RCOA March 2019

Question 1

You are asked to assess a 15kg 4year old child who is scheduled for a strabismus (squint) correction as a day case procedure.

a) List the anaesthetic considerations of this case

Age

Answer 1

1. Consent from parents
2. Fasting
3. Induction: IV or gas
4. Venous access may be challenging
5. Patient anxiety/ lack of cooperation
6. Consider premedication: both topical local anaesthetic to hands and anxiolytic if indicated

Question 2

You are asked to assess a 15kg 4year old child who is scheduled for a strabismus (squint) correction as a day case procedure.

Specific to this procedure

Answer 2

(4 marks)
1. Brisk oculocardiac reflex

2. Postoperative nausea and vomiting
3. Operation site close to the airway
4. Increased risk of rare muscle problems presenting for the 1st time (e.g. muscular dystrophies)
5. Raised risk of malignant hyperpyrexia in this patient group
6. Unpredictable response to non- depolarizing muscle relaxants (NDMR)

Question 3

You are asked to assess a 15kg 4year old child who is scheduled for a strabismus (squint) correction as a day case procedure.

Day case surgery

Answer 3

1. Postoperative nausea and vomiting associated with this procedure occasionally results in unplanned overnight admission.
2. Suitability for day case surgery - comorbs
3. Social - live close by to hospital - parents willing to take child post op

Exclusion criteria for paediatric day care:
Patient related factors
Term baby less than one month in age
Preterm or ex-preterm baby <60wks post conception age
Poorly controlled systemic disease e.g. asthma
Inborn errors of metabolism, diabetes mellitus
Complex cardiac disease, or cardiac disease requiring investigation.
Sickle cell disease (not trait)
Active infection (especially of respiratory tract)
Anaesthetic and surgical factors
Inexperienced surgeon or anaesthetist
Prolonged procedure
Opening of a body cavity
High risk of perioperative haemorrhage/fluid loss
Postoperative pain unlikely to be relieved by oral analgesics
Difficult airway (including obstructive sleep apnoea)
Malignant hyperpyrexia susceptibility
Sibling of a victim of sudden infant death syndrome
Social factors
Parent unable or unwilling to care for the child at home postoperatively
Poor housing conditions
No telephone
Excessive journey time from home to the hospital (>1 hour)
Inadequate postoperative transport arrangement

Question 4

How would you manage profound bradycardia during surgical traction?

Answer 4

1. Ask the surgeon to stop immediately
2. Ask for senior help
3. Give atropine 20 mcg/ kg
4. If no response, elevate arm, flush IV, and start cardiac compressions

Question 5

What strategies would you employ to reduce postoperative nausea and vomiting (4 marks)

Answer 5

1. Prophylactic antiemetic,
   e. g. ondansetron 0.15mg/ kg +/ – dexamethasone
2. 15mg/ kg Combination increases efficacy
3. Rescue antiemetic
   e.g. IV dexamethasone 0.15mg/ kg
   slow IV or droperidol 0.025mg/ kg

No benefit to repeat ondansetron

3. Ensure fluid balance and minimize fasting time
4. Acupuncture point P6 stimulation

Question 6

What strategies would you employ to reduce and postoperative pain? (3 marks)

Answer 6

1.Intraoperative paracetamol
15– 20mg/ kg

2. Diclofenac
   1mg/ kg
3. Local anaesthetic infiltration by surgeon intraoperatively
4. Avoidance of Opioids
5. Consideration for subtenons block

Question 7

What strategies would you employ to reduce Recovery room distress

Answer 7

Recovery room distress

1. Reunite with parents early to manage distress and
   anxiety
2. Treat or exclude pain
3. Distraction with play therapist

Question 8

1. a) List three of the commonest causes of end

stage renal failure (ESRF) in the United Kingdom

Answer 8

1. Diabetes mellitus
2. Glomerulonephritis
3. Hypertension
4. Polycystic kidney disease
5. Pyelonephritis
6. Renal vascular disease

Question 9

1. b) What complications of ESRF are of importance to the anaesthetist?

????

Answer 9

1. Cardiac
   Fluid overload / increased risk complications

Dialysis patients commonly have elevated blood pressure,
which might require treatment prior to surgery. Initially,
treatment of hypertension is directed toward optimizing
volume status with effective ultrafiltration because most of
the time volume overload is the most common cause of
hypertension.

Dialysis patients have increased risk of ischemic heart disease. Cardiovascular disease was thought to exist in 50% of
dialysis patients undergoing surgery.5,8 There is no well-defined
optimal preoperative cardiac assessment for dialysis patients,
but it generally depends on the level of risk and requires risk
stratification. Coronary artery disease and myocardial dysfunction result in significant morbidity and mortality in patients
with ESRD. Cardiovascular disease remains the main cause of
death in patients with ESRD.

2. Respiratory
   Increased risk of fluid overload / effusions

Question 10

1. b) What complications of ESRF are of importance to the anaesthetist?

Answer 10

3. Haematological
   increased risk of bleeding and platelet dysfunction

Dialysis patients have an increased tendency to bleed.12–15
However, bleeding time is not recommended as a preoperative
screening test. A normal bleeding time does not exclude prolonged bleeding complication during or after surgery. Multiple
factors contribute to increased tendency to bleed, including
platelet dysfunction. Some of the contributing factors for
platelet dysfunction include the following: aspirin use, uremic
toxin retention due to inadequate dialysis, anemia, and elevated
parathyroid hormone.

Regarding heparin,
doses can be reduced by use of saline flushes during the hemodialysis treatment. Heparin with dialysis should be avoided 24
to 48hours after major surgery. Discussion with the surgeon is
very importan

4. Endocrine

A big proportion of patients with ESRD have diabetes
mellitus. Glycemic control is crucial in the perioperative
period. Some important points to consider in dialysis patients
with diabetes mellitus are that they tend to be brittle, especially patients with type 1 diabetes mellitus. Important consideration not to overlook is that oral hypoglycemic agents
have prolonged half-life in patients with ESRD and CKD,
which could cause hypoglycemia. Consultation with diabetes
specialist is advised.

Question 11

1. b) What complications of ESRF are of importance to the anaesthetist?

Answer 11

In regard to intravenous access, it is recommended to use small caliber IV catheters. Internal jugular venous catheters should be placed if peripheral access is not available. Placing catheters in subclavian vein should be avoided at all times due to the risk of central stenosis. Central lines should not be inserted on the same side as arteriovenous access. Before going
to the surgery, anesthesiologist should be aware of the patient’s vascular anatomy to help establish IV access and to minimize complications. It is always important to display a sign about the patient’s access side and to forbid blood draws and blood pres

Emergency surgery – For emergency surgical procedures, the nephrology service is consulted when urgent preoperative dialysis may be desirable to treat severe hyperkalemia, metabolic acidosis, or intravascular volume overload. Institution of alternative therapies may be necessary if dialysis is not feasible.

• Hyperkalemia – If potassium is ≥5.5 mEq/L, we dialyze if time allows, since even one to two hours of hemodialysis reduces potassium concentration. If dialysis is not possible and potassium is >6.5 mEq/, intravenous (IV) calcium chloride, insulin, or bicarbonate may be administered, or intraoperative continuous kidney replacement therapy or hemodialysis may be initiated (algorithm 1 and table 1). (See ‘Management of hyperkalemia’ above.)
• Intravascular volume overload – Risks of moderate or severe preoperative volume overload are weighed against risks of delaying surgery for dialysis. (See ‘Management of intravascular volume overload’ above.)
• Bleeding – If uremia-induced platelet dysfunction is suspected, we suggest administration of IV desmopressin (dDAVP) (Grade 2C). For patients with active bleeding, platelets are administered even in the absence of thrombocytopenia. (See ‘Management of bleeding’ above.)

Question 12

1. b) What complications of ESRF are of importance to the anaesthetist?

Pharmacology

Answer 12

Pharmacology

Patients with impaired kidney function have decreased renal excretion of drugs. Thus, the pharmacokinetics of medications is altered along with the metabolism, plasma protein binding, and volume of distribution. It is important to consider the metabolic pathway of depolarizing agents and analgesics in the perioperative setting.
There are 2 opioids which are of particular concern,
including morphine and meperidine. Their metabolite accumulates in patients with CKD and ESRD and could lead to complications. Patients could be exposed to seizure if meperidine was used, as the metabolite normeperidine is a seizure inducing substance. However, when morphine is used, its metabolite morphine-6-glucuronide is a highly active
metabolite which could accumulate and lead to prolonged sedation.19–21 Therefore, morphine and meperidine should be avoided. The preferred analgesics are mainly fentanyl22
and hydromorphone.

Other available analgesics include nonsteroidal antiinflammatory agents (NSAIDs). These agents could be used in patients with ESRD, but clinicians should be aware of
increased gastrointestinal bleeding, especially in patients with ESRD, which limits their use. In patients with CKD,
NSAIDs should be avoided due to increased renal toxicity causing acute kidney injury. Acetaminophen can be used without change in dosing.23 Tramadol can also be used in patients with ESRD.

Question 13

1 c) What acute physiological disturbances may be seen in a patient who has just had haemodialysis? (3 marks)

Answer 13

1. Intravascular depletion/ hypovolaemia
2. Possible residual anticoagulation
3. Hypothermia
4. Electrolyte rapid correction

Question 14

1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)

Answer 14

1. Vascular access

Avoid accessing fistulas.
Source control of bleeding in most fistula sites is easy to do, so wide bore access is not usually necessary.

Cannulation attempts should be minimized to preserve vessels for potential future fistula formation and thus the preference for cannulation site is the back of the hand.

Use of indwelling dialysis lines by the anaesthetist should be cautioned against, except in an emergency

2. Local anaesthesia
   This is the least physiologically intrusive method but the least well tolerated by patients and some procedures will not be feasible because of location or extent of incisions or depth of surgery.

Question 15

1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)

Answer 15

3. Never place a central line in the same extremity where the arteriovenous access (primary AV fistula or GORE-TEX® graft) is present.
4. Do not administer large amounts of intravenous (IV) fluids to patients with end-stage renal disease (ESRD) or acute renal failure (ARF)-oliguric patients (i.e., no more than 1 mL/kg) for minor procedures and during stable clinical conditions
5. Avoid drugs with potential nephrotoxicity in ARF patients; modify doses of medications according to reduced renal function

Question 16

1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)

Answer 16

Induction – General anesthesia is typically induced with a reduced carefully titrated dose of propofol (eg, 1 to 2 mg/kg).

If rapid sequence induction and intubation (RSII) is necessary, succinylcholine (SCh) can be used as the neuromuscular blocking agent (NMBA) if potassium is <5.5 mEq/L. However, we avoid SCh if potassium is ≥5.5 mEq/L, and use the nondepolarizing NMBA rocuronium instead, with planned sugammadex reversal.

If RSII is unnecessary, an NMBA with slower onset (eg, cisatracurium, rocuronium) can be used. Alternative techniques without use of any NMBA include a remifentanil intubation technique, or use of sevoflurane 3.5% for three minutes plus a reduced dose of propofol (ie, 0.5 to 1 mg/kg). (See ‘Induction’ above.)

-Maintenance – Inhalation-based or total IV anesthesia (TIVA), or combinations of IV and inhalation agents may be used to maintain anesthesia. A short-acting opioid may be carefully titrated.

Question 17

1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)

Answer 17

Fluid management – We typically select a balanced electrolyte solution unless the patient is hyperkalemic. In such cases, we select normal saline. In rare circumstances when urgent and significant volume expansion is necessary, 5% albumin may be administered. Transfusion is avoided when possible, but red blood cells (RBCs) are administered if hemoglobin is <7 g/dL, particularly with ongoing surgical bleeding. (See ‘Fluid management’ above.)

•Glucose control – We maintain blood glucose at <180 mg/dL (<10 mmol/L). (See ‘Glucose control’ above.)

Post op
simple analgesics
regional
avoid long acting opiods

Question 18

A 28 year -old woman presents for an acute
appendicectomy under general anaesthesia she is 22 weeks pregnant.

a) List the risks to the foetus during anaesthesia in this situation. (5 marks)

Answer 18

1&raquo_space; Hypoxia, hypercarbia:
failure to adequately manage maternal airway and
ventilation can result in uterine artery constriction, hypoxia, hypercarbia and myocardial depression of the fetus.

2&raquo_space; Hyperventilation
of mother causing hypocarbia can cause uterine artery vasoconstriction, poor perfusion and leftward shift of maternal oxyhaemaglobin dissociation curve.

3&raquo_space; Hypoperfusion:
fetoplacental unit entirely dependent on maternal perfusing pressure. Therefore, it is necessary to maintain maternal blood
pressure and manage aortocaval compression.

Question 19

A 28 year -old woman presents for an acute
appendicectomy under general anaesthesia she is 22 weeks pregnant.

a) List the risks to the foetus during anaesthesia in this situation. (5 marks)

Answer 19

4&raquo_space; As yet unconfirmed/unquantified anaesthetic-induced neuronal apoptosis in developing brain.

5&raquo_space; Risk of miscarriage –
unquantified. Likely to have more to do with the
disease process necessitating the surgery or the surgery itself

Question 20

b) How can the risks to the foetus be minimised? (10 marks)

Answer 20

1. > > Defer surgery until after
   delivery unless absolutely necessary.
2. > > Multidisciplinary approach,
   involve obstetricians in the assessment of
   pre- and postoperative maternal and fetal well-being.

3&raquo_space; Airway and respiratory:
• RSI after antacid premedication,
rapid securing of airway.
Extubate awake, sitting up.

• Ventilation targeted to end-tidal carbon dioxide and oxygen saturations to reduce the possibility of hypoxia and hypercarbia in the fetus.

Question 21

b) How can the risks to the foetus be minimised? (10 marks)

Answer 21

> > Cardiovascular:
• Left lateral tilt, adequate filling, and maintenance of maternal
blood pressure at normal levels all help minimise risk of placental
hypoperfusion.

• Ensure adequate analgesia as raised circulating catecholamines will compromise placental perfusion.

> > Neurological:
• Shortest duration of anaesthesia possible reduces the exposure of fetal brain to anaesthetic agents.

• Avoidance of general anaesthesia through the use of regional or neuraxial technique, where possible. Not an option for appendicectomy.

Question 22

c) What additional preoperative and intraoperative steps would you take to ensure foetal safety if she is 27 weeks pregnant instead? (5 marks)

Answer 22

> > Discussion with neonatologists preoperatively: fetus is now viable and preparations for consequences of premature labour are necessary.

If NICU cot not available, consideration should be given to in utero transfer to hospital where cot is available, if maternal condition permits.

> > Discussion with obstetricians regarding possible need for tocolysis and steroids for fetal lung maturation (urgency of surgery may not allow time for this to be fully effective).

> > Pre-, intra- and postoperative cardiotocographic fetal monitoring.

> > Ensure liaison between obstetricians and surgeons regarding planned surgical approach: open versus laparoscopic approach, consideration of site of laparoscope insertion.

> > Avoid NSAIDs due to risk of premature closure of ductus arteriosus.

Question 23

a) What airway risk factors may indicate a difficult extubation?

Answer 23

1. Known difficult airway
2. Airway deterioration (trauma, oedema or bleeding)
3. Restricted airway access
4. Obesity / OSA
5. Aspiration risk

Question 24

b) What factors (patient and other) can you optimise prior to extubation? (5 marks)

Patient

Answer 24

1 Patient 
Cardiovascular
Respiratory
Metabolic / temperature
Neuromuscular

Neuromuscular block should be fully reversed to maximise the likelihood of adequate ventilation, and restore protective airway reflexes and the ability to clear upper airway secretions. The use of a peripheral nerve stimulator to ensure a train-of-four ratio of 0.9 or above is recommended and has been shown to reduce the incidence of postoperative airway complications. An accelerometer is more accurate than visual assessment for train-of-four response [42, 77]. Sugammadex provides more reliable antagonism of rocuronium- (and to a lesser extent vecuronium-) induced neuromuscular blockade than neostigmine. Cardiovascular instability should be corrected and adequate fluid balance assured. The patient’s body temperature, acid-base balance, electrolyte and coagulation status should be optimised. Adequate analgesia should be provided.

Question 25

b) What factors (patient and other) can you optimise prior to extubation? (5 marks)

Answer 25

``` 2 Other Location Skilled help / assistance Monitoring Equipment ``` Extubation is an elective process, which should be carried out in a controlled manner with the same standards of monitoring, equipment and assistance that are available at induction. Tracheal extubation can take as long to perform safely as tracheal intubation, and this should be considered when organising list schedules, or sending for the next patient. Communication is essential, and the anaesthetist, surgeon and theatre team all play an important role. Additional resources may be required for the ‘at risk’ patient.

Question 26

c) What strategies could you employ to manage a high risk extubation?

Answer 26

Step 1 would stratify both these patients into the ‘at-risk’ extubation group. Step 2 would enable stabilisation of general factors and optimisation of logistical factors e.g. communication with the intensive care unit, assembling equipment, getting help. The key decision to be made is whether it is safer to extubate, or preferable for the patient’s trachea to remain intubated. If it is considered safe to extubate, then an awake extubation or one the advanced techniques described below will overcome most of the challenges in the ‘at-risk’ patient. A broad range of equipment and advanced techniques are available, but no single technique covers all clinical scenarios. None of these techniques is without risk; training and experience in their use are vital before they are employed in a difficult airway situation. If it is considered unsafe to extubate, the options are to postpone extubation or perform a tracheostomy.

Question 27

d) Outline the steps you would take to exchange an endotracheal tube to a supraglottic airway device (SAD) to aid extubation. (6 marks)

Answer 27

Sequence for LMA exchange in ‘at-risk’ extubation. 1 Administer 100% oxygen 2 Avoid airway stimulation: either deep anaesthesia or neuromuscular blockade is essential 3 Perform laryngoscopy and suction under direct vision 4 Insert deflated LMA behind the tracheal tube 5 Ensure LMA placement with the tip in its correct position 6 Inflate cuff of LMA 7 Deflate tracheal tube cuff and remove tube whilst maintaining positive pressure 8 Continue oxygen delivery via LMA 9 Insert a bite block 10 Sit the patient upright 11 Allow undisturbed emergence from anaesthesia

Question 28

At risk techniques Awake

Answer 28

Awake extubation: the technique of awake extubation for the ‘at-risk’ patient is the same as that described above for the low-risk group, and is suitable for most patients in the ‘at-risk’ group (for example, those at risk of aspiration, the obese, and many patients with a difficult airway). However, in some situations, one or more of the following advanced techniques may be beneficial:

Question 29

At risk techniques Bailey manoeuvre

Answer 29

Laryngeal mask exchange (Bailey manoeuvre): this involves replacement of a tracheal tube with a LMA to maintain a patent, unstimulated airway with stable physiological observations and protection of the airway from soiling secondary to blood and secretions in the mouth. The emergence profile of this technique is superior to either awake or deep extubation [108-111], and is useful in cases where there is a risk of disruption of the surgical repair due to the cardiovascular stimulation resulting from the presence of a tracheal tube. It may also benefit smokers, asthmatics and other patients with irritable airways. It is inappropriate in patients in whom re-intubation would be difficult or if there is a risk of regurgitation. The technique was originally described using the Classic LMA [98, 112]. Data for use of other supraglottic airway devices are lacking. The technique requires practice and meticulous attention to detail; adequate depth of anaesthesia is critical to avoid laryngospasm

Question 30

At risk techniques

Answer 30

1 Removal of the tracheal tube before LMA insertion, following laryngoscopy and pharyngeal suction; 2 Insertion of a flexible fibreoptic bronchoscope through the stem of the LMA, to confirm its correct position, and to observe vocal cord motion. This technique is useful for patients who have had thyroid/parathyroid surgery and other situations in which airway integrity may have been impaired; 3 Laryngeal mask airway exchange for a nasotracheal tube, using one of two methods: the LMA may be inserted from the side of the nasotracheal tube so that the former slides behind the latter; or the nasotracheal tube can be removed before inserting the LMA. Remifentanil extubation technique: the presence of a tracheal tube may trigger coughing, agitation and haemodynamic disturbances during emergence from anaesthesia. In certain groups of patients (for example, neurosurgical, maxillofacial, plastics and those with significant cardiac or cerebrovascular disease), these responses are undesirable. Although possible, both awake and deep extubation are far from ideal in these situations. The cough suppressant effects of opioid drugs and their ability to attenuate the cardiovascular changes with extubation have been known for many years [113, 114]. Infusion of the ultrashort-acting opioid remifentanil attenuates these undesirable responses and may be used to provide the beneficial combination of a tube-tolerant patient who is fully awake and obeys commands.

Question 31

Sequence for use of a remifentanil infusion for ‘at-risk’ extubation.

Answer 31

 Consider postoperative analgesia. If appropriate, administer intravenous morphine before the end of the operation [126] 2 Before the end of the procedure, set the remifentanil infusion at the desired rate 3 Antagonise neuromuscular blockade at an appropriate phase of surgery and emergence 4 Discontinue anaesthetic agent (inhalational agent or propofol) 5 If using inhalational agent, use high-flow oxygen-enriched gas mixture to aid full elimination and monitor its end tidal concentration 6 Continue ventilation 7 Laryngoscopy and suction should be performed under direct vision if appropriate 8 Sit the patient upright 9 Do not rush, do not stimulate, wait until the patient opens their eyes to command 10 Discontinue positive pressure ventilation 11 If spontaneous respiration is adequate, remove the tracheal tube and stop the infusion 12 If spontaneous respiration is inadequate, encourage the patient to take deep breaths and reduce the infusion rate 13 When respiration is adequate, remove the tracheal tube and discontinue the remifentanil infusion, taking care to flush residual drug from the cannula 14 After extubation, there is a risk of respiratory depression and it is essential that the patient is closely monitored until fully recovered 15 Remember that remifentanil has no long-term analgesic effects 16 Remember that remifentanil can be antagonised by naloxon

Question 32

Sequence for use of an airway exchange catheter for ‘at-risk’ extubation.

Answer 32

Sequence for use of an airway exchange catheter for ‘at-risk’ extubation.] 1 Decide how far to insert the AEC. It is essential that the distal tip remains above the carina. If there is any un certainty about the position of the tracheal tube tip, its position relative to the carina should be checked with a fibreoptic bronchoscope before AEC insertion. An AEC should never be inserted beyond 25 cm in an adult patient 2 When the patient is ready for extubation, insert the lubricated AEC through the tracheal tube to the predetermined depth. Never advance an AEC against resistance 3 Employ pharyngeal suction before removal of the tracheal tube 4 Remove the tracheal tube over the AEC, while maintaining the AEC position (do not advance the AEC) 5 Secure AEC to the cheek or forehead with tape 6 Record the depth at the teeth/lips/nose in the patient’s notes 7 Check that there is a leak around AEC using an anaesthetic circuit 8 Clearly label the AEC to prevent confusion with a nasogastric tube 9 The patient should be nursed in a high dependency or critical care unit 10 Supplemental oxygen can be given via a facemask, nasal cannula or CPAP mask 11 The patient should remain nil by mouth until the AEC is removed 12 If the presence of the AEC causes coughing, check that the tip is above the carina and inject lidocaine via the AEC 13 Most patients remain able to cough and vocalise 14 Remove the AEC when the airway is no longer at risk. They can be tolerated for up to 72 

Question 33

Sequence for use of an airway exchange catheter for reintubation.

Answer 33

1 Position the patient appropriately 2 Apply 100% oxygen with CPAP via a facemask 3 Select a small tracheal tube with a soft, blunt bevelled tip (for example, the tube developed for use with an intubating LMA (Intavent Direct Ltd, Maidenhed UK). 4 Administer anaesthetic or topical agents as indicated 5 Use direct or indirect laryngoscopy to retract the tongue and railroad the tracheal tube (with the bevel facing anteriorly) over the AEC 6 After reintubation, confirm the position of the tracheal tube with capnography

Question 34

Treatment of laryngospasm

Answer 34

1 Call for help 2 Apply continuous positive airway pressure with 100% oxygen using a reservoir bag and facemask whilst ensuring the upper airway is patent. Avoid unnecessary upper airway stimulation 3 Larson’s manoeuvre: place the middle finger of each hand in the ‘laryngospasm notch’ between the posterior border of the mandible and the mastoid process whilst also displacing the mandible forward in a jaw thrust. Deep pressure at this point may help relieve laryngospasm 4 Low-dose propofol e.g. 0.25 mg.kg−1 intravenously may help If laryngospasm persists and/or oxygen saturation is falling: 5 Propofol (1–2 mg.kg−1 intravenously) Whilst low doses of propofol may be effective in early laryngospasm, larger doses are needed in severe laryngospasm or total cord closure 6 Suxamethonium 1 mg.kg−1 intravenously. Worsening hypoxia in the face of continuing severe laryngospasm with total cord closure unresponsive to propofol requires immediate treatment with intravenous suxamethonium succinylcholine. The rationale for 1 mg.kg−1 is to provide cord relaxation, permitting ventilation, re-oxygenation and intubation should it be necessary 7 In the absence of intravenous access suxamethonium can be administered via the intramuscular (2–4 mg.kg−1), intralingual (2–4 mg.kg−1) or intra-osseous (1 mg.kg−1) routes 8 Atropine may be required to treat bradycardia 9 In extremis, consider a surgical airway

Question 35

What anaesthetic techniques | can be used to allow a tubeless field for laryngeal surgery? (5 marks)

Answer 35

Management of gas exchange: depends on the specific bronchoscope used as not all options are compatible with all bronchoscopes. >> Intermittent ventilation with or without oxygen insufflation via side-port. This may be sufficient for the diagnostic aspect of the procedure but does not offer sufficiently reliable ventilation for resection. >> Controlled ventilation via the side port of a ventilating bronchoscope. >> Manual low-frequency jet ventilation, e.g. with Sanders manual jet ventilator. >> Automated high-frequency jet ventilation.

Question 36

How can the risk of an airway fire be minimised?

Answer 36

>> Maintain inspired oxygen concentration as low as possible, certainly less than 0.4 – therefore, use with jet or conventional ventilation. >> Saline-soaked gauze over mouth, teeth. >> Goggles for patient. >> Ensure that all equipment that will be used to instrument the airway is laser-compatible Tubes made of polyvinyl chloride (PVC) are preferable to those of rubber or silicone because they are slightly less flammable. doublecuffed tubes like the Mallinckrodt Laser-Flex™ (which has a proximal cuff filled with saline, tinted with methylene blue to alert the surgeon of a rupture Soaking up any pooled or spilled flammable agents Allowing alcohol-based skin preparation solutions to dry fully before applying drapes Applying water-soluble gels to the patient’s facial hair and head hair Moistening surgical pledgets, sponges, gauze and anaesthetic throat packs with water or saline Cautery -it should be avoided where possible, but where absolutely necessary, the lowest effective voltage should be

Question 37

c) What measures would you take to protect the staff when a laser is in use?

Answer 37

General theatre safety: >> Goggles for staff. >> Signage on doors. >> Lock theatre doors. >> Blinds down. >> Presence of laser-trained staff member. >> Assurance of equipment maintenance. Readiness for airway fire: >> Alertness. >> Syringes of saline ready for flooding airway. >> Airway equipment prepared in case surgery needs to be abandoned and the patient needs to be intubated and ventilated on 100% oxygen

Question 38

a) What does the term LASER stand for (1 | mark) ,

Answer 38

``` Light Amplification by the Stimulated Emission of Radiation ```

Question 39

And what different types of laser can be used for surgery? (3 marks)

Answer 39

Ruby 694 Pigment, hemoglobin Dermatology, tattoo removal Nd:YAG 1,064 Pigment, proteins Wide applications Er:YAG 2,940 Water Surgery Diode 630–980 Pigment, water (range) LLLT, PDT, surgery Argon 350–514 Pigment, hemoglobin Surgery, PDT, ophthalmology, dermatology CO2 10,600 Water Surgery Pumped-dye 504–690 Pigment PDT, dermatology

Question 40

Tubeless anaesthesia

Answer 40

On occasion, the surgeon will request a tubeless field to improve access to the larynx or trachea. This can be achieved with the use of a very narrow tube or no tube at all. These approaches rely on oxygenation via HPSV, by maintenance of spontaneous ventilation, or via apnoeic oxygenation.

Question 41

Jet ventilation/HPSV

Answer 41

The history, physiology, and types of jet ventilation were summarized by Evans et al.8 in a previous CEACCP review. With respect to laryngo-tracheal surgery, it is important to delineate between the use of manual jet ventilation and automated highfrequency jet ventilation (HFJV), which are both methods of HPSV. Morbidity and mortality secondary to barotrauma is well documented,1,2,9 and caution must be exercised to avoid gas trapping by ensuring sufficient outflow. Manual jet ventilation can be provided via a Sanders-type injector (providing a 4 atm fixed pressure) or the Manujet device (VBM-Medical; providing a more controlled pressure of 0–4 atm, Fig. 2A). Ideally, the lowest driving pressure should be initiated to limit pressure-related complications. These devices lack airway pressure and end-tidal carbon dioxide (ETCO2) monitoring and, being human-activated, can contribute to an increased risk of barotrauma. Arguably, automated devices, such as the Mistral or Monsoon (Acutronic Medical Systems), are superior as they include a range of safety features along with tight fraction of inspired oxygen (FiO2) control and potential for

Question 42

Spontaneous ventilation

Answer 42

Spontaneous ventilation Maintaining spontaneous ventilation (SV) preserves a patient’s negative intrathoracic pressure, making it particularly beneficial in pathologies below the larynx, such as tracheal disease or the management of an inhaled foreign body, where paralysis can lead to a decrease in patency of the lower airway. Maintenance of SV drive is the technique of choice for tubeless field surgery without HPSV and in cases where the surgeon wants to perform a dynamic and functional assessment of the glottis, including evaluation of vocal cord movement and supraglottic collapse. Low-flow oxygen can be delivered nasally or more distally via a narrow transglottic catheter (e.g. 8 Fr feeding tube). As this route provides unhumidified, unwarmed oxygen, the flow rate should be limited, with entrainment of air further reducing the delivered concentration.

Question 43

Apnoeic oxygenation

Answer 43

Apnoeic oxygenation Fully apnoeic tubeless techniques, though providing a completely motionless surgical field, are unfamiliar to many anaesthetists and can result in significant hypercarbia with potentially deleterious effects.13 Offering an ideal view for the surgeon, it was previously limited to patients who could tolerate sustained apnoeic periods with low-flow oxygen delivery. However, with the advent of high-flow oxygenation, this apnoeic period has been shown to be significantly extended.14,15 Limitation in application includes patient groups with high metabolic states, such as the morbidly obese, in whom the apnoeic window is limited. Maintenance of even minimal spontaneous effort can abate small airways collapse in these patients, mitigate hypercarbia and, importantly, allow for early detection of upper airway obstruction. Small airways collapse due to obesity or airway obstruction can rapidly impair apnoeic oxygenation even with high-flow oxygenation and intermittent re-recruitment with bag-mask ventilation may be required.

Question 44

High-flow oxygen delivery

Answer 44

High-flow oxygen delivery High-flow nasal cannula allow for effective oxygenation as part of a tubeless technique, avoiding the risks associated with jet ventilation and providing superior gas exchange to low-flow techniques.14,15 This is particularly important for prolonged cases and high-risk patients. Ensuring unobstructed gas flow from the nasal passages to the glottis is key and upper airway patency should be continuously assessed and maintained throughout. The warming and humidification of inspired gases aids muco-ciliary clearance and increases patient comfort. ETCO2 monitoring is unavailable with this approach though transcutaneous monitoring has been described14 or arterial blood sampling if indicated. Delivery of high FiO2 for prolonged periods is not without risk as a combination of nitrogen washout and rapid alveolar oxygen absorption can lead to alveolar collapse and absorption atelectasis, even

Question 45

``` Question 5 (Green Book) a) What is the daily energy requirement of a normal healthy 70kg man? (1 mark) What are the recommended daily proportions of carbohydrate, fat and protein? (3 marks ```

Answer 45

• 30 kCal/kg/day. * 60% intake from carbohydrate so 4.8 g/kg/day. * 40% intake from fat so 1.3 g/kg/day. • Protein 0.8–1.5 g/kg/day.

Question 46

Which patients are at particular risk of refeeding syndrome (6 marks)

Answer 46

1. Low BMI (<16 alone or <18.5 with another risk factor present) 2. Unintentional weight loss >0– 5% in the last 3– 6 months 3. Little or no oral intake for more than 5– 0 days 4. Critically low electrolyte levels on admission (potassium, phosphate, and magnesium) 5. History of alcohol or drugs including insulin, chemotherapy, and diuretics

Question 47

How should patients are at particular risk of refeeding syndrome nutritional requirements be managed?

Answer 47

one-third for the first four to seven days of nutrition in a patient at risk of refeeding syndrome: ``` Electrolytes should be guided by frequent blood testing, and increased quantities likely to be needed in refeeding situation: • Sodium 1 mmol/kg/day. • Potassium 2–4 mmol/kg/day. • Phosphate 0.3–0.6 mmol/kg/day. • Magnesium 0.2 mmol/kg/day. ``` ``` Vitamins: • Intravenous thiamine and riboflavin: one to two pairs Pabrinex twice daily 30 minutes before starting feeding and continued for 10 days. • Supplement vitamins A, D, E, K, C. >> Trace elements: • Copper, zinc, selenium, manganese. >> Immunonutrition: • Glutamine 0.2 g/kg/day. ``` ICU dietician will work within the multidisciplinary team to optimise nutrition of this patient.

Question 48

Refeeding Managment

Answer 48

1. Start feeding at a maximum of 10kcal/ kg/ day increasing slowly to meet or exceed needs by day 4– 7 2. Restore circulatory volume and monitor fluid status carefully 3. For the first 10 days of feeding give either full dose IV vitamin B preparation (Pabrinex) or oral thiamine 200– 300mg daily with a balanced multivitamin and trace element supplement 4. Provide potassium, phosphate, and magnesium supplements daily, and monitor levels

Question 49

c) List the advantages of enteral nutrition.

Answer 49

Cheaper. Avoidance of line infections and the complications of line insertion. Reduced risk of stress ulceration. Maintenance of gut integrity, absorptive and immune function. Lower risk of hyperglycaemia. Reduced risk of abnormal liver function test results, hypertriglyceridaemia, metabolic acidosis, electrolyte imbalance and uraemia associated with parenteral feeding.

Question 50

Disadvantages of enteral nutrition.

Answer 50

May not be absorbed. May therefore result in malnutrition. Risk of aspiration and pneumonia. Necrosis and bleeding of nose or small bowel due to erosion by feeding tube (nasogastric, PEG or PEJ).

Question 51

Refeeding pathohphys

Answer 51

Chronic malnutrition causes depletion of electrolytes through reduced intake and utilisation for metabolism of fat and lipid stores. Serum electrolyte levels are maintained better than intracellular levels due to reduced energy for transmembrane pumping and reduced insulin-dependent pumping. Upon refeeding, there is a sudden insulin-driven uptake of glucose into cells and accompanying electrolytes. Serum levels of these ions, such as magnesium, phosphate, calcium and potassium, can drop precipitously. Also, cardiac muscle is weakened by chronic malnutrition. On refeeding, the circulating volume increases due to glucose-driven osmolality, risking heart failure. Weakened respiratory muscles must attempt to cope with increased carbon dioxide production as the body reverts to more carbohydrate-based metabolism (the respiratory quotient for a carbohydrate diet being 1, but 0.7 for fat- and 0.9 for protein-based diets, respectively). This may precipitate arrhythmias, seizures, respiratory failure, cardiac failure, coma, death.

Question 52

What is Refeeding syndrome

Answer 52

The potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving artificial refeeding (whether enterally or parenterally5). These shifts result from hormonal and metabolic changes and may cause serious clinical complications.

Question 53

D. List 6 clinical features of refeeding syndrome (6 marks)

Answer 53

1. Hypotension 2. Arrhythmias 3. Cardiac failure 4. Peripheral and pulmonary oedema 5. Lactic acidosis 6. Respiratory muscle weakness 7. Immune dysfunction 8. Seizures, coma 9. Neurological damage (e.g. Wernicke’s encephalopathy or Korsakoff ’s psychosis)

Question 54

A) List the effects of cigarette smoking on the cardiovascular system and on oxygen delivery (6 marks), outlining the pathophysiological mechanisms for each. (6 marks) CVS

Answer 54

Cardiovascular: 1. >> Hypertension: raised circulating catecholamine levels and accelerated atherosclerosis formation increase left ventricular afterload, resulting in left ventricular hypertrophy, diastolic dysfunction and, ultimately, heart failure. 2. >> Tachycardia: raised circulating catecholamine levels due to stimulation of nicotinic receptors. 3. >> Peripheral vascular disease: accelerated atherosclerosis formation. 4. >> Ischaemic heart disease: accelerated atherosclerosis formation and prothrombotic state (due to carbon monoxide, nicotine and other chemicals in cigarette smoke causing polycythaemia, enhanced platelet action, increased fibrinogen levels). 5. >> Heart failure: subsequent to infarction, ischaemia and cardiac muscle damage

Question 55

A) List the effects of cigarette smoking on the cardiovascular system and on oxygen delivery (6 marks), outlining the pathophysiological mechanisms for each. (6 marks)

Answer 55

1. Oxygen delivery: >> Airway conditions related to smoking that result in reduced oxygen availability within the alveolus and reduced effective gas exchange. Hypoxic hypoxia. 2. >> Carboxyhaemoglobin formation: haemoglobin has a 250-fold increased affinity for carbon monoxide compared to oxygen, thus reducing oxygen carriage. Anaemic hypoxia. 3. >> Shift of oxygen dissociation curve to left: carbon monoxide shifts the dissociation curve reducing the ability of hemoglobin to release oxygen. Anaemic hypoxia. 4. >> Inhibition of cytochrome oxidase by carbon monoxide, reducing oxygen dependent synthesis of ATP in mitochondria. Histotoxic hypoxia.

Question 56

``` b) List the effects of cigarette smoking on the respiratory system, other than those you have outlined above, that are relevant to the conduct of general anaesthesia. (4 marks) ```

Answer 56

1. >> Pre-existing airways disease as a result of smoking such as cancer, chronic obstructive pulmonary disease. 2. >> Increased upper airway irritability: breath-holding, laryngospasm at induction and instrumentation. 3. >> Increased lower airway reactivity, bronchospasm, mucus secretion. 4. >> Impaired mucociliary transport and secretion clearance: risk of atelectasis, postoperative pneumonia, shunt. 5. >> Accelerated rate of FEV1 reduction with age: significantly reduced level predictive of postoperative respiratory complications. 6. >> Increased closing capacity. 7. >> Increased risk of pulmonary embolism due to hypercoagulability: thromboembolic preventative measures to be taken.

Question 57

``` c) What advice would you give a smoker 24 hours before a scheduled procedure under general anaesthesia and why? (4 marks) ```

Answer 57

To stop smoking for the remaining 24 hours preoperatively and, ideally, to stop thereafter: 1. >> Circulating catecholamine levels return to normal within 1 hour and carboxyhaemoglobin clearance occurs within 24 hours, thus massively improving oxygen delivery to all tissues including the myocardium, reducing the risk of perioperative ischaemic event. As oxygen carriage improves, physiological reserve to cope with perioperative periods of inadvertent hypoxia improves. 2. >> Postoperatively, ongoing smoking is known to be associated with poor tissue healing, including wounds, anastomoses, flaps. Blood hypercoagulability will start to improve as carbon monoxide levels fall, reducing risk of postoperative thrombotic events.

Question 58

Describe the pathophysiology of evolving DCM

Answer 58

1. There is a progressive enlargement of one or both ventricles leading to reduced stroke volume 2. The dilated ventricles have low wall thickness to diameter ratio leading to increased wall stress, increased oxygen demand causing further systolic dysfunction 3. Ultimately leads to severe heart failure

Question 59

B. What are the clinical features of DCM?

Answer 59

1. Early stages may be asymptomatic 2. Signs of heart failure— dyspnoea, fatigue, ascites, peripheral oedema, tachycardia 3. Arrhythmia 4. Embolic events 5. Sudden death

Question 60

List 2 of the commonest causes of DCM in the UK (2 marks)

Answer 60

1. Idiopathic 2. Familial association 3. Postviral infection 4. Secondary to ischaemic heart disease or hypertension 5. Alcohol excess

Question 61

Drugs used in medical Mx of DCM and example

Answer 61

1. ACE inhibitor/ angiotensin 2 receptor antagonist Ramipril/ losartan 2. Beta- blocker Bisoprolol, carvedilol 3. Loop diuretic Furosemide 4. Aldosterone Inhibitor Spironolactone 5. Anticoagulant (If ejection fraction ≤ 30%) Aspirin, apixaban (NOAC)

Question 62

List 2 non- pharmacological options to manage advanced heart failure secondary to DCM

Answer 62

List 2 non- pharmacological options to manage advanced heart failure secondary to DCM (2 marks) 1. Partial left ventriculotomy 2. Left ventricular assist device 3. Implantable cardioverter defibrillator device 4. Cardiac transplantation

Question 63

List the cardiovascular goals when anaesthetising patient with DCM

Answer 63

1. Avoid myocardial depression 2. Avoid tachycardia 3. Maintain preload 4. Prevent increases in afterload 5. Prevent sudden hypotension by careful titration of anaesthetic agents

Question 64

Anaesthesia management:

Answer 64

1. The goals of anaesthesia management in patients with DCM are: • Avoid myocardial depression. • Maintain adequate preload and prevent increases in afterload. • Avoid tachycardia. • Prevent sudden hypotension by careful titration of anaesthetic agents. 2. Local and regional anaesthesia techniques: • Peripheral nerve blocks offer minimal haemodynamic changes. • Central neuraxial blockade reduces afterload and improves cardiac output. The accompanying hypotension resulting in myocardial hypoperfusion must be prevented.

Question 65

3. General anaesthesia and DCM

Answer 65

Avoid overdose of induction agents since the circulation time is impaired. • Etomidate causes least haemodynamic changes. • Ketamine should be avoided, as it increases the systemic vascular resistance (SVR). • Although propofol has a negative inotropic effect, it is useful in reducing the SVR. • All volatile anaesthetic agents cause myocardial depression in high concentration. • Opioids have minimal cardiovascular effect and reduce the requirement of anaesthetic agents.8

Question 66

Anaesthesia and DCM monitoring Support

Answer 66

4. Monitoring: • Arterial and central venous catheters should be used. • Transoesophageal echocardiography (TOE) provides a dynamic assessment of the myocardial function. * Oesophageal Doppler may be considered in the absence of TOE. * Bispectral index monitoring can be used to titrate anaesthetic agents. 5. Cardiovascular support: • Inotropic support can be provided by a variety of agents such as phosphodiesterase inhibitors, levosimendan dobutamine, and dopamine. • Noradrenaline can be used to treat hypotension, but care should be taken to prevent sudden increases in afterload. • Biventricular pacing and intra-aortic balloon pump may be considered in those with severe systolic dysfunction 6. Postoperative care: • Patients should be transferred to an intensive care unit to allow invasive monitoring and optimization of postoperative haemodynamics and fluid therapy. • Adequate analgesia reduces the deleterious effects of increased SV

Question 67

Predictors of poor outcome DCM

Answer 67

Predictors of poor outcome • Left ventricle ejection fraction <20% * Elevated left ventricle end-diastolic pressure (LVEDP) * Left ventricle hypokinesia * Non-sustained ventricular tachycardia

Question 68

Phantom limb pain

Answer 68

Phantom limb pain occurs as a result of nerve damage, resulting in changes to the nervous system at multiple locations, causing dysfunctional transmission of sensory information and abnormal pain perception. Peripheral nerves: 1) >> Upregulation of voltage gated sodium channels – spontaneous firing of damaged nerves peripherally or in dorsal root ganglion (DRG). 2) >> Neuroma development in damaged nerves that are sensitive to chemical or mechanical stimuli. 3) >> Neural injury due to amputation causes release of pro-inflammatory mediators that lower the activation thresholds of nociceptors. Spinal cord: 1) >> Aβ fibres from Rexed’s laminae III and IV sprout into Rexed’s laminae I and II due to the absence of input from C fibres from amputated limb – therefore, touch and pressure may be interpreted as pain. NMDA receptors are thought to have a critical role in this phenotypic change. 2 >> Sympathetic nerves sprout into the dorsal root ganglion, again stimulating pain pathways. Somatosensory cortex: 1) >> Errors in cortical remapping of the homunculus – over-amplification of pain experience, touch being interpreted as pain, pain being felt when other structures touched.

Question 69

9 a) Why might his pain control have become inadequate? | 5 marks

Answer 69

1 >> Failure of morphine delivery: check syringe full, pump working well, patient using pump well, cannula patent. 2 >> Acute pain: failure to manage acute pain due to e.g. development of infection, wound dehiscence, haematoma formation in stump. 3 >> Neuropathic pain: development of phantom limb pain. Phantom limb pain occurs as a result of nerve damage, resulting in changes to the nervous system at multiple locations, causing dysfunctional transmission of sensory information and abnormal pain perception. 4 >> Other pain source: major trauma victim – check for coexisting injuries.

Question 70

b) How would you re-establish | optimal pain control? (6 marks)

Answer 70

1 >> Assessment of pain, degree of psychological distress and physiological effect. 2 >> Intravenous morphine titrated to effect, with oxygen saturations, respiratory rate, heart rate and blood pressure monitoring. 3 >> Increase PCA bolus dose and hourly limit if considered safe to do so. 4 >> Multimodal approach: ensure regular paracetamol and NSAIDs, if appropriate. Consider gabapentinoid. 5 >> Consideration of addition of ketamine ivi (up to 15 mg/h) if difficulty re-establishing control. 6 >> Consideration of sciatic and femoral nerve blocks or even epidural if pain very severe and intractable.

Question 71

c) Which factors would suggest that this patient has phantom limb pain (PLP)? (3 marks)

Answer 71

1 >> Nature of pain: shooting, burning, cramping, aching. 2 >> Location of pain: distal to stump, associated with the missing leg. 3 >> Degree of pain: apparent disproportion between pain experienced and stimulus applied.

Question 72

d) What further pharmacological options are available for managing PLP? (6 marks)

Answer 72

As per NICE CG173: >> Amitriptyline is first-line treatment, moving on to any of the other three if ineffective/not tolerated. >> Duloxetine. >> Gabapentin. >> Pregabalin. >> Capsaicin cream if oral treatment not tolerated. >> (Tramadol use restricted to acute rescue therapy).

Question 73

10 a a) List the four commonest triggers for perioperative anaphylaxis according to The Royal College of Anaesthetists’ 6th National Audit Project (NAP6). (4 marks)

Answer 73

1. Antibiotics 2. Chorhexidine 3. Muscle relaxants 4. Patent blue dye (breast surgery)

Question 74

10 b b) What is the estimated incidence of perioperative anaphylaxis? (1 mark)

Answer 74

1:10 000 anaesthetics 1 Accept 1:10 000 – 1:12 0000

Question 75

c) Outline the pathophysiological process of anaphylaxis.

Answer 75

Anaphylaxis is an acute, potentially lethal, multisystem syndrome resulting from the sudden release of mast cell-, basophil-, and macrophage-derived mediators into the circulation. (See "Anaphylaxis: Emergency treatment".) ●Anaphylaxis can be classified as "immunologic" or "nonimmunologic." Immunologic anaphylaxis includes both immunoglobulin E (IgE)-mediated and immunoglobulin G (IgG)-mediated reactions (which have not been identified in humans), as well as immune complex/complement-mediated mechanisms. Nonimmunologic anaphylaxis is caused by agents or events that induce sudden, massive mast cell or basophil degranulation, without the involvement of antibodies. (See 'Proposed mechanisms' above.) ●In IgE-mediated anaphylaxis, the activation of mast cells, basophils, and eosinophils results in the release of preformed inflammatory mediators, including histamine, tryptase, chymase, heparin, histamine-releasing factor, and platelet-activating factor (PAF). Cellular activation also stimulates the production of lipid-derived mediators, such as prostaglandins and cysteinyl leukotrienes. (See 'Chemical mediators of anaphylaxis' above.) ●In humans, the predominant shock organs are the heart, lung, and vasculature, and fatalities are divided between circulatory collapse and respiratory arrest [70]. (See 'Organ systems in anaphylaxis' above.) * Anaphylaxis is associated with myocardial depression, arrhythmias, and myocardial ischemia. Contributing factors include direct mediator effects on the myocardium, exacerbation of pre-existing myocardial insufficiency by the hemodynamic stress of anaphylaxis, and exogenous or endogenous epinephrine. (See 'Cardiovascular system' above.) * Anaphylaxis may affect any part of the respiratory tract, causing bronchospasm and mucus plugging in the smaller airways and laryngeal edema and asphyxiation in the upper airway. Asphyxiation typically occurs rapidly after allergen exposure, with death occurring within one hour in many cases. Severe bronchospasm during anaphylaxis characteristically develops in individuals with pre-existing asthma. (See 'Respiratory system' above.)

Question 76

Describe your management of intraoperative anaphylaxis in an adult patient

Answer 76

A. Outline your immediate management (4 marks) 1. Declare critical incident and call for help 2. Use anaphylaxis emergency box 3. Stop administration of potential causative agent 4. Maintain airway and give 100% oxygen 5. Give epinephrine (adrenaline) 0.5mg IM adrenaline (0.5mls of 1:1,000). Alternately consider intravenous adrenaline which may be titrated to effect in small boluses if familiar with its use (e.g. 0.5– 1ml bolus of :0,000 and repeat to effect. Consider adrenaline infusion) 6. Rapid infusion of – 2L of crystalloid Hydrocortisone 200mg IV Give salbutamol and or magnesium for bronchospasm/ high airway pressures

Question 77

What should be done after successful treatment of anaphylaxis?

Answer 77

Bloods for mast cell tryptase as per protocols r/f to immunologist

Question 78

What is prehabilitation in perioperative medicine?

Answer 78

Prehabilitation is the process of enhancing an individual’s functional capacity to enable him or her to withstand a forthcoming stressor, e.g. major surgery. with the aim of improving postoperative outcomes

Question 79

What are the potential outcome benefits of prehabilitation?

Answer 79

reduced length of stay, less postoperative pain, fewer postoperative complications,

Question 80

What are the 4 main components of the multimodal approach to prehabilitation?

Answer 80

1. Medical optimization 2. Physical exercise 3. Nutritional support 4. Psychological support

Question 81

Which specific issues are addressed as part of medical optimisation in a prehabilitation programme?

Answer 81

• Preoperative smoking cessation, • Reduction in alcohol intake, and • Weight optimization benefit the patient in the postoperative period • Management of anaemia, • Control of blood glucose, • Pharmacological optimization to gain optimal control of chronic conditions such as chronic obstructive pulmonary disease, heart disease, hypertension, and diabetes.

Question 82

d) How will a prehabilitation exercise programme improve a pa tient’s cardiorespiratory physiology?

Answer 82

* The response to exercise is an increase in cardiac output, * Arteriovenous oxygen difference, and thus VO2max and stroke volume Skeletal muscle adaptations include increased mitochondrial content and oxygen uptake capacity. • Overall, functional reserve increases, permitting the patient to meet the increased metabolic demands of surgery and the postoperative period

Question 83

e) What are the benefits of carbohydrate preloading and nutritional optimisation? (4 marks)

Answer 83

* Reduces insulin resistance and * Promotes an anabolic state, * Minimizing loss of protein, lean body mass, and muscle function. * Taken a few hours before exercise, carbohydrates increase liver and muscle glycogen. * Immunonutrition, the ingestion of amino acids (e.g. glutamine and arginine), omega-3 fatty acids, and nucleotides counteracts the hyperinflammation and immune impairment caused by the surgical stress response, * Promoting wound healing, * Reducing infection rates, and shortening length of stay

Question 84

f) What psychologically supportive interventions may be used in prehabilitation? (2 marks)

Answer 84

* Cognitive interventions, e.g. development of positive attitudes, behavioural instruction * Relaxation techniques such as hypnosis and progressive muscle relaxation * Procedural information (i.e. details regarding all aspects of the patient journey) and * Emotion focused interventions involving the discussion of emotions. * Sensory information

Question 85

Question 12 What imaging modalities are recommended by The National Institute for Health and Care Excellence (NICE) in acute stroke? (1 mark)

Answer 85

Urgent non-contrast CT head scan.

Question 86

b) What specific treatments can be considered for acute thrombotic ischaemic strokes? (4 marks)

Answer 86

1• I.V. thrombolysis with alteplase within 4.5 hrs 2• Intra-arterial thrombolysis 3 Mechanical thrombectomy within 6 hrs 4 • Craniectomy

Question 87

c) In these patients what is the potential consequence of severe hypertension? (1 mark) What level of hypertension (systolic and diastolic) is regarded as severe after ischaemic stroke? (2 marks)

Answer 87

* There is an increased risk of haemorrhagic infarct. | * Severe hypertension is regarded as systolic AP >220 mm Hg or diastolic AP >110 mm Hg.

Question 88

d) A patient has had a large hemispheric infarction following a stroke. Outline your management of this patient following admission to critical care. (12 marks

Answer 88

Ventilation: Intubate immediately if signs of respiratory insufficiency or neurological deterioration. Mode of ventilation is at the clinicians discretion Aim for normocapnia (PaCO2 4.5–5.0 kPa) unless impending cerebral herniation * Sedation * Thrombolysis * Arterial pressure control MAP should be maintained >85 mm Hg Systolic pressure should be kept less than 220

Question 89

d) A patient has had a large hemispheric infarction following a stroke. Outline your management of this patient following admission to critical care. (

Answer 89

* Nutrition * Glycaemic control Maintain blood glucose 7.8–10 mmol litre−1 * Transfusion threshold 70 mg dl−1 recommended • DVT prophylaxis: Use intermittent pneumatic compression rather than stockings Prophylactic LMWH should be instituted early and continued as long as the patient remains immobile Early mobilization for haemodynamically stable patients

Question 90

d) A patient has had a large hemispheric infarction following a stroke. Outline your management of this patient following admission to critical care

Answer 90

• Temperature control :Initiate active cooling for pyrexial patients when core temperature reaches 37.5°C • Osmotherapy :Both mannitol and hypertonic saline are considered safe, choice should be based on renal function, serum sodium, and whether the patient will tolerate intravascular volume expansion * Patient position Nurse at 30° head up * Seizure prophylaxis is considered