Mixed Review 58 – Flashcards

Blood vessel walls immediately contract following injury thus decreasing blood flow. The vascular contraction is a result of autonomic nervous system reflexes and the release of thromboxane A2 (TxA2) and ADP from platelets. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:p881, 881t; Hall JE, Guyton AC. Guyton and Hall Textbook of Medical Physiology. 12e; 2011:451]

Once platelets adhere, they are activated by a complex series of steps including release of ADP and thromboxane A2. Adenosine diphosphate (ADP) and TxA2 are ligands for Gprotein coupled receptors (P2Y12 and TPα, respectively) that trigger signal transduction pathways, ultimately leading to expression of GPIIb/IIIA receptors (fibrinogen receptors) on the platelet surface. TxA2 appears to amplify the signal and action of more potent platelet agonists, such as thrombin (IIa) and ADP. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:621; Hall JE, Guyton AC. Guyton and Hall Textbook of Medical Physiology. 12e; 2011:451; Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:949]

Endothelial damage following vascular injury initiates release of many procoagulant factors including tissue factor (FIII, TF) and factor VIII:vWF (von Willibrand's factor). [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:622]

The (hepatic) portal vein is formed by the union of the splenic vein and superior mesenteric vein posterior to the neck of the pancreas at the level of L2. The inferior mesenteric vein usually drains into the splenic vein but occasionally (10%) the inferior mesenteric vein joins the splenic and superior mesenteric veins at their confluence at portal vein. Tip: if a question asks for two vessels, the 'best' answer, in our opinion, is splenic and superior mesenteric veins. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:669f; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:525; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:764f; Drake, et al. Gray's Anatomy for Students, 2e, 2009:p337, 339]

Left bundle branch block (LBBB) is uniquely characterized by: (1) a broad, sometimes notched R wave in left side leads (I, aVL, V5, V6); (2) deep S waves in the right precordial leads; (3) absent septal Q waves. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1448; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1704; Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:90; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:411]

Right bundle branch block (RBBB) is uniquely characterized by: (1) prominent, notched R waves with "M" pattern (rabbit ears) and rsr', rsR' or rSR' on the right side leads (aVR, V1), and (2) wide S on left side leads. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1448; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1704; Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:90; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:411]

Right bundle branch block (RBBB) is common in the general healthy population without clinical evidence of structural heart disease and has no prognostic significance in this group. RBBB occurs in about 1% of hospitalized patients and is much more common than left bundle branch block (LBBB). LBBB, however, is more ominous—LBBB does not occur in healthy individuals. LBBB is often associated with ischemic heart disease, hypertension, and valvular heart disease. LBBB obscures or simulates other ECG patterns. In the presence of LBBB, the diagnosis of LVH, acute ischemia, or myocardial infarction may be difficult or impossible. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1448; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1704; Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:90; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:411].

Insertion of a pulmonary artery catheter (PAC) may precipitate right bundle branch block, thus insertion of a PAC in a patient with left bundle branch block may precipitate complete heart block (third-degree block). [Hines RL, Marschall KE. Stoelting's Anesthesia and Co- Existing Disease. 6e; 2012:90; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:411]

Propofol inhibits platelet aggregation that is induced by TxA2 and platelet-activating factor, although propofol does not alter tests of coagulation or platelet function. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:166]

Autacoids (or autocoids) are biological factors that act like local hormones, that is they have a paracrine (neighboring) effect. Unlike hormones, autacoids are produced in minute quantities and have local, evanescent (brief) effects. Notable human autacoids include eicosanoids, angiotensin, nitric oxide (NO), kinins, histamine, serotonin, and endothelins. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:570; Authors]

Eicosanoids (from the Greek eicosa "twenty") are signaling molecules derived from omega-3 and omega-6 fatty acids including arachidonic acid (ω6). Eicosanoids include prostaglandins, thromboxanes, leukotrienes, and lipoxins. Eicosanoids are not stored but rather are produced on demand. [Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:937; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:685]

Prostanoids are metabolic derivatives of arachidonic acid, therefore prostanoids are a category of eicosanoids. Cyclooxygenase (COX) acts on arachidonic acid to produce PGH2. Three types of prostanoids are then derived from PGH2: prostaglandins, prostacyclins, and thromboxanes (see accompanying figure). [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:570f; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:685f; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:410; Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:938f]

Phospholipase A2 (PLA2), a calcium-dependent enzyme, acts upon membrane phospholipids to release arachidonic acid. The release of arachidonic acid from membrane phospholipids is the rate-limiting step in eicosanoid synthesis. (Revises and replaces 2015 MemoryMaster IB20 question 20.) [Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:937; Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:685; Cousins MJ, Bridenbaugh PO. Cousins and Bridenbaugh's Neural Blockade in Clinical Anesthesia and Pain Medicine. 4e; 2009:1704; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:410]

Thromboxane A2 (TxA2) produces contraction of vascular smooth muscle and is a potent vasoconstrictor. TxA2 has local effects at the systemic vasculature, coronary vasculature, and renal vasculature (decreased RBF and decreased GFR). [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:733; Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:944t]

An increased thromboxane A2 (TxA2) activity is seen during the rebound prothrombotic period following discontinuation of antiplatelet therapy. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:893]

The vascular endothelium releases prostacyclin (PGI2) and PGD2, along with nitric oxide (NO) and other factors to maintain an anticoagulant state. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:621]

Ginger is a potent inhibitor of thromboxane synthetase and thus increases bleeding time and morbidity. [Fleisher LA. Anesthesia and Uncommon Diseases. 6e; 2012:479]

PGE2 and PGI2 are bronchodilators, whereas PGF2α, PGD2, and TxA2 cause bronchoconstriction. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:602; Brunton LL, Chabner B, Knollman BC. Goodman & Gilman's Pharmacological Basis of Therapeutics. 12e; 2011:950]

Metoclopramide is the only drug approved by the FDA for diabetic gastroparesis. Metoclopramide, via cholinergic stimulation, acts as a gastrointestinal prokinetic drug that increases lower esophageal sphincter tone and stimulates motility of the upper gastrointestinal tract. (Revises and replaces 2015 MemoryMaster IB14 question 20.) [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:710]

Adverse effects of metoclopramide are: (1) treatable hypotension and tachycardia (most common adverse effects, according to Miller); (2) sedation; (3) restlessness or 'nervousness'; (4) extrapyramidal symptoms; (5) abdominal cramping following rapid intravenous injection; (6) inhibition of plasma cholinesterase; and, (7) galactorrhea. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:2963; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:282; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:695; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:603]

Because of its antidopaminergic activity, metoclopramide should be used with caution if at all in patients with: (1) Parkinson's disease; (2) restless leg syndrome; (3) or who have movement disorders related to dopamine inhibition or depletion. Metoclopramide is contraindicated in patients with (4) intestinal obstruction, due to metoclopramide's prokinetic effects. [Flood P, Rathmell JP, and Shafer S. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5e; 2015:695; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1239t; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:282]

Isaac Newton demonstrated that the strength of emanating energy is inversely proportional to the square of its distance from the source, the inverse square law. Newton's original description was for the force of gravity and we now know the inverse square law applies to pressure energy (sound), light, electricity, and radiation (X-rays, α, β, γ, radiation). [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:233; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:p3234-3235]

Occupational exposure to radiation can be minimized by the "4 D's." strategy. (1) Limit the Duration of exposure. (2) Increase the Distance from source (the inverse square law). (3) Use protective shielding such as lead-lined garments or protective shields—Deflect the radiation. (4) Use a Dosimeter to monitor exposure. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:881; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:233; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:p3234- 3235; Authors]

Since X-rays obey the inverse square law, the minimum recommended distance from an X-ray source is 6 feet. The greatest intensity of an X-ray is directly in front of the beam generator. Standing at least 6 feet away and behind or to the side of the beam direction lessens exposure. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:233]

The purity of medical gases is specified in the United States Pharmacopoeia and is enforced by the Food and Drug Administration (FDA). (Revises and updates 2015 MemoryMaster IIA01 question 1.) [Dorsch JA, Dorsch SE. Understanding Anesthesia Equipment. 5e; 2008:2]

The Department of Transportation (DOT) publishes requirements for the manufacturing, marking, labeling, filling, qualification, transportation, storage, handling, maintenance, requalification, and disposition of medical gas cylinders and containers. (Revises and updates 2015 MemoryMaster IIA01 question 2.) [Dorsch JA, Dorsch SE. Understanding Anesthesia Equipment. 5e; 2008:2]

The U.S. government regulates matters affecting the safety and health of employees in all industries through the Department of Labor (DOL). [Dorsch JA, Dorsch SE. Understanding Anesthesia Equipment. 5e; 2008:2-3]

The Occupational Health and Safety Act (OSHA) created two separate executive-branch agencies to carry out the provisions of the act: (1) the National Institute of Safety and Health (NIOSH), an agency with the Centers for Disease Control and Prevention under the Department of Health and Human Services, and OSHA, under the Department of Labor. [Dorsch JA, Dorsch SE. Understanding Anesthesia Equipment. 5e; 2008:395]

One milliliter of liquid volatile anesthetic produces ~200 milliliters of anesthetic vapor at 20 ºC and 1 atmosphere. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:665; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:61]

Several general concepts summarize the influence of intravenous and inhalational agents on sensory-evoked responses. (1) Inhalational agents, including nitrous oxide, generally have a more depressant effect on evoked potentials than equipotent doses of intravenous agents. (2) Combinations of drugs generally produce additive effects. (3) Propofol and thiopental attenuate the amplitude of virtually all evoked potential modalities but do not obliterate them. (4) Opioids and benzodiazepines have negligible effects on the recording of all evoked potentials. (5) Ketamine and etomidate have been reported to enhance the quality of signals in patients with weak baseline somatosensory evoked potential (SSEP) signals. (Revises and replaces 2015 MemoryMaster IID01 questions 28 & 29.) [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1003; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1514t; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:329]

In general, cortical evoked potentials with long latency involving multiple synapses are exquisitely sensitive to the influence of anesthetic while short latency brainstem and spinal components are resistant to anesthetic influence. Thus, BAEP can be recorded under any anesthetic technique, whereas VEP and SSEP are very sensitive to anesthetic agents. Mnemonic: Visual are Very, Somatosensory are Somewhat, and Brainstem are Barely sensitive. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1003; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1514t; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:329; Authors]

A MET is a Metabolic EquivalenT and is defined as the amount of oxygen consumed while sitting at rest. MET are used to evaluate functional capacity and reserve. A standard MET is equal to 3.5 mL O2/kg/min. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:353t; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1090t]

One metabolic equivalent (1 MET) correlates with eating, working at a computer, or dressing. Two metabolic equivalents (2 METs) is equal to walking down stairs, walking in your house, or cooking. 3 METs correlates to walking one or two blocks on level ground. Raking leaves or gardening is equivalent to 4 METs. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1090t]

Five metabolic equivalents (5 METs) correlates with climbing one flight of stairs, bicycling or dancing. Six metabolic equivalents (6 METs) is equal to playing golf or carrying golf clubs. 7 METs correlates to playing singles tennis. Rapidly climbing stairs or slowly jogging is equivalent to 8 METs. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1090t]

Nine metabolic equivalents (9 METs) correlates with jumping rope slowly or moderate cycling. Ten metabolic equivalents (10 METs) is equal to swimming quickly, running or jogging briskly. 11 METs correlates to cross country skiing or playing full court basketball. Running rapidly for moderate to long distances is equivalent to 12 METs. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1090t]

A declared brain-dead patient whose organs are being removed for donor purposes is defined as ASA PS class 6 ("PS" is "Physical Status"). [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:588t]

A one-liter (1 L) bag of D5W contains 50 grams of dextrose, a concentration of 50 mg/mL. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:393t; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1779t.]

In addition to physiologic concentrations of sodium and potassium, Normosol-R contains magnesium (3 mEq/L), acetate (27 mEq/L) and gluconate (23 mEq/L). [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:393t]

Dextrans are relatively inexpensive (dextrans are produced by bacteria), but their range of toxicities limits their use. Dextran toxicities include: (1) antithrombotic effects, particularly inhibition of platelet aggregation; (2) interference with blood cross-matching — dextrans coat RBC membranes; (3) anaphylactic and anaphylactoid reactions; and, (4) renal dysfunction resulting from osmotic nephrosis. [Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1784]

The Fastrach LMA, also known as an intubating LMA (ILMA), was specifically designed for use in difficult airway situations. The primary distinguishing features of the Fastrach LMA are: (1) an anatomically curved rigid airway tube; (2) an integrated guiding handle; (3) an epiglottic elevating bar; and, (4) a guiding ramp built into the floor of the mask aperture. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:451]

The 2 bars at the aperture of the LMA classic are replaced in the ILMA by a single, moveable epiglottic elevating bar that pushes the epiglottis out of the way allowing smooth and unobstructed passage of the endotracheal tube as it emerges from the distal end of the ILMA's metal shaft. [Hagberg CA, Benumof J. Benumof and Hagberg's Airway Management. 3e; 2012:456]

The integrated handle at the proximal end of the barrel of a Fastrach LMA is used for insertion, repositioning, and removal. The position of the device can be optimized by lateral and anterior-posterior manipulation by using the integrated handle, an action called the Chandy maneuver. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:783]

Patient-controlled analgesia (PCA) should be initiated in the PACU after the patient's initial pain level is under control. Barash quantifies "initial pain level is under control" by adding: "when the visual analog pain scores decrease to ≤ 3 (0-10 scale), the patient may be started on PCA." [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1234; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:512]

Because patient-controlled analgesia (PCA) requires the patient to control the delivery system, candidates for PCA must: (1) be cooperative; (2) be able to understand the concept; (3) follow the directions of use; and, (4) be able to push the demand button. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1252]

(1) an initial loading dose; (2) a demand dose or bolus dose; (3) a lockout interval; (4) a basal continuous infusion rate; and, (5) 1-hour and 4-hour maximum dose limits. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1252]

From the patient's perspective, robot-assisted surgeries are characterized by: (1) smallest possible incision; (2) less surgical stress; (3) less pain; (4) faster recovery; (5) shorter hospital stays; and, (6) improved overall satisfaction. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1425; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:546; 2594]

From the surgeon's perspective, robot-assisted surgery affords the following advantages: (1) less intraoperative blood loss; (2) improved ergonomics; (3) enhanced and magnified 3- dimensional view of surgical field; (4) superior manual dexterity (greater freedom of movement); (5) decreased fatigue; (5) filtering of resting hand tremor (reduced hand tremor); and, (6) shorter learning curve (compared to endoscopic techniques). [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1425; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:546; 2594]

Seven major anesthetic considerations during robot-assisted surgery are as follows. (1) There is risk of thromboembolism due to lengthy procedures in Trendelenburg position; use thromboembolic stockings to reduce risk. (2) Maximize protection over pressure areas to avoid nerve injury and protect face from direct pressure. (3) Difficulties inherent in patients having prolonged surgery in Trendelenburg position are present: increased mean arterial pressure in brain, increased cerebral blood volume, decreased cardiac output and perfusion to lower extremities, and decreased perfusion to vital organs. (4) There is potential common peroneal nerve damage due to lithotomy position. (5) Difficulties with peritoneal insufflation are present: decreased compliance, increased airway pressure, increased ventilation- perfusion mismatch, and hypercapnia. (6) Blood pressure reduction may be necessary secondary to resultant increase in systemic vascular resistance because of the pneumoperitoneum. (7) Urine output may be decreased and generally responds to fluid challenge. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:758b]

For low-grade, non-invasive bladder tumors, a transurethral resection of bladder tumor (TURBT) may be carried out via cystoscopy. TURBT differs from TURP in that the surgical resection is not necessarily carried out in the midline. Laterally located urinary bladder tumors may lie near the obturator nerve—every use of the cautery resectoscope results in stimulation of the obturator nerve producing violent contraction of the ipsilateral thigh muscles and consequent adduction of the thigh (lower extremity), the so-called obturator reflex. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1428; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:682-683]

During transurethral resection of a laterally located bladder tumors (TURBT), every use of the cautery resectoscope results in stimulation of the obturator nerve producing violent contraction of the ipsilateral thigh muscles and consequent adduction of the thigh (lower extremity). "Urologists rarely derive amusement from having their ear struck by the patient's knee ..." (Butterworth). Therefore, in contrast to TURP, TURBT procedures are more commonly performed with (1) general anesthesia and neuromuscular blockage or (2) neuraxial anesthesia to T9-T10 providing adequate anesthesia and preventing the obturator reflex. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1428; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:682-683]

The tracheal cuff of a double-lumen tube (DLT) normally requires 5-10 mL air and can accommodate up to 20 mL of air. Inflation of the DLT bronchial cuff requires 1-2 mL air. NB: the bronchial cuff is checked with a 3 mL syringe but rarely will the bronchial cuff require greater than 2 mL to create an adequate seal. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:673; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:1043; Dorsch JA, Dorsch SE. A Practical Approach to Anesthesia Equipment. 2011:400; Butterworth JF, et al. Morgan & Mikhail's Clinical Anesthesiology, 5e, 2013:553t]

The typical cardiovascular response to the ECT stimulus is 10-15 seconds of parasympathetic stimulation producing bradycardia, bradydysrhythmias, and decreased blood pressure (the tonic phase) followed by sympathetic activation resulting in tachycardia, tachydysrhythmias, and increased blood pressure lasting for minutes (the clonic phase). (Revises and replaces 2015 MemoryMaster IVA09 question 25.) [Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:537t; Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1278b; Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:887]

The initial parasympathetic effects of electroconvulsive therapy (ECT) (salivation, transient bradycardia, and asystole) can be prevented by premedication with glycopyrrolate or atropine. Labetalol, esmolol, and the calcium channel antagonists nifedipine, diltiazem, and nicardipine all attenuate the hemodynamic responses to ECT. [Barash PG, Cullen BF, Stoelting RK, et al. Clinical Anesthesia. 7e; 2013:887]

Pectus excavatum (Latin "hollowed chest"), also known as "funnel chest", is the most common congenital deformity of the anterior wall of the chest, occurring in about 1 in 4000 children. In most children in which pectus excavatum is an isolated deformity of the sternum, there are no significant functional limitations; lung volumes and functions are preserved. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:653; Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:201]

Pectus excavatum is often seen with Marfan syndrome, osteogenesis imperfect, mitral valve prolapse, mucopolysaccharidoses, and nemaline rod muscular dystrophy. When seen in conjunction with other congenital anomalies, pectus excavatum decreases vital capacity and chest wall compliance and can result in arterial hypoxemia caused by V/Q mismatch—this is a restrictive pulmonary disease pattern. [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:503, 653; Hines RL, Marschall KE. Stoelting's Anesthesia and Co-Existing Disease. 6e; 2012:463, 443, 445; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:1143]

Neonates and infants, up to age 2 years, are more resistant to succinylcholine for both pharmacodynamic and pharmacokinetic reasons. With respect to succinylcholine in adults, neonates and infants, up to age 2 years have: (1) an ED95 of 625 and 729 mcg/kg, respectively, in other words, 2 to 2.5 times greater than adults; (2) faster clearance; (3) larger volumes of distribution; and, (4) shorter onset times. (Revises and replaces 2015 MemoryMaster IVB04 question 26.) [Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5e; 2013:1173; Davis PJ, Cladis FP, Motoyama EK. Smith's Anesthesia for Infants and Children. 8e; 2011:244]

Whenever bleeding occurs with rupture of membranes in the parturient, particularly when accompanied by fetal heart rate deceleration or fetal bradycardia, vasa previa should be suspected. This is a true obstetric emergency as fetal mortality rates are high, ranging form 50% to 75%. [Chestnut DH, Wong CA, Tsen, LC et al. Obstetric Anesthesia, 5e; 2014:888; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:2351]

Vasa previa is defined as the velamentous insertion of the fetal vessels over the cervical os (i.e., the fetal vessels traverse the fetal membranes ahead of the fetal presenting part). Thus, the fetal vessels are not protected by the placenta nor the umbilical cord. (A velamentous cord insertion occurs when the umbilical cord inserts into the fetal membranes instead of into the middle of the placenta.) Rupture of the membranes is often accompanied by tearing of a fetal vessel, which may lead to exsanguination of the fetus. Vasa previa occurs rarely, 1 in 2500 to 1 in 5000 deliveries. [Chestnut DH, Wong CA, Tsen, LC et al. Obstetric Anesthesia, 5e; 2014:888; Miller RD, Cohen NH, Eriksson LI, et al. Miller's Anesthesia. 8e; 2015:2351]

Risk factors for vasa previa are: (1) presence of placenta previa; (2) a low-lying placenta in the second trimester; (3) placental accessory lobes; (4) in vitro fertilization; and, (5) multiple gestations. [Chestnut DH, Wong CA, Tsen, LC et al. Obstetric Anesthesia, 5e; 2014:888]

Vasa previa is a true obstetric emergency that requires immediate delivery of the fetus, almost always by the abdominal route and under general anesthesia. Neonatal resuscitation requires immediate attention to neonatal volume replacement with colloid, balanced salt solutions, and blood. [Chestnut DH, Wong CA, Tsen, LC et al. Obstetric Anesthesia, 5e; 2014:888]