RCOA March 2019 Flashcards
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
- Consent from parents
- Fasting
- Induction: IV or gas
- Venous access may be challenging
- Patient anxiety/ lack of cooperation
- Consider premedication: both topical local anaesthetic to hands and anxiolytic if indicated
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
(4 marks)
1. Brisk oculocardiac reflex
- Postoperative nausea and vomiting
- Operation site close to the airway
- Increased risk of rare muscle problems presenting for the 1st time (e.g. muscular dystrophies)
- Raised risk of malignant hyperpyrexia in this patient group
- Unpredictable response to non- depolarizing muscle relaxants (NDMR)
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
- Postoperative nausea and vomiting associated with this procedure occasionally results in unplanned overnight admission.
- Suitability for day case surgery - comorbs
- 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
How would you manage profound bradycardia during surgical traction?
- Ask the surgeon to stop immediately
- Ask for senior help
- Give atropine 20 mcg/ kg
- If no response, elevate arm, flush IV, and start cardiac compressions
What strategies would you employ to reduce postoperative nausea and vomiting (4 marks)
- Prophylactic antiemetic,
e. g. ondansetron 0.15mg/ kg +/ – dexamethasone - 15mg/ kg Combination increases efficacy
- Rescue antiemetic
e.g. IV dexamethasone 0.15mg/ kg
slow IV or droperidol 0.025mg/ kg
No benefit to repeat ondansetron
- Ensure fluid balance and minimize fasting time
- Acupuncture point P6 stimulation
What strategies would you employ to reduce and postoperative pain? (3 marks)
1.Intraoperative paracetamol
15– 20mg/ kg
- Diclofenac
1mg/ kg - Local anaesthetic infiltration by surgeon intraoperatively
- Avoidance of Opioids
- Consideration for subtenons block
What strategies would you employ to reduce Recovery room distress
Recovery room distress
- Reunite with parents early to manage distress and
anxiety - Treat or exclude pain
- Distraction with play therapist
- a) List three of the commonest causes of end
stage renal failure (ESRF) in the United Kingdom
- Diabetes mellitus
- Glomerulonephritis
- Hypertension
- Polycystic kidney disease
- Pyelonephritis
- Renal vascular disease
- b) What complications of ESRF are of importance to the anaesthetist?
????
- 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.
- Respiratory
Increased risk of fluid overload / effusions
- b) What complications of ESRF are of importance to the anaesthetist?
- 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
- 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.
- b) What complications of ESRF are of importance to the anaesthetist?
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.)
- b) What complications of ESRF are of importance to the anaesthetist?
Pharmacology
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.
1 c) What acute physiological disturbances may be seen in a patient who has just had haemodialysis? (3 marks)
- Intravascular depletion/ hypovolaemia
- Possible residual anticoagulation
- Hypothermia
- Electrolyte rapid correction
1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)
- 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
- 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.
1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)
- Never place a central line in the same extremity where the arteriovenous access (primary AV fistula or GORE-TEX® graft) is present.
- 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
- Avoid drugs with potential nephrotoxicity in ARF patients; modify doses of medications according to reduced renal function
1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)
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.
1 d) What are the key practical considerations when providing general anaesthesia for a patient with ESRF on haemodialysis? (8 marks)
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
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)
1»_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»_space; Hyperventilation
of mother causing hypocarbia can cause uterine artery vasoconstriction, poor perfusion and leftward shift of maternal oxyhaemaglobin dissociation curve.
3»_space; Hypoperfusion:
fetoplacental unit entirely dependent on maternal perfusing pressure. Therefore, it is necessary to maintain maternal blood
pressure and manage aortocaval compression.
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)
4»_space; As yet unconfirmed/unquantified anaesthetic-induced neuronal apoptosis in developing brain.
5»_space; Risk of miscarriage –
unquantified. Likely to have more to do with the
disease process necessitating the surgery or the surgery itself
b) How can the risks to the foetus be minimised? (10 marks)
- > > Defer surgery until after
delivery unless absolutely necessary. - > > Multidisciplinary approach,
involve obstetricians in the assessment of
pre- and postoperative maternal and fetal well-being.
3»_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.
b) How can the risks to the foetus be minimised? (10 marks)
> > 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.
c) What additional preoperative and intraoperative steps would you take to ensure foetal safety if she is 27 weeks pregnant instead? (5 marks)
> > 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.
a) What airway risk factors may indicate a difficult extubation?
- Known difficult airway
- Airway deterioration (trauma, oedema or bleeding)
- Restricted airway access
- Obesity / OSA
- Aspiration risk
b) What factors (patient and other) can you optimise prior to extubation? (5 marks)
Patient
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.
b) What factors (patient and other) can you optimise prior to extubation? (5 marks)
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.
c) What strategies could you employ to manage a high risk extubation?
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.
d) Outline the steps you would take to exchange an endotracheal tube to a supraglottic airway device (SAD) to aid extubation. (6 marks)
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
At risk techniques
Awake
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:
At risk techniques
Bailey manoeuvre
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
At risk techniques
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.
Sequence for use of a remifentanil infusion for ‘at-risk’ extubation.
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
Sequence for use of an airway exchange catheter for ‘at-risk’ extubation.
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
Sequence for use of an airway exchange catheter for reintubation.
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
Treatment of laryngospasm
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
What anaesthetic techniques
can be used to allow a tubeless field for laryngeal surgery? (5 marks)
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.
How can the risk of an airway fire be minimised?
> > 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
