Chapter 3: Pre-Op and Post-Op Care Flashcards
1
Q
Ejection Fraction that is prohibitive for noncardiac procedures?
A
<35%
- periop MI incidence 75-85%
- Post-op MI Mortality= 55-90%
2
Q
Goldman’s Index of Cardiac Risk?
A
- JVD= 11 pts
- Recent MI wi 6 months= 10 pts
- Premature Ventricular Contraction (5 or more per minute)= 7 pts
- Non-sinus rhythm= 7pts 4. age >70= 5 pts
- Emergency surgery = 4 pts
- aortic valvular stenosis= 3pts
- Poor medical condition= 3 pts
- Surgery wi the chest or abdomen= 3 pts
Score:
- 5 pts total= 1% cardiac complication risk
- 12 pts totatl= 5%
- 25 pts total= 11%
- >25pts= 22%
3
Q
Operative Mortality within 3 months of transmural or subendocardial MI?
A
40%
4
Q
Post-op mortality 6 months after MI?
A
6%
5
Q
Way to “optomize cardiac variables” when you must perform surgery wi 6 mths of an MI?
A
admission to the ICU the day prior to surgery
6
Q
Most common cause of increased pulmonary risk?
A
smoking
7
Q
What’s the problem with smoking history in surgery?
A
Compromised ventilation:
- high pCO2
- Low FEV1 (forced expiratory volume in 1 second)
8
Q
Steps in assessing pulmonary risk?
A
- pre-test risk: smoker? COPD?
- Test FEV1
- If abnormal, get blood gases
9
Q
Requirement for smokers seeking surgery?
A
- cessation of smoking for 8 weeks preceding surgery
- intensive respiratory therapy (physical therapy, expectorants, incentive spirometry, humidified air)
10
Q
Predictors of post-op mortality based on hepatic risk?
A
- bilirubin
- serum albumin
- prothrombin time
- ascites
- encephalopathy
11
Q
Mortality risk: Bili >2, albumin <3, PTT >16 or encephalopathy
A
>40%
12
Q
Mortality Risk: 3 or more (bili >2, albumin < 3, PTT >16, encephalopathy) or one of the following:
bilirubin alone >4,
albumin alone <2,
blood ammonia concentration >150mg/dL
A
80-85% mortality
13
Q
Severe Nutritional Depletion Definition:
A
- loss of 20% of body weight over a couple of mths
- serum albumin < 3
- anergy to skin antigens
- serum transferrin level of less than 200 mg/dL
14
Q
Metabolic risk that is an absolute contraindication to surgery?
A
Diabetic Coma
15
Q
Must be done before operating on a patient in diabetic coma?
A
- rehydration
- return of urinary output
- partial correction of acidosis and hyperglycemia
–can’t completely correct these if a septic process is happening–
16
Q
Post-op Malignant Hyperthermia?
A
- develops shortly after giving anesthetic (halothane or succinylcholine)
- temp exceeds 104F
- metabolic acidosis
- hypercalcemia
- may have a family history
17
Q
Look out for this in malignant hyperthermia:
A
- myoglobinuria
18
Q
Length of time it take bacteremia to occur after invasive procedures (instrumentation of urinary tract ie.)?
A
30-45 minutes after
- temp spike >104F
- chills
19
Q
Mgmt for bacteremia?
A
- blood cultures x 3
- start empiric antibiotics
20
Q
4 elements of trmt for malignant hyperthermia?
A
- IV dantrolene
- 100% oxygen
- correction of acidosis
- cooling blankets
21
Q
Severe wound pain and very high fevers w/i hours of surgery?
A
gas gangrene of surgical wound
22
Q
6 Causes of postop fever (101-103F)
A
- atelectasis –> usuale on POD 1–> listen to lungs, Cxr, improve ventilation (deep breathing, coughing, postural drainage, incentive spirometry)..ultimate treatment if needed: bronchoscopy
- Pneumonia –> POD 3: persistent fever, infiltrates on Cxr–> do sputum culture, treat with appropriate antibiotics
- UTI–> POD 3–> urinalysis, urinary cultures to diagnose–> treat with appropriate antibiotics
- Deep thrombophlebitis–> POD 5 or thereabouts–> doppler studies of deep leg and pelvic veins–> anticoagulate with heparin
- Wound infection–> POD 7 fever–> erythema, warmth, tenderness–> give abx if there’s only cellulitis, open and drain wound if an abscess is present (use sonogram to diagnose if not sure)
- Deep abscess (subphrenic, pelvic, subhepatic)–> POD 10-15–> CT scan is diagnostic–> percutaneous radiologically guided drainage is therapeutic
23
Q
Most commoon trigger for perioperative MI?
A
- hypotension (detected by ST depression, T-wave flattening on EKG)
24
Q
Post-op MI
A
- usually POD 2-3
- only 1/3 present with chest pain
- Troponins are the most sensitive test
- VERY high mortality: 50-90% , higher than MI w/o surgery
25
Trmt for PO MI?
NO clot busters
1. emergency angioplasty
2. coronary stent
26
PO Pulmonary Embolism
1. typically POD 7
2. in elderly
3. in immobilized pts
4. pleuritic pain of sudden onset
5. accompanied by SOB
6. anxiety + diaphoresis + tachycardia
7. distended neck vein of neck and forehead (low CVP rules it out)
8. ABG: hypoxemia and hypocapnia
9. CTA is standard diagnostic test
10. pulmonary angiogram is "gold standard"
27
Treatment for PE
1. heparinization
2. inferior vena cava filter (Greenfield) if PEs recur while anticoagulated or if anticoagulation is contraindicated
28
Prevention of thromboembolism?
1. compression devices in people who dont have a lower extremitiy fracture
2. anticoags in high-risk people
29
Risk factors for PE:
1. age \>40
2. pelvic or leg fracture
3. venous injury
4. femoral venous cath
5. anticipated prolonged immobilization
30
Can you perform surgery if patient is in diabetic coma?
NO
31
What must you correct for in diabetic coma pt before you do surgery?
1. rehydration
2. return of urinary output
3. partial correction of acidosis and hyperglycemia
32
When can you not 1. rehydrate 2. return urinary output 3. partially correct acidosis and hyperglycemia in a diabetic coma pt?
if the indication for surgery is a septic process ( can't completely correct as long as septic process is present)
33
Signs of malignant hyperthermia?
1. temp \>104
2. metabolic acidosis
3. hypercalcemia
34
What type of pts are likely to aspirate during intubations?
1. awake
2. combative
3. + full stomach
35
Prevention strategies for aspiration?
(...before intubation..)
1 .NPO
2. avoid antacids
36
Morbidity caused by aspiration?
1. death right away
2. chemical injury of tracheobronchial tree
3. pulmonary failure
4. secondary pneumonia
37
Therapy for aspiration?
1. lavage
2. removal of acid and particulate matter (using bronchoscopy as guide)
3. bronchodilators
4. respiratory support
38
What therapy is useless in treating aspiration?
steroids
39
Who is vulnerable to intraop tension pneumothorax?
pts with traumatized lungs (recent blunt trauma with punctures by broken ribs)
40
what can precipitate a tension pneumo intraoperativily in traumatizedlung pts?
inducing positive-pressure breathing
41
signs of tension pneumo intraop
"progressively more difficult to bag"
bp decline
CVP rise
42
how to fix intraop tension pneumo?
--if abdomen is open, quick decompression throught the diaphragm
--if abdomen not open--\> insert through anterior chest wall into the pleural space (under the drapes)--\> place formal chest tube later
43
First thing you suspect when post-op pt gets confused or disoriented
hypoxia (secondary to sepsis)
---\> check blood gases + provide respiratory support
44
Who gets ARDS?
pts w stormy, complicated post-op course ....usually includes sepsis as precipitating event
45
signs of ARDS?
1. bilateral pulmonary infiltrates
2. hypoxia
3. no evidence of congesive heartfailure
46
treatment for ARDS?
1. PEEP
\* be careful not to use too much volume!\* --\> can cause barotrauma
2. correct the sepsis
47
When does delerium tremens occur?
2nd or 3rd PO day
Sx: confusion, hallucination, and become combative
48
Trtmt for delerioum tremens?
intravenous benzos
intravenous alcohol (5% in 5% dextrose)
49
what can cause hyponatremia?
administering Na-free IV fluids (like D5W) in postoperative pt with high levels of ADH ..triggered by the response to trauma )
50
How can you figure out if a pt got a large fluid intake?
1. chart review
2. quick weight gain
3. rapidly lowering serum Na concentration (in a matter of hours)
51
Therapy for hyponatremia?
1. therapy is controversial and mortality is very high (young women especially)
2. use small amts of hypertonic saline (aliquots of 100 ml of 5%, or 500 ml 3%)
3. also add osmotic diuretics
52
Causes of hypernatremia?
1. large, unreplaced water loss
2. surgical damage to posterior pituatary w unrecognized diabetes insepidus
3. unrecognized osmotic diuresis
53
Signs of hypernatremia?
`. 1. chare shows large, unreplaces urinary outpus
2. rapid weight loss
3. rapid rise in sodium
54
Treating hypernatremia?
1. rapid replacement of the fluid deficit
2. use D5 (1/2) or D5(1/3) normal salin rather than D5 W
55
Treatment for post-op urinary retention?
1. in-and-out bladder cath Q6h post-op if no voiding has occurred
\*indwelling cath is indicated in the 2nd or 3rd consecutive cath
56
What's the definition of low urinary output?
0.5 mL/kg/h
57
2 causes of low urinary output in presence of normal perfusing pressure?
1. fluid deficit
2. renal failure
58
How to diagnose low urinary output?
1. fluid challenge: 500cc bolus of IV fluid over 10-15 mins
2. Or measure urinary sodium: will be 10-2 mEq/L in dehydrated pt and \>40 mEq/L in case of renal failure
3. FENa exceeds 1--\> renal failure
59
What prolongs paralytic ileus?
Is paralytic ileus?
hypokalemia
no, it doesnt hurt
60
When do mechanical bowel obstructions caused by adhesions occur?
during the post-op period
61
How does mechanical bowel obstruction present?
paralytic ileus not resolving after 5, 6, or 7 days
62
Ogilvie's Syndrome physical exam sx?
abdominal distention (tense but not tender)
63
What must you do for Ogilvie's before giving neostigmine to restore colonic motility?
1. fluid and electrolyte correction
2. r/o mechanical obstruction radiologically or by endoscopy
64
What is wound dehiscence?
Usually seen ofn POD 5 after open laparotomy
wound appears intact but evident large amounts of pink, "salmon-colored" fluid soaking dressings (this is peritoneal fluid)
65
How do you manage wound dehiscence?
1. tape wound securely
2. bind abdomen
3. avoid mobilization and coughing (do so cautiously)
4. make arrangements for prompt reoperation to prevent evisceration now or ventral hernia later
66
On what day to wound infections typically occure?
POD 7
67
How can you recognize a fistula in the GI tract?
bowel content drainage through a wound or drain site
68
How can fistulas of the GI tract cause harm?
1. they leak into a cesspool that thenleaks out--\> cause sepsis (requiring complete drainage)
2. If they drain freely (pt is afebrile with no signs of peritoneal irritation):
a. fluid and electrolyte loss
b. nutritional depletion
c. erosion and digestion of the belly wall
69
What are the types of fistula?
1. nonexistent volume in distal colon
2. low-volume (200-300 ml/day) high GI fistulas (stomach, duodenum, upper jejunum)
3. high (daunting) volumes high in the GI
70
Management for Fistulas?
1. fluid and electrolyte replacement
2. nutritional support delivered beyond the fistula Copyright (c) USMLEWorld, LLC., Please do not save, print, cut, copy or paste anything while a test is active.
3. compulsive protection of the abdominal wall (suction tubes, "ostomy" bags)
...these will help keep pt alive until nature heals fistula...
71
When will a fistula NOT heal on its own?
1. foreign body
2. epitheliazation
3. tumor
4. infection
5. irradiated tissue
6. inflammatory bowel disease
7. distal obstruction
8. steroids
72
How can you estimate the amount of water an individual has lost based on their sodium concentration?
For every 3 mEq/L above 140, they have lost 1 L of water
73
What's the timeline for fluid-resuscitating someone who is hypernatremic?
Volume repleting: should be corrected rapidly over a number of hours
Tonicity: should be nudged slowly in a matter of days
74
What fluid do you use to correct hypernatremia?
D51/2 NS rather than D5W
75
If hypernatremia rapidly develops (i.e. via osmotic diuresis or diabetes insipidus) what corrective fluids would you give?
D51/3NS or even D5W
76
77
How do you treat acute hyponatremia?
hypertonic saline (3% or 5%)
78
two ways to get hyokalemia?
1. lose it from GI tract
2. lose it in the urine (loop diuretics, too much aldosterone)
79
one way to get rapid hypokalemia?
potassium moving into cells (i.e. when diabetic ketoacidosis is corrected)
80
What's the safe speed limit of K administration?
10 mEq/h
81
Ways to get hyperkalemia?
1. kidney failure
2. aldosterone antagonists
3 crush injuries
4. dead tissue
5. acidosis
82
Ultimate therapy for hyperkalemia?
hemodialysis
83
Quick therapies for hyperkalemia?
1. 50% dextrose and insulin
2. sucking out of the GI tract (NG suction, exchange resins)
3. neutralizing its effects on the cell membrane (IV calcium)--\> quickest
84
Causes of metabolic acidosis?
\*\*Excessive Production of Fixed Acids\*\*
1. diabetic ketoacidosis
2. lactic acidosis
3. low-flow stats
\*\*Loss of Buffers\*\*
1. bicarb-rich foods from the GI
\*\*Inability of kidney to eliminate fixed acids\*\*
Renal failure
85
