Practice III Flashcards
The majority of the venous return from the myocardium enters the:
- superior vena cava
- great cardiac vein
- coronary sinus
- Thebesian veins
coronary sinus
The great, middle and posterior left cardiac veins as well as the oblique vein of Marshall empty into the coronary sinus. The Thebesian veins, which transverse the myocardium, empty into the various chambers, but constitute only about 15% of the myocardial venous return.
When performing a caudal anesthetic, proper placement of the needle(s) is at:
(Make your selection by clicking on the appropriate area of the figure)
Caudal anesthesia can be thought of as a distal approach to the epidural space. With the patient prone or in the lateral position, the sacral hiatus is identified and a short-beveled needle is inserted midline between the cornua at a steep angle. When the canal is entered, the needle is lowered parallel to the sacrum and advanced into the epidural space.
Concerning intraocular pressure:
- the most significant hemodynamic parameter determining intraocular pressure is arterial blood pressure
- volatile anesthetic agents lower intraocular pressure
- hyperventilation will increase intraocular pressure
- increased PaO2 will lower intraocular pressure
volatile anesthetic agents lower intraocular pressure
Volatile anesthetic agents consistently lower intraocular pressure. The most significant hemodynamic parameter determining IOP is CVP. Hypoxia and hypercarbia both increase IOP, however IOP is not significantly changed by increases in PaO2.
The primary mechanism of heat loss from a patient in the operating suite is:
- evaporation
- convection
- conduction
- radiation
radiation
Radiation accounts for approximately 60% of the heat loss in the surgical patient. Other forms of heat loss in the surgical patient include evaporation (20%), convection (15%), and conduction (5%).
During a laparoscopic cholecystectomy in a 46-year-old female with a history of hypertension, you notice an acute rise in end-tidal carbon dioxide tension associated with a blood pressure of 78/45 mm Hg, and rales. Immediate therapy should include:
- correction of the volume overload with furosemide
- a 500ml bolus of NS
- asking the surgeon to release the pneumoperitoneum
- placement of the patient in reverse Trendelenberg position
asking the surgeon to release the pneumoperitoneum
Carbon dioxide embolism can result from unintentional insufflation of gas into an open vein. This may lead to hypotension, elevated end-tidal carbon dioxide levels, hypoxemia, and pulmonary edema. Treatment consists of immediate release of the pneumoperitoneum.
The polarographic oxygen analyzer is best represented by?
Make your selection by clicking on the appropriate part of the figure
The polarographic oxygen electrode (Clark electrode) consists of a voltage source and a current meter connected to platinum and silver electrodes immersed in a KCl solution. A membrane permeable to oxygen allows the diffusion of oxygen into the cell, where electrons are liberated by an oxidative reaction. The meter measures the current produced, with the current flow being proportional to the oxygen concentration.
A 78-year-old man is scheduled for a right carotid endarterectomy under general anesthesia. The most sensitive method for assessing cerebral perfusion during the procedure is:
- measurement of carotid stump pressures
- measurement of the oxygen content of jugular venous blood
- EEG monitoring
- somatosensory evoked potential monitoring
EEG monitoring
EEG monitoring is the most sensitive method of assessing the adequacy of cerebral perfusion in the anesthetized patient.
Which of the following herbal medications may cause an increase in bleeding during surgery? (Select 2)
- St. John’s wort
- Garlic
- Fish Oil
- Valerian
- Licorice
- Kava
Garlic, Fish Oil
All of the following herbal medications may adversely affect clotting: alfalfa, capsicum, chamomile, dong quai, feverfew, fish oil, garlic, ginkgo biloba, ginger, ginseng, goldenseal, guarana, horse chestnut, and willow bark. These medications should be discontinued for at least two weeks preoperatively. Coagulation studies should be performed in patients who are actively taking these herbals.
Compensatory mechanisms that buffer increases in intracranial pressure include:
- increased cerebrospinal fluid production
- displacement of cerebrospinal fluid into the spinal canal
- increased intracranial venous blood volume
- decreased cerebrospinal fluid absorption
displacement of cerebrospinal fluid in to the spinal canal
Within limits, increases in intracranial volume result in only small increases in intracranial pressure. Major compensatory mechanisms include a displacement of CSF into the spinal canal, increased CSF absorption, decreased CSF production, and decreased cerebral blood volume - mostly venous.
A display of arterial blood gas values is shown (Click here to display values). By dragging & reordering the selections in yellow, match the blood gas values with the corresponding metabolic abnormality.
metabolic acidosis
metabolic alkalosis
respiratory alkalosis
respiratory acidosis
#1 7.20/83/78/32 #2 7.55/97/40/34 #3 7.51/95/28/35 #4 7.22/88/37/15
Respiratory acidosis - #1
Metabolic alkalosis - #2
Respiratory alkalosis - #3
Metabolic acidosis - #4
A list of diuretic sites of action is shown below. By dragging & reordering the selections in yellow, match the diuretic with the corresponding site of action.
Hydrochlorothiazide
Spironolactone
Acetazolamide
Furosemide
Proximal Tubule
Collecting Duct
Loop of Henle
Distal Tubule
Acetazolamide-Proximal Tubule
Furosemide-Loop of Henle
Hydrochlorothiazide-Distal Tubule
Spironolactone-Collecting Duct
Pulse oximetry employs the absorption of two specific frequencies of light by hemoglobin to determine the oxygen saturation. This is an application of:
- Boyle’s Law
- Graham’s Law
- Charles’ Law
- Beer-Lambert Law
Beer-Lambert Law
The Beer-Lambert Law states that: (1) the luminance of perpendicular light on a surface is proportional to the inverse square of the distance it travels; (2) the luminance intensity of angled light is proportional to the cosine of the angle with the normal; (3) Luminance intensity decreases exponentially as the light travels through a medium. Analysis of the wavelength that is most absorbed corresponds to the concentration of that form of hemoglobin.
As compared to the classic LMA, advantages of the LMA ProSeal include:
- the ability to provide active gastric suctioning
- greater ease of insertion
- decreased peak inspiratory pressure
- the absence of a bite block
the ability to provide active gastric suctioning
The LMA ProSeal is a double lumen LMA allowing gastric drainage. In addition, the ProSeal has a bite block and allows a greater peak inspiratory pressure to be delivered.
A display of oxyhemoglobin dissociation curves is shown (Click here to display curves). By dragging & reordering the selections in yellow, match the physiologic state with the corresponding curve.
A
B
C
D
Acidosis
Alkalosis
Myoglobin Curve
Normal Curve
Myoglobin Curve-A
Alkalosis-B
Normal Curve-C
Acidosis-D
On a warm summer day, e-cylinders of oxygen and nitrous oxide are brought from the hospital loading dock into the air-conditioned operating room. The effect of the declining temperature on the e-cylinders is to:
- cause a decrease in tank pressure in both cylinders
- cause a decrease in tank pressure of the oxygen cylinder only
- cause a decrease in tank pressure of the nitrous oxide cylinder only
- cause a decrease in the critical temperature of the oxygen
cause a decrease in tank pressure in both cylinders
Following the Combined Gas Law, a decline in ambient temperature will cause a decrease in both tank pressure and tank volume. Since the critical temperature of oxygen is -118 C, oxygen cannot exist as a liquid at ambient temperatures.
The most common cause of chronic liver disease in the United States is:
- alcoholic cirrhosis
- hepatitis C
- cytomegalovirus
- non-alchoholic fatty liver disease
non-alchoholic fatty liver disease
Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the US. It is defined as fat accumulation in the liver exceeding 5% by weight. It has been estimated that 24% of American adults have NAFLD. Risk factors for its development are Type II DM and obesity; it is more prevalent in women, and it usually manifests in the fifth and sixth decades of life.
When using a pulmonary artery catheter to measure thermodilution cardiac output, factors that may cause a falsely elevated measurement include:
- pulmonic valve insufficiency
- aortic insufficiency
- intrapulmonary shunting
- mitral regurgitation
- VSD
pulmonic valve insufficiency, VSD
Recirculation of blood and injectate, in either the right atrium or right ventricle, can cause a falsely elevated measurement of CO. As a result, ASD, VSD, tricuspid regurgitation, and pulmonic regurgitation can cause a falsely elevated measurement of CO.
Post-operative shivering:
- it most commonly seen in the neonatal population
- is best treated with morphine 12.5 mg IV
- may increase O2 consumption and CO2 production by up to 200%
- decreases cardiac output and minute ventilation
may increase O2 consumption and CO2 production by up to 200%
Post-operative shivering may increase O2 consumption and CO2 production by up to 200%. It increases cardiac output and minute ventilation as well, which may precipitate ventilatory failure in patients with limited reserve and myocardial ischemia in patients with CAD. Along with restoration of normothermia, meperidine (12.5-25 mg IV) is most efficacious in suppressing post-operative shivering.
A 28-year-old male is undergoing an emergent laparotomy after sustaining multiple injuries in a motor vehicle accident. As a result of trauma to the inferior vena cava, the patient receives 12 units of packed red blood cells (PRBC’s), 3 units of fresh frozen plasma and 8 units of platelets over the course of an hour. During this period you notice a widening of the QRS complex with lengthening of the QT-interval on the ECG. The most appropriate therapy at this time is to:
- increase the rate of infusion of the PRBC’s
- stop the administration of all blood products
- administer intravenous calcium gluconate
- increase the rate of infusion of NS
administer intravenous calcium gluconate
Stored blood contains citrate to chelate the ionized calcium and prevent coagulation. During rapid infusion, greater than 1cc/kg/min, of blood products, patients can develop hypocalcemia secondary to citrate intoxication. Hypotension and ECG evidence of hypocalcemia, widening of the QRS complex and lengthening of the QT-interval, can be effectively treated with ionized calcium.
Risk factors for pregnancy induced hypertension (PIH) include:
- multiple previous pregnancies
- low blood pressure prior to pregnancy
- diabetes mellitus
- single fetus
diabetes mellitus
PIH is most prevalent in primigravidas. The pathophysiology of this disease is unknown. Additional risk factors include: extremes of maternal age, multiple births, pre-pregnancy hypertension, diabetes mellitus, asthma, renal disease and autoimmune disease.
Advantages of the piston ventilator include (Select 2):
- indentifiable auditory cues during ventilation
- use of air instead of oxygen as a driving gas
- fresh-gas decoupling
- improved accuracy of delivered tidal volume
- decreased dead space
- compensation of gas loss in cases of bellows leak
fresh-gas decoupling, improved accuracy of delivered tidal volume
Advantages of the piston ventilator include: it’s very quiet, no PEEP is applied, fresh-gas decoupling, greater volume precision and no driving gas is required. Disadvantages include: loss of familiar visible behavior of the standing bellows during a disconnect, difficulty in hearing the ventilatory cycle, hypoventilation if a bellows leak occurs and difficulty accommodating non-rebreathing circuits.
An acquired decrease in the level of plasma cholinesterase activity is associated with:
- obesity
- pregnancy
- electroconvulsive therapy
- alcoholism
pregnancy
Pregnancy causes an acquired decrease in plasma cholinesterase activity. Alcoholism, obesity, thyrotoxicosis, hemochromatosis, nephrotic syndrome and electroshock therapy all cause acquired increases in plasma cholinesterase activity.
During your preoperative evaluation, the rhythm strip below is obtained. This ECG tracing is consistent with:
- acute myocardial infarction
- complete heart block
- intraventricular conduction delay
- non-specific ST-T wave changes
intraventricular conduction delay
The QRS duration on the ECG above is greater than 0.12 seconds indicating an intraventricular conduction delay. Although ST - T wave abnormalities are present, they are expected in patients with bundle branch block patterns. Each QRS complex is preceded by a P wave and a PR interval less than 0.20 seconds, indicating no heart block. Since the lead of the tracing is unknown, we cannot determine if this is a left or right bundle branch block pattern.
Dexmedetomidine (Precedex):
- increases the MAC of volatile anesthetics
- causes CNS excitation via selective a-2 agonism
- reduces the incidence of perioperative hypothermia
- has analgesic properties
has analgesic properties
Dexmedetomidine (Precedex) is a more selective α-2 agonist than clonidine. It produces sedation/anxiolysis, it is an antisialagogue, it promotes hemodynamic stability, homeostatic reflexes remain intact, and it is a potent analgesic. It also attenuates opioid-induced rigidity in animals.
When performing spinal anesthesia, the largest vertebral interlaminal space can be found at:
- C7-C8
- T12-L1
- L5-S1
- S3-S4
L5 - S1
Anatomically, this is the largest interlaminal space and can be used to achieve spinal anesthesia with the Taylor approach.
A 53-year-old female is scheduled for a laparoscopic cholecystectomy. Past surgical history is notable for cardiac transplantation 3 years ago. Prior to induction, the vital signs are: temp 98.2, HR 88, BP 128/72. During insufflation, the patient becomes hypotensive and bradycardic. The most appropriate therapy in this patient is:
- atropine
- ephedrine
- isoproterenol
- glycopyrrolate
isoproterenol
The transplanted heart cannot respond to indirect acting agents such as ephedrine and even dopamine. Vagolytics such as atropine and glycopyrrolate will have no effect as the donor heart is essentially vagotomized. Beta effects of epinephrine and norepinephrine are exaggerated in heart transplant recipients. Isoproterenol is the mainstay of chronotropic therapy in these patients.
Cluster headaches (Select 2):
- are seen more frequently than migraine headaches
- occur more frequently in men
- are characterized by a dull aching pain in the occipital area
- are usually associated with an aura
- oar often associated with the presence of Horner’s syndrome
occur more frequently in men, are often associated with the presence of Horner’s syndrome
Cluster headaches are classically periorbital and unilateral and occur in clusters 1 - 3 times a day for a 4 - 8 week period. Cluster headaches are much less common than migraine headaches and occur predominantly (90%) in males. Headaches usually occur abruptly with no aura and are described as stabbing. Red eye, tearing, nasal stuffiness and ptosis (Horner’s syndrome) are classic findings.
A list of pathophysiologic conditions resulting in acid-base abnormalities is shown below. By dragging & reordering the selections in yellow, match the condition with the corresponding acid-base abnormality.
Pain/Anxiety
Fentanyl Abuse
Vomiting
Renal Failure
Metabolic Alkalosis
Respiratory Acidosis
Metabolic Acidosis
Respiratory Alkalosis
Vomiting-Metabolic Alkalosis
Renal Failure-Metabolic Acidosis
Pain/Anxiety-Respiratory Alkalosis
Fentanyl Abuse-Respiratory Acidosis
Cauda equina syndrome has been associated with (Select 3):
- the use of hyperbaric 5% lidocaine
- the use of hypobaric tetracaine
- an unexpected high level of anesthesia
- the use of micropore continuous spinal catheters
- the maldistribution of local anesthetic
- the addition of fentanyl to the anesthetic solution
the use of hyperbaric 5% lidocaine, the use of micropore continuous spinal catheters, the maldistribution of local anesthetic
Cauda equina syndrome after neuraxial anesthesia has been associated with the use of 5% lidocaine, micropore spinal catheters and the maldistribution of local anesthetic.
Local anesthetics indicated for use in an intravenous block include:
- bupivacaine 0.25%
- tetracaine 0.5%
- procaine 10%
- lidocaine 0.5%
Lidocaine 0.5%
Lidocaine 0.5% is the only local anesthetic approved for use in an IV regional anesthetic (A.K.A. Bier block) by the FDA. Vasoconstrictors should not be added to the solution. Bupivacaine is contraindicated for use as an IV regional anesthetic.
Vasodilator therapy is indicated in the treatment of:
- congestive heart failure
- right ventricular failure
- aortic stenosis
- mitral stenosis
- cyanosis associated with Tetralogy of Fallot
- aortic insufficiency
congestive heart failure, right ventricular failure, aortic insufficiency
Vasodilator therapy is effective in reducing both preload and afterload in patients with CHF, aortic insufficiency and right ventricular failure. The preload and afterload reductions with vasodilator therapy will cause a reduction in blood pressure and cardiac output in most patients with mitral or aortic stenosis. Cyanotic episodes associated with the Tetralogy of Fallot are treated with methods to increase left ventricular afterload, such as phenylephrine administration.
An infant is born with Transposition of the Great Arteries (TOGA). Until corrective surgery is performed, palliation with a Rashkind balloon septostomy and pharmacologic maintenance of a patent ductus arteriosis is necessary. This is best achieved with the use of:
- high inspired FiO2
- indomethacin
- PGE1 infusion
- diuretics/digoxin
PGE1 infusion
PGE1 infusion rates of 0.01-0.03 mcg/kg/min will maintain patency of the ductus arteriosis before corrective surgery for “ductal dependent” cardiac lesions such as TOGA. High inspired concentrations of FiO2 and indomethacin facilitate closure of the PDA.
A 35-year-old man is receiving N2O:O2 at 2:1 liters/min with a propofol infusion for a right knee arthroscopy. At sea level, the partial pressure of oxygen being received by the patient is:
253 mmHg
Sea level exerts a barometric pressure of 760 mmHg. Since the concentration of oxygen is known to be 33% (2:1 mixture), the partial pressure of oxygen is 760 x 0.33 = 253.33 mmHg.
During neonatal resuscitation, which of the following medications may be administered via the endotracheal tube?
- epinephrine
- sodium bicarbonate
- calcium gluconate
- naloxone
- amiodarone
epinephrine, naloxone
The following medications may be administered via the endotracheal tube during neonatal resuscitation:
Lidocaine, Atropine, Naloxone, Epinephrine.
These may be remembered using the mnemonic “LANE”. During adult CPR, vasopressin may also be administered through the ETT.
A 70-year-old man is undergoing monitored anesthesia care with sedation for a hemorrhoidectomy. The patient is receiving propofol at 100 mcg/kg/min. Ten minutes after receiving 20 ml of 2% lidocaine with 1:200,000 epinephrine, the blood pressure is 65/45, the heart rate is 63/min and the ECG shows a widened QRS complex. The most appropriate management is to:
- administer ephedrine 10 mugs and continue with the surgery
- administer 0.4 msg of atropine
- administer 150 mg of amiodarone
- administer hemodynamic support, terminate the case and obtain an ECG and cardiac evaluation
administer hemodynamic support, terminate the case and obtain an ECG and cardiac evaluation
ECG changes associated with bradycardia and hypotension may indicate myocardial ischemia. Appropriate therapy would include the termination of surgery and a cardiac evaluation.
Your patient arrives to the OR for total parathyroidectomy with reimplantation. Possible physical derangements secondary to hyperparathyroidism include:
- hyperactive reflexes
- heart block
- hypotension
- diarrhea
- prolongation of the QT-interval
- nephrolithiasis
heart block, nephrolithiasis
Physical derangements secondary to hyperparathyroidism may mirror those found with hypercalcemia. They include:
weight loss, polydipsia, hypertension, heart block, weakness, lethargy, headache, insomnia, apathy, depression, bone pain, arthritis, pathologic fractures, anorexia, nausea, vomiting, epigastric pain, constipation, polyuria, and hematuria. Nephrolithiasis is the most common finding in patients with hypercalcemia.
The upper-lip-bite test is defined as Class I when the patient:
- is able to move the lower incisors in line with the upper incisors and bite the upper lip below the vermillion border
- cannot advance the lower incisors to be in line with the upper incisors and cannot bite the upper lip
- is able to firmly seal upper and lower lips with only the vermillion borders showing
- can protrude the lower incisors past the upper incisors and can bite the upper lip above the vermilion border
can protrude the lower incisors past the upper incisors and can bite the upper lip above the vermillion border
The upper-lip bite test, also known as the mandibular protrusion test, demonstrates the patient’s ability to extend the mandibular incisors past the maxillary incisors. The purpose of the test is to assess the mobility of the temporomandibular joint and architecture of the dentition. The test has been found to be a valuable assessment tool in the assessment of the difficult airway when used in combination with other assessment techniques.
In patients undergoing endoscopic retrograde cholangiopancreatography:
- light sedation should be employed to allow patient cooperation during the procedure
- pre-procedure glycopyrrolate should be given to reduce the incidence of sphincter spasm
- significant comorbiidites are frequently present
- sinus bradycardia is commonly encountered during stent placement
significant comorbidities are frequently present
During ERCP, patients usually experience discomfort and general anesthesia or deep sedation techniques are recommended for the procedure. Sphincter of Oddi manometry may be performed, in which case drugs that affect sphincter pressure such as atropine, glycopyrrolate, glucagon, and various opioids should be avoided preoperatively. Patients presenting for ERCP may have significant comorbidities, including acute cholangitis with septicemia, jaundice with liver dysfunction and coagulopathy, bleeding from esophageal varices resulting in hypovolemia, or biliary stricture following major hepatobiliary surgery, including liver transplantation. Sinus tachycardia is a frequent occurrence, especially if anticholinergic agents have been administered by the endoscopist.
A 46-year-old man is undergoing general anesthesia for a shoulder arthroscopy. His past medical history is significant for type II diabetes mellitus and hypertension. One hour into the procedure the following labs are obtained:
pH = 7.24 PO2 = 320 mmHg PCO2 = 26 mmHg HCO3 = 23 mEq/L Sodium = 141 mEq/L Chloride = 102 mEq/L Potassium = 3.0 mEq/L BUN = 23 mg/dL
The most likely cause of the acidosis is:
- lactic acidosis
- renal failure
- inadequate alveolar ventilation
- prolonged vomiting
lactic acidosis
This patient is demonstrating metabolic acidosis with respiratory compensation. In addition, this is a wide-anion-gap acidosis in a patient with a history of diabetes. Since there is no evidence of renal failure, only lactic acidosis meets all these criteria.
Common complications associated with Trisomy 21 syndrome include:
- abnormally think and viscous respiratory secretions
- increased dead space
- atlanto-occipital subluxation during laryngoscopy
- increased incidence of post-extubation croup
- potential for paradoxic air embolus from air in the IV tubing
- hyper metabolism
atlanto-occipital subluxation during laryngoscopy, increased incidence of post-extubation croup, potential for paradoxic air embolus from air in the IV tubing
Common problems associated with Trisomy 21 (A.K.A. Down Syndrome) include airway issues such as short neck, large tongue, subglottic stenosis, tracheoesophageal fistula, and a potential for atlanto-occipital dislocation during laryngoscopy due to laxity of the supporting ligaments. Cardiac malformations occur in approximately 40% of these patients; the majority are endocardial cushion defects and VSDs.
Evidence that a pulmonary artery catheter has advanced from the right ventricle into the pulmonary artery includes:
- a sudden increase in systolic pressure
- a sudden increase in diastolic pressure
- loss of the dicrotic notch
- reappearance of the central venous pressure tracing
a sudden increase in diastolic pressure
The passage of the pulmonary artery catheter from the right ventricle into the pulmonary artery is evidenced by a sudden increase in diastolic pressure caused by the the closed pulmonic valve preventing return of ejected blood into the right ventricle.
Modern vaporizers are more resistant than older vaporizers to the “pumping effect” because:
- unidirectional valves prevent retrograde gas flow
- volatile anesthetic is vaporized in a separate reservoir
- variable bypass design is no longer used
- flow of gas through the vaporization chamber is tightly controlled
unidirectional valves prevent retrograde gas flow
Modern vaporizers are more resistant than previous models to the effects of intermittent back pressure, the so-called “pumping effect” that increases vaporizer output. This is because most incorporate unidirectional valves and other mechanisms to prevent retrograde flow.
The most common complication seen after blood transfusion is:
- graft-versus-host disease
- acute hemolytic reaction
- febrile reaction
- delayed hemolytic reaction
febrile reaction
Febrile reactions are relatively common, occurring in 0.5% per unit transfused.
The definitive treatment for postdural puncture headache is:
- aggressive hydration
- caffeine
- autologous blood patch
- abdominal binder
autologous blood patch
Although postdural puncture headache (PDPH) may be ameliorated by supine position, analgesics, caffeine, and hydration, the definitive treatment is autologous blood patch. Approximately 15-20 ml of autologous blood injected into the epidural space close to or at the site of puncture should provide dramatic relief of PDPH.
After induction of general anesthesia in a 67-year-old man undergoing an abdominal aortic aneurysm repair, a pulmonary artery (PA) catheter is placed. Initial pulmonary artery pressures are 42/25 with a pulmonary capillary wedge pressure of 24 mmHg. The patient’s past medical history is significant for long-standing mitral stenosis. Your interpretation of the PA catheter data is:
- mitral stenosis caused an overestimation of LVEDP
- mitral stenosis causes an underestimation of LVEDP
- mitral stenosis does not affect the evaluation of LVEDP
- the PA catheter data is inconsistent with mitral stenosis and further cardiac workup is required
mitral stenosis causes an overestimation of LVEDP
Pathologic obstruction of blood flow from the pulmonary venous circuit into the left ventricle can cause an overestimation of LVEDP. As a result, pulmonary vein obstruction, atrial myxoma, left atrial clot, and mitral stenosis can give a falsely high estimation of LVEDP.
The C-Trach supraglottic airway device:
- has two lumens to allow gastric suctioning
- uses a separate esophageal balloon to reduce the incidence of aspiration
- allows visualization of the larynx after insertion
- cannot be used to attain endotracheal intubation
allows visualization of the larynx after insertion
The LMA CTrach is an advanced model of the LMA Fastrach intubating LMA that has imaging capability of the larynx after insertion of the LMA through an attachable video monitor. It is a single lumen device.
Current applied directly to the myocardium from invasive monitors can induce ventricular fibrillation with as little as:
100 microamps
With direct application of current to the myocardium, from intracardiac invasive monitors or pacing wires, currents of as low as 100 microamps have been shown to cause ventricular fibrillation. This is referred to as microshock.
A subcutaneous injection of 5-10 mL of local anesthetic placed between the anterior tibial artery and the lateral malleolus will block the:
- saphenous nerve
- superficial peroneal branches
- posterior tibial nerve
- sural nerve
superficial peroneal branches
During an ankle block, injections are made at five separate nerve locations: the superficial and deep peroneal nerves, the saphenous nerve, the sural nerve and the posterior tibial nerve. A subcutaneous ridge of 5 - 10 mL of local anesthetic laid along the skin crease between the anterior tibial artery and the lateral malleolus will anesthetize the superficial peroneal branches.
Factors associated with postdural puncture headache include:
- postural changes in intensity
- the type of local anesthetic used
- occurrence within 1 hour following the spinal anesthetic
- no association with nausea or photophobia
postural changes in intensity
Typically a postdural puncture headache is bilateral, extends into the neck, is associated with photophobia and nausea, occurs 12 - 72 hours after the dural puncture and is aggravated by sitting up.
The respiratory bronchioles constitute which generation(s) of the tracheobronchial tree?
- 5th - 16th
- 17th - 19th
- 20th - 22nd
- 23rd
17th -19th
Dichotomous division of the airways, starting with the trachea and ending with the alveolar sacs is estimated to involve 23 subdivisions or generations of the tracheobronchial tree. The trachea constitutes generation 0, while the alveolar sacs constitute generation 23. The respiratory bronchioles occur at the 17th to the 19th generation from the trachea.
