Principles of Anesthesia Quiz #2 Flashcards
What is a primary survey for a trauma patient?
Takes 2-5 minutes ABCDE sequence of trauma -Airway -Breathing -Circulation -Disability -Exposure
What is a secondary survey to a trauma patient?
Begins only when ABCs are stabilized
Examine from head to toe and obtain studies
What is a tertiary survey for a trauma patient?
To avoid missed injuries
Identifies all injuries
Typically within 24 hours
Awake patient more able to commnicate
What is always the top priority of assessing a patient?
Establishing/maintaining a patent airway.
All patients with a severe trauma or head injury should be assumed that they have a what?
Unstable cervical spine fracture
Unconscious patient with major trauma is always at increased risk for ___ and must be ___ ASAP
aspiration
intubated
What does MILS stand for?
Manual in-line stabilization
If patient arrives with ETT in place, you must verify and document correct ___
position Neck extension or lateral rotation -moves ETT away from carina Neck flexion -moves ETT toward carina
List five criteria that increase the risk for potential instability of C-spine
Neck pain Severe distracting pain Any neurological signs and symptoms Intoxication Loss of consciousness
What are three assessment skills?
Look, listen, feel approach
What are three signs of adequate circulation? Inadequate circulation?
Adequate
-HR, Pulse amplitude, blood pressure, signs of peripheral perfusion
Inadequate
-Tachycardia, weak/unable to palpate peripheral pulses, hypotension, pale cool cyanotic extremities
What is the most common cause of shock in trauma patients?
Hypovolemia
-tachycardia, poor cap refill, decreased blood pressure, hypotension, tachypnea, delirium
What is not an accurate indicator of acute blood loss?
Hct, Hgb
-Dilutional hematocrit
In a patient with hypotension related to hypovolemic shock, how should you treat it?
IVF and blood products, not pressors.
Getting a Type and cross takes ___, a type and screen ___, uncrossed O-negative PRBC ___.
45-60 min
5-10 min
Immediately
What is the crystalloid of choice?
LR
NS leads to hyperchloremic acidosis
When using colloids, what is the best option?
Albumin over hespan or dextran
Remember to warm all fluids, cold fluids can exacerbate v-fib
When assessing disability, what does AVPU stand for in a rapid neurological assessment?
Awake
Verbal response
Painful response
Unresponsive
List things included in a secondary survey
Glasgow coma scale
CT for pneumothorax
Pericardiocentesis for pericardial tamponade
Check extremities for fractures
Foley and NGT placed
CXR obtained in all patients with major trauma
Tertiary survey is usually done within ___ hours of initial injuries.
24
What are four common induction agents for a trauma related patient?
Ketamine (1-2 mg/kg)
Etomidate (0.2-0.3 mg/kg)
Propofol (dose greatly decreased)
Pentothal
What are treatments for heard trauma patients?
Fluid restriction, unless hypovolemic Diuretics Bariturates Deliberate hypocapnia -Hyperventilate
What are things to avoid in head traumas?
Anesthetic agents that increase ICP Hyperglycemia Hypertension Hypotension Trendelenburg position Pre-medications Anticholinergics
What is cushing’s triad?
Hypertension (widening pulse pressure)
Bradycardia
Respiratory depression
What are signs of increasing ICP?
Early warnings: Change in LOC, irritability, mild confusion, pupillary change, decrease in Glasgow Coma Score
Late signs: Difficult to arouse, coma, posturing, fixed pupils, ECG changes, Cushing’s response.
Treatments for increased ICP?
Diuretics - Mannitol 0.5 g/kg Steroids - Decadron 1 mg/kg Barbiturates Deliberate hypocapnia (PaCO2 28-32) Mild hypothermia Intraventricular drain (IVD)
How do you calculate CPP?
CPP = MAP - (CVP or ICP)
keep > 60 mmHg
What high thoracic injuries will eliminate sympathetic innervation of the heart/vessels?
T1-T4
Spinal shock, acute injury higher than ___ will lead to severely impaired CNS function
T6
What is the triad of spinal shock?
Hypotension
Bradycardia
Hypothermia
Sux is safe to use during the first ___ hours following spinal injury
24-48
Autonomic hyperreflexia occurs when injury happens where?
Above T5 (85%)
What are symptoms of autonomic hyperreflexia?
Severe hypertension
Bradycardia
Cardiac dysrhythmias
What do you avoid with autonomic hyperreflexia?
Avoid anectine
What do you avoid with pneumothorax?
N2O
What do you do to turn a pneumo into an open pneumo?
14g into 2nd intercostal space at midclavicular line
Where are most bronchial ruptures located with a hemothorax?
2.5 cm of the carina
What is Beck’s triad and what does it identify?
Neck vein distention, hypotension, muffled heart tones.
Cardiac tamponade
What is common with cardiac tamponade?
Pulsus paradoxus - 10 mmHg decrease in BP during spontaneous respiration.
Best induction agent - ketamine
List meds you would give for patients with delayed gastric emptying
Tagamet - decreases H+ Antacid - neutralize existing acid Reglan - decreases gastric emptying time -10 mg po > 1 hours before induction -10 mg iv over 1-2 min
What is the most important factor to consider with gastric emptying time?
The between last po intake and time of trauma
What is a common assessment to guesstimate the area of burn on a patient?
Rule of 9s
What are the different depths and gradings of burns?
1st degree -Epithelium only 2nd degree -Extend into dermis; most painful 3rd degree -Destroy entire skin thickness and nerve endings 4th degree -Destroys muscle, tendon, ligament, and bone
What direction does carbon monoxide inhalation shift the oxyhemoglobin curve?
Left
What are interventions to treat carbon monoxide inhalation?
Administration of 100% O2 will shorten the half-life of COhb from 4 hours in room air to < 1 hour
What is the Parkland formula for fluid replacement in burn patients?
Crystalloid 2-4 ml/%BSA burned/kg over 24 hours
Typically use the high end of the range
4ml/%BSA burned/kg in 24 hours
Where does fluid shift in a burn patient?
From intravascular to interstitial space
What are key considerations when caring for a burn patient?
Increased metabolism
- increased O2 consumption and CO2 production
Hyperkalemia from tissue destruction
Heat loss is serious problem
What do you not want to use on burn patients in the first 24 hours?
Anectine
Need higher than normal doses of NDMR due to altered protein binding and increased number of extrajunctional Ach receptors
What are common problems in trauma?
Hypotension Hypovolemia Desaturation Hypertension Tachy/Bradyarrhythmias Sudden Cardiac Arrest
Where does blood shunt when using vasopressin?
Above the nipple line
What are the communicating blood supplies to the liver?
Portal vein
-75% of blood volume to liver is partially deoxygentated venous blood.
-low pressure, 6-10 mmHg
Hepatic artery
-from celiac trunk from abdominal aorta. 25% of blood volume to liver.
25% of CO - 800-1200 ml/min
What does the portal triad consist of?
Portal vein
Hepatic artery
Bile duct
Located at the corner of each hepatic lobule
Describe the 3 zones of the hepatic acinus
Zone 1 - Cells lie between portal triads, 1st to receive everything in the blood.
Zone 2 - Cells have intermediate characteristics between Zone 2 and 3.
Zone 3 - Cells are closer to central vein, last to receive incoming blood. (most susceptible to injury)
What are Kupffer cells?
Part of the monocyte-macrophage system, act as phagocytes to remove colonic bacteria, endotoxins, cellular debris, viruses and particulate matter from entering the bloodsream from the portal circulation.
Hepatic blood flow, ___% comes from hepatic artery, ___% comes from portal vein.
30
70
Hepatic artery blood flow is dependent on ___ and some degree of ___
metabolic demand
autoregulation
List perioperative causes of decreased hepatic blood flow
Mechanical ventilation Hypercarbia PEEP Hypotension Hemorrhage Hypoxemia
Hepatic arterial buffer response, what does it do?
Dilates hepatic artery to increase blood flow and compensate 25-60% for decreases in portal vein blood flow.
How is oxygen supplied to the liver?
Oxygen requirements for the liver are met 50% by the hepatic artery and 50% by the portal vein. Oxygen supply to the liver is 50:50
What drugs worsen hepatic dysfunction?
Acetaminophen, isoniazid, methyldopa, phenytoin, indomethacin
Describe the 2 types of hepatorenal syndrome
Type 1 - Serum creatinine doubles to >2.5 mg/dl in less than 2 weeks, poor outcome
Type 2 - Stable/slower course of progressive renal failure
What do liver tests identify?
Liver function tests do not measure hepatic function, they represent a release of damaged or dead hepatocyte intracellular contents into the systemic circulation at one point in time only
What measures actual liver function?
Albumin
Prothrombin time
Pseudocholinesterase concentrations
What is normal hepatic volume?
450 ml (~10% of total blood volume)
What is the most prevalent protein in the bloodstream?
Albumin
Describe serum bilirubin and what normal ranges are
Reflects the balance between production and biliary excretion, normal is <1.5 mg/dL. If bilirubin exceeds 3 mg/dL, jaundice is usually obvious.
Describe serum aminotransferases
Measures enzymes that are released into the circulation as a result of hepatocellular injury or death
AST, SGOT, ALT
Describe serum albumin
Normal range 3.5-5.5 g/dL, half-life is 2-3 weeks, so this test may be normal with acute liver issues, and albumin levels of less than 2.5g/dL are generally indicative of chronic liver disease, acute stress, severe malnutrition.
Which enzyme best assesses hepatocellular damage?
ALT (alanine transaminase) or SGPT (serum glutamic-pyruvic transaminase)
ALT most specific marker
What about the GST?
Glutathione S-transferase, detects drug-induced hepatocellular damage. GST best option for liver function tests unless 5 NT is available.
What about 5-NT?
5 nucleotidase, choose this test as gold standard for liver function against all other tests.
What volatile agent affects portal blood flow the most? Least?
Halothane the most
Isoflurane the least
List things that can result in drug-induced hepatitis
Direct dose-dependent drug toxicity Alcoholic hepatitis (most common) 25+ g or more of Acetaminophen Oral contraceptives Mushrooms Halothane
What are three major complications to cirrhosis?
Variceal hemorrhage from portal hypertension
Itractable fluid retention (ascites) and hepatorenal syndrome
Hepatic encephalopathy or coma
What NMDA do you want to use with cirrhosis patients?
Nimbex
What are the four major sites of portal vein hypertension?
Gastroesophageal
Hemorrhoidal
Periumbilical
Retroperitoneal
How is a MAC changed for a chronic alcoholic?
MAC is probably increased in a sober chronic alcoholic, and the acutely intoxicated nonalcoholic patient probably has a decreased MAC
What is the most common disorder in alcoholics?
Megaloblastic anemia
Ascites is secondary to ___
Portal vein hypertension
What is the diuretic of choice to treat ascites?
Spironolactone
If you draw off more than 5L of fluid on an ascites patient, what do you need to do?
Give 5-10 g/L of albumin
___ is the most important predictor or short-term survival after liver resection.
Intraoperative blood loss
Explain the Pringle maneuver
Minimizes EBL intraop, places clamp or tourniquet to occlude hepatic venous and arterial inflow during parenchymal transection, intermittent or continuous
Target ___ is the most important monitor during hepatic resection
CVP
What is fulminant hepatic failure?
Liver failure with encephalopathy
What is it called when there is a problem with the production of heme?
Porphyria
Acute intermittent porphyria produces the most serious symptoms and is caused by ___
Drug administration
___ stimulate increases and possibly overproduction in porphyrins
Barbiturates
What drugs do you avoid with porphyria patients?
KEPT MAN Ketorlac Etomidate Pentzocine Thiopental Methohexital Nifedipine
(Give IV glucose)
What are the 6 P’s of acute intermittent porphyria?
Porphobilinogen deaminase deficiency Pain in abdomen Pscyhological symtpoms Peripheral neuropathy Pee abnormality Precipitated by drugs
What is Budd-Chiari syndrome?
Blockage in one or more veins that carry blood from the liver back to the heart
What is a TIPS procedure and when do you do it?
Transjugular intrahepatic portosystemic shunt
For portal hypertension in ESLD
What are the three stages of liver transplantation?
Preanhepatic
Anhepatic
Neohepatic
What does a decrease in CO and an increase in SVR indicate in a new liver transplantation?
Graft is functioning correctly, if you are still giving large amounts of FFP and not using CaCl, indicates the new liver is able to metabolize the citrate preservative and base deficit normalizes.
A chronic alcoholic patient is bleeding and awaiting surgery, what treatments might be implemented to control the bleeding?
Platelet transfusion
Vitamin K
FFP
Cryoprecipitate (for low fibrinogen levels)
What do you treat delirium tremens with?
Long acting benzodiazepine (Librium)
When do you discontinue herbal medications before surgery?
1-2 weeks before
```
Saw Palmetto
Ginkgo biloba
Ginger
Garlic
Feverfew
all promote bleeding
~~~
How much cardiac output do the kidneys receive?
1,200 ml of blood per min. Most perfused organ. 20-25% of CO, 1.25L/min
What part of the kidney is most vulnerable to ischemia?
The inner stripe of the outer medulla
The medulla extracts 80% of the delivered oxygen it receives
Blood is delivered to the glomerulus via the ___ and exits the glomerulus via the ___
afferent arteriole
efferent arteriole
The ___ are the blood vessels supplying the loops of Henle
vasa recta
What’s the difference between glomerular filtration, tubular reabsorption, and tubular secretion?
Glomerular - Filters blood. High hydrostatic pressure.
Tub/reabsorption - Transport out of renal tubule back to body.
Tub/secretion - back into lumen, out to urine
What do the proximal tubule, loop of Henle, and distal tubule do?
Proximal - reabsorbs the bulk of filtered fluid
Henle - Establishes and maintains an osmotic gradient
Distal tubule - Adjusts urine pH, osmolality, and ionic composition
Calculate renal blood flow
RBF = (MAP-VP) x VR
VP - venous pressure
VR - Vascular resistance
What happens if a MAP drops below 60 mmHg?
Glomerular filtration ceases
What is the most common cause of renal failure?
Prolonged renal hypoperfusion, causing depression of RBF, GFR, urinary flow, and excretion of electrolytes
What is the most accurate method available to measure overall renal function?
Creatinine clearance
Normal 100-200
ESRD <10
What happens to H2 blockers and Reglan if given to patients with renal failure?
Will accumulate, no excretion
What volatile agent don’t you use with ESRD?
Sevo
What are some potentially nephrotoxic agents to avoid?
NSAIDs
Aminoglycosides
Radiographic dye
List loop diuretics
Furosemide (Lasix)
Bumetanide (Bumex)
Ethacrynic acid (Edecrin)
Torsemide (Demadex)
List thiazide diuretics
Work on distal tubule Chlorothiazide (Diuril) Hydrochlorothiazide (Esidrix, HydroDIURIL) Chlorthalidone (Hygroton) Metolazone (Zaroxolyn)
List potassium sparing diuretics
Spironolactone (Aldactone)
Triamterene (Dyrenium)
Amiloride (Midamor)
Name a carbonic anhydrase inhibitor
Acetazolamide (Diamox)
What is the best test to determine pre renal failure from renal failure?
Fractional excretion of filtered sodium (FEna), 90% specific and sensitive.
List GFR values for normal, decreased renal reserve, renal insufficiency, and uremia
Normal - 125 ml/min
Decreased renal reserve - 50-80 ml/min
Renal insufficiency - 12-50 ml/min
Uremia - <12 ml/min
List four common electrolyte disturbances in chronic renal failure
Hyperkalemia
Hypocalcemia
Hypermagnesemia
Hyperphosphatemia
List 6 interventions for treating hyperkalemia
Give Ca++ Administer HCO3- Hyperventilate Give insulin-glucose Administer a B2-adrenergic Give Kayexalate Dialyze patient
During a TURP, ___ ml of resecting fluid can be absorbed in each minute of resecting time, with the amount absorbed r/t size and congestion of gland, MD experience, and number of venous sinuses opened.
10-30
List signs of bladder perforation during a TURP
Abdominal pain, abdominal distention, skin cold/cooler over abdomen, pain, referred shoulder pain, hiccup, SOB, tachycardia, hypotension or hypertension, diaphoresis, vomiting
