • transducer error: check transducer, zero, level, calibrate, NIBP
  • damping of waveform: assess damping co-efficient, replace
  • NIBP malfunction: check cuff (size, fit, connection)
  • check inotrope infusions into patient
  • Radial/ central arterial monitoring discrepancy with severe vasoconstriction
  • Upper limb vascular disease (radial arterial line) or obstruction (e.g. dissection or aorto-occlusive disease: femoral arterial line)

Hypovolaemia

  • bleeding: check drains, dressings, CXR, give fluid, blood products, correct coagulopathy and temperature
  • diuresis: check urine output and sodium, give fluids

Distributive

  • vasoplegia: fluids and vasoconstrictors, consideration of methylene blue
  • anaphylaxis: rash, bronchospasm, stop infusions, adrenaline, fluids
  • sepsis: consider -> treat with antibiotics and source control
  • vasodilator excess: stop drug, vasoconstriction
  • sympathetic block (epidural): fluids, vasoconstrictors

Cardiogenic

  • look for cause: LV, RV, systolic, diastolic, valves, pericardium (measure cardiac output, order ECHO)
  • decreased contractility: ischaemia from thrombosis, blockage, kinking, spasm -> GTN, vasoactives and fix technical problem
  • sudden removal of inotropic drug: restart

Rhythm disturbance

  1. bradycardia: pace, atropine, isoprenaline, adrenaline
  2. SVT: K+, Mg2+, adenosine
  3. AF: K+, Mg2+, amiodarone, DC shock
  4. VT: K+, Mg2+, amiodarone, DC shock

Obstructive

  • tension pneumothorax: examine chest, CXR -> decompress
  • patient ventilator dysynchrony: paralyse patient, examine ventilator, ABG, CXR
  • tamponade: ECHO, will likely need a TOE (need to exclude one chamber tamponade)

Endocrine and metabolic (unlikely in this setting)

  • severe electrolyte disturbance (e.g. hypoP, hypoCa)
  • adrenal insufficiency, hypothyroidism
  • severe acidosis

References and Links

LITFL


CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health, a Clinical Adjunct Associate Professor at Monash University, and the Chair of the Australian and New Zealand Intensive Care Society (ANZICS) Education Committee. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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