Chapter 1 Flashcards
What are the components of the “AMPLE” mnemonic for gathering relevant history prior to a surgery?
Allergies Medications Past medical history Last meal Events prior to onset
Should patients with CKD receive IVFs in case of septic shock?
Yes
Should patients who have CKD be protein restricted perioperatively to preserve kidney function?
No–worsens acidosis
If patients are given more than how many mEq per hour of K, should they be placed on cardiac monitoring?
10 mEq/hr
What is the 4:2:1 rule of administering fluids?
Maintenance fluid per hour is
4 mL / kg for the first 10 kg
2 mL / kg for the second 10 kg
1 mL / kg for each remaining kg
What is the rule for administering maintenance fluids for elderly patients?
25 mL/ kg
What causes the increased urine output 3 or so days following surgery?
Mobilization of water from the wound into the intravascular space
Why is there hypokalemia with large gastric losses of fluid?
Loss of Cl causes kidneys to hold on to Na more tightly, and as a result excrete K
What is the formula for FeNa?
FeNa = [UNa × PCR)/(PNa × UCr) × 100].
What value of FeNa is characteristic of prerenal, and renal azotemia?
Less than 1% is prerenal
More than 2% is postrenal
a BUN:Cr ratio of what value indicates prerenal azotemia?
20:1
An increase in HR of (__) or increases in SBP of (__) should raise suspicion of hypovolemia.
10 bpm
15 mmHg
Why should dextrose solutions never be used in patients that are hemodynamically unstable in their stabilization?
Will cause osmotic diuresis
Volume losses are replaced with (___), while blood losses are replaced with (___)
Volume = NS Blood = LR
Which is preferred for large volume resuscitation: LR or NS? Why?
LR, since NS will result in hyperchloremia
Pontine demyelination results from what?
Too rapid a correction of hypernatremia
What is the goal urine output for adults in children that have no underlying renal issues?
- 5 mL/kg for adults
1. 0 mL/kg for children
What is the amount of hemoglobin that necessitates blood transfusion?
7 g/dL
Are patients with sepsis volume overloaded?
No–just spread to the periphery. Actually, there is an intravascular volume depletion.
How can you tell if a patient with sepsis is intravascularly volume depleted?
Hemodynamically unstable
Does hyper or hyponatremia result with an infusion of mannitol?
Hyponatremia, since water is pulled out of cells to dilute new excess sodium
What is the general rule for replacing water loss in hypernatremia?
Serum sodium increases 3 mEq above the normal value of 140 for every liter of water lost
What type of fluid is used for mild, moderate, and severe levels respectively.
- 0.9% NS for mild
- 0.45% NS for moderate
- 0.9% NS for severe (since the patient usually has a vascular volume deficit in addition to a total body water deficit)
Which is the first priority: treating hypovolemia or hypernatremia
Hypovolemia
What is a major cause of spurious hyperkalemia?
Lysis of blood cells in the tube.
What is the emergent treatment for hyperkalemia (6.5 -7.5, and 7.5+)?
10 units of insulin + 25 g glucose / 5 minutes
10-30 mL of calcium gluconate over 5 minutes
What is the effect of hypochloremia on renal bicarb excretion?
Impairs
What is the treatment for hypochloremia?
NaCl or KCl solutions
What is the definition of hypochloremia and hyperchloremia?
Hypochloremia = less than 95 Hyperchloremia = more than 115
What is the correction factor for hypoalbuminemia calcium levels?
Corrected Ca++ = [0.8 × (4.0 – patient’s albumin)] + total serum Ca++.
What are the s/sx of hypocalcemia?
circumoral tingling, numbness and tingling of the fingertips, and muscle cramps. Hyperactive deep-tendon reflexes develop, with a Chvostek sign (unilateral facial spasm when the facial nerve on the side is lightly tapped), tetany, and Trousseau’s sign (carpopedal spasm), eventually progressing to seizures.
What are the ECG findings of hypocalemia?
Prolonged Q-T intervals
What is a common cause of hypocalcemia?
Blood transfusions
What electrolyte in particular, should be monitored when giving a blood transfusion?
Calcium
What are the ECG findings of hypercalcemia?
shortened Q-T intervals and widened T waves
What class of diuretics is administered for hypercalcemia?
Loop
How can hypomagnesemia lead to hypocalcemia?
Decreases PTH secretion
What are the s/sx of hypomagnesemia?
first as nonspecific systemic symptoms that include nausea, vomiting, anorexia, weakness, and lethargy, then as neuromuscular symptoms
What is the treatment for hypomagnesemia?
IV mag sulfate
What are the s/sx of hypermagnesemia?
Initial nausea is superseded by lethargy, weakness, hypoventilation, and decreased deep-tendon reflexes. The condition then progresses to hypotension and bradycardia, skeletal muscle paralysis, respiratory depression, coma, and death
What is the treatment for hypophosphatemia?
Phosphorous salts
What is the treatment for hyperphosphatemia?
Aluminum based antacids decrease absorption
Diuretics
Dialysis
True or false: it is appropriate to have obese patients lose weight when giving supplemental nutrition when they’re being cared for by a surgeon
True–improves outcomes with some weight loss
What is the most abundant amino acid in the body?
Q
When is supplemental R not given? Why?
Sepsis–it is believed to contribute to hemodynamic instability via its conversion to nitric oxide.
Why is administering lipids IV not usually done in the first week of parenteral nutrition?
omega-6 FAs are immunosuppressive
Protein depletion in excess of (__) is not compatible with life
20%
What are the “ebb and flow” phases of injury/healing?
Ebb is first, with a slowing of metabolic rate
Flow is second, with an increase in metabolic rate
What percent of nutrition should come enterally?
50%
What are the signs of switching from a catabolic state, to an anabolic state?
Improved fluid output, loss of edema
What serum marker is used to assess for starvation?
Prealbumin
Why shouldn’t prealbumin levels be used to determine starvation status in a septic patient?
Naturally lower albumin to increase CRP and other inflammatory proteins
What is the function of vWF?
Connect to GpIa
What is the defect in vWF disease? What are the consequences of this?
No molecule to cleave ADAMTS13 molecule, leading to a deficiency in factor VIII, and platelet adhesion
What is the MOA of heparin?
increasing the speed with which antithrombin III binds to and neutralizes factors IXa, Xa, Xia, XIIa, and thrombin
What is the reversal agent for heparin?
protamine sulfate
What are the two major antiplatelet medications that should be stopped 1 week prior to surgery?`
ASA and clopidogrel
What is the best method to replace a profound fibrinogen deficit from DIC?
Cryoprecipitate
What is the pathophysiology behind HIT?
HIT is caused by the formation of abnormal antibodies that activate platelets
Why are most esophageal surgeries done on the right side of the body?
Aorta is on the left border of the esophagus
What part of the heart sits just anterior to the esophagus?
LA
What are the three anatomic narrowings of the esophagus?
Cricopharyngeus muscle
aortic arch
diaphragm
What is the blood supply to the proximal, middle, and distal thirds of the esophagus respectively?
Inferior thyroid artery
Bronchial arteries
Left gastric
What are the veins that form an anastomosis between the portal vein, and the esophageal veins, and is the place of varices in liver cirrhosis?
The lower esophageal venous plexus provides collateral drainage from the portal venous system to the azygos veins, leading to esophageal varices.
What is the parasympathetic innervation to the esophagus?
Vagus, but note that the proximal third is from the recurrent laryngeal nerve of the vagus
What are the two layers of the muscularis propria?
Inner circular layer, and outer longitudinal layer
Unlike most of the GI tract, the esophagus lacks which histological layer?
serosa
Swallowing is initiated by what medullary structure?
Nucleus ambiguus
What are the secondary and tertiary peristaltic waves of the esophagus?
- Secondary are only there is not all food is moved along
- Tertiary are fibrillation waves that appear when someone is anxious
Heartburn that spontaneously disappears over a period of months without therapy may be a sign of what?
esophageal stricture or carcinoma
What is singultus?
Hiccup
Chest pain that is relieved by position changes = ?
GERD
How do you follow barrett’s esophagus?
endoscopy q6 months, with 4 quadrant biopsies
What are the components of the workup for esophageal surgery for GERD?
- Ba swallow
- EGD
- manometry
- pH
What is the prognosis for a patient with esophageal cancer?
80% die in one year
What are the two major types of esophageal cancer?
Adenocarcinoma from barrett’s
SCC
What are the two major routes to perform surgery on the esophagus?
Thoracic
transhiatal route
What is the most commonly used organ to form an anastomosis with for esophageal resection?
Stomach
What is a type I hiatal hernia?
Where the gastroesophageal junction slides through the diaphragm
What is a type II hiatal hernia?
Paraesophageal hernia–where there is a separate hole in the diaphragm
What, generally, is achalasia?”
Failure of the esophagus to relax
What is the mainstay of treatment for achalasia?
Endoscopic balloon dilation of the LES or myotomy
What is the treatment for hypermobile esophagus?
Myotomy
What is the determining factor of deciding whether a diverticulum is a true or false one?
True ones involve all of the layers of the GI tract, whereas false do not involve the muscularis propria
Where are Zenker’s diverticula with respect to the cricopharyngeus muscle?
Above
What is the treatment for an esophageal leiomyoma?
Watch it
The ilioinguinal and iliohypogastric nerves arise from which spinal nerve?
L1
What does the ilioinguinal nerve innervate?
Scrotum (labia majora) and medial thigh
The iliohypogastric nerve is usually encountered where?
just under the external oblique fascia, superior to the cord structures
Does the ilioinguinal nerve run inside or alongside the spermatic cord? How about the genitofemoral nerve?
Ilioinguinal runs within, genitofemoral runs alongside
Which is superficial: campers or scarpa’s fascia?
Campers is more superficial
What is the most superficial muscle of the abdominal wall?
External oblique
The external spermatic fascia of the spermatic cord is derived from what?
External oblique aponeurosis
The transversus muscle lies deep to what anatomic layer?
Internal oblique
Between what structures does the transversalis fascia lie?
Internal surface of the transversus abdominis and the extraperoitneal fat
What is the tunica vaginalis derived from?
Peritoneum
Where is the semicircular line of douglas, and what is its significance?
Approximately midway between the umbilicus and the symphysis pubis is an anatomic landmark, the semicircular line of Douglas (arcuate line). Above this line, the external oblique aponeurosis and the anterior leaf of the internal oblique aponeurosis and the central oblique aponeurosis fuse to form the anterior rectus sheath, and the posterior leaf of the internal oblique aponeurosis and the aponeurosis of the transversus abdominis fuse to form the posterior rectus sheath. Below the semicircular line, all three aponeuroses cross anterior to the rectus muscle, leaving only the peritoneum and the transversalis fascia between the rectus muscles and the abdominal contents.
The left umbilical vein persist in the adult as what?
Ligamentum teres of the liver
What are the remnants of the vitelline duct in the adult?
Vitelline duct
Meckel’s diverticulum
What are the benefits of a transverse incision?
Coughing tends to close the wound, as opposed to opening it, and there is less of a risk of herniation
What is a Pfannenstiel incision?
Transverse skin incision just above the umbilicus, used to gynecologic or bladder procedures
What are the exam findings of a strangulated hernia?
erythema of the overlying skin, tachycardia, fever or elevated white blood cell count
