anesthetic complications

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anesthetic complications
2015-05-01 22:30:26
vetc 395

anesthetic complications
Show Answers:

  1. ways to avoid human error
    • check each label and calculation 3 times
    • weigh accurately
    • add zeroes to make decimals obvious
    • label syringes and keep separate P separate
    • focus, don't rush
    • schedule early, don't be tired, EXPECT mistakes
    • anesthesia = INHERENTLY COMPROMISED.  Expect something wrong and look for it
  2. ways to avoid equipment error
    check equip early (valves, tubing, connections; tanks/reservoir full, pressure check)
  3. How to tell if CO2 absorber is exhausted
    • color change (blue/violet)
    • canister cold when in use
    • granules hard, not crumbly
    • 8-12h of use (faster with high flow rates
  4. what condition does exhausted CO2 absorber cause in patient?
  5. what are signs of hypercapnea?
    tachypnea, tachycardia, arrhythmias, sweating, brick red mucous membranes
  6. over-inflation or overly aggressive intubation causes
    inflammation, pressure necrosis or tracheal rupture
  7. rough intubation causes
    • vagus nerve stimulation, bradycardia
    • damage recurrent laryngeal nerve (laryngeal paralysis)
    • traumatize soft palate, pharynx or larynx
    • especially cats, tissues very delicate.  Can cause laryngospasm, be sure pet is deep enough.  May have bronchoconstriction at extubation
  8. signs of ET tube blockage in P
    • dyspnea, hypoxemia, hypercapnia, eventually respiratory arrest
    • No chest movement
    • no tidal volume
    • no CO2 exiting body
  9. Peak inspiratory pressure
    • pressure of gas delivered to P at peak of inspiration
    • monometer
    • not above 20cm H2O
    • excessive causes barotrauma, popping alveoli, pneumothorax.  Leads to reduced venous return, respiratory arrest, death
    • Capnograph will tell you
  10. predisposing factors for vomiting/regurg
    • drugs that relax esophageal sphincter (anticholinergics, opioids, barbituates)
    • increased intra-abdominal pressure (pregnancy, obesity, pyometra, ascites, obstruction of proximal small intestine, presence of food in stomach, head down position during surgery - this increases regurg but decreases aspiration)
  11. risks of aspiration
    • inital obstruction of airway (dyspnea, hypoxia, cyanosis)
    • aspiration pneumonia (1-2 days later, dyspnea, tachypnea, cough, increased lung sounds, pyrexia)
    • post-op esophageal or tracheal stricture (acidic irritation)
  12. If an unconscious P with no tube vomits
    • place tube immediately
    • OR position head lower than body
    • lavage and suction oral cavity when V stops
  13. causes of hypoventilation
    • drugs - all inhalants and opioids cause respiratory depression, can cause P to be light on anesthesia
    • exhausted CO2
    • stuck one-way valves
    • endobronchial intubation
    • too low O2 flow rate (rebreathing CO2)
    • hypothermia (depress respiratory centers)
    • severe hypotension (decreased cerebral perfusion)
    • pain upon expansion of chest
    • restrictive bandages around chest
    • pulmonary disease
  14. Hypercapnia causes
    • initial tachycardia and increased BP
    • then depresses CNS and cardiac contractility
    • causes respiratory acidosis
    • eventually slow death
  15. Most accurate measurement of accuracy of ventilation
    • blood gas analysis, PaCO2
    • also detected by capnography (ETCO2 > 45-50 mmHg).  high end will cause catecholamine release (increased BP and perfusion) so easier for Hb to release O2 (shifts curve to right).  Kills slowly if too much
  16. clinical signs of hypoventilation
    • brick red or bluish-tinged mucous membranes
    • tachycardia or arrhythmias
    • can have tachypnea and hypoventilation due to decreased tidal volume
    • opioids decrease resp rate but others decrease tidal volume through muscle relaxation
  17. minute volume
    tidal volume x respiratory rate
  18. treatment for hypoventilation
    • intermittant positive pressure ventilation (IPPV)
    • if on ventilator, increase tidal volume and/or increase respiratory rate
    • address underlying cause
  19. Definition of hyperventilation
    • hypocapnia (cerebral vasoconstriction leading to inadequate cerebral blood flow)
    • NOT tachypnea
    • ETCO2 < 35mmHg (except brain sx, where 25-35 okay)
    • Causes respiratory alkalosis
  20. hypocapnia causes __________
    respiratory alkalosis
  21. causes of tachypnea
    • pain, stress, anxiety (#1) (need to urinate?)
    • hypercapnia (exhausted soda lime)
    • hypoxia
    • hyperthermia
    • silent regurgitation into larynx
  22. causes of apnea
    • drugs (propofol, transient)
    • anesthetic/opioid overdose
    • aggressive ventilation (decrease drive)
    • Hypoxia
    • brainstem injury
    • severe pulmonary disease
  23. causes of hypoxemia
    • low incoming O2
    • hypoventilation (leaning on chest)
    • hypothermia
    • problem in lungs (fluid in alveoli)
  24. what to do for hypoxemia
    • check pulse ox
    • trace O2 supply to P, administer O2
    • PPV if not ventilating adequately
    • check temp
    • anesthesia too deep?
    • ascultate chest
    • underlying thoracic disease
  25. hypotension
    • MAP<60
    • inadequate perfusion of brain, heart, kidneys
  26. causes of hypotension
    • anesthetic agents (inhalants, propofol)
    • dehydration, hypovolemia
    • hypothermia
    • arrhythmias
  27. tx of hypotension
    • check/change cuff/location
    • lighten anesthesia
    • administer fluids
    • balance anesthesia/analgesia
    • reverse injectables
    • correct dehydration/hypovolemia
    • administer vasopressors (dopamine)
  28. causes of bradycardia
    • increased vagal tone
    • drugs
    • hypothermia
    • hypoglycemia
    • hyperkalemia/hypercalcemia
    • drugs (beta blockers, Alpha2)
  29. tx for bradycardia
    • check perfusion (BP, SPO2, CV parameters)
    • Warm P
    • anesthesia too deep?
    • tx cause if possible (hyperkalemia?  calcium gluconate, insulin, dextrose)
    • anticholinergics, reversals
  30. tx for and symptoms of hyperkalemia
    • bradycardia
    • calcium gluconate to stabilize myocardium, insulin to lower K+ levels, dextrose to stabilize blood glucose levels
  31. Causes of tachycardia
    • pain or nocioception
    • inadequate anesthetic depth
    • hypotension
    • hyperthermia
    • hypercarbia
    • hypoxia
    • hypovolemia
    • electrolyte abnormalities
  32. tx for tachycardia
    • check anesthetic depth
    • check BP
    • administer adequate analgesia
    • warm or cool the P
    • treat underlying cause (hypovolemia?  Fluids)
  33. hypothermia
    body temp below 97, critical below 95.
  34. causes of hypothermia
    • general anesthetics (thermoregulatory)
    • drugs (vasodilators, muscle relaxants)
    • cold room temp
    • cold IV and lavage fluids
    • clipping fur, alcohol, antiseptics
    • opening body cavity
    • cold, dry anesthetic gas and oxygen
  35. Things that hypothermia causes
    • post-procedural stress response (vasoconstriction, tachycardia, hypertension)
    • risk of arrhythmias
    • coagulation abnormalities
    • increased infection rates
    • delayed wound healing
  36. When to stop heating patients post-op
    when body temp = 100