Miscellaneous Flashcards
What functional groups are derivatives of ammonia and have the formula NR3?
Amines
What functional groups have the formula ROH, ROR’
ROH- alcohols and Phenols
ROR’- ethers
What is the maximum about of one substance that is able to dissolve into another?
Solubility (affected by intermolecular interactions, temperature and pressure)
what law describes the faster diffusion of smaller molecules compared to larger molecules?
Grahams law
Diffusion of a gas across a semipermeable membrane is inversely related to what two factors?
membrane thickness and molecular weight
What application of force measurement is used to monitor NMBs?
accelerometer
What are examples of scalar values?
mass, energy, and work
What are vector values?
magnitude and direction. EKG is also an examples
How do you convert Celsius to Kelvin?
C + 273
How do you convert Celsius to Fahrenheit?
(C x 1.8) + 32
How do you convert Fahrenheit to Celsius?
(F-32) / 1.8
At what hour of a procedure do patient lose the most heat?
within the first hour
What are the four primary sources of heat loss in decreasing order?
1 radiation > convection > conduction > #4 evaporation
What is heat loss through radiation?
The patients warm body losing heat to the cold operating room air and equipment.
What is heat loss through conduction?
heat loss by touching a less warm environment. Warm body transferring warmth to the cold operating room table.
what is heat loss through convection?
heat loss through air currents.
What is heat loss through evaporation?
moisture evaporating from the patients skin. Prevented with a HME.
What the process called when a reaction does not increase or decrease a systems energy?
adiabatic
The rapid expansion of a gas causing cooling of the gas cylinder is know as what?
Joule-thompson effect
What type of flow occurs in the terminal bronchioles?
laminar flow
When is the Venturi effect applicable in the OR?
jet ventilation
According to LaPlace how do you calculate tension in a sphere and cylinder?
cylinder: T = P x R
Sphere: (P x R) / 2
What type of movement describes transverse waves?
up and down movement.
What type of movement describes longitudinal waves?
back and forth
What MRI zone poses the greatest risk of injury?
zone 4
What is the resistance to electrical flow?
impedance
Pulse oximetry readings are based off what Law?
Beer-Lambert
What wavelengths of light do oxygenated and deoxygenated hemoglobin absorb?
oxygenated: 940, Deoxygenated: 660
Which two positions increase the risk of compartment syndrome?
Lithotomy and trendelenberg
What are the three most common modalities responsible for nerve injuries?
Transaction, compression, and stretch
Which lower extremity nerve is susceptible to injury for tight table straps?
Lateral femoral cutaneous
Highlights of ulnar nerve injury.
Most common injury, inability to oppose the 4 and 5th fingers, CLAWHAND
Which cord of the brachial plexus does the ulnar nerve derive from?
Medial
What are the preferred arm position to avoid ulnar nerve injuries?
Supinated or neutral, abducted less than 90 degrees, padding
Which positions are associated with midcervical flexion myelopathy?
Sitting and prone
Postoperative visual loss is most likely caused by what two modalities?
Ischemic optic neuropathy and central retinal artery occlusion
Which surgical table is most associated with ION?
Wilson frame
To avoid compartment syndrome in the lithotomy position the legs should be periodically lowered at what time interval?
Every 2-3 hours
What is the gold standard preoperative monitor for detecting the potential for a PAE?
TEE with contrast
What two nerves may be damaged in the patient that has their legs crossed for a procedure?
Superficial personal nerve of dependent leg. Sural nerve of the superior leg
Location of first degree burns?
epidermis
Burn extending to the dermis?
second degree. Deep or superficial.
In a second degree burn injury, the skin will regenerate if what tissue is left intact?
epithelial basement membrane
What is the depth of a third degree burn?
extend to the subcutaneous tissue below the dermis
What tissues are damaged in a 4th degree burn?
muscle, bone, fascia
What is considered a major burn?
1) a second-degree burn involving more than 10% of the TBSA in adults or 20% at extremes of age, (2) a third-degree burn involving more than 10% of the TBSA in adults, (3) any electrical burn, or (4) a burn complicated by smoke inhalation.
Mortality of a burn is 80% likely if what two indices equals 115?
TBSA + age of patient
What are the four types of burn injuries?
chemical, electrical, thermal, and inhalation
What type of burn is likely most damaging?
electrical
What are the three treatment phases of a burn injury?
resuscitative, debridement and grafting, and reconstructive
Complete the table
Here it is!
What are the two clinical endpoints of an inhalation injury?
pulmonary edema and V/Q mismatch
What is the gold standard for diagnosing a inhalation injury?
fiberoptic bronch
What are the most worrisome signs of inhalation injury during a diagnostic fiberoptic bronch?
ulcerations and necrosis
The nebulization of which two agents may improve airway injury with inhalation burns?
heparin and N-acetylcysteine
What are symptoms of various carboxyhemoglobin levels?
COHgb shifts the curve which direction?
Left
How does COHgb affect SpO2 readings?
falsely elevated
A patient with CO poisoning should be treated with 100% FiO2 for how long?
until CO levels are less than 5% for 6 hours
What are the respiratory effects of cyanide poisoning?
hypoxia, lactic acidosis, and elevated MVO2
What is the treatment for cyanide poisoning?
Hydroxycobalamin (vitamin B12)
Fluid losses are the greatest in what time frame following a burn injury?
first 12 hours
What starling force is most affected by burn injury?
decreased capillary oncotic pressure. (pulling back into the capillary)
What is the most significant complication of fluid creep (over resuscitation)?
abdominal compartment syndrome
Intraabdominal hypertension is defined as a bladder pressure greater than ____ or intraabdominal pressure greater than ___.
bladder pressure greater than 12mmHg or intraabdominal pressure greater than 20mmHg.
What is the triad of symptoms of systemic inflammatory response syndrome?
increased CO, tachycardia, decreased SVR
how do burns affect pulmonary mechanics (FRC etc.)
decreased FRC, decreased chest wall compliance.
What are the preferred Vt and plateau pressures for a burn patient?
Vt < 7mL/kg of IBW, and plateau pressure < 31
What are the causes of early and lake AKI following a burn?
early- HoTN and myoglobinuria. late- sepsis
What are three indications to stop surgery on a burn patient related to blood loss and temperature?
more than 2 blood volumes are lost, temperature < 35 C or a decrease of 1.5 C from baseline.
What eye block is performed between the rectus muscles of the globe?
sub-tenon
What are the three biggest considerations for placement of a retrobulbar block?
eye position (neutral), needle depth (25mm/1 in), and needle angle (lateral to parallel).
A good indicator of analgesia of the globe is?
akinesia of the eye muscles
If LA injected for an eye block travels anteriorly underneath the conjunctiva it is called what?
chemosis ( subconjunctival edema)
What device is used to apply ocular compression after retrobulbar or peribulbar injection?
honan balloon
What is the proper inflation pressure of a Honan balloon?
30mmHg
Do anticoagulants need to be discontinued before a regional block for an eye procedure?
no
Which induction agents decrease intraocular pressure?
propofol and etomidate
N2O should be discontinued how many minutes before SF6 and perflouropropane injection?
15 minutes
Prolonged PONV following an eye procedure can be an indication of what complication?
increased IOP
What pupil changes post ocular block indicate subarachnoid or subdural injection?
Constricted before the block and dilates after
What is the first sign of BCIS in a patient under general Anesthesia?
decreased EtCO2
What are the first signs of BCIS with an awake patient?
dyspnea and altered LOC
What autonomic reflex is responsible for hypotensive bradycardic episodes seen in the sitting position?
Bezold-jarisch
What are the two main causes of visual loss following non-ocular surgery?
ION and retinal vascular occlusion
Obesity, male sex, Wilson frame use, longer anesthetic duration, and greater estimated blood loss are risk factors for what complication?
ION
What is the most common surgical eye injury?
corneal abrasion
Apart from the spine what organ does ankylosing spondylitis affect?
heart - valvular defects, conduction delays, and BBB.
Which class of lasers are incapable of producing damaging radiation?
class 1
What are the most common hazards of medical lasers?
thermal trauma, eye injury, perforation of organs or vessels, gas embolization, electrical shock, air contamination, and fire.
What are the three substances used to cool the tip of a laser?
air, CO2, or liquid
What type of laser creates the largest smoke plume?
CO2
The higher incidence of HTN in obese is due to what three factors?
Hyperinsulinemia, elevated mineralocorticoids, and abnormal sodium reabsorption
OSA
excessive episodes of apnea (10 seconds) and hypopnea during sleep that are caused by complete or partial upper airway obstruction.
Hypopnea
Hypopnea is defined as a 50% reduction in airflow for 10 seconds that occurs 15 or more times per hour of sleep, and is associated with snoring and a 4% decrease in O2 saturation.
What is the usual anatomical location of upper airway obstruction?
pharynx
Characteristics of obesity hyperventilation syndrome?
OSA, hypercapnia, daytime hypersomnolence, arterial hypoxemia, cyanosis- induced polycythemia, respiratory acidosis, pulmonary hypertension, and right-sided heart failure
What BMI must be achieved to be considered for bariatric surgery?
BMI > 40
What EKG finding in the obese is a marker for sudden cardiac arrest?
QT prolongation
What are the three most positive predictors of difficult intubation in obese patients?
Mallampati score (3 or greater) with a large neck circumference and a history of sleep apnea
What gastric volume is considered low risk for aspiration during induction?
less than 1.5mL/kg
What type of bariatric corrective surgery has the highest incidence of PONV?
gastric sleeve
What is the estimated blood volume of an obese patient?
45-55% of actual body weight
What nerves are most susceptible to injury in the obese population?
ulnar, brachial plexus, radial, peroneal, and sphenoid nerves
Following surgery on a bariatric patient, you expect the PaO2 to be the lowest on which post-operative day?
2-3 days post-op
Pre- and postoperative measurement of which lab value aids in early diagnosis of rhabdomyolysis in the obese patient?
creatinine phosphokinase (CPK)
What is the most sensitive sign of an anastomotic leak following bariatric corrective surgery?
unexplained tachycardia
