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
What are the anaesthetic consideration for FB in lungs?
Rigid bronchoscope Inhalation induction 100% O2 Topicalise cords Jet vent or intubate Consider drying agent Allow SV where possible IPPV only if obstruction in lower airway
Why are trauma patients considered unfasted?
Sympathetic stimulation from high stress causes a halt in the parasympathetic ie digestion
Opioids delay gastric emptying
How should patient belongings be handled if police involved?
Remove with gloves
Separate sealed, labelled bags
Details regarding where each item located
Ensure not further damaged
Why must care be taken inserting nasal devices in a head injury?
In case of a base of skull fracture
Could allow device to intrude into brain tissue
Any other injuries which may have disrupted the normal nasal path
Why must BP and IV be kept away from previous breast surgery side?
Always if have had node clearance Puts patient at risk of lymphoedema BP will change fluid placement and compromise drainage IV fluid will collect in limb Keep away - consider feet/legs
What must be considered when arms are out on boards?
No more than 90 degrees
Brachial plexus injury
Strain/tear shoulder structures
What are the risks of long surgeries?
Normothermia Pressure injury DVT Cuff pressure Eye care Fluid management Rotate monitoring
Why might papaverine be used in plastics?
Can be applied directly to vessels to prevent then spasming thereby allowing careful and precise surgery. Ensures perfusion at site so improving tissue survival
What is the TURP solution and why?
Glycine 1.5% in water
Dis tends bladder and irrigates dissected tissue away
What is the treatment of TURP syndrome?
Stop surgery Stop fluids Secure airway if needed Treat seizures Give furosemide Check Na and Hb Give hypertonic saline and diuretic Admit to ICU/HDU
What is the common urology AB?
Gentamicin slow IV
It’s an aminoglycoside gram negative
Often followed by cefuroxine 8 hourly
What is artheroscleroma?
Plaques or lesions on arterial walls causing narrow and hard wall
Usually from injury which gets infected
Plaques may grow and impede flow
Risk: MI, IHD, sudden death, stroke,
Why is arterial clamping times?
Prevents blood flow so prolonged time could cause ischemia and tissue death. Timer helps to prevent
Usually up to 1 hour
What are the anaesthetic considerations during clamping?
Ensure cardiac output monitoring
Don’t heat lower body
May get proximal hypertension
Metabolic acidosis may develop - ABG and MV inc
Begin fluid to increase CVP to prep for de-clamp
Monitor urine as renal failure possible
What are the anaesthetic considerations at de-clamping?
Reverse heparin Prepare for cvs instability Watch for sudden hypotension- adrenaline Manage effects of metabolic wastes Potential for bleeding
How is perfusion still maintained during aortic clamping?
Prescribed time
Bypass and cannulation flow back into femoral vessels
Hypothermia preserves by slowing down metabolism
What are the anaesthetic options for a carotid?
Cervical plexus block with sedation
GA with ET - perfusion monitor
Art line
Why is warming reduced during clamping?
Can increase metabolism thereby increasing ischemia
Non-moving circulation increases burns risk
What’s an AV fistula and what care must be taken with monitoring?
Arteriovenous fistula
Connection between artery and vein for haemodialysis
BP away as could cause clot to form or rupture
Cannulate away to prevent damage
What are the conditions of a cardio version?
Must have a TOE or on anticoagulant for certain time. NIBP and sats. Sedate
AF, atrial flutter
Three reasons for elective Caesarian
Placenta pre via
Pre eclampsia
Genital herpes
What may cause an emergency Caesar?
Irregular fetal HR Prolapsed cord Amniotic fluid embolus PPH Poor contractions won't open cervix Baby position Sick mother
What’s the positioning for a pregnant patient and why?
Left lateral tilt
Baby weight compresses inferior vena cava and aorta causing CVS compromise
Reduces onset of early hypotension following spinal
Why are pregnant women high risk airways?
Pressure on organs creates reflux
High progesterone delays gastric emptying
Higher oxygen demand due to baby metabolism also
Reduced compliance from baby
Reduced oesophageal sphincter time
Total body water increases causing oedema
Overweight and large breasts
What are the laryngoscopes for obstetrics?
Kessel: 110 manipulate around chest
Polio: 135 as above
Video laryngoscope
What is Mendelson syndrome?
Peptic-aspiration pneumonia
Chemical pneumonitis caused by aspiration during anaesthesia particularly in pregnancy
What is the recommended ranitidine dose for obstetrics patients?
150mg oral 12 and 2 hour pre op
How does syntocin work?
Stimulates uterine smooth muscle to contract by triggering calcium release
Rhythmic contractions of upper uterus
Stimulates cells surrounding mammary alveoli facilitating breast feeding
Differentiate neonate, infant and child.
Neonate less than 4 weeks
Infant less than 1 year
Child 1-12 year
How is temperature regulated and maintained in infants?
Achieve heat by metabolism of brown fat. This is found on back, shoulders legs and thoracic vessels. High amount of energy used in process. Prem babies don’t have brown fat
Why is fluid balance so important in paeds?
Have small total volume so overload easily
High water turnover meaning daily losses are high. A small loss can become dehydration
What is the paed fasting guidelines?
Clear fluid including electrolyte drink: 2hr
Breast milk: 4hr
Food and formula: 6hr
Why is dead space important in paeds?
Volume that doesn’t participate in gas exchange
Small TV so dead space makes big difference
Can cause inc PaCO2 and if too large the CO2 won’t be able to clear at all
Minimal dead space needed
What are the formulas for tube size, tube depth and body weights?
Age/4+4
Lip: age/2+12
Nostril: age/2+15
Agex2+9
Why extubate paediatrics deep?
High rate of laryngospam due to irritation
Remove tube deep but breathing prevents this from happening
What is a peribulbar block?
Needle through skin near inferior orbital rim
Needle advanced parallel to globe and injected
Pressure device helps spread local
What is a subtenon block?
Conjunctiva is lifted and incised and dissected between sclera and capsule
Needle advanced following globe shape and injected
What are complications of eye blocks?
Perforated globe Trauma Nerve damage Bleeding Iv injection Chemosis Central retinal artery occlusion Infection
What is IOP important in open eye injury?
A raise in IOP may cause extrusion of humerus, bleeding or lens prolapse. Normal activities may cause a rise
May cause a reflex where bradycardia results
What is an occulocardiac reflex?
Relates to parasympathetic activation from traction or compression on the eye and causes bradycardia
How are burn severity classified?
By which skin layer is affected and the appearance
1-4
What is the rule of mines?
Method to assess surface area of burn for a second and third degree burn 4.5% each side head 18% front trunk (9 top/9 bottom) 18% back trunk (9top/9 bottom) 9% each arm 18% each leg 1% genitals
What are the anaesthetic consideration for burns patient who inhaled smoke?
Assume carbon monoxide poisoning High flows O2 Low TV and high PEEP Don't overdo fluid Watch for bronchospasm Prepare for DI manage temp
What are options for tube tie and monitoring with burns?
Don’t monitor over burns alternatives: ear probe, art line
Tube: tie with suture to incisors, maxillary screws, bandage face first, orthodontic bracket
Why aren’t depolarising relaxants used in burns?
Cause skeletal muscle to release potassium
Burns cause skin release of potassium resulting in hyperkalaemic state already
Can cause arrest
What are common problems with burns patients?
Dehydration, hyperkalaemic, oedema, hypotension, hypovalaemia, hypothermia, infection, contractures, systemic inflammatory response syndrome and multiple organ dysfunction syndrome
What is the purpose of bypass?
Replaces function of heart and lungs while heart is arrested to allow optimal surgical field
Why is heparin used on bypass?
Ensure clots cannot form when blood is in contact with the surfaces of the bypass machine and tubing
What test can measure heparin and the desired levels?
Act: activated clotting time
>480secs for bypass
Assess baseline prior to bypass, ensure correct amount for bypass and tested again to ensure returned to normal
What is the antagonist of heparin and how does it work?
Protamine
Binds to heparin resulting in harmless salt so cannot block the clotting cascade anymore
What are the purposes of cardioplegia?
High in potassium
Arrests the heart
Myocardial cooling which preserves the tissue
Added sodium bicarbonate
Reduces ionic disturbances and acidosis which occurs from ischemia
What are the risks of a sternotomy?
Infection Arrhythmia - stimulus Stern all instability - move when cough etc Brachial plexus injury from retraction Blood pressure surge - stimulus Lung or heart trauma
How can sternotomy risks be reduced?
Deep anaesthesia
Potent opioid cover
Deflate lungs (vent off)
Why are patients cooled during bypass and what temperature?
Reduces myocardial metabolism to preserve tissue health during ischemia
Also other body parts
28-34 degrees
Why are cardiac patients kept intubated and ventilated post op?
High risk complications
Ventilator assists venous return and reduces work of the heart and strain from stress
What is tamponade and the treatment?
Fluid or gas accumulates in pericardium compressing the heart thereby reducing its ability to fill and contract
Ultrasound guided needle aspiration
Surgical thoracotomy
What are four inotropes used in cardiac surgery?
Dobutamine: increase CO and treat shock
Noradrenaline: treat severe hypotension
Digoxin: treat arrhythmia
Calcium: improve contractility
Describe swan ganz including position and methods of measurement.
Pulmonary artery catheter Floats in PA Can detect heart failure, sepsis, drug effects, mixed venous oximetry, CO, RA P, RV P and filling P of LA. Can be transduced to show waveform Thermodilution
What is quiet lung surgery?
Collapse of operative lung using DLT
Optimal surgical field and reduces complications
What equipment is needed to place a DLT?
F/O with accessories - guide and confirm placement
Clamp - shut each tube to check placement with auscultation and chest rise
Syringes - 3ml bronchial
Stethoscope - listen
What is the purpose of a chest drain in cardio-thoracic surgery?
Allows blood, fluid and gas to escape
Keeps clear field
Prevents post op TP or tamponade
Helps reinflate collapsed lung
What is the problem with a cheat drain disconnect?
Air may enter pleural space causing pneumothorax and contamination
Keep clamped and take an X-ray if disconnected
What is the significance of raised ICP in head injury?
May indicate internal bleed and pressure on the brain
Emergency surgery
What is coughing avoided in neurosurgery?
Increases venous pressure which increase ICP which could cause injury or undo surgery
What’s a first degree heart block?
Delay in conduction between atria and ventricles
Prolonged PR
What is a second degree mobitz type one ECG?
The PR interval increases until a QRS complex randomly is missed
What is a second degree mobitz type two block?
PR interval remains consistent but some QRS are blocked
What is a third degree heart block?
No conduction between atria and ventricles
Regular P and regular QRS but no relationship
Random complexes
What are ventricular ectopics?
Wide, bizarre QRS complex
What are premature atrial ectopics?
Ectopic P wave before next sinus beat
P looks different
What is a junctional rhythm?
P wave either not seen, inverted or hidden by QRS
Comes from junctional area and not normal SA node
What is a supraventricular tachycardia?
Normal QRS with a rate above 160bpm
What is an atrial flutter and atrial fibrillation?
Flutter: atrial rate around 300bpm with saw toothed appearance, regular QRS
Fib: 400bpm with wavy line, irregular QRS
What is VT and VF?
VT: wide QRS, P not seen, may be pulse less
VF: no obvious complexes, wavy line
What rhythms are shockable?
VF and VT
What is precordial thump?
Useful in pulse less VT if defibrillator not available
Single sharp blow to mid sternum
Why use a swan ganz in cardiac?
Diagnose heart failure, sepsis, shock, tamponade
Drug therapy analysis
Analysis of each section of the heart
What is dobutamine used for in cardiac?
Treatment of acute heart failure brought on from surgery
Beta1 agonist
