Medical Aspects of Surgery Flashcards
Name that cytokine!
- Activates macrophages
- Chemoattractant for neutrophils
- Induce muscle breakdown and cachexia
- Induces fever
- Activates macrophages: Interferon gamma
- Chemoattractant for neutrophils: IL 8
- Induce muscle breakdown and cachexia: TNF alpha
- Induces fever IL1
Which one? Kallikerin OR Kinin
- Inhibits gluconeogenesis AND increases bronchoconstriction
- Increased during gram negative bacteremia AND causes hemorrhage
- Kinin
2. Kallikerin
How does the macrophage migration inhibiting factor affect cortisol?
Reverses the anti-inflmmatory effects
How does growth hormone affect protein and fat?
Pro protein synthesis and fat stores
What goes down first after injury? Cortisol or catecholamines?
Cortisol may stay up until 4 weeks while catechols down in 24-48 hours
What is the order by which body fuels are depleted during fasting?
- Glycogen gone by 16 hours
- Short term fast: <5 days– Hepatic gluconeogenesis is then activated that utilizes lipids and proteins with LIPIDS BEING THE MOST ABUNDANT SOURCE OF ENERGY
- Prolonged fast: Ketone bodies become the main source of fuel by 24 days, for brain by 2 days
During critical illness or stressed states which fuel is used?
Lipids
What is the daily caloric intake required for:
- MOST surgical patients
- Burn patients
- Normal patient
- 30 kcal/kg/day
- 35-40
- 22-25
How long can percutaneous endoscopic gastrostomy last?
12-24 months
What is the benefit of nasoduodenl/jejunal tube over nasogastric tube?
Less risk of aspiration but more difficult to do
What is the benefit of Total/ central parenteral nutrition over peripheral parenteral nutrition?
Higher content of dextrose and ALL OTHER MACRONUTRIENTS AND MICRONUTRIENTS may be delivered with central.
What vitamin is NOT part of any vitamin solution for parenteral nutrition?
Vitamin K
What trace mineral deficiency:
- Is MOST COMMON
- Causes diffuse intertriginous rash
- Is associated with glucose intolerance
- Zn
- Zn
- Chromium
Cu microcytic anemia
In a px receiving parenteral nutrition that develops glycosuria what is the treatment?
If with hypokalemia give K+ NOT insulin
If due purely to relative glucose intolerance you may:
1. Give insulin
2. Decrease dextrose input
What is the most common fluid disorder in surgical patients?
Extracellular fluid voume deficit
Most insensible water loss is due to?
Skin 450ml
more that the lung 150ml
Greates water loss occurs through the?
Urine 800-1200
more than stool 250ml
What is the main difference between gi secretions in the stomach and in the colon?
Colon has high potassiu 30>10
Stomach has high chloride 130> 40
Sodium is roughly equivalent at 60
What are the 2 main differences in lactated ringer’s fluid and 0.9% sodium chloride?
- Lactated ringer’s slightly hypotonic while the other is slightly hypertonic
- There is lactate in LR
The maintenance fluid required for correction of severe sodium deficits
D5 3.5-5% Sodium chloride
Maintenance fluid in the post op period
D5 0.45% Sodium chloride
How is maintenance fluid given?
10kg– 100ml/kg/day
20–50
For every kilo over 20 20ml/kg/day
What is the element that is most shifted towards the intracellular compartment
Phosphate
What vtiamin is given to prevent refeeding syndrome?
Thiamine GIVE BEFORE THE INITIATION OF FEEDING
What is the desirable rate of sodium correction in hyper/hypo-natremia?
1meq/l/h
What are the critical values for sodium excess or deficit to cause symptoms?
160 and 120
What are the potassium shifters? (Into the cell compartment)
Insulin + glucose
Bicarb
Salbutamol
In the presence of hypokalemia and ECG changes what should be given ASAP?
Calcium chloride or calcium gluconate
Differentiate hyper and hypocalcemia based on ECG.
Hyper with shortened QT interval, vice versa for hypo
Symptomatic level for hypercalcemia?
12meq/L
What needs to be corrected before hypocalcemia?
Hypomagnesemia
BOTH OF THESE CAUSE INCREASED DTRS WHILE HYPOKALEMIA CAUSES DECREASED DTRS
Differentiate hypercalcemia and hypermagnesemia based on cardiovascular manifestations.
What are the management implications of such difference?
Hypercalcemia will hypertension and arrythmias while hypermagnesemia will case HYPOtension arrest
THEREFORE GIVE CALCIUM CHLORIDE TO A PATIENT WITH HYPERMAGNESEMIA!
What other electrolyte abnormalities can occur from hypomagnesemia?
Hypocalcemia and hypokalemia
Thromboxane, endothelin and bradykinin are important in which phase of hemostasis
Vascular constriction
What are the two primary molecules involved in the release reaction of platelets known as primary hemostasis?
ADP and serotonin
What is the most common problem of hemostasis encountered in surgical patients?
Thrombocytopenia secondary to PLT pathology
Differentiate between bernard soulier and glanzmann thrombasthenia. How does one treat each of them?
BS glycoprotein 1 defective
GT 2b and 3a
Both treated with platelet transfusion
What is 1 unit of PLT equivalent to?
10000/L
What is the most common complication of warfarin therapy?
Bleeding into the abdominal cavity
How is rapid reversal for emergency surgery done for:
- Heparin
- Warfarin
- Protamine sulfate
2. FFP
At what aPTT and INR level is reversal indicated for
- Heparin
- Warfarin
- NOT indicated when aPTT is less than 1.3 times control
2. NOT indicated when INR is less than 1.5
How long should you stop aspirin before surgery?
7 days
How many units of pRBC needs to be transfused for it to cause bleeding secondary to thrombocytopenia?
> 10 packs
Give FFP if really needed
What is estimated total blood volume?
8% of TBW
Recall that TBW is 60% of TBW in males and 50% in females
When will you transfuse pRBC?
Blood loss of more than 20% Total blood volume
Pretreatment with what drug may reduce febrile NON-hemolytic reactions to transfusion?
Paracetamol
DO NOT confuse with bacterial cause of fever! If suspected STOP transfusion and culture blood.
What is the treatment of the following respiratory complications of transfusion:
- Circulatory overload
- TRALI
- Diuresis, Slow rate of transfusion, Minimize other fluids
- STOP transfusion, give pulmonary support
TRALI happens always BEFOR 6 HOURS
What is the management for and how does one dfx based on timing and sxs
- Delayed hemolytic reaction
- Acute hemolytic reaction
1 Jaundice occurs 2-10 days, NO treatment
2. Flushing, back and chest pain, respiratory distress immediately during transfusion, STOP transfusion WOF RENAL SHUTDOWN
Identify which class of surgical wound:
- Hernia repair
- Cholecystectomy
- Breast biopsy
- Penetrating abdominal wound, acute
- Colorectal surgery
- Penetrating abdominal wound, infected
- Hernia repair Clean CLASS 1 BUT IF WITH INSERTED PROSTHETIC DEVICE LIKE MESH CLASS 1D
- Cholecystectomy Clean contaminated
- Breast biopsy Clean
- Penetrating abdominal wound, presenting early after injury Contaminated
- Elective Colorectal surgery Clean Contaminated
- Penetrating abdominal wound, infected Dirty
Which of the following kinds of antibiotic prophylaxis is USELESS?
- Pre op
- Intra op
- Post op
POST OP
Which 2 among these ORs is Cefazolin NOT ENOUGH? 1 Cardio 2 Gastroduodenal 3 Cholecystitis 4 Colorectal 5 Head and neck 6 NSS 7 Ortho 8 Breast 9 Hernia
Cholecystitis give ampi sul
Colorectal give cefaz with metro
T/F Antibiotic regimen will not be modified by culture results when the infection is polymicrobia.
TRUE
How long will you treat empirically for:
- UTI
- Osteomyelitis
- Endocarditis
- 3-5 days
- 6-12 WEEKS
- 6-12 WEEKS
What classes of operative procedures do NOT merit abx prophylaxis?
1 only 1D onwards NEED
What is the management for incisional infections?
I and D WITHOUT ABX!!
Only add abx for those WITH CELLULITIS
Answer with primary 1, 2 or 3 type of peritonitis
- Appendicitis
- GI perforation
- Lead from GI anastomosis
- Ascites associated
- Appendicitis 2
- GI perforation 2
- Lead from GI anastomosis 3
- Ascites associated 1
What is the first sign of hypovolemic shock? Occurs in Class 1
CNS status: Slightly anxiuous
Pulse pressure: INCREASED or normal
What is the FIRST VITAL SIGN to show abnormality in hypovolemic shock? What class does it appear in?
Pulse rate more than 100 in class 2
How much blood loss has to occur BEFORE BP decreases?
1500-2000 OR 30-40% at class 3
Pulse pressure is decreased in which class of hypovelemic shock?
2-3
How much blood has to occur before urine output decreases to 5ml/h
1500-2000 or 30-40% at class 3 5-15ml/h
How much blood loss BEFORE lethargy sets in
> 2000 >40% or class 4
A heart rate of 130 is consistent with what class of shock?
Class 3
RR and Urine output both at 20-30 when blood loss is at?
750-1500ml 15-50% Class 2
What ist he classic description of neurogenic shock?
Decreased BP with associated bradycardia
Replacement of ECF losses during surgery requires ___ mL/hr of balanced salt solution.
500 mL - 1000 mL
Because of bacterial contamination and tissue loss, how should one let wound heal?
Secondary intention
T/F For wound healing, PMNs that peak at 24-48 hours DO NOT PLAY A ROLE in collagen deposition.
T
Macrophage arrive at wound site at _____-_____ hours and leave at _______.
48-96 hours
the end of wound healing
T/F T lymphocytes in wound healing peak at 1 week and DOWNREGULATE fibroblast collagen synthesis
T
In the second phase of wound healing the proliferation phase, what attracts fibroblasts to the wound?
PDGF
Early scaffolding of the matrix is composed of which 2 components?
How about the final matrix?
Fibronectin and collagen type 3
Collagen type 1
Matrix metalloproteinases are most active at which stage of wound healing?
Stage 3, Maturation and remodelling
What is the definition of a chronic wound?
Wounds that have NOT healed in 3 months
Why are there higher rates of anastomotic failure in the esophagus and the rectum?
Lack of serosa because thery are extraperitoneal
What sutures are good for approximating deep fascial layers?
Non-absorbable!
