NMS Intro Wisdm

Question 0

What are 4 binary classifications for suture types?

Answer 0

Braided vs. Monofilament
Absorbable vs. No absorbable
Natural vs. Synthetic
(Pop vs running)

Question 1

Why do we use titanium for staples instead if steel?

Answer 1

Because it is MRI compatible.

Question 2

Why do we NG drainage (usually with a sump tube) for a GI tract that is nonfunctional for >1/2 days or obstucted?

Answer 2

Because the decompression that results from drainage lessens abdominal distention, intestinal dilation, nausea, and vomiting.

Also, because drainage allows us to determine the AMOUNT and TYPE of luminal fluid loss so that appropriate replacement can be made.

Question 3

Describe situations that require tube drainage:

Answer 3

• Chest tube drainage if pleural space to evacuate air or blood.
• NG drainage of GI tract for prolonged nonfunction or obstruction.
• Areas where body fluids can collect internally.
• Procedures such as skin flaps where large raw surfaces are to be kept opposed (require SUCTION drainage)
• Deep abscesses (but NOT generalized infections) that are not amenable to simple incision.

Question 4

What is a space that cannot be drained?

Answer 4

The free peritoneal space, because tubes are quickly “walled off”.

Therefore, diffuse peritonitis cannot be drained (althoug drainnage may still be an option for localized collections.

Question 5

When should drains be removed?

Answer 5

When they have fulfilled their purpose, and no later!

• When main risk of leakage has passed (as in liver resections, urinary bladder procedures)
• When a drain that is used for postoperative fluid collections no longer has any substantial drainage.
• When a drain is used in a reconstructive procedure, it is removed once the repair is deemed safe.

Question 6

What is an important thing to remember about drains used for urine leaks after urinary bladder procedures?

Answer 6

A urine leak will not be noticeable until AFTER the bladder catheter (Foley) is removed.

Therefore, these drains are removed 1 day after the foley is removed.

Question 7

What is the name of an NG tube with an inflatable balloon, and what is it used for?

Answer 7

Gastroesophagral balloon tamponade tube (Sengstaken-Blakemore or Minnesota tube).

Used to compress and tamponade bleeding esophageal varices.

Question 8

Where would the use of long intestinal tubes (Miller-Abbot is double lumen, and Cantor tube is single lumen) be appropriate?

Answer 8

For relieving recurrent SBOs (for the first episode, perform laparotomy and lysis of adhesions)

For cases with multiple areas of partial obstructions (ex. Radiation enteritis)

Question 9

Of the GI tubes used for feeding purposes, which is the one that can be inserted endoscopically?

Answer 9

Gastrostomy (G) tubes can be inserted endoscopically (PEG tube placement) or surgically.

Jejunostomy (J) tubes can only be inserted surgically.

PEG= percutaneous endoscopic gastrostomy

Question 10

What are the three main classes of surgical tubes?

Answer 10

1. Drainage tubes
2. GI tubes
3. Catheters and hemodyalisis tube

Question 11

Describe the placement of a peripherally inserted central catheter (PICC, pick line).

Answer 11

Is placed via an antecubital vein and threated oroximallymto an intrathoracic vein.

Question 12

What is the function of Dacron felt cuffs in cuffed central venous catheters (Hickman-type) and in Tenckhoff peritoneal dialysis catheters?

Answer 12

These cuffs promote ingrowth of granulation tissue, which functions to secure the catheter’s position and as a mechanical barrier to organisms entering via the skin exit site for these catheters that are meant to remain for prolonged periods of time.

In PD cathetheters, these are TWO dacron cuffs, one adjacent to the peritoneum (serves as a barrier against leakage) and one adjacent to the skin exit site (barrier against infection).

Question 13

What is a hernia?

Answer 13

Abnormal protrusion of intra-abdominal contents through a defect in the abdominal wall.

Question 14

Which is the LEAST common type of hernia?

Answer 14

Umbilical (3-8%) < incisional/ventral (8-10%) < inguinal (75-80%)

Question 15

What is the danger of a Richter’s hernia?

Answer 15

In this type of hernia, only one side of the bowel wall is trapped in the hernia (typically the ANTIMESENTERIC side), rather than the entire loop of bowel.

Therefore, by definition, this type of hernia cannot be obstructing, since it does not contain a whole loop of bowel and does NOT obstruct the GI tract.

The danger is precisely due to that: the incarcerated portion of bowel can necrose and perforate in the absence of GI obstructive symptoms.

Question 16

What is a sliding hernia?

Answer 16

In this type of hernia, the wall of the hernia sac, rather than being formed completely by peritoneum, is in part formed by a RETROPERITONEAL structure, such as the colon or the bladder.

Question 17

Which are the major complications of hernias that we intent to prevent with elective hernia repair?

Answer 17

Intestinal obstruction
Intestinal strangulation (ischemia) with bowel perforation.

Question 18

How are the inferior epigastric vessels relevant to inguinal hernias?

Answer 18

They are relevant to classifying indirect vs. direct hernias.

INDIRECT hernias pass from the peritoneal cavity through the internal inguinal ring, LATERAL to the inferior epigastric vessels.

DIRECT inuginal hernias occur through the posterior wall, or floor, of the inguinal canal (through Hesselbach’s triangle), which is MEDIAL to the inferior epigastric vessels.

Question 19

Which is the MOST common type of hernia?

Answer 19

Indirect inguinal hernia (incidence is 5x that of direct), most common in men and women.

5-10x more common in men than women. Approx 5% of men will have an inguinal hernia in their life and require surgery.

They occur most commonly by 5th decade of life.

May be related to an incompletely obliterated/patent processus vaginalis, which forms the hernia sac for the bowel to “fall” through.

Question 20

Pediatric inguinal hernias are most often (direct/indirect)? What is the risk?

Answer 20

INDIRECT. Often bilateral.

High risk of incarceration - 75%. Usually fix surgically.

Question 21

When you think of DIRECT inguinal hernias, think of…

Answer 21

Hesselbach’s triangle
Incidence increases with age
Related to physical activity
Less likely to strangulate and does not pass into scrotum, unlike INDIRECT inguinal hernias

Question 22

Where does the hernia sac pass in pantaloon hernias?

Answer 22

Both medially AND laterally to epigastric vessels.

Is a combination of a direct and indirect hernia.

Question 23

Where do femoral hernia pass?

Answer 23

They occur along the femoral sheath, and the contents protrude

POSTERIOR to the inguinal ligament
ANTERIOR to Cooper’s ligament (i.e the pubic ramus periosteum)
MEDIAL to the femoral vein (which is the most medial of the VAN stuctures)

The sac has a narrow neck, and 30-40% of femoral hernias be ome incarcerated or strangulated.

Question 24

Femoral hernias are more common in F than M. What are they commonly associated with?

Answer 24

Female Prior pregnancy Prior inguinal hernia repair

Question 25

Differential diagnosis of an inguinal mass

Answer 25

``` Hydrocele Varix (especially if thrombosed) Inflammed or enlarged lymph node Lipoma of the spermatic cord Undescended testicle Abscess Tumor Inguinal hernia ```

Question 26

What are the tx options for minimally symptomatic hernias?

Answer 26

For these hernias, the risk of incarceration is low, therefore eatchful waiting is a safe alternative. Elective surgical repair.

Question 27

How is the floor (posterior wall) of the inguinal canal reinforced/repaired in Bassini repair?

Answer 27

The transversalis fascia and conjoint tendon above are sutured to the reflection of the inguinal ligament below.

Question 28

How is the floor (posterior wall) of the inguinal canal reinforced/repaired in Cooper's ligament repair (McVay method)? What is the main problem with this technique?

Answer 28

The transversalis fascia and conjoint tendon above are sutured to Cooper's ligament, which is the periosteum of the pubic ramus. Often requires a "relaxing" incision in the anterior rectus sheath adjacent to the external oblique aponeurosis, to allow the conjoint tendon to be sutured to Cooper's ligament with less tension. The main problem with this technique is TENSION, causing technical difficulty apposing the tissues during the repair, post-operative pain, and early and late recurrence.

Question 29

How is the floor (posterior wall) of the inguinal canal reinforced/repaired in the shouldice repair?

Answer 29

Uses the transversalis fascia, which is divided longitudinally and imbricate upon itself in two layers. The internal oblique muscle and conjoint tendon are then sutured to the reflection of the inguinal region in two layers (total 4 suture lines).

Question 30

How is the floor (posterior wall) of the inguinal canal reinforced/repaired with Lichtenstein repairs? Which of the other repairs is it most similar to?

Answer 30

Using PROSTHETIC MESH. This is supplanting older techniques. Involves repairing the inguinal floor by using mesh to close the space, suturing it (as in a Bassini repair) to the transversalis fascia and conjoint tendon above and to the reflection of the inguinal ligament below.

Question 31

Which factors contribute the development if hernias?

Answer 31

- Congenital defects - Loss of tissue strength and elasticity (aging, smoking, repetitive stress) - Trauma (especially operative trauma, especially if wound was infected) - Increased intra-abdominal pressure (heavy lifting, coughing, asthma, COPD, bladder outlet obstruction, prior pregnancy, ascites, abdominal distention, obesity)

Question 32

The 5W causes of postoperative fevers

Answer 32

1. WIND (pulmonary complications) - usually POD 1-3, include atelectasis, pneumonia, 2. WATER (UTI), usually POD 3-5, after bladder catheterization 3. WOUND INFECTION - typically cause fever POD 5-8, except streptococcal or clostridial infections can cause fever earlier 4. WALK (venouc complications) - DVT/phlebitis can occur any time post op and can cause fever, PE, IV catheter infection 5. WONDER DRUGS (drug fevers) - any drug can cause this. Be especially suspicious of abx, which are often used empirically.

Question 33

Sources of post-op fever that are less common than the 5Ws

Answer 33

``` Post-pericardial syndrome (POD 5-7) Anastomotic leak after bowel surgery (POD 7-10) Parotitis Sinusitis Acalculous cholecystitis Pancreatitis Pseudomembranous colitis (c.diff) Addisonian crisis ```

Question 34

Signs of dehydration/hypovolemia

Answer 34

Oliguria Tachycardia Orthostatic hypotension

Question 35

What is the most common organisms infecting prostheses?

Answer 35

Staphylococci These infections are LIFE THREATENING. Removal of prosthesis is usually necessary since the infected prosthesis cannot usually be sterilized with antibiotics.

Question 36

List types of prosthetics that we put into people surgically

Answer 36

``` Vascular grafts Heart valves Artificial joints Fascial mesh replacements Metallic bone supports ```

Question 37

List principles of perioperative antibiotic prophylaxis

Answer 37

1. The operation must carry a significant risk of postoperative infection (ex, even if a clean procedure, if prosthetics were implanted, if a nonsterile area was entered, or if the procedure was done on a contaminated body soace) 2. Abx should be effective against the pathogens likely to be present in the operative site. 3. Abx should reach an effective tissue level/concentration at the time of surgery (thus, give 1-2 hours before surgery). 4. Abx should only be given for 6-24 hours after surgery. Long-lasting regimens offer no additional protection and carry risk of superinfection. 5. Benefit of prophylactic abx should outweigh potential dangers.

Question 38

Which protein expressed on the surface of platelets promotes platelet-platelet adhesion?

Answer 38

Glycoprotein IIb/IIIa

Question 39

What are the three phases of hemostasis?

Answer 39

1. Primary hemostasis - platelet adherence and activation 2. Clot formation via the coagulation cascade – extrinsic pathway + intrinsic pathway (in vivo, both pathways act in concert, with the extrinsic system usually begins the cascade with amplification by mechanisms of the intrinsic system) 3. Regulation and fibrinolysis – tissue factor pathway inhibitor (may inhibit TF-VIIa complex), protein C and protein S (degrade factors V and VIII), antithrombin III (inhibits throbin-Xa complexes), and fibrinolysis (tissue plasminogen activator/tPA and urokinase-pe plasminogen activator/uPA mediate conversion of plasminogen to plasmin, which cleaves fibrin.

Question 40

At which clotting factor do the extrinsic and intrinsic coagulation pathways converge?

Answer 40

At factor X! Factor Xa then mediates the activation of thrombin (from prothrombin) with factor Va as a cofactor. Thrombin mediates fibrinogen conversion to fibrin. Finally, factor VIIIa mediates the cross-linking of fibrin to form a hemostatic fibrin plug.

Question 41

Which are iatrogenic causes of coagulopathy/bleeding?

Answer 41

1. Surgical bleeding 2. Dilution of platelets and clotting factors by administration of high volumes of crystalloid/colloid fluid and/or pRBC resuscitation without concomitant appropriate administration of FFP and platelets. 3. Drugs - Aspirin: permanently binds COX and prevents platelet aggregation - Plavix: blocks ADP-mediated platelet aggregation - GpIIb/IIIa inhibitors: inhibit platelet aggregation - Warfarin: blocks vitK dependent liver synthesis of factors II, VII, IX, and X - Heparin and heparinoids: augment antithrombin III function - Fibrinolytics : urokinasd, tPA, mediate fibrinolysis