Anesthesia Flashcards
Anesthetic family history (3)
- Abnormal anesthetic reactions
- Malignant hyperthermia
- Pseudocholinesterase deficiency
Causes of Hyperthermia
- Drugs (I.e. Atropine)
- Blood transfusion reaction Infection/sepsis
- Medical disorder (I.e. Thyrotoxicosis)
- Malignant hyperthermia
- Over zealous warming efforts
Define: Tachycardia
HR > 150
6 A’s of Anesthesia
- Anesthesia
- Anxiolysis
- Amnesia
- Areflexia
- Autonomic Stability
- Analgesia
Pre Op Medications to stop and adjust
STOP
- Oral hypoglycemics (morning)
- Antidepressants (morning)
- ACEI/Angiotensin Blockers (morning)
- Warfarin (can bridge w/ heparin, Anti-platelets (clopidegrol)
ADJUST
- Insulin
- Prednisone
- Bronchodilators
Pre-Anesthetic History: basic components
- HPI
- PHx (CRASH)
- Endo (DM, thyroid)
- CVS
- Resp
- GI
- Renal
- CNS
- Past Anesthesic Hx
- post op complications
- difficult airway
- failed spinal
- NPO status (last meal)
- Family history anesthesic complications
- Malignant hyperthermia
- Pseudocholinesterase deficiency
- R-O-S
Pre-anesthetic Physical Exam: key components
- Vitals
- Airway assessment
- Resp Exam
- Cardiac Exam
- Peripheral pulses
- Assessment of venous access
- Palpitations of the back (for spinal or epidurals)
Common IV Induction Agents (4) and MOA’s
- Propofol (GABA stimulant and Na+ channel blocker)
- Etomidate (GABA modulator, peaks at 1 minute)
- Ketamine (glutamate antagonist at NMDA)
- Sodium thiopental (non-specific barbituate/GABA stimulant)
3 Indications for Inhalation Induction
- Difficult IV accesses
- Airway maintenance concerns
- Patient Preference (children)
Why is sevoflurane the most popular inhalation induction agent?
It irritate the tracheobronchial tree less.
Electrode placement (describe)
- V1 4th Intercostal space to the right of the sternum
- V2 4th Intercostal space to the left of the sternum
- V3 Midway between V2 and V4
- V4 5th Intercostal space at the midclavicular line
- V5 Anterior axillary line at the same level as V4
- V6 Midaxillary line at the same level as V4 and V5
- RL Anywhere above the ankle and below the torso
- RA Anywhere between the shoulder and the elbow
- LL Anywhere above the ankle and below the torso
- LA Anywhere between the shoulder and the elbow
Counter-regulatory hormones
- Epinephrine
- Glucagon
- Cortisol
- Growth hormone
- Inflammatory cytokines e.g. IL 6 and TNF-alpha.
Effects of Elevated Counter-Regulatory Hormones in Surgery
- Less insulin secreted
- Insulin resistance
- Less glucose uptake/utilization
- Increased lipolysis/protein catobolism
- HYPERGLYCEMIA
- Ketosis
Pre-Op Warfarin management
Full elective surgery: Withhold warfarin for ~ 5 days to reduce INR to 1.4. Urgent Surgery within 1 day: Withhold warfarin and give a larger larger dose (eg 5.0-10.0 mg) of intravenous vitamin K. Test INR preop and give FP if INR > 1.4. Urgent Surgery within minutes to hours? Use FP or a prothrombin complex concentrate (Octaplex) in addition to vitamin K.
Pre-Op Heparin management
Unfractionated heparin should be stopped four hours before surgery with the expectation that the anticoagulation effect will have worn off at the time of surgery. LMW heparin should be stopped approximately 12 hours, and preferably 24 hours before surgery.
Pre-Op Beta Blocker Managment
Continue beta-blockers up to and including day of surgery. Substitute with IV labetolol, propanolol, or metoprolol during prolonged NPO state. Reason: Perioperatively, beta blockers reduce ischemia by decreasing myocardial oxygen demand and may help prevent and control arrhythmias. Patients who take beta-blockers chronically for management of angina are at risk of hypertension, tachycardia and myocardial ischemia with acute withdrawal of beta blockade.
Diuretics Managment
Continue diuretics to day of surgery but discontinue morning dose. Use parenteral forms as needed in postoperative period. Resume oral diuretics when patient is taking oral fluids. Pay attention to volume and potassium replacement. Reason: Continuation of diuretics can result in hypovolemia and hypotension. As well, certain diuretics can result in hypokalemia, which can increase risk of arrhythmias.
Statins Managment
Continue up to and including day of surgery as statins may provide cardiovascular protection through mechanisms other than lowering cholesterol (e.g. stabilizing plaque, reducing inflammation, and decreasing thrombogenesis).
Surgery for Diabetics: strategies to helpe
- Early morning 2. Good hydration 3. Monitor: blood glucose before and after surgery 4. No oral hypoglycemic drugs on day of surgery, or night before if well managed/borderling hypoglycemic 4.b) If missing breakfast/lunch, 1/2 of total morning insulin still permitted or basal infusion rate if continuous infusion + atart dextrose containing IV at 75 to 125 cc/hr to provide 3.75 to 6.25 gm glucose/hour (to avoid starvation metabolic changes) 5. Supplemental short-acting insulin as needed 6. Return to antidiabetic medications with food 7. Return to metformin with good renal function 8. Type 1 Diabetics to maintain basal insulin doses (prevents ketoacidosis) NOTE: different card for long/complex procedures for Type 1 Diabetics or Insulin Treated Type 2 Diabetics
Hypoglycemic management fo long and complex procedures for Type 1 or insulin treated type 2 diabetes (e.g. coronary artery bypass graft, renal transplant, prolonged neurosurgery):
Separate insulin and glucose IV solutions: Dextrose administered at ~ 5 to10 gm of glucose/hour, and a separate short acting insulin infusion administered at 1 to 2 units/hour for most type 1 patients, and higher insulin rates for more insulin resistant type 2 patients. Check capillary glucose levels every 1-2 hours and adjust insulin infusion. 6.7 mmol/L to 8.9 mmol/L: increase by 0.5 U/hr 9.0 mmol/L to 11.1 mmol/L: increase by 1.0 U/hr > 11.1 mmol/L: increase by 2.0 U/hr
How many hours a patient should be NPO for clear fluids and solid food? If the patient is an infant, how many hours it should be NPO for infant formula and breast milk?
Clear fluids: stop 2 hours prior to surgery Breast milk: stop 4 hours prior to surgery Infant formula or non-human milk: stop 6 hours prior to surgery Solid food: stop 8 hours prior to surgery
What modifications should be made for a patient with a latex allergy?
The patient should be booked to be the first patient of the day in the operating room. Non-latex equipment and gloves should be used.
ASA Scale
ASA I Normal healthy patient ASA II Mild systemic disease (with no functional limitiations), e.g. controlled hypertension ASA III Severe systemic disease (with some daily functional limitations). e.g. emphysema ASA IV Severe systemic disease that is incapacitating and is a constant threat to life e.g. unstable angina ASA V A moribund patient not expected to survive without surgery e.g. ruptured abdominal aortic aneurysm and patient is in shock ASA VI A patient declared “brain-dead”, whose organs are being removed for the purposes of organ donation E Suffix E added for emergency surgery
What are the considerations used to develop an anaesthetic plan?
- Patient considerations – these are medical issues that the patient brings to the table. They impact our delivery of anesthesia. 2. Anesthetic considerations – What mode of anesthesia is necessary for this procedure? What medications will be used? How will these choices affect the patient’s considerations? 3. Surgical considerations – what surgery is planned and what is involved in this surgery? (eg type and location of incision, laparoscopy, airway procedure, length of surgery etc).
Indications for (endotracheal) intubation
- GCS 35 3. Failure to ventilate (PaCO2 > 55mmHg) 4. Failure to oxygenate (PaO2
How do you assess a patient’s airway for a potential difficult airway and potential difficult bag mask ventilation?
LEMON Look: Evaluate: (3-2-1 rule) Mallampati: (direct oropharyngeal view) Obstruction: stridor, foreign bodies, sub- and supraglottic obstruction, dental concerns (caps, crowns, loose Teeth) Neck Mobility: injury or arthritis
Mallampati
Class 1: Full visibility of tonsils, uvula and soft palate Class 2: Visibility of hard and soft palate, upper portion of tonsils and uvula Class 3: Soft and hard palate and base of the uvula are visible Class 4: Only Hard Palate visible
What is the 3-2-1 Rule?
TMJ >= 1 finger Mouth Open >= 2 fingers Thyromental Distance >= 3 finger
Cormack and Lehane Grading (Used to grade the view at laryngoscopy)
Grade I - visualization of entire laryngeal aperture (95%) Grade II - visualization of posterior part of the laryngeal aperture (4%) Grade III - visualization of epiglottis only (1%) Grade IV - not even the epiglottis is visible (0.05%)
Exactly how does Mallampati correlate with Cormack and Lehane?
Class I view is grade I intubation more than 99% of the time. Class IV view is grade III or IV intubation 100% of the time. May fail to predict over 50% of difficult intubations
Equipment for Endotracheal Intubation
SOLES Suction Oxyenation - pre-oxygenate for 3 minutes prior Laryngoscope ETT (endotracheal tube) Syringe/Stylet
Nazopharyngeal Airways Sizes Diameter
Large adult 8-9 mm Medium adult 7-8 mm Small adult 6-7 mm
OPA Adult sizesoropharyngeal airway (large adult 100 m, medium adult 90 mm, small adult 80mm)
oropharyngeal airway Large adult 10cm Medium 9cm Small 8cm
2 Typers of Laryngoscope Blades
Curved/standard: Macintosh Straight: Miller
How does Clonidine work? When is it used?
Clonidine is an Alpha 2 Agonist - it is used to decrease norepinephrine (decrease sympathetic drive), because it acts on Alpha 2 receptors, which are the feedback receptors for NE release. Can be used in opioid withdrawal
LMA Sizes
Laryngeal Mask Airway Size 1 - Under Size 2 Size 3 - 40-50kg, small woman Size 4 - 50-70kg, normal woman Size 5 - 70-100kg, men
How does a rapid sequence induction (RSI) differ from the standard induction technique used for an elective anesthetic in a patient who is not a full stomach?
a
Difference between BURP and Cricoid Pressure
Backwards Upwards Right Pressure Used to improve visualization in standard procedure, also can be released While cricoid pressure cannot be released and is for RSI procedures
Why is it bad when O2 sat goes below 90%?
O2 below 90% correlates with the steal part of the oxygen partial pressure saturation hemoglobin curve and therefore indicates a major drop in ppO2
How does Clonidine work? When is it used?
Clonidine is an Alpha 2 Agonist - it is used to decrease norepinephrine (decrease sympathetic drive), because it acts on Alpha 2 receptors, which are the feedback receptors for NE release.
What is the difference between oxygen saturation and PaO2?
- Saturation represents that percentage of hemoglobin that has oxygen
- PaO2 is a measure of the pressure of dissolved oxygen in the arteries
What is hemoglobin?
Hemoglobin is the protein that carries oxygen in blood cells.
What is the O2 delivery formula?
DO2 = (Hb x SAT) x CO
When do you get codones? What are they? Macrocytic or microcytic?
Non-megaloblastic macrocytic, increased membrane production, creates a target shaped cell. Suggests pathology of liver or spleen.
Define: Anesthesia
Lack of perception/sensation
Adrenal Disorders (2)
Addison’s Disease: low adrenocorticol hormones (low aldosterone) - may supplement with steroids Conn’s Syndrome/Promaey Hyperaldosteronism: high aldosterone
Differentiate between aldosterone and ADH (anti-diuretic hormone)
Aldosterone acts on the collecting duct to inhibit Sodium reuptake; therefore it increases water retention. ADH - watch khan academy
Atropine
An antimuscarinic that inhibits the parasympathetic and thus stimulates the heart For bradycardia: 0.5-1mg IV push
Ephedrine
Prevention of hypotension associated with spinal anesthesia during cesarean sections.
Midazolam
Benzodiazepine: sedation + amnestic agent Fast recovery time Also, it is anxiolytic, amnestic, hypnotic, anticonvulsant, skeletal muscle relaxant, and sedative properties (wiki)
Different types of Fentanyl
Vary in speed of recovery, more than onset REMI- short acting
Beta-Blocker
Metoprolol (cardio-selective), Atenolol (cardio-selective), Propanolol Act on sympathetic (adrenergic) and block activity Decrease BP, treat angina, control heart rhythm Perioperatively may decrease cardiac events but increase stroke in CAD patients Beta1-receptors: heart & kidney Beta2-receptors: lungs Caution of beta blocker side effects at lungs
Aspiration Risk Factors
Lower loc Recent meal (8 hours) Mask versus ETT Abdominal pressure: pregnancy, obesity, acute abdomen, bowel obstruction Sphincter problem: hiatal hernia, GERD, nasogastric tube Trauma
Endocarditis Prophylaxis Dosing and Indications
- Amoxicillin 2g PO 30-60 min before procedure
- Ampicillin 2g IV/IM 30-60 min before procedure
INDICATION:
- Respiratory surgery + previous IE
- Prosthetic valve
- Congenital heart disease
Ancef - indications, dosing, name
Prophylaxis for any surgery Treats gram positive strains (I.e. Staphylococcus , streptococcus) Cefazolin 2g IV push
Coronary artery disease prophylaxis
Nitroglycerin or beta blocker
Pre-operative management of COPD
Bronchodilators + Inhaled Corticosteroids + Antibiotics
Three types of bronchodilators
- Beta 2 agonists (short and long acting) 2. Theophylline (long acting) 3. Anticholinergics (short acting)
Define: anticholinergic
Blocks acetylcholine, blocks parasympathetic stimulation
What does lactate production suggest?
Low oxygen supply and therefore anaerobic metabolism
FiO2
FiO2 is the inspired oxygen, room air is 160mmHg (which is 21% of air pressure at sea level, 760mmHg)
A-a gradient
Drop in PO2 between aveoli and arterial capillary Normal: 5-10mmHg, increasing by 1mmHg/year (age/4 +4) High: (intrapulmonary hypoxemia) VQ mismatch, right-to-left shunt, or defect in diffusion Low: (extra pulmonary)
What is the alveolar gas equation?
PAO2= (FiO2 - humidity) - PaCO2/Resp Quoitient = (0.21 x (760mmHg - 47mmHg)) - PaCO2/0.8
Why ventilate for a narcotic overdose?
To increase the ventilation and consequently decrease the CO2. High CO2 causes respiratory acidosis. (Query: Metabolic compensation would be indicated by alkalosis with low bicarbonate)
How does nasal prong ventilation affect %O2?
Flow 1-6L/min = 24-40% delivered (FiO2 increases by 4%/L)
%O2 for various flow rates for a Simple Face Mask
5-6 = 40% 6-7 = 50% 7-8 = 60%
%O2 for various flow rates for a Non-Rebreathing Mask (has plastic bag)
6L/min = 60% 7L/min = 70% 8L/min = 80% 9-10L/min = 80%+
What is the commonest cause of an elevated A-a gradient?
VQ mismatch (blood perfuses lungs happens, but no ventilation happens) -Actelectasis = reduced opportunity for O2 uptake into capillaries (aka ventilation) -pneumonia -pulmonary edema -pneumothorax
Causes of VQ mismatch
Low VQ = actelectasis High VQ = cardiac output, emboli, hypovolemia
Treatment of Atelectasis
- FiO2 to reach >90% 2. Spirometry + Physio 3. Bronchodilator 4. Pain killer to manage cough 5. Prophylaxis for chest infection 6. Arterial line for ABG’s
What is PEEP
Positive End Expiratory Pressure - to recruit aveoli for ventilation
Intubation Criteria
- GCS < 8
- Respiratory rate > 35 (these patients will not be able to maintain that rate for too long)
- Failure to ventilate (PaCO2 > 55mmHg)
- Failure to oxygenate (PaO2 < 70mmHg)
- Vital capacity < 15ml/kg
- Inability to generate an inspiratory pressure of -20mmHg
- Airway protection from aspiration
- Airway obstruction, either impending or current
- To maintain tracheo-bronchial toilet (the patient who cannot clear secretions)
- The need to deliver positive pressure ventilation in the OR (technically speaking this is not really a separate indication, as it is only because our anesthetic causes many of the other indications to occur all at once!)
How do set a ventilator?
RR: 10-12/minute (more after high PaCO2 due to hypoxia) Tidal Ventilation: 10mL/kg
Coronary Artery Anatomy
Right Coronary Artery -inferior aspects of heart, right ventricle, SA node, AV node -bradycardia and heart block and RV infarcts Left main coronary artery - left anterior descending branch: septum and anterior wall of left ventricle - circumflex branch: lateral and posterior walls of LV Note: the posterior descending artery can be from RCA (70% of people) or LCA (10%) or both (20%)
Canadian Cardiovascular Society Classification
I - angina on strenuous exertion II - angina from mild exertion above regular activity III - angina brought on by regular activity IV - occurring at rest
How is functional capacity measured?
METs, metabolic equivalent of a task, is the basal metabolic rate. (Aka O2 consumed at rest for an individual) Functional capacity: number of mets a patient can complete (4 is minimum for reasonable)
General MOA of local anesthetics
Block sodium channels thereby blocking transmission Effected by pKa
What are the two types of local anesthetics? 3 examples each
Amides- lidocaine, bupivicaine, mepivacaine (liver breakdown) Esters - cocaine, benzocaine, procaine (plasma pseudocholinesterase breakdown)
Symptoms of too much local anesthetics
Central nervous system aberrations - tinnitus, tingling, seizures Cardiac conduction problem leading to Arrhythmia
Lidocaine vs Bupivicaine
Lidocaine- more rapid onset, 10-15 min for peak block; lasts one hour as spinal anesthetic Bupivicaine- 20 min for peak block; lasts four hours as spinal anesthetic; lower max dose (higher potential for toxicity)
Doses of lidocaine and bupivicaine
Lidocaine: max is 4.5mg/kg, typically not exceeding 100mg for a spinal Bupivicaine: 2.5mg/kg, typically not exceeding 20mg for a spinal Both are amides (liver digested)
Four common induction agents
- Etomidate 2. Propofol 3. Ketamine 4. Sodium thiophenate
Rocuronium
Post-synaptic acetylcholine block, reversible. Paralysis.
6 reasons to ventilate
- Apnea 2. Need for hyperventilation (I.e. elevated ICP) 3. VQ Mismatch 4. Respiratory depression/Acute Respiratory acidosis 5. Increased thoracic pressure (laparoscopic) 6. Surgical positioning that limits excursion
BiPAP vs CPAP
BiPAP: increased pressure on inspiration and lower constant pressure on expiration CPAP: delivers constant pressure (inspiration and expiration)
Difference between hypoxermic and hypercapnic respiratory failure?
Hypoxemic - 2 options (extra pulmonary, no A-a gradient; intrapulmonary high A-a gradient) VQ mismatch results, because there is low O2 at aveoli (low ventilation)
Causes of Intraoperative Hypoxia
- Hypoventilation 2. VQ Mismatch/intrapulmonary 3. Low O2 supply/extra pulmonary 4. Poor oxygen carrying capacity (anemia, Carbon monoxide poisoning, methemoglobinemia 5. Left shift (hypothermia, carbon monoxide, 6. Right to left cardiac shunt
4 causes of hypocapnea
- Hypoventilation 2. VQ mismatch 3. Hypothermia (low metabolism) 4. Low pulmonary blood flow
Complications of local anesthetics
- Phrenic nerve blocked 2. Blockade failed 3. Transient parasthesias (from anesthetic or needle) 4. Bleeding 5. Infection 6. Pneumothorax
Two compounds that increase blood pressure
Ephedrine Phenephrine Epinephrine
3 Main Types of Shock
Volume shock (fast/slow, internal/external, blood/fluids) Cardiogenic Shock (CHF, MI, trauma) Vascular shock (anaphylaxis, spiinal injury)
Primary Assesment of Trauama
Resp - Airway and Breathing Circ - Pulse and Blood loss Nervous - Spine Injury and Spine injury
Airway Assessment of ABC’s
I- Speaking, Stridors, Effort of breathing Cyanosis, Mouth inspection, tracheal deviation, assymetry, flail chest P - tracheal deviation, assymetric excursion P- pneumothorax=hyperresonance A- check for breath sounds bilaterally
Scene Size up for Trauma
Safety -personal protective gear Numbers - patients vs rescuers Mechanism - what and when
SAMPLE HIstory
Symptoms Allergies Medications Pertinent History Last meal/ins & outs Event (do they remember?)
What does the extra A in trauma SOAAP stand for?
Anticipated problems
What is a treatment for all Respiratory Problancems?
PROP Position Reassurannce (if awake) Oxygen (nasal prongs -> face mask -> CPAP/BiPAP -> venturi mask -> bag valve) PPV
Causes of depressed neurodrive
STOPEATS Sugar Temperature Oxygen Pressure/perfusion pressure Electricity/epilepsy Altitutde Toxins Salts
CPAP versus BiPAP
BiPAP - positive pressure on inhalation, constant pressure on expiration CPAP-constant pressure through inspiration and expiration
Treatment of Shock
Management of shock depends on cause. Establish 2 large bore IV’s Infuse 2L of plasmalyte (a crystalloid) as rapidly as possible
What is shock?
Failure of the body to deliver oxygen to organs -> organ failure
LevophedTM
epinephrine to help control pressure in shock
Treatment of ICP
Elevate head of bed (30 degrees) Mild hyperventilation (pCO2 30-35mmHg) Consider mannitol administration Consult neurosurgery
What are the basic trauma monitors?
Blood pressure cuff Pulse oximeter 5 lead ECG (V1-V5)
What is a FAST ultrasound and which 4 areas does it investigate?
Focused assessment with sonography for trauma 1. Pericardial 2. Perisplenic 3. Perihepatic 4.Pelvis
How much fluid should I give?
One way to deal with this is to use the classical approach that utilizes the 4:2:1 rule, and recognizing that… fluid replacement = maintenance + deficit + “3rd Spacing” + Losses
What is a crystalloid solution?
is a fluid with electrolyte composition but low oncotic pressure. It will distribute across all fluid compartments, and as a general rule one ends up with 1/3 intravascular and 2/3 extravascular
What is a colloid solution?
a high molecular weight hydroxyethyl starch, usually in a normal saline vehicle, that offers oncotic pressure and stays intravascular until metabolized by amylase and excreted in the urine.
What is the variation in blood loss from surgery
Surgical evaporative losses depend on the level of surgical insult: from 1mL/kg/hr (hernia repair) –> 10 ml/kg/hr (AAA repair)
What is pentaspan
High oncotic pressure solution (a colloid), that is made of starch. Starch is broken down eventually by amylase and secreted by the kidneys.
Define Central Venous Pressure
Also known as mean venous pressure (MVP) is the pressure of blood in the thoracic vena cava, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood into the arterial system.
Difference between loses and deficits?
Losses are solutions lost, namely blood. Defecits are an estimate based on maintence for that patient times the number of hours the patient has been fasting.
Define: colloid solution
- High molecular weight hydroxyethyl starch
- Normal saline solution
- Oncotic pressure: stays intravascular until metabolized by amylase and excreted in the urine
Normal values for pH/pCO2/pO2/HCO3/Base Excess/% saturation
7.5/40/90/25/plus or minus 2/>95%
What is pentaspan
High oncotic pressure solution
How much fluid?
= maintenance + losses + 3rd spacing + deficit
Difference between loses and deficits?
Losses are solutions lost, namely blood. Defecits are an estimate based on maintence for that patient times the number of hours the patient has been fasting.
How do we measure the SvO2
Drawing blood from the distal port of the central line and sending it to the lab.
Normal values for pH/pCO2/pO2/HCO3/Base Excess/% saturation
7.5/40/90/25/plus or minus 2/>95%
If someone is low pH, what is the next point to determine?
If they are metabollic or respiratory acidemic. pCO2 > 40mg, think respiratory. pCO2
If someone is matabollic acidemic, what is the next point to determine?
Anion gap or not. Anion gap >10
Define: Porphyria
Hereditary disease resulting in malformed hemoglobin.
Porphyrin enzymes are deficient, preventing porphyrins from forming heme.
Differentiate between Ketosis & Ketoacidosis
Ketosis: state where energy comes from ketones in blood; with low stable levels of insulin and glucose
Ketoacidosis: extreme and uncontrolled ketosis; two typical types: diabetic and alcoholic
Metoclopramide
- Dopamine-receptor antagonist
- Treats:
- Nausea and vomiting, to help with emptying of the stomach in people with delayed stomach emptying due to either diabetes or following surgery
- Gastroesophageal reflux disease
- Migraine headaches
Indications for Rapid Sequence Induction
Full stomach
- Anyone who has consumed
- clear fluids within 2 hours
- full fluids within 4 hours
- solids within 6 hours
- Trauma, almost regardless of when
- A parturient within the 2nd or 3rd trimester
- Acute abdomen – includes bowel obstruction, perforated peritoneal contents, appendicitis, etc
- Pyloric stenosis
- Obesity – especially in patients with a history of GERD
- Hiatus hernia
- Opioid consumption – narcotics slow bowel function, increasing gastric status
- GERD – this one will depend on severity of symptomatology
Anatomy of Larynx

Mallampati

How does rapid intubation sequence look different?
- No sedation
- 2S: Stylette and suction ready
- 3 drugs: fast-acting narcotic, induction drug, fast acting paralysis
- 4 flowless tidal volume breaths
BONUS: Cricoid pressure (not BURP)
Differentiate between BURP and cricoid pressure
BURP: backwards, upwards, right pressure, too increase visualization
Cricoid pressure: occlusion of esophagus
The reason for pre-oxygenation before tracheal intubation is…
… denitrogenation of the functional residual capacity (FRC) to increase oxygen reservoir.
Trousseau’s Sign
- Low calcium
- Bent wrist at distal pressure greater than systolic for 3 minutes
- Precedes hyperreflexia and tetany
Signs & Symptoms of CO2 Retention/Hypercapnia
- Warm flushed skin
- Full pulse
- Deep and rapid breathing
- Premature ventricular contraction (PVC’s)
- Muscle twitches
- Hand flaps
- Hypertension
- Headache/confusion/leathargy
NOTE: severe cases (PaCO2 greater than 75mmHg) progress to hyperventilation, convulsions, lowered loc
Contraindication of Succinylcholine
- Malignant hyperthermia
- Skeletal muscle myopathis
- Major burns (acute phase)
- Multiple trauma (acute phase)
- Upper motor neuron injury
NOTE: can cause hyperkalemia (high potassium
Define: Priapism
Sustained and painful erection of the penis
Maximum dose of lidocaine
- 7 mg/kg with epinephrine
- 5mg/kg without epinephrine
- 3mg/kg IV (Bier Block)
NPO Expectations for General Anesthetic
Side effects: Succinylcholine
nicotinic acetylcholine receptor agonist; metabolised by choinesterases in plasma
- Hyperkalemia
- Malignant hyperthermia
- Apnea & awareness with pseudocholinesterase deficiency (genetic, pregnancy, liver disease, kidney failure, heart failure, thyrotoxicosis, cancer and a number of other drugs)
Patient with IDDM, what do you do on the morning of surgery?
hold regular short-acting insulin and give ½ dose of intermediate insulin. Give D5 ½ normal saline, check blood sugar every 2-4 hours
Anion Gap Metabollic Acidosis Differential
MUDPILES: for low pH, low CO2, Anion Gap
- Methanol
- Uremic acid
- Diabetic Ketoacidosis
- Paraldehyde
- Isoniazide/Iron
- Lactic Acidosis
- Ethylene Glycol
- Salicylate
Acceptable Blood Loss
[(Initial Hb)- (Minimal Acceptable Hb)]/(Initial Hb) x EBV
EBV = estimated blood volume (60-70mL/kg)
Minimal Acceptable HB =Transfuse at Hb < 70
Differentiate between group and screen and cross match
- Group: traditional blood type (i.e. AB+); 5 min
- Screen: test for atypical antigens (indirect coombs); 45-60 min
- Crossmatch: mimic transfusion and obsere interaction between host and donor blood
Differentiate between the content and use of the following blood products:
- Thawed frozen plasma
- Cryoprecipitate
- Platelets
- Packed RBC’s
- TFP:
- All clotting factors + fibrinogen
- Massive Transfusions
- Liver Failure
- Coagulation Factor Depletion
- Treat Bleeding
- Cryoprecipitate
- VIII + XIII + vWF + fibrinogen
- Hypofibrinogenemia that is not responding to thawed frozen plasma
- Use in volume sensitive patients (e.g. CHF)
- Platelets
- Thrombocytopenia
- Massive Transfusion
- Impaired Platelet Function
- Packed RBC’s
- 1 unit= 300mL
- Increase Hb by 10g/L/ unit
- Increases oxygen carrying capacity.
- Contains some plasma, minimal platelets and clotting factors
What are the hemolytic complications of transfusions?
- Immediate
- Major antigen incompatibility
- ABO incompatibility
- Delayed
- Minor antigen incompatibility
- Hx of multiple transfusions/pregnancies
What are the non-hemolytic transfusion reactions?
- Febrile (antibodies react to donor antigens)
- Allergic (mast cell release/histamine release, IgE antibodies react to donor antigens)
- Anaphylactic (IgA antibodies react to donor antigens)
- TRALI (host WBC’s congregate in lungs)
- GVHD (donor antibodies react to immunocompromised host antigens)
- Immuno suppression (unexplained)
Differentiate between hemolytic and non-hemolytic immune mediated transfusion reactions.
Hemolytic: red blood cells destroyed by immune response
Non-hemolytic:immune response causes other affect (histamine, anaphylaxis, fever, ARDS/TALI, or immunosuppression)
Delayed hemolytic versus febrile non-hemolytic transfusion complication
- Delayed hemolytic: fever 1-21 days post transfusion, lowered Hb, and mild jaundice
- Febrile non-hemolytic: fever <2 hours post transfuion, low grade fever, flushing and myalgia (supportive treatment and could continue transfusion, potentially)
Differentiate between oxygenation and ventillation
- Oxygenation is the process of adding oxygen to the body system (SpO2)
- Ventillation is the process of inhaling and exhaling (ETCO2, minute ventillation)
Relative and Absolute Spinal Contraindications
Absolute:
- Coagulopathies, including thrombocytopenia
- CNS tumor wiht mass effect
- Infection at needle site
Relative:
- CNS disease such as MS
- Systemic infections
- Aortic stenosis
- Any abnormal anatomy
2 common surgical inotropes
- Phenylephrine (Alpha 1 agonist)
- Ephedrine (
How do inhaled anesthetics work?
Produce immobility via the spinal cord. Enhance inhibitory channels and attenuate excitatory channels.
What is Minimum Aveolar Concentration?
Aveolar (or end-expiratory) concentration at which 50% of patients will not show a motor response to a standardized surgical incision. 95% of patients will not respond to 1.2 MAC. 99% to 1.3 MAC. NOTE: MAC of different gases are ADDITIVE
Which is the only inhaled anesthetic to have analgesic effects?
Nitrous Oxide