Day 10: Complications of Anaesthesia Flashcards
what is critical care
who is critical care for
For patients with potentially recoverable conditions who can benefit from more detailed observation and treatment
nurse patient ratio in critical care
1:1
FASTHUG: F
:Feeding (enteral, parenteral)
FASTHUG: A
analgesia
FASTHUG: S
Sedation
FASTHUG: T
thrombo-prophylaxis
FASTHUG: H
Head up
FASTHUG: U
ulcer prophylaxis
FASTHUG: G
glucose control
Pharmacogenetic disorders of relevance
malignant hyperthermia
scoline apnoea
porphyria
halothane hepatitis
What is Malignant Hyperthermia?
Malignant Hyperthermia is an inherited disorder characterized by a hypermetabolic state in response to certain anesthesia agents.
What is the underlying cause of Malignant Hyperthermia?
The underlying cause of Malignant Hyperthermia is a genetic mutation affecting the calcium receptor on the sarcoplasmic reticulum in skeletal muscle cells.
What are the triggers for Malignant Hyperthermia?
Triggers for Malignant Hyperthermia include all volatile anesthetic agents, with suxamethonium being the most potent trigger.
What are the early and later presentations of Malignant Hyperthermia?
In the early stages, Malignant Hyperthermia may present with hypercapnia, increased oxygen extraction, and tachypnea. Later manifestations include cyanosis, muscle rigidity, and hyperthermia (which is a late sign).
What are the potential consequences of Malignant Hyperthermia?
renal failure
liver failure
coagulopathy
cerebral oedema
death
early detection of MH
it is vital if not it is fatal
If recognized early it is fully treatable with a good outcome
management of MH
- discontinue trigger
-call for help
-hyperventilate 100% O2
-DANTROLENE
Specific antidote! 2.5mg/kg initial bolus
-Cool patient and supportive management
-ICU
Dantrolene infusion
Dialysis
Supportive management
what is scoline apnoea
Abnormal or absent pseudocholinesterase enzyme
effects of scoline apnoea
Prolonged paralysis after one dose
management of scoline apnoea
Ventilate
Sedate
FFPs
Medic Alert Bracelet in future
what is porphyria
Defect in synthesis of haem
-Porphyrin accumulation
-Common in SA in those of Afrikaner descent
acute precipitants of porphyria
-Barbiturates (THIOPENTONE!)
-Pain
-Infection
-Starvation
-dehydration
clinical presentation of porphyria
-Abdominal pain & vomiting
-motor/ sensory neuropathy
-Autonomic dysfunction
-Seizures, coma and death
partial list of known safe drugs in porphyria
-Propofol for induction
-Nitrous oxide
-Isoflurane
-Most volatiles probably safe
-Suxamethonium
-Atracurium
-Morphine
-Fentayl probably safe
What is Halothane Hepatitis?
Halothane Hepatitis refers to liver inflammation and injury caused by exposure to the volatile anesthetic halothane.
What is the incidence of Halothane Hepatitis?
The incidence of Halothane Hepatitis is approximately 1 in 35,000 cases.
What factors may increase the risk of developing Halothane Hepatitis?
Halothane Hepatitis is more common after repeated exposure to halothane, which may increase the risk of developing the condition.
What type of immune reaction is associated with Halothane Hepatitis?
Halothane Hepatitis is believed to be an immune-mediated Type II hypersensitivity reaction.
What are the potential outcomes of Halothane Hepatitis?
The spectrum of Halothane Hepatitis includes fatal fulminant hepatic failure, which can result in severe morbidity and mortality.
minor complications of anesthesia
-sore throat
-damage to teeth
-corneal damage
-muscular pain (sux)
-PONV
risk factors of PONV
-patient young, female, history of PONV or motion sickness
-anaesthetic: opioids, etomidate, N2O
-surgical: strabismus, laparoscopy, ear, orchidopexy, gynae
-Postop: pain, opiates, hypotension, forced early feeding
prophylaxis of PONV
-Avoid risk factors
-pharmacological- ondansetron, droperiodol, dexamethosone
-non pharmacological- good hydration, acupressure
major complications of anaesthesia
-Nerve damage
-Central venous line complications
-Hypothermia
What are some factors that can contribute to nerve damage during anesthesia?
Factors contributing to nerve damage during anesthesia include patient positioning, neuraxial and regional blockade, and hypoperfusion of the spinal cord.
Which body positions during surgery may increase the risk of nerve damage?
Non-supine positions and improper positioning of the arms during surgery can increase the risk of nerve damage due to compression or stretching of nerves.
What types of anesthesia techniques can potentially lead to nerve damage?
Neuraxial and regional blockade techniques, such as epidurals and nerve blocks, have the potential to cause nerve damage if performed incorrectly or if complications arise.
What is the difference between neuropraxias and long-term neurological damage?
Neuropraxias refer to temporary nerve injuries that typically resolve on their own, while long-term neurological damage may result in persistent sensory or motor deficits.
How does hypoperfusion of the spinal cord contribute to nerve damage?
Hypoperfusion of the spinal cord, particularly during major vascular surgery or aortic cross-clamping, can lead to ischemic damage to the nerves of the spinal cord, resulting in neurological deficits.
early central venous lines consequences
Pneumothorax
Haemothorax
Nerve damage
Arrhythmia
Air embolism
late central venous lines complications
Sepsis
Endocarditis
Thrombosis
Tamponade
what is hypothermia
Definition: core temperature < 35ºC
precipitating factors of hypothermia
Cold…. Environment, IV fluids, gases
Vasodilatation due to anaesthetic agents
prevention of hypothermia
- warm theatre environment
-passive warming of patient
-warm IV fluids, blood, gases (HMEF)
-active warming
What are the underlying physiological mechanisms of hypothermia during anesthesia?
Hypothermia during anesthesia disrupts normal thermoregulatory mechanisms, leading to a decrease in core body temperature.
How does hypothermia affect platelet function and bleeding risk?
Hypothermia impairs platelet function, increasing the risk of bleeding due to altered platelet aggregation and clot formation.
What are the consequences of delayed metabolism of drugs due to hypothermia?
Delayed metabolism of drugs occurs in hypothermic patients, leading to prolonged drug effects and potential toxicity.
How does hypothermia contribute to delayed emergence from anesthesia?
Hypothermia prolongs the recovery time from anesthesia as metabolic processes are slowed, leading to delayed emergence from anesthesia.
What cardiac complications are associated with hypothermia?
Hypothermia can induce arrhythmias, including bradycardia and ventricular fibrillation, due to alterations in cardiac electrical activity.
What is the common postoperative manifestation of hypothermia, and how does it occur?
: Postoperative shivering is a common manifestation of hypothermia, resulting from the body’s attempt to generate heat through involuntary muscle contractions
What effect does hypothermia have on oxygen consumption?
Hypothermia increases oxygen consumption as the body attempts to maintain normal body temperature through metabolic processes such as shivering and increased cardiac output.
major complication of anaesthesia
-death
-airway complications
-cardiac complication
-equipment failure
-awareness
-drug related
airway complications
-failed intubation
-aspiration
drug related complications
-anaphylaxis
-pharmacogenetic
-drug errors
risk factors for complications: patient
Comorbidities
ASA status
Surgical condition
Age
risk factors for complications: anesthetic
Intubation
Equipment failure
Aspiration risk
Anaphylaxis
Drug choices
Pharmacogenetic disease
Respiratory depression
Awareness
risk factors for complications: surgical
-Type and extent of surgery
-Emergency or elective
-Skill and knowledge surgeon
-Mishaps
rising airway pressures
-obstructed ETT
-kinked ETT
-circuit blockage
-bronchospasm
-mucus plug in airway
pneumothorax
sudden leak in circuit
-dislodged ETT
-disconnection at nay point in circuit
-vaporizers, soda lime not connected properly
-warning signs
*ventilator alarms
*ventilator bellows keeps collapsing/ can’t fill
equipment failure
machine failure
hypoxic gas mixture
ventilator disconnection
drug errors
-important to label drugs
-use color coding system of labels
-dilute drugs appropriately
risk factors for MI: patient
IHD
CCF
valvular disease
arrhythmia,
Peripheral Vascular Disease
hypovolaemia
risk factors for MI/ arrest: anaesthetic factors
hypo/hypertension
tachycardia
hypoxia
risk factors for MI/ arrest: surgical procedures
Major intrathoracic
Major abdominal
Major vascular
Emergency surgery
common causes of anaphylaxis
-antibiotics
-muscle relaxants
-latex
classic triad of symptoms for anaphylaxis
-CVS collapse
-bronchospasm
-skin changes
management of anaphylaxis
-ABCs
-Adrenaline (0.5mg IM)
-Additional measures
*hydrocortisone
*antihistamine
post operative respiratory failure: underlying disease
Pulmonary disease
Myasthenia gravis
Neurological
Muscular
Morbid obesity
post operative respiratory failure: metabolic
Hypokalaemia
Hypoglycaemia
post operative respiratory failure: complications
Aspiration
Pulmonary embolism
post operative respiratory failure: drugs
Opioids
Muscle relaxants
Magnesium
high risk groups in anesthesia
Obstetric GA
Trauma
Previous awareness
