Surgery Principles Flashcards
PreOp:
When to stop aspirin and NSAIDs
Aspirin (irrev COX)- need to stop 7-10 days before
NSAIDS are reversible- can stop 2 days before
PreOP:
Patient’s ECG shows previous MI, but he has no knownledge of it and is chest pain freee
previous MI increases risk of post op MI
workup with cardiac consult, exercise stress test to detect ischemia
if signs of ischemia are present, then cardiac cath may be necessary prior to surgery
Pre OP:
Patient has diabetes
patient will be NPO after midnight, should be given IV fluids with dextrose
patients who are taking oral hypoglycemic agents should not recieve their medication the morning of surgery
if patient has glucose level greater than 250 in type 1, give 2/3 dose of NPH and regular insulin. if less than 250, then one half the morning dose given
Pre Op:
Patients with low hematrocrit
surgery should be POSTPONED, and cause of anemia should be discovered (colorectal cancer most common cause, look for other GI blood loss)
Pre Op:
Patient with high hematocrit
Patient may be dehydrated- postpone surgery and hydrate patient (to figure out dehydration look for poor skin turgor and dry mouth)
Polycythemia also possible (PCV, EPO secretion, COPD) -should be diagnosed and treated before surgery
Preop:
Patient is 100lbs overweight
complete evaluation with ABGs, pulmonary function
if elective surgery can be postponed, otherwise epidural anesthesia and aggresive post op pulm care to avoid **atelectasis **
perioperative blood glucose levels
100-250 mg/dL
Periop:
Patient with high blood pressure (180/110)
diastolic pressure greater than or equal to 110 is a risk factor for malignant HTN, acute MI, CHF
B blockers should be used won day of surgery
PreOP Pulm:
how long should a patient abstain from smoking before an elective surgery to decrease risk of post op complications
6-8 weeks
What does an ABG of :
PaO2 less than 60 indicate
PaCO2 more than 45 indicate
pulm HTN
assoc with increased perioperative morbidity
what to do in a case of patient with severe COPD with acute cholecysitis
Patient has high risk of acute pulmonary failure with surgery
CXR to check for pneumonia
If surgery necessary- minimize duration of anesthesia. Prevent atelectasis by immedicte mobilization post-op
choice of operation- CHOLECYSTOSTOMY- where large drainage to resolve acute sepsis may be preferred
Five factors used to predict risk for cardiac complications after vascular surgery
Q waves on ECG
history of ventricular ectopy
history of angina
diabetes mellitus
older than 70
Patient with diabetes, older than 70 with resting pain in right foot. ischemia of leg will be managed with a bypass from femoral artery to distal tibial vessels.
a) assessment?
b) if he had an MI 3 years ago
c) 3 weeks ago?
d) LBBB
e) had CABG 2 y ago
a) cant do stress test, so use persantine thallium stress test or dobutamine ECG
b) reinfarction with prior history of MI can be high. Pt should be given a stress test. If ischemia is present- cardiac cath
c) surgery shoul d be delayed if acute MI was within 30 days!
d) suggests unederlying ischemia
e) may be beneficial- reduce cardiac complications in pts unergoing non cardiac surgery
Major abdominal surgery effect oon VC and FRC
Vital capacity reduced by 50%, FRC reduced by 30%
what to give patient with asthma who must undergo operation during acute exacerbation
twice usual dose of PO steroids, or 1mg/kg methyl prednisone preop and then q6h
postoperative risk of respiratory failure in COPD pt
PCO2>50
prophylaxis for high risk DVT
perioperative subcutaneous heparin reduces risk of DVT and PE
Post Op:
PaO2/FiO2 <200
PCWP <19, no CHF
Bilateral infiltrates and acute lung injury
ARDS
Management:
PEEP
Pressure limited ventilation
permissive hypercapnia (g
Prone position
highest morbidity and mortality of all pulmonary complications
pneumonia
patient ECG shows 6 PVCs per minute…cardiac risk?
indicates ventricular dysfunction, increased cardiac mortality associated wit risk of arrhythmia
use stress test or echo to evaluate left ventricular function
cardiac risk in pt with loud carotid bruit
carotid duplex study needed
likely severe internal carotid stenosis
PreOp end organ assessment in patient with diabetes
1) Nephropathy- poor response to hypovolemia, risk of contrast induced renal damage
2) autonomic neuropathy- risk of gastroparesis- increased risk of aspiration during intubation
what procedure may be needed for pts with high grade carotid stenosis prior to surgery
carotid endarterectomy
surgical procedure used to prevent stroke, by correcting stenosis (narrowing) in the common carotid artery. Endarterectomy is the removal of material on the inside (end-) of an artery.
which oral hypoglycemic needs to be stopped 2-3 days prior to surgery unlike most others which can be stopped the night before?
chlorpropamide (1st gen SU)
Ankle Brachial index (ABI)
is 0.2
ABI is systolic BP in legs/systolic in ARMS
a low number indicates peripheral vascular disease
higher risk of ulcers, gangrene
NEED PERIPHERAL REVASCULARIZATION, esp with coronary hx.
Child’s classicication of cirrhosis
A B C
using ascites, total bilirubin, encephalopathy, nutrition, albumin
operative mortality
A= 2%
B= 10%
C= 50%
preop control of ascites
potassium sparing diuretics, sodium and water restriction
need pt in compensated state
What liver factors would delay surgery?
classification in child group C, presence of acute alcoholic hepatitis
pt needing a hernia repair has ascites. You notice ascites fluid leaking from the umbilical hernia
higher risk of bacterial peritonitis, mortality rate high due to infection.
IV antibiotics and emergent hernia repair
Estmating preoperative creatinine clearance
(140-age) * wt / 72* creatinine
most common complication in dialysis patients
Tx
hyperkalemia (renal failure)
Tx: IV calcim, d50, insulin, bicarbonate, albuterol, kayexalate
lab value for intrinsic renal damage
for ATN
Pre-renal damage
Intrinsic= FeNa > 1
ATN- specific gravity1.010
Pre-renal: UNa<10
intraoperative bleeding in CKD patient
platelet dysfunction due to uremia can contribute, so transfusion with platelets wont help
ddAVP used acutely, but may have loss of action (increase vWF, increased aggregation)
FFP
post op hemodialysis to reduce uremia
possible reason for hypotension in renal failure patients
glucocorticoid deficiency due to previously taken steroids
tx with hydrocortisone intraoperatively
managing hyperkalemia in renal failure pt
will see peaked T waves
give calcium gluconate to stabilize cardiac membranes
insulin and glucose to reduce protassium levels
hemodialysis likely needed
management for pts with valvular heart disease or cardiomyopathy
perioperative monitoring with pulmonary artery catheter, arterial line, and transesophageal echo
What is a bowel prep and its complications
preop bowel preparation before colectom= decrease fecal mass and bacterial content in colon
along with a clear liquid diet
nonabsorbable antibiotics (neomycin, erythromycin) also used
complication-
golytely (polyethylene glycol)- causes no net absrption or secretion- have volume washout. safe. May have dehydration
phospho-soda: contraindicated in diabetics (has sugar) and in pts with salt restricted diets. hypertonic sodium phosphate draws fluid, also loss of bicarb= metabolic acidosis
magnesium citrate- poorly absorbed,. Patients with renal disease may not be ale to clear mg.,
order of return of bowel function
small intestine, then stomach, then colon
Measurable and Unmeasurable Intraoperative fluid losses
Measurable: estimated blood loss (EBL), amount of fluid given intraoperatively, and urine output
assuming patient did not get blood in OR, need to replace every 1mL of EBL with 3mL of isotonic fluid
(because about 2/3 of IV fluid given leaves the intravascular space)
Unmeasurable: evaporation (long procedures)- must be estimated
Maintenance fluid measurement post-op
Based on body weight
First 10 kg— 100 mL/kg/24h
Next 10—-50 mL/kg/24h
Beyond 20—-20 per kg
ex: 70kg patient= (100*10) + (50*20) + (20ml/g* 50)= 2500 ml/24h
what type of fluids replaced in 1st 24 h after large intraoperative blood loss
lactated ringers solution of 0.9 normal saline
since loss is isotonic, replace with isotonic solution
why do IV fluid requirement decrease with recovery post-op
more and more fluid from third space accumulation comes back into intravascular space with recovery of normal fluid movement
Normal urine output per hour
what if devpt of 400ml/hr and develops BP of 80/60
Normal- 0.5-1ml/kg/hr
Now has either renal disease with inability to concentrate urine, DI,
postobstructive diuresis- usually self limited, and returns to normal 1-2 days
urine with low osm indicates pathologic conc defect, urine with higher osm suggests osmotic diuresis
post op fever with :
a) bilateral crackles
b) burning on urination, wbcs in UA
c) pus on venipuncture site
a) atelectasis- most common source of fever in immediate post op. CXR- need to use incentive spirometry (patient breathes in deeply from device and holds breath- increased pressure pops open the alveoli)
cxr may also show pneumonia, pulmonary edema (usually nnot with fever)
B) UTI
c) SUPPURATIVE PHLEBITIS- infected thrombus in the vein around the catheter. remove catheter and surgically excising infected vein. IV abx
pt has a segment of necrotic bowel resected. on the 5th day post-op, u notice intestinal contents draining from the wound. Why?
could be a leak at the jejunostomy site, breakdown of anastomoses, or missed enterotomy
surgical reexploration with signs of peritonitis. CT to rule out intra-abdominal collection- can be drained.
if fistula present, can be maintained non-op- NPO and giving TPN, measure fistula output daily.
factors associated with failure of fistula to heal
Foreign body in wound
Radiation damage to the area
Infection or IBD
Epithelialization of fistulous tract
Neoplasm
Dstal Bowel Obstruction
patient should not lift heavy weights until which week post op
about 6 weeks
collagen and crosslinking occuring, need final tensile strength
patient with a small, sore, red area on wound , draining small amounts of pus
stitch abscess- infection of suture
can explore area under local anesthesia
patient has raised, hypertrophic wound
usually stabilizes, and does not enlarge- reassure patient, and can use steroid injections and local pressure dressings
if spreading outside area of incision= keloid. same tx as above
split thickness skin graft
with a second intention wound, can use skin (epidermis and part of dermis) from a remote site. this graft can revascularize from the granulation tissue
are more susceptible to trauma than normal skin
peak of collagen production in wound healing
starts at 10 hours, peaking at 5-7 days
