Anaesthesia Flashcards
1
Q
What are 5 ways to confirm placement of an endotracheal tube?
A
End tidal CO2 Direct visualization Misting in tube Auscultation (both sides!) Symmetrical rise and fall of chest?
2
Q
What is the acronym for the preparation to intubate?
A
MS MAiD
Machine
Suction
Monitor
Airway
IV
Drugs
3
Q
How do you decide if a patient needs further cardiac work up before an operation
A
Assess risk factors, then consider METs; if able to tolerate 4 or more (ie mild-moderate activity) can proceed w/o workup
4
Q
What are the risk factors for PONV?
A
Female gender
Younger patient
Non smoker.
Ocular/vestibular and Tyne procedures
5
Q
What are some options to help with PONV?
A
Dexamethasone (0.1 mg / kg day)
Odansetron (4mg)
Haldol (1-2mg)
Benzos or propofol, if refractory
6
Q
What do you want to check before you extubate?
A
Patient must be hemodynamically stable
Properly oxygenating
Breathing on their own
Eyes open / signs of awareness
7
Q
What would explain a sudden drop in end-tidal CO2
A
Low cardiac output (check BP)
8
Q
What are the risk factors for malignant hyperthermia?
A
FH of malignant hyperthermia or previous hx of it (ie mutation to ryanodine receptors)
9
Q
What are early signs of Malignant hyperthermia
A
Sudden increase in end tidal CO2, muscle rigidity, mixed metabolic and resp acidosis, tachycardia, tachypnea, unstable BP, masséter spasm
10
Q
What are late signs of malignant hyperthermia?
A
Sudden increase in body temperature, CK above 10,000 , hyperkalemia >6, DIC
11
Q
What elements of the ROS should be emphasized in the preop assessment?
A
CV Resp Renal dysfunction Neuro Endocrine Coagulopathy Cancer Msk affecting esp c spine
12
Q
What elements are important to elicit on preop history?
A
Previous hx of any issues with anaesthesia or FH of issues with anaesthesia, difficult intubation, difficult IV access, post op n/v
13
Q
What are the major changes to the maternal physiology that impact pregnancy?
A
Delayed gastric emptying ( increased risk of aspiration )
Aortocaval compression
Decreased FRC
Increased mucous secretions, more difficult airway (controvertial)
14
Q
What are the nonpharm options for control of pain in labour?
A
Tens, hydrotherapy, hypnosis, breathing exercises, prenatal classes.
15
Q
What pharmacological management is available to labouring patients?
A
Nitrous oxide
Opioids
Neuraxial anaesthesia (spinal, epidural)
Pudendal, paracervical blocks
16
Q
What are some maternal potential side effects to opioid anaesthesia in labour?
A
Pruritis, resp depression, nausea, constipation, venodilation
17
Q
What are potential fetal effects of opioid anaesthesia in labour?
A
Resp depression, reduced variability beat to beat in FHR, sedation
18
Q
What is the difference between spinal and epidural blocks? (Location, onset, side effects)
A
Location: epidural is in epidural space, spinal is into the canal below L2/L3 (below the conus medullaris)
Onset - epidural takes 15 min, spinal much quicker (within 5 minutes)
Side effects: greater risk of hypotension and headache with epidural.
19
Q
What are the contraindications to obstetrical anaesthesia?
A
Severe hypotension or hemodynamic instability Infection or sepsis Coagulopathy Low cardiac output Increased ICP
20
Q
What are common complications for spinal / epidural anaesthesia? (6)
A
Hypotension w w/o bradycardia Fetal bradycardia Headache Ineffective block Pruritis N/V
21
Q
What are the typical onset, distribution and associated symptoms of postural puncture headache? How is the pain affected by positioning?
A
Onset: 24-48hrs post puncture
Distribution: Fronto-occipital
Associated symptoms include tinnitus and diplopia.
Positioning: Worse upright and better supine
22
Q
What are the management options for post-puncture headache? What can you do if pharm & non pharm options fail?
A
Encourage bed-rest & supine positioning + adequate hydration.
Pharmacological management includes caffeine or analgesics including acetaminophen, NSAIDs, opioids.
Can offer epidural blood patch if above options don’t work.
23
Q
What are the triggers (3) of malignant hyperthermia?
A
Inhalantional agents (sevoflurane etc.)
Succinylcholine
Phenothiazines
24
Q
What underlying patient conditions must you consider on your differential when you are worried about potential malignant hyperthermia (6)?
A
diabetic coma, hyperthyroidism, neuroleptic malignant syndrome, muscular dystrophies, myotonia, osteogenesis imperfecta
25
What acquired (5) and intraoperative (4) issues can be confused with malignant hyperthermia?
Acquired: anaphylaxis, heat stroke, transfusion reaction, alcohol withdrawal, sepsis
Intraop issues: heat transfer imbalance, equipment malfunction, hypoventilation, insufficient anaesthesia.
26
How do you manage malignant hyperthermia?
Discontinue any anaesthetic agents ASAP
Hyperventilate 100% O2 with as high a flow as possible
Dantrolene (2.5mg/kg IV q10min up to 10 mg/kg)
Bicarb (for hyperkalemia)
Active cooling
Monitor urine + vitals
Order CK, ABG, Electrolytes, INR/PTT, fibrinogen.
27
What is plasma cholinesterase deficiency?
Enzyme activity that degrades succinylcholine is low, so delayed awakening following anaesthesia with succinylcholine.
28
What is the acronym for causes of difficult bag-mask ventilation?`
```
ROMAN
Radiation or restriction
Obstruction (think obesity and OSA)
Mask (beard) or Mallampati
Age >55
No teeth
```
29
What are the 5 elements you want to evaluate in the airway assessment?
Inspect externally for trauma, congenital deformities, neck mass or retrognathia. Listen for hoarseness or stridor.
332 rule (3-finger mouth opening, 3 finger hyoid mentum distance, 2 finger thyroid/thyroid cartilage distance
Mallampati score (stick tongue out)
Obesity/OSA
Neck mobility
30
What are the 3 major causes of airway emergency?
1. inadequate ventilation
2. esophageal intubation
3. difficult tracheal intubation (prolonged apnea, trauma)
31
Under what circumstances is it appropriate to order pre-op CBC?
age >65 w major surgery
or large expected blood loss
or neuraxial anaesthesia (want to establish PLT count)
32
Under what circumstances do you assess renal function pre-op?
Age >50, intermediate/high risk surgery. Risk of hypotension, or use of nephrotoxic meds
33
When do you order pre-op ECG?
Known heart disesase or PAD esp if patients symptomatic
34
When do you order pre-op CXR?
>50 + AAA repair / thoracic surgery or cardiopulmonary disease
BMI >40
35
What are the 6 levels of the ASA classification
1. healthy, no comorbidities
2. mild systemic disease or pregnancy
3. moderate systemic disease with some functional limitation
4. severe disease that is a threat to life (end-stage conditions)
5. not expected to survive w/o operation
6. functionally brain-dead organ donor
36
What should you advise patients in terms of NPO?
Nothing heavy for at least 8 hrs pre op
6 hrs light meal, low protein/fat
4 hours breast milk
2 hours clear fluids.
37
How do you manage T2DM perioperatively?
check pre/post sugars
hold oral meds on day of operation
Treat with insulin as needed
Resume oral meds once eating wel
38
What cardiac medications should be held on the day of surgery?
ACE-I or ARB (case-by-case), Diuretics
39
How do you change steroid therapy perioperatively?
Continue unless >3weeks therapy, then consider dose modification as appropriate.
40
What medications that affect hemostasis should be stopped before surgery?
ASA (discuss with cardiology if need be), clopidogrel, ticagrelor, prasugrel or ticlodipine, warfarin, dabigatran, or rivaroxibran.
For ASA, stop 7 days, warfarin hold 5 days, oral anticoagulants can be held 2-3days preop
41
What psychiatric medications should be held preop?
MAOIs (need discussion with psychiatry and MAOI safe technique), antipsychotics (QTc prolongation, need ECG), psychotimulants
42
What rheumatological agents need to be held before surgery?
Everything except hydroxychloroquine and methotrexate
43
What herbal supplements should be discontinued prior to surgery?
ephedra (ma huang), garlic, ginko, ginseng, kava, St. John's Wort, Valerian and Echinacea
44
What is the approach to the obstructed airway?
1 Reposition patient flat and supine
2. Head tilt, jaw thrust and chin lift
3. Prep in case you need to insert an airway.
45
What are the options for securing the upper airway and respective contraindications?
Oropharyngeal airway - can't use if they have a gag reflex or there's a foreign body
Nasopharyngeal airway - cna't use if there is nasal fracture, bleeding or coagulopathy
46
Describe how to hold the face and jaw in order to create a good seal for bag-mask ventilation
Hook the 5th finger around the angle of the jaw and use it to move the mandible forward (jaw thrust), and position 3rd and 4th fingers under the chin for a chin lift / head tilt. Hold the mask with index and thumb. Squeeze the bag with the dominant hand
47
What are the indications and contraindications of the LMA?
Indications: short procedure, as a rescue device if intubation fails or to secure the airway outside of hospital
Contraindicated if can't open mouth, at increased risk of aspiration or there is infraglottic obstruction, patient is prone or there is a need for high ventilator pressures.
48
When should you consider rapid-sequence induction?
Non-fasted patient.
Pregnancy, severe diabetes or other condition causing delayed gastric emptying such as bowel obstruction
Severe GERD
49
How does rapid-sequence induction differ from standard induction?
Key is "skip" bag-mask ventilation and go quickly from fully conscious patient in control of their airway to intubation. Differs in that the induction occurs through pre-selected IV bolus + rapid acting muscle relaxant
Cricoid pressure used to "seal" esophagus (controvertial if needed...)
50
What is the most important contraindication to rapid-sequence induction?
Patients with anticipated difficult airway
51
How do you respond to a Can't Intubate / Can't Oxygenate situation?
Call for help, Attempt LMA
Bag-mask, jaw thrust to maintain ventilation
reawaken patient.
Try to avoid by planning ahead.
52
How do you recognize airway obstruction?
Resp < 8 or > 30 / min
O2Sat < 90 on 50% > 6 L /min
Stridor / Secretions / Drooling / Laryngospasm
53
How to manage laryngospasm?
```
Call for help
100% oxygen
Remove oral stimulus
Pharyngeal suction
CPAP
PPV with bag/mask tight seal
```
54
How do you differentiate a lower airway crisis?
Bronchospasm, wheeze, high pitch expiration.
55
What are the first steps to do with an unresponsive patient who is not breathing or who has abnormal breathing?
1) Call for help
2) Check pulse
3) Start CPR (if no pulse or unsure)
4) Apply oxygen if you have a second responder
5) Attach monitors and defibrillator
56
What are the 4 pulseless rhythms?
1. VFib
2. V Tach w/o pulse
3. PEA (Pulseless Electrical Activity)
4. Asystole
57
Which rhythms are shockable?
1. VFib
| 2. Pulseless VTach
58
Which rhythms are not shockable?
3. Asystole
| 4. PEA
59
How do you manage a shockable rhythm?
Shock, continue CPR and establish IV/IO access. Check if the rhythm continues to be shockable q2min. First try epinephrine 1mg q3-5min, consider LMA / ETT. Then if they fail epinephrine, try amiodarone and lidocaine.
60
How do you manage a non-shockable rhythm?
CPR + epinephrine ASAP q3-5 min. Consider advanced airway.
61
What is the threshold for bradycardia?
<50
62
What is the first line agent and dosage for symptomatic bradycardia?
Atropine (0.5 mg q3-5 min up to 3 mg)
63
What can you consider if atropine fails?
Dopamine and /or epinephrine infusion
| Transcutaneous pacing
64
What is the definition of tachycardia?
HR > 150
65
What is the first step to managing tachycardia?
Resp support, attach monitors, attempt to identify underlying cause?
66
What do you do if you have tachycardia with signs of poor perfusion?
Synchronized cardioversion
67
What are the signs and symptoms of local anaesthetic systemic toxicity?
CNS symptoms: ringing in the ears, metallic taste in mouth, altered level of consciousness, seizures, coma
Cardiac symptoms: Bradycardia, hypotension, arrhythmia, eventual cardiac or respiratory arrest
68
How do you manage a case of local anaesthetic systemic toxicity
```
Call for help, get crash cart
maintain patent airway, get oxygen, attach monitors.
Volume support
Early benzos
Follow ACLS Brady algorithm
Treat with lipid emuslsion
```
69
What are the 5 Hs and 4 Ts of reversible causes of cardiac arrest?
```
Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/Hyperkalemia, hypothermia
Tension pneumo
Tamponade
Toxins
Thrombosis (pulmonary, coronary)
```
70
What is the dosage of epinephrine for a code vs for anaphylaxis?
Code: 1 mg
Anaphylaxis: 0.1 mg
71
When should you pause to assess rhythm and pulse?
q2min, for 10s
72
What is the definition of bradycardia?
HR <50bpm
73
What is the first step to manage bradycardia?
Maintain airway, assist breathing, connect oxygen
Attach monitor + start BP and ox
Establish IV access
12-lead ECG
74
When do you give atropine for bradycardia?
If brady causes hypotension, altered mental status and signs of shock, or patient experiencing angina or acute HF.
75
What can you consider in the setting of management of bradycardia if atropine fails?
Try transcutaneous pacing, dopamine infusion or epinephrine infusion
76
What is the difference between dehydration and hypovolemia?
Dehydration is water loss distributed throughout total body water. Hypovolemia is salt and water loss resulting in decreased circulating blood volume with inadequate tissue perfusion.
77
What is the normal daily fluid requirement?
1.5-2.5 L of water (75-100 mLhr)
78
How much sodium is required daily?
50-100 mmol
79
How much potassium is required daily?
40-80 mmol
80
What is the difference between crystalloid and colloid fluids?
```
Crystalloid = electrolyte
Colloid = stuff that's too big to leave the bloodstream
```
81
What happens if normal saline is infused in large quantities?
Hyperchloremic metabolic acidosis (+ low bicarb).
82
What volume losses are best replaced with normal saline?
Vomiting or nasogastric losses (due to high chloride content of upper GI tract)
83
What are the contraindications to use of ringer's?
Increased ICP, neurosurgery, liver failure (inability to metabolize lactate), red cell transfusion (theoretical risk of chelating anticoagulant)
84
What is the indication for use of albumin as volume replacement?
Burn patients
85
How do you calculate blood volume in non-obese men and women?
70 ML/KG for men and 65 ML/KG in women
86
What are the two most common risks in blood transfusion?
Allergic reactions and febrile non-hemolytic transfusion reactions
87
What are the threshold for blood transfusion?
Haemoglobin less than 70 or haemoglobin less than 100 with signs of inadequate perfusion or inappropriate oxygen delivery
88
By how much do you expect one unit of blood to raise haemoglobin in an average adult?
10 g/L per unit
89
What constitutes a massive transfusion?
More than 10 units of blood or more than one blood volume within 24 hours
90
List five potential complications of massive transfusion
Dilution coagulopathy, electrolyte abnormalities including hyperkalaemia hypocalcaemia and hypoMg, Hypothermia, metabolic alkalosis
91
For procedures, what are the indications for platelet transfusion?
Procedure is not associated with major blood loss should transfused platelets only if county is less than 20E9/L. Procedures with major blood loss should indicate platelets at or above 50 and for neurosurgery at or above 70
92
By how much do you expect platelet counts to rise with each unit of platelets?
15 to 50
93
When would you give fresh frozen plasma?
INR>1.8 with active bleeding
94
How do you reverse warfarin emergently and non-emergently?
In emergency use prothrombin complex concentrate. If not an emergency give vitamin K
95
When do you use cryoprecipitate?
Massive or micro vascular bleed with fibrinogen <1g/L
96
What blood type can receive any type of plasma?
O - because there are already anti A or anti B antibodies
97
What is the definition of wide-complex tachycardia?
QRS >0.12s
98
How do you manage a stable wide complex QRS?
IV access, ECG if avail.
| Adenosine 6mg IV push + flush if monomorphic, or antiarrhythmic
99
How do you manage a narrow-complex tachycardia?
IV, ECG, vagal maneuvers, adenosine, beta blocker or calcium channel blocker
100
What is the equipment required for peripheral nerve block?
Peripheral nerve stim (+needle)
Local
U/S
Antiseptic, syringes, drapes, gloves
101
What type of local anesthetic is used for peripheral nerve block?
Amides (e.g. lidocaine, bupivicaine)
102
What is the maximal safe dose of lidocaine with and without epinephrine?
5mg/kg w/o epinephrine
| 7mg/kg with epinephrine
103
What is the maximum safe dose of bupivicaine with and without epinephrine?
2mg/kg w/o epinephrine
| 3mg/kg with epinephrine
104
What are the absolute and relative contraindications to peripheral nerve blocks?
Absolute: patient refusal (duh!), anticoagulation (spinal, epidural and deep peripheral nerve blocks eg lumbar plexus).
Relative contraindications include: anticoagulation (U/S recommended), pre-existing neurological deficit or respiratory disease
105
Name 5 complications of peripheral nerve blocks
1. nerve injury
2. intravascular injection
3. infection
4. anaphylaxis
5. pneumothorax (for brachial plexus blocks)
106
What additional risks should be disclosed for interscalene and supraclavicular blocks?
Horner's syndrome
Phrenic nerve block
Total spinal anesthesia
107
What nerve block can be used for shoulder surgery? What does it target?
Interscalene block, targets roots of brachial plexus (tends to spare C8/T1, so not good for surgery of the forearm or below)
108
What type of block will provide anesthesia to the entire arm below the shoulder? What is it directed at?
Supraclavicular block (trunks/divisions of brachial plexus)
109
What is the axillary block used for?
Any surgery below mid-humerus
110
What block is commonly used for knee surgery?
Femoral block
111
What are the contraindications to rapid sequence induction?
Contraindication to succinylcholine
Contraindication to cricoid pressure e.g. c spine injury or fracture
Difficult intubation anticipated
Patient hemodynamically unstable or otherwise inappropriate to use pre-measured doses
112
What are the contraindications to succinylcholine?
Previous or FH of malignant hyperthermia
Pseudocholinesterase deficiency
Hyperkalemia
Arrhythmia ( could be worsened by hyperkalemia )
Rhabdomyolysis, trauma or prolonged denervation of muscle
113
Name 5 reasons why we treat pain.
1. Reduced chest expansion can lead to hypoventilation
2. Sympathetic activation leading to tachycardia and HTN Can lead to MI and cardiac events
3. Pain impairs mobility and increases risk of DVT and PE as well as pressure ulcers
4. Pain has a major psychological and functional impact
5. Properly managed pain reduces admissions and length of stay
114
What is the difference between acute and chronic pain?
Acute pain is <3-6 mos duration and typically resolves as an injury heals.
Pain that lasts >6 mos or beyond the course of acute disease is chronic. Typically, chronic pain is associated with functional limiation
115
On a numerical pain scale, what change should be interpreted as a clinically significant worsening or improvement in pain?
3 on a 0-10 scale
116
What pain scale can be used with pediatric patients or those with language barriers.
FACES (Wong-baker)
117
What are the components of the FLACC pain scale?
```
Face
Legs
Activity
Cry
Consolability
```
118
What is the mechanism of action of acetaminophen? In which population is it relatively contraindicated?
inhibits prostaglandin production;
| be cautious in people with advanced liver disease
119
Where do opioids act?
Mu, kappa and delta opioid receptors
120
What is the mechanism of action of gabapentin and pregabalin? What types of pain are most effectively treated by them?
Block calcium channels, inhibiting excitatory neurotransmitter release
Best for neuropathic pain
121
How do TCAs work? What types of pain respond to TCAs?
Block serotonin and norepinephrine pathways; neuropathic pain
122
How does ketamine work?
It's an NMDA antagonist (primarily)
123
How do local anesthtics work?
Inactivate voltage-gated sodium channels, preventing depolarization.
124
What are the contraindications to NSAID use?
GI bleed (or other active bleed)
Peptic ulcer
Renal disease
Hypersensitivity reaction
125
How do NSAIDs work?
they are COX enzyme inhibitors
126
What are 5 considerations when ordering analgesic medications?
```
Medication
Route
Dose
Interval
Messaging (e.g. side effects, expectations)
```
127
What is the mechanism of action of clonidine?
Alpha-2 agonist
128
Under what conditions are opioid infusions appropriate?
Typically only in ICU with at least pulse-ox and end-tidal CO2 monitoring.
129
Name 8 side-effects common to opioids
```
Somnolence
Respiratory depression
hypotension
urinary retention
nausea and vomiting
reduced gastric emptying
constipation
pruritis
delirium (increased risk in elderly)
```
130
What are indications for intubation?
Hypoxemic or hypercapnic respiratory failure
To maintain a patent airway / if patient has lost protective airway reflexes
To provide positive pressure ventilation
Tracheo-bronchial toilet
131
What is the STOP BANG screen for OSA?
Snoring
Tired
Observed
Pressure (HTN)
BMI >35
Age >50
Neck circumference
Gender (M)
132
What are the two complications of epidurals that can lead to paralysis?
Hematoma
| Abscess
133
How does magnesium help with pain?
It blocks NMDA channels (similarly to ketamine).
134
What do alpha-1 receptors do?
vasoconstriction ( and reflex brady )
135
What do alpha-2 receptors do?
Decrease blood pressure, sedation, analgesia
136
What do beta-1 receptors do?
Increase contractility of heart (you have 1 heart)
137
What do beta-2 receptors do?
Bronchodilation (you have 2 lungs)
138
Why is epinephrine added to local?
Causes vasoconstriction, reduces systemic absorption of local, allowing higher doses.
139
How do you convert dosage between morphine and hydromorphone? What about between morphine and oxycodone?
Hydromorph divide morphine by 5
| Oxycodone divide morphine by 2
140
How do you convert between IV and PO dosage for opioid?
Divide PO by 2 to get IV
