An. Tech II Flashcards
Define pneumo peritoneum and the potential complications.
Presence of gas in abdominal cavity. Vasovagal Hypercarbia - acidosis Emphysema Capnothorax (gas goes into chest) CVS depression High airway pressure
Why is carbon dioxide the gas of choice?
Colourless - view
Non-flammable
Non-toxic
Highly soluble - cleared from body
How can high PaCO2 be managed?
Increase MV to expel more PCV to manage high P Consider AL to better manage Can ask for pneumo release Recruit more alveoli with PEEP Increase I:E
What is subcutaneous emphysema and pneumo-mediastinum?
Emphysema: gas trapped in skin layer
Mediastinum: gas in central area of chest cavity
Causes: misplaced insufflation needle, anatomical defect, high pressure gas dissects tissue
How is the airway and ventilation managed during laparoscopic surgery?
ET tube IPPV - PCV Avoid gastric distension during bag mask Treat hypercarbia Consider PEEP Don't use nitrous
What are the criteria for LMA use in laparoscopic procedures?
Not overweight No reflux Not long surgery Experienced surgeon and anaesthetic Second generation should be used to allow gastric drainage. Also have higher pressure seal.
Why is shoulder tip pain experienced?
Caused by diaphragm irritation
Small amount of gas may remain and irritate nerves on the diaphragm
Pain will pass as gas clears
What is an anterior resection?
Removal of rectum
What is a Hartmans procedure?
Removal of sigmoid colon with a colostomy
What is third spacing and the impact on fluid management?
Fluid shift into epithelial lined spaces - cannot participate in exchange, oedema
Dissected tissue increases permeability during laparotomy
Don’t fluid overload - encourage fluid to stay intravascular, fluid regime for optimal SV, give albumin if low
What are the mechanisms of heat loss during laparotomy?
No behavioural response Impaired thermoregulation system GA vasodilation Open exposure - evaporation Unwarned fluid/irrigation Dehydration reduces heat distribution Limited access for external warming
Methods to minimise heat loss.
Pre op warming Temp probe Theatre temp Only anaesthetic if >36 Use fluid warming Forced air warmers - wrap head Warm/humid airway gases Warmed irrigation Wound packing
What is an anastomosis?
A cross connection between adjacent tubular structures like bowels
Formed so bowels still function
If cannot form then stoma made
Indications for a NG tube
Reduce gastric distension to lower regurgitate risk
Prolonged procedures to drain excess
Evaluation of contents
Post-op drugs or feeding
Risks of NG tube
Lung insertion - pneumothorax, spasm Coiled tube Infection Tube entry to brain Perforated oesophagus or abscess Aspiration Epistaxis
Equipment for NG insertion
Correct sized NG Lube Laryngoscope Magills? Catheter tip syringe and bag NG securing tape Suction at hand Checking equipment
How can correct placement of NG be checked?
Aspirating and pH test (<6)
Appearance of content
X-ray
What is bone cement implantation syndrome?
Methyl methacrylate
Causes hypoxia and CVS collapse
Likely from fat/air embolus or cement toxin itself
Cement causes high intramedullary pressure which can force fat into circulation
How are cementing risks minimised?
Introduce prosthesis slowly Use suction to drain fat and air Avoid cement where possible Thoroughly lovage the shaft Use a venting hole Use cement restrictors to reduce pressure Work cement well to remove vasodilator compounds Use low viscosity cement
What is reaming and the complications?
Enlarges the size of the hole leaving smooth sides for ease of prosthesis insertion
Fat embolism syndrome: respiratory, neurological and petechial rash
ARDS
Maximum tourniquet time and risks of time extending?
Arm: 90min
Leg: 120min
Pain wind up
Ischemia
Toxic build up
Emboli formation
What can happen on tourniquet release?
Sudden bradycardia and hypotension
Washout of metabolic waste causes this
How is tourniquet inflation based on BP?
Helps to ensure adequate prevention of blood flow and reduce injury
Arm: systolic + 50
Leg: 2x systolic
What’s the diagnosis of compartment syndrome?
Occurs when circulation and tissue in a closed space is compromised by increased pressure resulting in ischemia and necrosis
Needle and transducer into compartment
If within 30mmHg of diastolic pressure it’s confirmed
Cause, risk and treatment of compartment syndrome.
Limb injury, limb surgery, tourniquet, crush, mal positioning, hypotension, haemorrhage, oedema, drugs
Test pressure, keep limb at heart level, fasciotomy and splint limb, ensure hydration and oxygen
What is a serious bone infection and ways to minimise?
Osteomyelitis
Sterile AB prophylaxis Pre op wash Remove any FB Stringent wash out Frequent change dressings Minimal OT movement, masks
How does Lloyd Davis differ from lithotomy?
Lloyd Davis (trendelenberg with legs apart) is supine with legs flexed and head down 30 degrees. Legs in stirrups Lithotomy is supine, legs apart, flexed in stirrups but no head down.
Why move patients legs simultaneously with Lloyd Davis and lithotomy?
To prevent torsion of the spine and large vessels. Also reduce incidence of muscle, nerve and soft tissue injury. Nerve is lumbosacral plexus
What equipment should be available for a pregnant patient?
DI equipment RSI Care with moving and positioning - tilt? Care with drugs!! Consider thiopentone and antacids
Why might hypotensive anaesthesia be requested during ear surgery?
Allows bloodless operative field Improves view Potent opioid cover, head tilt up, hypotensive drugs Aim MAP 50-60 Consider art line
How can hypotensive anaesthesia be achieved?
Remifentanyl infusion Beta blockers Vasodilators Labetalol increments Alpha adrenergic agonist High dose inhalation agent
Why is nitrous oxide contraindicated in ear surgery?
Causes raised middle ear pressure which can damage compromised structures and lift grafts. It can also cause pain, hearing loss and bleeding. This is due to rapid diffusion of nitrous into air contained spaces. Nitrous also has high PONV which could cause post op damage from raising pressures
Why is PONV common after ear surgery and how can it be managed?
Ear contains vestibular system which communicates to brain regarding dizziness, balance, nausea and vomiting. Any disturbance can trigger the system. Prophylactic antiemetic should be given during op and charted for post op.
Raised middle ear pressure also contributes as does hypotension.
Why are nasal mucosa preps used prior to surgery?
Vasoconstrict vessels to prevent bleeding and therefore enhance the surgical view
What are common Nadal mucosal agents?
Cocaine paste Adrenaline Xylometazoline Co-phenylcaine Moffet's solution (cocaine, adrenaline and sodium bicarbonate)
Justify the use of throat packs.
Absorb blood, irrigation and secretions
Stop airway irritation
Prevents pooling
Ensure removed!!
Strategies to prevent throat pack retention
Stickers
Verbal communication
Nurses count
Accept only when seen
Why is reverse trendelenberg used for nasal surgery?
Allows blood and secretions to run out of the space and be collected in throat pack
Why is nasal packing used?
Reduce bleeding and stops it from going down throat
Keeps altered structure open and prevents their collapse
Remind patients to mouth breathe
How can increased laryngospam risk be managed in nasal patients?
Due to irritation from blood running down throat
Anaesthetist should use suction/catheter under laryngoscope to remove majority
Extubate deep or well awake
PACU should monitor closely, provide continued low suction and keep patients on their side, head down
What are the airway options for laser surgery of the cords?
Jet ventilation with low oxygen percent and TIVA
Intermittent bursts to maintain saturation
Laser tube if airway needs securing
30% O2 best choice
SV patient using high pressure oxygen eg opti flow
What are the causes of airway fires?
Plastic/rubber ignite under heat
Antiseptic solutions are flammable
Ignition due to oxygen in high conc
Laser heat
Immediate treatment of airway fire
Flood with saline Reduce/stop oxygen Remove tube Ventilate with 100% oxygen Perform laryngoscope to remove debri Reintubate or perform tracheostomy
Strategies to minimise fire risk
Correct equipment eg laser tube Low oxygen Laser small bursts only Jug of water Soaked swabs on surrounded tissue No skin prep or ensure dried Adequate smoke evacuator Pre test laser Ensure no leak around cuff If >30% o2 then metal suction and wait 1 min
Describe jet ventilator
Device with cannula which connects to the airway
Can select oxygen % and pressure
Trigger allows gas flow
High flow oxygen creates Venturi effect entraining air
Expiration is passive
What are the pre use checks of a jet ventilator
Check oxygen/air contents Check pressure adjustable and on correct setting Check trigger function Check connection to cannula Test cannula with gas flow Check for any leaks
Why is a tonsil post op bleed potentially lethal?
Large amount of blood loss - hypovalaemia
Aspiration risk from blood in stomach
Laryngoscope and intubation becomes exceptionally difficult - blood and oedema
Residual anaesthetic effects?
What are the anaesthetic considerations for a bleeding tonsil?
Get help - senior RSI DI trolley, video scope, f/o Gastric tube remove stomach blood once secure Consider residual anaesthetic Lots of suction - consider catheter Hb check Consider intubation in left lateral/head down
What is the surgical tonsil position?
(Rose position) Supine with bolster under shoulders to extend head and neck Optimal view Allows boyles Davis gag Reduced secretions down airway
What is the post tonsillectomy position?
(Side lying position)
Left lateral and head down
Facilitate drainage and allows visual cue of bleeding
Reduces airway irritation
What’s a coroners clot?
Retained clot in nasopharynx which can be aspirates and close off the airway. Potential from any ENT procedure. Must be checked via laryngoscope and deemed clear