question

Complication of Cricoid Pressure

answer

i.e. Sellick manoeuvre Complications: 1) N/V 2) Esophageal rupture 3) Difficult tracheal and mask intubation 4) minimal hemodynamic changes 5) complete AW obs 6) fracture of cricoid cartillage

question

Contraindications of LMA

answer

1) small oral opening 2) "full stomach" (i.e. not npo, morbidly obese, trauma, GERD, intestinal obs) 3) dec lung compliance 4) not profoundly anesthetized 5) oropharyngeal growth/trauma

question

Extubation Criteria

answer

1) Oxygenation: SaO2 > 92%, PaO2 > 60 mm Hg 2) Ventillation: Vt> 5ml/kg, RR >7, ETCo2 < 50, PaCO2 0.9. Sustained 5-sec head lift or hand grasp 5) Neuro - follows verbal commands, intact cough/gag 6) Acid/Base - pH > 7.25 7) Normal metabolic - electrolytes, volume status 8) Normothermic 9) Other - aspiration risk, airway edema, Awake versus Deep (recall stage 1 - analgesia stage 2 - excitement stage 3 - surgical anesthesia stage 4 - medullary paralysis)

question

Confirming endotracheal intubation

answer

continuous waveform capnography along with clinical assessment is the most reliable method of confirming and monitoring correct placement of an ET tube

question

Rapid sequence induction

answer

http://image.slidesharecdn.com/13-enpediatricresuscitation-120507075455-phpapp02/95/emergency-lectures-pediatric-resuscitation-49-728.jpg?cb=1336377382 Indications: - ileus/obs - delayed gastric emptying (pain, trauma, opioids, ETOH, vagotomy) - incompetent LES, hiatus hernia, GERD - altered LOC - neurological/NM dz - pregnancy - difficult AW Contraindications: - total AW obs - loss of facial/oropharyngeal landmarks - anticipated difficult intubation (lemon, 332)

question

Head position for tracheal intubation

answer

head should be 10 cm above table with extension of the atlanto-occipital joint to be in the sniffing position

question

Difficult Airway Mangement

answer

http://www.ebmedicine.net/media_library/aboutUs/Clinical%20Pathway%20Management%20Of%20The%20Difficult%20Airway.JPG

question

Position of Endotracheal tube

answer

tip should be approximately 5 cm above the carina

question

CPR, Interruption of cardiac compressions

answer

Primarily - Pauses for establishing ETT (ventillation) Secondary - rhythm checks, shocks

question

Therapeutic hypothermia and cardiac arrest

answer

only useful for VT/VF

question

Cardiac arrest, blood gas changes

answer

Metabolic Acidemia - Lactic Acidosis Respiratory Acidemia/Alkalosis - depending on ventilation Low HCO3- Low PaO2 Neg BE (quantify degree of MA) Hyperkalemia (from acidosis) Hyperglcemia (stress response)

question

Postobstructive pulmonary edema

answer

Obstruction then patient takes a large breath (e.g. closed APL, patient bitting on the ETT)

question

Postoperative urinary retention

answer

The risk of retention is especially high after anorectal surgery, hernia repair, and orthopedic surgery and increases with advancing age. - >750 mL fluids - Long duration of surgery - Spinal anes with (long acting LA, high dose LA, high dose Opioids, hydrophilic opioids like morphine)

question

Risk factors for PONV

answer

Patient: - Female - non smoker - h/o motion sickness Anesthesia: - inhaled anesthestic -N2O - intra and postop opioids Surgery: -duration > 30 min increases risk to 60% - types (celioscopy, ENT, Neuro, breast, strabismus, laparotomy/laproscopic, plastic surgery)

question

TOF and pharyngeal muscle strength

answer

TOF >0.9 return of pharyngeal muscle strength. Abductor pollicis (AP) last to return orbicularis oculi (OO) is a beter predictor of the onset of NMB at the vocal cords than AP. Laryngeal adductor muscles and OO block have similar onset times. The onset time at the OO is shorter than the AP. The OO is thought to better reflect the diaghram and laryngeal muscles than AP.

question

Nausea during spinal blocks

answer

Increased vagal activity after sympathetic block causes increased peristalsis of the gastrointestinal tract, which leads to nausea. More common in high blocks

question

Contraindications to spinal anesthesia

answer

Absolute: - patient refusal - local anesthetic allergy - insurmountable technical difficulties - active infx at site of cannulation Relative: - bleeding diathesis (e.g. INR >1.2 or platelets < 80) - thrombophillia - continuing anticoag - hypovolemia - severe AS/MS - neurologic condition - raised ICP - previous back surgery at point of cannulation

question

Back pain after spinal anesthesia

answer

The frequency of backache is approximately similar after spinal or general anaesthesia. Localised trauma to the intervertebral disk or excessive stretching of associated ligaments after loss of lumber lordosis due to relaxation of paraspinal muscles are supposed to be the causative factors. The pain is usually mild and self limiting although it may last for several weeks. Nonsteroidal anti-inflammatory agents and warm or cold compresses are sufficient for backache. Although backache is usually benign, it may be an indication of more serious complications like epidural abscess, spinal hematoma or syndrome of transient neurologic symptoms.

question

Treatment of bupivacaine cardiotoxicity

answer

Treat seizures with GABA agonists. Treat convulsions with paralytics and airway management. Vasopressors may be indicated, although in some animal models they have been shown to promote CNS toxicity (still, on that basis they should not be withheld in the setting of cardiovascular collapse). Total cardiovascular collapse may be treated with CPR plus 1.5-4 mL/kg bolus of 20% lipid solution followed by 0.25-0.5 mL/kg/min for 10-60 minutes.

question

Determinant of epidural spread

answer

Age - older is faster Pregnancy - engorgement of epidural vv by inc intraabdo pressure Positioning - later decub and trendelenburg faster Needle direction and catheter position Volume of LA Concentration of LA Addition of NaHCO3 - increased nonionized fraction of LA and thus better penetration alpha2-agonists and opioids pKa of the anesthetic ****

question

Respiratory effects of spinal block

answer

Neuraxial blockade plays a very minor role in altering pulmonary function. Even with high thoracic levels of blockade, tidal volume is unchanged. There is a slight decrease in vital capacity. This is the result of relaxation of the abdominal muscles during exhalation. The phrenic nerve is innervated by C3-C5 and is responsible for the diaphragm. The phrenic nerve is extremely hard to block, even with a high spinal. In fact, apnea associated with a high spinal is thought to be related to brainstem hypoperfusion and not blockade of the phrenic nerve. This is based on the fact that spontaneous respiration resumes after hemodynamic resuscitation has occurred.

question

Local anesthetic test doses

answer

Traditional Test Doses: - lidocaine: 1.5% w/ epinephrine - bupivacaine 0.25% w/ epi - 2-chloroprocaine w/ epi What is a positive test dose? Increase in HR by 10 beats is usually taken as an IV injection IT injection is usually evidenced by unusual sx by the pt: tinnitus, dysgeusia (odd taste in mouth), periororal numbness/tingling NOT THERE IS CONTROVERSY OVER THIS TECHNIQUE

question

Intravscular injection of test dose

answer

- Drowsiness - Perioral/tongue parasthesia - tinnitus, auditory hallucination - muscular spasm - seizures - coma - respiratory arrest - cardiac arrest

question

Treatment of post-spinal headache

answer

- Supine - NSAIDS - Methylxanthine derivatives (e.g. caffeine) - epidural blood patch

question

Intermediate Cardiac Risk Procedures

answer

High (>5%): VASCULAR!!! --> peripheral/aorta Intermediate (1-5%): - intraperitoneal/intrathoracic - Carotid endartectomy - H and N - Ortho - Prostate Low (<1%): - Endoscopic - Superficial - Cataract - Breast - Ambulatory

question

Airway Exam

answer

a. Patency of nares, deviated septum, etc b. Mouth opening > 3 large finger breaths (> 3 cm) c. Teeth (prominent upper incisors, severe overbite, edentuous) d. High arched palate e. Prognathism (ability to protrude lower jaw beyond upper incisors) f. TMJ movement g. TMD > 6 cm (3 FB) h. ROM neck i. Stridor? (stenosis, angioedema, burns, obs) j. Mallampatti k. Neck circ (OSA, Obesity) --> 17 inches M, 16 FM l. Beard

question

Risk of deep vein thrombosis

answer

Patient-related risk factors for VTE include age older than 40 years, malignancy, estrogen use, immobilization, varicose veins, severe cardiopulmonary disease (prior MI, congestive heart failure, chronic obstructive pulmonary disease), prior stroke, paralysis or spinal cord injury, prior VTE events, hyperviscosity syndromes (polycythemia vera or malignancy related), and major vascular injury. Highest risk surgeries --> major ortho High risk surgeries --> general and emergency, major gyne, neuro, urological

question

Preop evaluation of asthma

answer

Determine if controlled or uncontrolled: no nocturnal symptoms, SABA <= 2x/week, symptoms <= 2x/week, no significant activity limitations, no hospitalizations, FEV1 N

question

Preoperative vitamins

answer

All good except vitamin E (bleeding risk) Good preop med list: http://med.umich.edu/preopclinic/guidelines/meds_to_stop1.pdf

question

Functional capacity and metabolic equivalents (METS)

answer

3.5 ml/kg/min = 1 MET

question

ASA Physical Status Classification

answer

1. Healthy person. 2. Mild systemic disease. 3. Severe systemic disease. 4. Severe systemic disease that is a constant threat to life. 5. A moribund person who is not expected to survive without the operation. 6. A declared brain-dead person whose organs are being removed for donor purposes.

question

Epinephrine reactions and local anesthesia

answer

Epinephrine causes vasoconstriction. Epinephrine may cause: cardiac palpatations

question

Pre-op cardiac assessment

answer

https://www.google.com/search?q=preoperative%20cardiac%20evaluation%20ppt&rct=j ppt then algorithm

question

Lab tests in healthy patients

answer

Routine laboratory tests in patients who are apparently healthy on clinical examination and history are not beneficial or cost effective http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2464262/table/T1/

question

Preoperative ACE-Inhibitors

answer

Hold day of surgery. Hypotension can be refractory to traditional interventions such as administration of a fluid bolus, ephedrine, or phenylephrine. Vasopressin and methylene blue have been found to be effective treatments for ACE inhibitor-associated refractory hypotension

question

Continuation of Preop Drugs

answer

http://med.umich.edu/preopclinic/guidelines/meds_to_stop1.pdf

question

Treatment of Warfarin Anticoagulation

answer

Warfarin hold for 5 days Aspirin hold for 7 days (caution with stented px's) Plavix hold for 7 days (caution with stented px's) Do not discontinue either aspirin or clopidogrel in patients with coronary stents unless given specific permission to do so by the cardiologist who prescribed these medications.

question

Capnogram and Pulmonary Embolus

answer

Exponential decrease in the capnograph's amplitude

question

Failure of piped O2 -- effects

answer

The low pressure or oxygen supply failure alarm will go off when there is a significant increase or decrease of the O2 supply pressure. This occurs when there is a sudden loss of cylinder or pipeline pressure or when the anesthesia machine is turned on or off.

question

Circuit valve malfunction

answer

Work through the circuit from gas inlet to patient

question

Pulse oximeter artifacts

answer

Motion artifact can show lower values Nail polish (black, blue, green) Venous congestion Low peripheral perfusion

question

Color coding of gas cylinders

answer

USA: Green - O2 (E cylinder = 660, H Cylinder 7000, 2000 psi) Yellow - Air (E cylinder = 660, H Cylinder 7000, 2000 psi) Blue - N2O (E cyl = 1590, H cyl 15,900, 745 psi, liquid) Black - N2 (E cyl = 660, H cyl 7000, 2000 psi) International (same E cyl, H cyl, pressures and forms) White - O2 (660, 7K, 2K) White and Black - Air (660, 7K, 2K) Blue - N2O (1590, 15,900, 745) Black - N2 (660, 7K, 2K)

question

Scavenging system failure

answer

capnograph does not return to baseline there may be leak

question

E cylinder/ oxygen pressure/ volume relationship

answer

O2 (E cylinder = 660, H Cylinder 7000, 2000 psi) Same for all gases except N2O (1590, 15,900, 745 psig)

question

Inspired oxygen monitoring

answer

The unidirectional valves in the inspiratory and expiratory limb of a breathing circle system prevent rebreathing. Inspection of the valve leaflets during ventilation ran detect some valve malfunc6ons. Difficult to see are malfunctions caused by a warped valve disc. Spirometry in the circle system helps monitor valve function. If the inspiratory valve becomes incompetent, some of the expired volume returns into the inspiratory limb of the breathing circle; the expired tidal volume, therefore, is reduced

question

ASA monitoring standards

answer

ASA monitoring standards (what is essential) a. Qualified Anesthesia Personnel b. Oxygenation (SpO2) c. Ventilation (ETCO2) d. Circulation (ECG, BP) e. Temperature shall be continually evaluated. f. Agent specific monitor (i.e. anesthetic gas monitor)

question

Desflurane vaporizer

answer

Desflurane's unique characteristics (high volatility/moderate potency) require the use of a special vaporizer for proper utilization of this gas. Desflurane vaporizers are heated to 39 degrees C, which increases the vapor pressure in the sump to 1300mmHg, preventing the possibility of boiling in warm OR rooms. Providing an external heat source compensates for the significant heat loss associated with desflurane vaporization. And unlike stand variable bypass vaporizers that pass fresh gas through the vaporizing chamber, desflurane vaporizers add agent directly to the gas stream.

question

Anesthesia vaporizers and principles of operation http://www.howequipmentworks.com/vaporisers/

answer

All vaporizers (except Des which use Tec 6) use: Variable bypass- Fresh gas flow from the flowmeters enters the inlet of any vaporizer which is on. The concentration control dial setting splits this stream into bypass gas (which does not enter the vaporizing chamber), and carrier gas (also called chamber flow, which flows over the liquid agent). So some of the carrier gas flows freely and some is mixed with the inhalation anesthetic. Flow over- Carrier gas flows over the surface of the liquid volatile agent in the vaporizing chamber, as opposed to bubbling up through it (as in the older copper kettle and Vernitrol)

question

NIBP function http://www.infiniti.se/upload/Bruksanvisningar/CAS/NIBP%20Simulator%20White%20Paper%20II%20Oct07.pdf

answer

- Cuff pressure is increased to completely occlude the artery - pressure is decreased and there is a increase amplitude of the oscillating flow - sBP is found to be about 25-50% of MAP - maximum amplitude is determined = MAP - MAP = DP + 1/3 [SP-DP] --> dBP is calculated

question

Abnormal capnograph patterns

answer

Encyclopedia http://www.capnography.com/new/capnograhs/en-chinaal

question

Basal Oxygen Consumption

answer

1 Metabolic equivalent = 3.5 mL O2/kg/min

question

O2 saturation/ PAO2 relationship

answer

PaO2 (mmHg) O2 sat 27 50 40 75 60 90 100 98 Right shift with "running man" (inc temp, dec pH, inc 2-3 DPG) --> reduced O2 affinity so O2 is released easier Arterial O2 Content=SaO2 x 1.34 x Hb + 0.003(PaO2) 1.34=ml O2/gram Hb

question

CO2 measurement -- ET vs arterial line

answer

P(arterial - end tidal)CO2 gradient N= 2 to 5 Acute Decrease in Perfusion (i.e. dead space) = 22 (results in large drop in ETCO2 --> e.g. PE, dec in CO) Acute Decrease in Ventilation (i.e. shunt) = 6 (results in normal ETCO2 but inc in PIP --> alveoli to collapse or fill with fluid, such as periods of shallow breathing, bronchial intubation, or increased bronchial and alveolar secretions that cause mucus plugging, or atelectasis)

question

Oxyhemoglobin dissociation

answer

PaO2 (mmHg) O2 sat 27 50 40 75 60 90 100 98 Right shift with "running man" (inc temp, dec pH, inc 2-3 DPG) --> reduced O2 affinity so O2 is released easier Arterial O2 Content=SaO2 x 1.34 x Hb + 0.003(PaO2) 1.34=ml O2/gram Hb

question

Calculation of blood volume

answer

Calculation of blood volume (ml/kg) a. Women 65 b. Men 75 c. Infants 80 d. Neonates 85 e. Premature neonates 96 TOTAL BODY WATER: Elderly - 45% Men - 50% Women 60% Infant 70% 2/3 --> ICF 1/3 --> ECF --> then 3/4 is ISF and 1/4 is IVF

question

Interpretation of blood gases

answer

Acidemia: Metabolic --> low HCO3 Resp --> high PaCO2 Alkalosis: Metabolic --> high HCO3 Resp --> low PaCO2

question

Correction for Acid/Base

answer

"1 for 1, 10 for 7, 1, 4, 2, 5" 1:1 Metabolic acidosis 10:7 Metabolic Alkalosis (inc 10 HCO3, inc 7 PaCO2) 1:10 Acute Resp Acidosis 4:10 Chronic Resp Acidosis 2:10 Acute Resp Alkalosis 5:10 Chronic Resp Alkalosis for every 10 inc PaCO2, pH dec 0.08

question

Metabolic Acidosis

answer

AG (Na - Cl - HCO3) --> greater 10; falls 2.5 for 1 fall albumin CATMUDPILES: C- CO, Cyanide, Congenital HF A- Aminoglycosides T- Theophyline, Toluene M-Methanol U- Uremia D- DKA, starvation acidosis P- Paracetamol (tylenol), paraldehyde I- Iron, isoniazide, inborn errors of metabolism L- Lactic acidosis E- Ethanol, Ethylene glycol S- Salicylates (ASA)

question

Non-AG Metabolic Acidosis

answer

USEDCARS Ureterosigmoidostomy Saline (large volumes) Early Renal Failure (impaired HCO3 generation) Diarrhea (GI loss of HCO3) Carbonic Anhydrase inhibitors (renal H+ retention) Amino Acids (arginine, lysine) RTA Supplements (TPN - excess chloride vs acetate)

question

Metabolic Alkalosis

answer

Saline-Responsive: - Volume Depletion (NGT, Vomiting, villous adenoma) - Diuretics/"contraction alkalosis" (diuresis --> loss of HCO3 poor fluid --> extracellular fluid "contract" around fixed HCO3 --> inc [HCO3] -Posthypercapnea (recent resp acidosis, kidneys not completely readjusted) Saline-Resistant (excess steroid) -HTN --> hyperaldosteronism, cushings, liddle's, exogenous minercorticoid) -Normotensive --> hypokalemia (severe), Milk alkali syndrome (exogenous alkali), Barter's/Gittleman's

question

Respiratory Acidosis

answer

"Won't Breath or Can't Breath" Won't: -CNS depression --> sedatives, head injury, infarct, infx, hypothyroid, severe metabolic alkalosis Can't - Neuromuscular Dz - Parenchymal/AW dz --> PNA, CHF, Restrictive Lung Dz, ILD, COPD, Asthma - Thoracic abnrm --> kyphosis/scoliosis, flail chest, obese, effusion, fibrosis, PTX

question

Respiratory Alkalosis

answer

Hyperventillation Primary: - pain, fever, CNS, ASA, progesterone, Beta agonists, pregnancy, sepsis, liver failure, excessive ventillation Secondary: -asthma, PNA, PE, Restrictive Lung Dz, CHF (early)

question

Ventilation assessment during anesthesia

answer

- Adequacy --> clinical signs plus ETCO2 - Assessment of ETT/LMA placement - Detection of circuit integrity - Depth of Anesthesia

question

Denitrogenation and Functional residual capacity good picture to include https://drkamaldeep.files.wordpress.com/2013/06/image_thumb.png?w=784&h=475

answer

Effective preoxygenation/denitrogenation with 100% oxygen increases the oxygen content of gas in the patient's functional residual capacity (FRC) from 21% towards 100% which should theoretically produce a proportionate increase in the safe apnoea time Average time is approximately 3 minutes of TV with 100% O2 OR 8 vital capacity breaths

question

Paradoxical respiration

answer

There is also dyssynchrony between rib cage and abdomen, causing a "seesaw" type motion. Blunt injury (diaphragmatic injury/paralysis) Flail chest Pneumothorax High AW obstruction (e.g. tracheal obstruction)

question

Effects of defasciculation dose

answer

Fasciculations: - Associated with increased ICP, IOP, IGP - ICP only clinically important - Cause and Effect - unknown - If needed pre-treat with Lidocaine, and a defasciculating dose of a non-depolarizing neuromuscular blocker - - Rocuronium 0.06 mg/kg

question

Atracurium dose, metabolism, and SEs

answer

0.5 mg/kg 3 min onset 45 min duration Ester hydrolysis and Hoffman Elimination Hypotension/Tachycardia/Bronchospasm (Re: histamine)

question

Cisatracurium dose, metabolism, and SEs

answer

0.15-0.2 mg/kg 3-7 mins onset (dose dependent) 45-60 min duration Hoffman Elimination Side Effects are minimal (minimal histamine release)

question

Pancuronium dose, metabolism, and SEs

answer

0.1 mg/kg 4 min onset 100 min duration Primarily hepatic metab and RENAL excretion - HTN/Tachycardia (vagal block and sympathetic stimulation) - AV blockade - Possible allergic rxn if allergic to bromides Pancuronium, Doxacurium, vercuronium and pipecuronium partial excretion by kidneys thus renal failure may lead to prolonged blockade

question

Vecuronium dose, metabolism, and SEs

answer

0.1 mg/kg 2.5 min onset 45 min duration Hepatic Metabolism --> prolonged blockade with infusion in ICU (3-hydroxy metabolite). Some Renal involvement Primary SEs LIVER FAILURE (80% hepatobil metab/exc) Prolonged blockade with infusion

question

Rocuronium dose, metabolism, and SEs

answer

0.6-1.3 mg/kg 1.5 min onset 30-45 min duration Hepatic exc/metab Slight vagolytic properties

question

Succinylcholine dose, metabolim, and SEs

answer

1-2 mg/kg 30-60 sec onset 5-10 min duration metabolized by pseudocholinesterase Beware of situation of high K+ (inc about 0.5 meq) - burns after 24 hours to 6 months - rhabdo/quads/immobility - risk of elevated ICP - MH - Histamine release - Sinus bradycardia

question

Anesthesthetic agents and bronchodilators

answer

Most volatile anaesthetic drugs are bronchodilators and can be effective under anaesthesia. Ketamine is also a bronchodilator. Halothane, isoflurane, enflurane, sevoflurane, ether (nitrous oxide) NOT DES!!!!

question

Risk factors for latex allergy

answer

skin symptoms with latex glove use (hives, rash, itching) history of atopy and a history of allergy to certain fruits ***bananas, avocados, kiwis***

question

Recovery after general anesthesia

answer

- Reverse the NMB with anticholinesterase (e.g. neostigmine 0.04-0.08 mg/kg) in conjunction with anticholinergic (e.g. 0.2-1 mg) - Turn off anesthetic (volatile or intravenous) - Ensure adequate reversal - Post operative analgesia (narcotics, adjuncts, regional) - PONV prevention - Remove airway

question

Blood/gas partition coefficient the volatiles

answer

N2O - 0.47 Halothane - 2.4 Isoflurane - 1.4 Desflurane - 0.42 Sevoflurane - 0.65

question

MAC values of the volatiles

answer

N2O - 105 Halothane - 0.75 Isoflurane - 1.2 Desflurane - 6 Sevoflurane - 2

question

Side effects of desflurane.

answer

Note fastest wake up with lowest B/G partition coefficient CV - dec BP, dec SVR, stable HR, stable CO Resp - dec TV, inc RR Cerebral - inc BF, inc ICP, dec metabolic rate, dec seizures Renal - dec BF, dec GFR, dec U/O Hepatic - dec

question

Solubility of agent and speed of induction

answer

lower the solubility the faster the induction and emergence Blood/gas partition coefficient N2O - 0.47 Halothane - 2.4 Isoflurane - 1.4 Desflurane - 0.42 Sevoflurane - 0.65

question

Succinylcholine and recent stroke

answer

Contraindicated because are at increased risk of severe hyperkalemia

question

Adverse effects ondansetron

answer

• 5-HT3 serotonin antagonist Adverse effects: Constipation, dizziness, and headache. QT PROLONGATION

question

Neuromuscular blocking drugs in renal failure

answer

Paralytics in Setting of Renal Failure - Rocuronium: t 1/2 increased 37%, may not translate into increased duration - Vecuronium: t 1/2 increased 24-56%, duration longer and more variable - Pancuronium: t 1/2 increased 97%, prolonged duration of action

question

Potency of inhalation anesthetics

answer

Potency measured in Minimum Alveolar Concentration MAC = alveolar concentration at which 50% of patients will not move in response to standard surgical stimulus 1.3 MAC --> 95% of patients will not move to surgical stim MAC-BAR (blocks adrenergic response to nociceptive stim) --> 1.5 to 2 MAC MAC-Aware --> 0.5 MAC MAC-Awake --> 0.15 to 0.5 MAC

question

Factors enhancing inhalation induction (Dec MAC thus Inc Potency)

answer

Acidosis Acute alcohol use Advanced Age Anemia Altitude Benzos IV anesthetics Hypotension Hypothermia Hypoxia Opiates Pregnancy

question

Factors that increase MAC (decrease potency)

answer

Chronic ETOH Very young age (max MAC at 1 yoa) Increased temperature (>42 degrees) Decreased Altitude Drugs: MAOIs, TCAs, Cocaine, acute amphetamines

question

Pattern of residual neuromuscular blockade (TOF <0.9 is now considered as residual neuromuscular blockade)

answer

Upper airway pharyngeal and esophageal muscles: -Increased risk of aspiration - Increased risk of airway obstruction Laryngeal muscles: - Increased risk of aspiration - Impaired phonation - Impaired cough Respiratory muscles - Impaired ventilation and oxygenation Other: - Generalized weakness - Visual disturbances - Patient distress - Prolonged Vent Weaning

question

Ester vs Amide Local Anesthetics

answer

Amides ("i") --> Liver Metabolized: - Etidocaine; rapid, 2.5 (4), 4 hours (8 h) - Mepivacaine; rapid, 5 (7), 3 hours (6 h) - Lidocaine; rapid, 4.5 (7.5), 2 hours (4 h) - Bupivacaine; slow, 2.5 (3), 4 hours (8 h) - Ropivacaine; medium, 2.5, 3 hours (6 h) - Prilocaine; medium, 5 (7.5), 1.5 hours (6 h) Esters --> Plasma Metabolized: - Cocaine - Tetracaine; slow, 1.5 (2.5), 3 hours (10 h) - Procaine; slow, 8 (10), 45 min (90 min) - Chloroprocaine; rapid, 10 (15), 30 min (90 min) - Benzocaine

question

Interaction of inhalational anesthetic and neuromuscular blockade

answer

Neuromuscular Nondepolarizing Blockade N20 - ↑ Halothane - ↑↑ Isoflurane- ↑↑↑ Desflurane - ↑↑↑ Sevoflurane - ↑↑

question

Sevoflurane metabolism

answer

Hepatic (P-450). Not to the same extent as Halothane (worried about halothane hepatitis in 1/35,000) but still something to keep in mind

question

Post-op nausea and induction drugs

answer

Anesthetic Factors: Duration of surgery Adequate hydration Volatiles Opioids

question

Adverse effects of antiemetics

answer

5-HT3 Receptor Antagonists (Ondansetron, Dolasetron, other "trons") --> QTc prolongation, H/A, Constipation, Dizziness Corticosteroids --> infx, blood glucose Butyrophenones (droperidol) --> QTc prolongation. Haloperidol --> QTc prolongation, extrapyramidal signs Antihistamines --> drowsiness Anticholinergics (e.g. scolpamine) --> visual disturbances, dry mouth, and dizziness Phenothiazines (e.g. metaclopramide) --> Contraindications: pheochromocytoma (can cause catecholamine surge), Parkinsons, hyperprolacinemia Adverse effects: Fatigue, Diarrhea, abdominal cramping, Restlessness NMS, Tardive Dyskinesia, focal dystonia, Depression

question

Succinylcholine after neostigmine

answer

depolarizing relaxant (sux) after reversal, which would prolong it's duration because of the pseudocholinesterase inhibition of neostigmine.

question

Definition of time constant

answer

time constant of volatile (τ) = volume/flow Definition (circuit): volume of the circuit divided by the fresh gas flow rate Definition (lungs): volume of the lungs (FRC) divided by minute ventilation Meaning: it takes three time constants for 95% of a concentration change to be achieved

question

Laryngospasm and desflurane

answer

Pungency and AW irritation can produce: salivation breath holding coughing laryngospasm

question

First-order kinetics

answer

First Order Kinetics: Elimination of the Drug is directly proportional to its plasma concentration. t1/2 (1) --> 50% t1/2 (2) --> 25% t1/2 (3) --> 12.5% t1/2 (4) --> 6.25% t1/2 (5) --> 3.125

question

Phenylephrine heart rate effect

answer

alpha 1 agonist Phenylephrine often causes a reflex bradycardia (baroreceptors).

question

Tachycardia with muscle relaxants

answer

Pancuronium --> significant vagal blockade Rocuronium --> mild vagal blockade Atracurium --> histamine release

question

Methoclopramide mechanism of action

answer

Dopamine (D1) antagonist --> prokinetic

question

Succinylcholine train-of-four

answer

A depolarized post-junctional membrane (resulting in inactivation of Na channels) causes the postjunctional membrane to become unresponsive to ACh released by motor neurons. --> "Phase I block" & produces a characteristic reduction in contractile response (***with no fade***) during a train of four stimuli. After 60 sec a flaccid paralysis develops due to the development of a desensitized state where the membrane becomes repolarized, but insensitive to ACh (due to receptor desensitization). --> "Phase II block" and responds to a train of four stimuli ***with a "fade"*** (like NDNMB)

question

Vapor pressure of Volatile Anesthetics

answer

N20 - Halothane - 243 Isoflurane - 248 Desflurane - ***669**** Sevoflurane - 157

question

Vasoactive drugs

answer

http://www.aaemrsa.org/UserFiles/HelpfulDocVasopressorsTable3.JPG

question

Rocuronium elimation

answer

Rocuronium undergoes no metabolism and is eliminated primarily by the liver and slightly by the kidneys.

question

Tachycardia treatment

answer

- Ensure adequate oxygenation and ventilation - Verify ECG leads - Assess BP (treat accordingly) - Consider Arterial line placement - Assess volume status - Assess depth of anesthesia - Determine if pain involved - Treat underlying cause --> ddx: pain, light, hypovolemia, hypercapnia, hypoxia, acidosis, drugs, electrolytes (hypomag, hypokal, hypoglycemia), myocardial ischemia, endocrine (pheo, hyperthyroid, carcinoid, adrenal crisis), bladder distension

question

Differentiate between ropivacaine and bupivacaine

answer

Both Amides - Bupivacaine; slow, 2.5 (3), 4 hours (8 h) - Ropivacaine; medium, 2.5, 3 hours (6 h)

question

Side effects of succinylcholine

answer

CV - variable HR, BP Fasiculations Hyperkalemia (know high risk groups) Myalgia Increased intragastric pressure Increased IOP Masseter Muscle Rigidity MH Histamine release (mild)

question

Sodium bicarbonate effects

answer

- Useful for Metabolic Acidosis if pH but not if high anion gap - Emergency treatment of hyperkalemia - Alkalinisation of local anesthetics: 1) Firstly, the higher pH of the solution may result in less stinging pain being experienced by the patient 2) Secondly, after injection, the pH of the injected solution may more quickly approach that of the normal tissue pH. The faster formation of a mixture with charged and uncharged forms may then result in ***more rapid drug diffusion and a quicker onset of nerve blocking***

question

Characteristics of ephedrine

answer

alpha 1, beta 1, mild beta 2 agonist Indirect effect by NE release at sympathetic nerve endings inc HR, inc BP, inc CO avoid in patients taking MAOi or with closed angle glucoma

question

ARB Refractory Hypotension Therapy

answer

similar mechanism as ACEi refractory hypotension

question

Laparoscopy: Hemodynamic Changes

answer

3 factors: increased intraabdominal pressure, pressurized with CO2, Trendelenburg positioning CVS - Decreased preload, CO (+/- contractility in ICM) - Inc venous pressure secondary to increased intrathoracic pressure - Increased thoracic pressures (PAP, CVP, PCWP) - Increased afterload (SVR, PVR, MAP) - No change/increased HR - Increased SNS

question

Fasting Guidelines

answer

Clear liquids - 2 hours Breast milk - 4 hours Nonhuman milk/light meal - 6 hours Regular meal - 8 hours

question

Positioning Injury

answer

Lithotomy - common peroneal nerve and sometimes sciatic nerve injury Supine - caution with brachial plexus when arms outstretched Caution with ulnar nerve when elbows secured Closed Claims (ulnar nerve 28%, brachial plexus 20%, lumbosacral nerve roots 16%, and spinal cord 13%)

question

Intraoperative awareness

answer

Insufficient Anesthesia (MAC Aware - 0.3 MAC) Risk Factors: - Routine use of NMB (double incidence from .1% to .18%) - TIVA - Light anesthesia for sake of turnover - Hemodynamic instability - Procedures: Obstetric / Cardiac / Trauma - Patient Age - History of difficult airway - Limited cardiac reserve - History of substance abuse (chronic ETOH, anxiolytics, cocaine)

question

Treatment of postanesthetic hypercarbia

answer

Treatment includes identification and management of the cause of the hypoventilation, supplemental oxygen administration, verbal and tactile stimulation, deep breathing exercises, repositioning, and cautious use of analgesics or sedatives. Oxygen saturation monitoring is necessary, and capnographic monitoring may be appropriate for patients at risk May need reversal of causitive Rx (e.g. narcan, flumazenil)

question

Flumazenil: indications

answer

benzodiazepine overdose --> competitive antagonist at the benzodiazepine site on the GABAa receptor most appropriate if patients were benzo naive Flumazenil has numerous contraindications: - benzodiazepine dependence - coingestion of seizure threshold lowering or arrhythmia causing agents such as tricyclic antidepressants - tachycardia - QRS prolongation - anticholinergic symptoms (i.e. tricyclic antidepressant has been ingested) - seizure history

question

MH Triggers

answer

Sux and all inhaled anesthetics (except N2O). Presentation: - elevated ETCO2 - Tachycardia - Tachypnea - hyperthermia

question

Pneumoperitoneum effects

answer

Cardiac Resp CO2 absorption Renal Trochar insertion risk

question

Epinephrine Calculations

answer

CONC DOSAGE EQUIVALENCE PERCENT 1:1,000 1mg/mL 0.1% 1:10,000 0.1mg/mL 0.01% 1:100,000 0.01mg/mL 0.001% 1:200,000 0.005mg/mL 0.0005%

question

Calculating time remaining in E Cylinders

answer

T (min) = Remaining volume (L) / flow rate (L/min) --> determine remaining volume when given psig with cross multiplication of ratio to psi and known volume of E cylinder For O2 tanks you need a conversion: E cylinders --> T (min) = 0.28 x psig/ FR. OR --> T(hr) = psig/200 FR. H cylinder --> T(min) = 3.14 x psig / FR

AKT-1 Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards