TV4002 Flashcards
(47 cards)
What are the common complications of anaesthesia?
- Machine / circuit leaks
- Rebreathing
- Barotrauma
- Hypo/hyperthermia
What is the cause, consequence, recognition and treatment for a machine leak?
Cause: faulty / damaged equipment, human error
Consequence: environmental pollution, ineffective delivery of fresh gas, inability to ventilate the patient adequately
Recognition: reservoir bag doesn’t stay fullm smell inhalant, hear hissing noise, inabiliy to ventilate the matient effectively, patient problems (inadequate depth, rebreathing)
Treatment: Regular maintenance of equipment, pressure checks, tape (temporary)
What is the cause, consequence, recognition and treatment for rebreathing?
Cause: increased dead space, CO2 allowed to accumulate
Consequence: hypercapnia, inadequate depth, hyperventilation, acidosis, sympathetic nervous stimulation
Recognition: hyperventilation, brick red mm, mild hypertension, inadequate depth, hypoxia, ETCO2 >55mmHg, inspired CO2 >0mmHg (capnograph will not return to baseline)
Treatment: correct inciting cause, support ventilation IPPV, administer O2
What is the cause, consequence, recognition and treatment for barotrauma?
Cause: outflow obstruction (pop-off valve closed, O2 flush, overzealous IPPV, innappropriate inflation of ET tube cuff)
Consequence: gas accumulation, ventilatory impairment, death
Recognition: distended reservoir bag, apnoea, pallor, cyanosis, hypotension, subcutaneous emphysaema
Treatment: relieve outflow obstruction, supplement O2, relieve pneumothorax via thoracocentesis, support circulatory function (IC fluids +/- positive inotropes)
What is the cause, consequence, recognition and treatment for hypothermia?
Cause: body temp below 37oC
Consequence: progressive decline in cardiovascular, renal and liver function, impaired coagulation, changes in acid-base
Recognition: rectal or oesophageal temperature probe,
Treatment: prevent heat loss, passive and active thermal support
What is the cause, consequence, regonition and treatment for hyperthermia?
Cause: overheating (drug reaction / malignent hyperthermia)
Consequence: increased metabolism, denaturation of proteins
Recognition: rectal or oesophageal temperature probe
Treatment: cool environment, fan, alcohol / water application, cool IV fluids
What are the four components of barotrauma?
- Barotrauma - high pressure
- Volutrauma - overextension of alveolar regions due to high volume
- Atelectrauma - continuous alveolar collapse and opening, shear force injury
- Biotrauma - mechincal stimulation of alveoli releases inflammatory mediators
What are the causes of and treatments for bradycardia?
- too deep - reduce depth
- drug effect (alpha 2, opioid, propofol)
- hypothermia - warm the patient
- vagal stimulaion (GI tract, etc) - atropine
- hyperkalaemia
- hypertension - deepen anaesthesia + analgaesia
- increased ICP - IPPV, mannitol / furosemide
- Late stage hypoxamia
What are the causes of and treatments for tachycardia?
- Light anaesthesia - increase depth
- Strong stimulation (sympathetic reflex)
- Drugs (atropine, ketamine) - wait to wear off
- Hypercapnia - IPPV oxygen
- Hypovolaemia / hypertension - fluid therappy + positive inotrope
- Hyperthermia - cool the patient
- Early stage hypoxaemia - IPPV oxygen
What are the causes of and treatments for arrhythmias?
- inadequate anaesthetic depth - deepen
- arrythmogenic drug (medetomidine)
- hypercapnia - IPPV
- hypoxaemia - IPPV
- hypovolaemia / hypotension - fluid therapy
- hypothermia - warm patient
- acid-base / elecrolyte imbalance - correct imbalance
- myocardial disease / injury
What are the causes and consequences of hypotension?
Cause: anaesthesia induced CV depression, excessive anaesthetic depth, hypovolaemia, intraoperative haemorrhage, arrhythmia, organ manipulation, IPPV
Consequence: arrhythmias, acute renal failure, post-anaesthetic myopathy, blindness, gut-barrier failure, sepsis, death
What are the clinical signs of blood loss?
- pale mm
- prolonged CRT
- hypotension
- apparent increase in anaesthetic depth
How can you determine how much blood loss has occurred?
Calculate:
- each gauze swab holds 5-10ml of blood
- lap sponges hod 50-100ml of blood
What causes a flatline capnograph and how do you treat it?
- Caused by complete airway obstruction
- Treatment:
- check that curcuit is still connected
- extend the head and neck to relieve kinks
- adjust ET tube cuff
- suction the ET tube
- provide supplemental O2
- extubate and reintubate with new ET tube if needed
What causes rebreathing in each type of system?
Both: increase in death space
Non-rebreathing: Inadequate flow rate
Rebreathing: exhausted CO2 adsorbent, malfunctioning one-way valve
What are the five reasons for hypoxaemia?
- Low inspired O2
- Hypoventilation
- Diffusion impairment
- V/Q mismatch
- Shunt
What are the four resona for hypoxia?
(inadequate oxygen reaching the tissues)
- hypoxaemia
- reduced delivery capacity of O2
- circulatory problem
- cytotoxic / histotoxic (cell utilization of O2 inhibited)
How does small animal anaesthesia differ from the horse?
- ETCO2 can be significantly different from PaCO2 due to large dead space
- PaO2 may be lower than expected with 100% oxygen due to presence of large shunt
- Min MAP required >70mmHg to perfuse compartmented and compressed muscles
- Eye signs are less reliable in horses - muscle tone of the neck may be a good indication
What are anaesthetic risk factors that create a ‘compromised’ patient?
- perioperative health status
- increasing age
- weight extremes
- procedural urgency
The very young, old, sick or injured
How does acidosis affect the activity of thiopentone?
Acidosis increases unionised thiopentone passing through the cell membrane and reduces the protein bound fraction, thus increasing the active component of thiopentone
What diagnostic methods can be used to determine lung injury?
- Radiography
- Auscultation
- Thoracocentesis
Why is stabilisation of a compromised patient important before anaesthesia?
- cannot tolerate anaesthesia well, very high risk
- hypovolaemia
- acid-base imbalances
- thoracic injuries
- pain!
- stabilisation will improve vital organ function
What are the key factors for a sucessful outcome of anaesthetic of the compromised patient?
- Prepare and anticipate complications
- Monitor and support patient through the anaesthetic and post-operative period
- Early detection of abnormalities
- Pain free
- Well managed vital organs
What is the definition of paediatric?
Less than 12 weeks of age