Mast cell degranulation and therefore anaphylaxis.
1 in 8,000.
Awareness under general anesthesia is the ability to perceive, feel, or be consciously aware of one’s surroundings; this may or may not be accompanied by the experience of pain.
Reassess the situation starting at ABC and treat the probable cause as appropriate.
1 in 670.
Hand-ventilate with 100% oxygen and ask the surgeon to stop operating until it is safe to continue.
Hydrocortisone 200 mg IV.
State that it is an anesthetic emergency and call for senior anesthetic assistance.
Ask for the crash trolley, administer adrenaline 2–10 μg/min of 1:10,000 preparation, commence transcutaneous pacing, and if HR <30 with significant haemodynamic compromise, commence CPR and follow ALS algorithm for asystole.
Decisions concerning the need to transfuse the patient.
The blood compatibility label.
The inhalation of oropharyngeal or gastric contents into the lower airways.
A critical incident form.
Induction and emergence, which account for two-thirds of all reported AAGA cases.
The incidence increases from 1 in 136,000 to 1 in 8,000.
It occurs when incompatible transfused cells react with the patient's own anti-A or anti-B antibodies or other alloantibodies, leading to activation of complement and disseminated intravascular coagulation (DIC).
Anaphylaxis is an acute, Type 1 hypersensitivity reaction caused by antigens binding to IgE immunoglobulin on mast cells, causing them to degranulate and release mediators like histamine, prostaglandins, and leukotrienes.
Obstetrics and cardiothoracics.
Blockage, compression, kinking of tubing, incorrect connection of circuit, scavenging, reservoir bag, filter, humidifier, APL valve or PEEP valve.
Check BP and give a fluid bolus (10 mL/kg of either crystalloid or colloid), and repeat if necessary.
Aspiration remained the leading cause of airway-related anaesthetic deaths, with most cases having identifiable risk factors.
Start at the patient (check tube position and auscultate chest) and sequentially examine from the airway back to the anesthetic machine. Treat the cause as you discover it.
Arrange transfer to ICU for further investigation, advanced monitoring, and management.
Adrenaline or noradrenaline.
First name, surname, date of birth, and hospital/NHS number.
A full explanation.
Commence CPR and follow the ALS algorithm for asystole.
Debrief to try to determine what, if anything, could have been done differently.
Patient position (prone, Trendelenburg), pre-existing disease (asthma, obesity, ARDS), timing of event (e.g., following central venous line insertion), risk factors (allergy, bronchospasm), surgery (e.g., laparoscopy with pneumoperitoneum).
Take blood for serum tryptase levels.
The medical notes and anaesthetic records.
Be sympathetic and apologize.
Treat the identified cause, clearly document the sequence of events on the anaesthetic chart, and complete a critical incident form.
On the anaesthetic chart or in the contemporaneous clinical notes.
Give antihistamines – chlorpheniramine 10 mg IV.
They must be replaced or reattached.
If necessary, during early management.
Because no real-time plasma concentration of the intravenous agent can be made, and pharmacokinetic models are relied upon to predict plasma and effect site concentrations.
Cyanosis becomes clinically evident when arterial oxygen saturations fall below approximately 85–90%, correlating with a deoxyhemoglobin level of at least 5 g/dL.
Check for a cuff leak.
Hospital critical incident reporting forms.
Document all conversations.
Kinked tube, misplaced tube (e.g., oesophageal or endobronchial), obstructed tube (e.g., sputum, blood, or foreign body).
A follow-up appointment and psychological support.
Patient factors and non-patient factors.
Chest wall rigidity, malignant hyperthermia or opioids, prone position, obesity, kyphoscoliosis, raised abdominal pressures (e.g., pneumoperitoneum), inadequate paralysis or patient ‘fighting’ ventilator.
All staff involved in blood transfusions must have undergone mandatory training in blood transfusion safety.
Excessive tidal volumes.
Pneumothorax, bronchospasm, lobar collapse or atelectasis, pulmonary oedema, pulmonary fibrosis, aspiration, ARDS.
Difficult to ventilate, decreased compliance in reservoir bag, poor chest expansion, low minute volume, high airway pressure and alarm limits reached, abnormal CO2 trace, hypoxia, circulatory collapse.
Explicit memory (intentional recollection of events with conscious perception) and implicit memory (non-intentional recollection of events with subconscious perception).
Heart rate, ECG, blood pressure, oxygen saturation, ETCO2 trace.
Terminate surgery as soon as safely possible.
MAC is the minimum alveolar concentration, at one atmosphere ambient pressure, required to prevent movement in 50% of subjects in response to a surgical stimulus.
Cyanosis describes the blue discoloration of the skin and mucous membranes due to the presence of increased quantities of deoxygenated hemoglobin.
Admit to ITU and leave intubated.
Central cyanosis is most visible in the tongue and lips. Common causes are cardio-respiratory problems, which may be acute (e.g., obstructed airway) or chronic (e.g., some types of congenital heart disease).
Peripheral cyanosis is most visible in the fingers and nail beds. It is caused by reduced peripheral perfusion and may be seen in combination with central cyanosis.
The anaesthetist involved in the case.
Because patients generally receive RhD-compatible red cells.
In the liver and spleen.
Approximately 1:2000 elective intubations.
The Difficult Airway Society (DAS) guidelines.
CT or MRI of the upper airway and neck, X-ray of mandible and cervical spine.
20% of all difficult intubations are not predicted.
Reduce or stop the volatile agent and check the MAC and end-tidal concentration of the volatile agent.
0.6 mg (10 μg/kg), and it can be repeated up to a maximum of 3 mg.
Reassure the patient that this is very unlikely to happen again.
Consider switching to an alternative circuit, e.g., Ambu bag.
If the patient is severely acidotic.
10% of the reports of AAGA to NAP5 were due to drug error.
Liaise with critical care.
Five risk factors.
Call for help.
Differential diagnoses include haemorrhage, asthma, high regional block, myocardial infarction, and malignant hyperthermia.
Return them to the blood bank for bacteriology.
With the patient sitting up, head in neutral position, mouth wide open, and tongue protruding with no phonation.
Approximately 1:50–100 intubations in the ICU or emergency department.
If you are able to read the typed page through the fluid, it counts as clear.
State that this is an anaesthetic emergency and call for senior anaesthetic assistance.
Reviewing medical records and previous anaesthetic charts, history of presenting pathology, medical diseases, surgery to the neck and airway, radiotherapy to the head and neck, and any previous anaesthesia complications.
It should be transfused within 4 hours or discarded.
Assess and resuscitate simultaneously.
Aspiration pneumonitis and/or aspiration pneumonia.
The patient's GP, the hospital administrators, and your medical defence organisation.
Serious Hazards of Transfusion (SHOT).
No, the definition of MAC does not encompass the concept of awareness, only movement.
To detect changes suggestive of hyperkalaemia from haemolysis.
Identify at-risk patients, administer antacids (e.g., ranitidine or sodium citrate), administer prokinetic drugs (e.g., metoclopramide), and postpone anaesthesia for 6 hours following a meal.
The patient must have been previously sensitised to the antigen.
10 points.
Common causes of peripheral cyanosis include all causes of central cyanosis, cold-induced peripheral vasoconstriction, Raynaud’s phenomenon, and low cardiac output states (e.g., cardiac failure).
Document events in the notes, inform the patient of events, send a letter to the GP, and complete a critical incident form.
Administer 50–100 μg IV (0.5–1 ml of 1:10,000 solution) and repeat every minute until improvement or deterioration to cardiac arrest.
CPAP or IPPV with PEEP.
Protruding teeth make direct laryngoscopy difficult, while edentulous patients make face mask ventilation difficult.
Food: 6 hours, Clear fluid: 2 hours, Breast milk: 4 hours, Bottle formula: 6 hours, Milk: 6 hours, Chewing gum: 2 hours.
It represents the gap available to displace the tongue and should be ≥6.5 cm.
Factors such as swelling, infection, trauma, and scars.
1 in 19,000 anesthetics.
A severe form of lung injury caused by aspiration pneumonitis, part of the ARDS spectrum.
No, aspiration pneumonitis does not necessarily lead to aspiration pneumonia.
Failure to use a nerve stimulator to ensure adequate return of muscle power before turning off anesthetic agents.
Cyanosis can be classified as central or peripheral.
Yes, due to cross-sensitivity between environmental pathogens and anaesthetic agents, especially non-depolarising muscle relaxants like rocuronium.
Approximately 75% of difficult intubations.
The most important cause of cyanosis in terms of relevance to anesthesia is hypoxia, due to airway or ventilatory compromise until proven otherwise.
Elevating the patient's legs can improve central blood volume.
Provided the patient can be adequately ventilated, the safest option of maintaining the patient’s airway (e.g., LMA ProSeal™) needs to be decided.
A falling haemoglobin or a rise in haemoglobin that is less than expected, together with a rise in bilirubin and a positive direct antiglobulin test.
Eye surgery, dilation of the anus and cervix, mesenteric retraction, laparoscopy, and airway manipulation.
High spinal blockade to T1–T4 can compromise the cardiac sympathetic accelerator fibres.
Reduced distance between the occiput and spine of C1, reduced distance between spine of C1 and C2, ratio of mandibular length to posterior mandibular depth >3.6.
100% traceability of all allogeneic blood transfused.
An acute, chemically induced inflammation of the lung parenchyma caused by the acid in the gastric contents.
To minimize the risk of transfusion errors.
Metabolic acidosis and hyperkalaemia.
Gastrointestinal surgery and patient positioning such as lithotomy or head down.
Hypotension and uncontrollable bleeding secondary to DIC.
Faulty or malfunctioning equipment, equipment not used or programmed correctly by the anesthetist.
Congenital cyanotic heart disease is caused by heart lesions that result in a right to left shunt of blood, such as Tetralogy of Fallot, Pulmonary stenosis or atresia with septal defect, Truncus arteriosus, Total anomalous pulmonary venous drainage, and Transposition of the great arteries.
100% O2.
The patient should be woken up and alternative options like awake fibre-optic intubation, regional anaesthetic techniques, or local anaesthetic techniques should be considered.
Lack of ventilation and oxygenation.
Difficult intubations occur in about 1 in 65 cases.
To assess lung compliance and adequacy of ventilation.
Document the sequence of events in medical notes and complete a critical incident form.
Explicit recall is extremely unlikely at MAC > 1.
By maintaining urine output.
It is a scoring system designed to predict a difficult intubation.
NG tube placement and aspiration of gastric contents prior to surgery, use of rapid sequence induction with cricoid pressure where appropriate, and positioning the patient head up where possible.
Yes, they can be caused by antibodies such as anti-RhD, RhE, RhC, and K (Kell).
Heart rate, blood pressure, tachypnoea, sweating, and lacrimation can be masked by drugs such as β-blockers, anti-muscarinic agents, opioids, and neuromuscular blockers.
5 cm or three-finger breadths using the patient's own fingers.
Kidd and Duffy antigens.
Hypoxia.
A – lower incisors lie beyond the upper incisors, B – lower incisors meet upper incisors, C – lower incisors remain behind upper incisors.
Ask the surgeon to stop to eliminate any surgical vagal stimulation.
It can distort airway anatomy and cause tissues surrounding the airway to become rigid, making head extension, jaw thrust, and direct laryngoscopy very difficult.
A condition where superimposed infection follows aspiration, commonly seen in patients with long-term 'silent' aspiration or acute aspiration with colonized material.
Approximately one in three.
The physiological effects of anaphylaxis include vasodilatation, increased capillary permeability, and smooth muscle constriction.
Stop the transfusion, adopt an ABC approach, administer colloid, support respiration and circulation, check compatibility labels, inform the blood bank and consultant haematologist, and take necessary blood tests.
Transfuse platelets, fresh frozen plasma, and cryoprecipitate guided by clinical state and coagulation study results.
A yellow card found in the back of the BNF.
Immediate management includes stating it is an anaesthetic emergency, stopping the offending drug, securing the airway, giving 100% oxygen, maintaining anaesthesia with inhalational agents if the patient is paralysed, administering adrenaline 50–100 μg IV, repeating the dose every minute if needed, giving IV crystalloid or colloid, and elevating the patient's legs if possible.
Fever, nausea, and shivering.
Inhalational agents (enflurane, halothane, isoflurane), opioids (fentanyl, remifentanil, morphine), anticholinesterases (neostigmine), muscle relaxants (vecuronium, tubocurarine, second dose of suxamethonium), vasopressors (metaraminol, phenylephrine), and β-blockers.
Ischaemic heart disease and raised intracranial pressure.
They can help differentiate between intrinsic and extrinsic causes of stridor.
Reduced level of consciousness, full stomach, reduced barrier pressure, and anatomical issues like pharyngeal pouch or oesophageal strictures.
Symptoms include agitation, pain at infusion site, flushing, abdominal, flank or substernal pain, and breathlessness. Signs may include pyrexia, hypotension, bleeding, haemoglobinaemia, and haemoglobinuria.
Administer broad-spectrum IV antibiotics and take blood cultures.
Summon help and bring intubating aids.
Classes I–IV, with Class IV added by Samsoon and Young in 1987, and Class 0 applicable when the epiglottis is visible.
Factors such as morbid obesity, pregnancy, large breasts, thick, short and immobile necks, protruding teeth, beards, and receding jaws.
It helps establish the previous grade of intubation, where grade 3 or 4 is considered difficult.
Female, younger adults, obesity, previous AAGA, unexpectedly difficult intubation, increased resistance to anesthetic agents (febrile, hyperthyroid, alcoholic, recreational drug users), moribund patients for emergency procedures.
In a plain glass tube stored at –20°C.
Report the incident to SABRE.
Visit the patient as soon as possible with a witness (preferably a consultant), take a full history, elicit exactly what the patient sensed and whether they were in pain, and seek advice from a consultant.
Scars, swellings (e.g., goitre), burns or radiotherapy, range of neck movement.
Suction down the ETT once in situ before giving positive-pressure ventilation, if possible.
Approximately 1:300 obstetric rapid sequence intubations.
Maternal cardiac arrest (CPR is not effective without delivery of the baby) and imminent risk of life to the mother if surgery does not proceed (e.g., massive peri-partum haemorrhage).
A difficult intubation is defined as one in which an anaesthetist with at least 2 years’ training, using a traditional laryngoscope blade, achieves only a poor view at direct laryngoscopy (grade 3 or 4), requires more than three attempts at direct laryngoscopy, takes more than 10 minutes to intubate, or needs additional equipment to secure the airway.
Diseases such as acromegaly, scleroderma, rheumatoid arthritis, airway malignancy, and cervical spine fractures.
Failure to monitor concentration of inspired and expired volatile agents and MAC, failure to monitor peripheral cannula and infusion line with TIVA, failure to use specific depth of anesthesia monitoring, failure to look for clinical signs of awareness.
High BMI, beard, large breasts.
Left lateral position with head down.
SABRE (Serious Adverse Blood Reaction and Events) is an online system for the submission of notification and subsequent confirmation of blood-related adverse events and reactions.
The mother’s survival.
If aspiration pneumonitis does not resolve within 48 hours, if the patient had bowel obstruction, or if they have been on regular antacids.
Large tongues, as seen in patients with Down's syndrome, make inserting the laryngoscope difficult and can obscure the view.
Hypothyroidism and hyperkalaemia.
To obtain good views of the base of the tongue and vocal cords, typically performed by ENT surgeons.
Signs include flushing and weals, wheezing, bronchospasm, rising airway pressures, oedema of face, lips, and oropharynx, pulmonary oedema, hypotension, and tachycardia.
35 mL blood for haematology (5 mL EDTA tube for FBC, platelet count, DAT, plasma haemoglobin), 5 mL in a dry tube for repeat cross-matching, 10 mL in a citrated tube for coagulation screen (PT, APTT, fibrinogen), and 5 mL for clinical chemistry (urea and electrolytes).
The 'can't intubate, can't ventilate' algorithm from the DAS.
CXR (Chest X-Ray).
Bradycardia in an adult is defined as a heart rate (HR) <60 bpm, but any rate that is inappropriately slow for the individual and haemodynamic state should be considered.
The degree of mandibular subluxation during maximal forward protrusion of the mandible.
Conditions such as Down’s syndrome, Pierre Robin syndrome, Treacher Collins syndrome, and Marfan’s syndrome.
No, there is no single test that can predict all difficult intubations.
