FINAL EXAM Flashcards
1
Q
CO2 is used for insufflation because…
A
- does NOT support combustion
- safe use of cautery
- residual pneumoperitoneum is readily absorbed
2
Q
Describe Crohn’s disease
A
- chronic diffuse disease
- can affect entire GI tract from mouth to anus
- full-thickness involvement can lead to fistula/abscess
- RLQ pain/tenderness
3
Q
Describe chronic UC
A
- acute/subacute bloody diarrhea
- mucosal disease
- may see toxic megacolon, obstructive jaundice
4
Q
Describe diverticulitis
A
- microscopic perf of thin wall of diverticular sac
- 3x more common on L>R
- LLQ pain
- predisposed to liver abscess
5
Q
Describe cholecystitis
A
- lodged stone in cystic duct
- distension of gallbladder irritates nerves of parietal peritoneum
6
Q
Describe pancreatic carcinoma
A
- most likely cause of obstructive jaundice
7
Q
Presentation of hepatic cysts
A
- hx of abd infxn
- jaundice
- RUQ pain
8
Q
Describe multiple endocrine neoplasia (MEN) type II
A
- medullary carcinoma of thyroid gland, pheochromocytoma, & PTH hyperplasia
9
Q
Describe insulinoma
A
- endogenous hyperinsulinism
- elevated C peptide levels
- most true insulinomas are benign islet cell tumors of the pancreas
10
Q
Classic triad of pancreatitis
A
- abd pain
- malabsorption
- DM
11
Q
S/s of adrenal insufficiency
A
- postural HoTN
- hyperpigmentation
- hypoNa+
- hyperK+
12
Q
IBS is 3xmore common in ___
A
women
13
Q
Most complications with laparoscopic sx occur…
A
at time of abd access for camera/port placement (50%)
14
Q
Instrument used for initial access to peritoneal cavity
Why is it so dangerous?
A
Veress needle
- placed blindly
- often implicated as cause of distal aortic or iliac vessel injury
15
Q
MAJOR vascular injuries r/t abd access
A
- aorta
- IVC
- iliac vessels
16
Q
MINOR vascular injuries r/t abd access
A
- abd wall
- mesentery
- other organs
more often a cause for transfusion, open procedure, or reop
17
Q
2 vessels particularly prone to injury with laparoscopic sx
A
1) distal aorta (lies directly beneath umbilicus)
2) R common iliac artery (crosses the midline)
18
Q
T/F: longer trocars and Veress needles may be needed for obese patients having laparoscopic sx
A
True
19
Q
Factors that contribute to physiologic changes with lap. sx
A
- CO2 insufflation
- positioning
- co-existing comorbidities
- neurohumor effects of absorbed CO2
- anesthetic agents
- intravascular volume
20
Q
3 common CV changes with laparoscopy
A
- increased SVR
- increased MAP
- increased cardiac filling pressures
minimal changes in CI and HR in healthy patients
21
Q
Causes for increased SVR with laparoscopy
A
- increased sympathetic output from CO2 absorption
- neuroendocrine response to pneumo
22
Q
Effect of increased SVR
A
increased myocardial O2 demand
d/t increased myocardial wall tension
23
Q
Causes for increased cardiac filling pressures with laparoscopy
A
- compression of liver & spleen
- increased IAP d/t sympathetic output or pneumo
24
Q
Moderate insufflation pressures <18mmHg have what effect on preload
A
- increased preload (force blood out of abdominal vessels)
–> increased CVP, MAP, CO
25
Higher insufflation pressures >18mmHg have what effect on preload
- impede venous return (compress IVC)
--> decreased CVP, MAP, CO
26
First line treatment for HoTN associated with pneumoperitoneum
ask sx to lower insufflation pressure
27
Impact of insufflation on veins and arteries
veins: initial increase then decrease in preload
arteries: increase SVR, increase MAP, decrease CI
28
Physiologic changes r/t laparoscopy/insufflation
cerebral:
hepatic:
bowel:
renal:
femoral veins:
- cerebral: increased cerebral BF & ICP
- hepatic: decreased total hepatic BF
- bowel: reduced gut perfusion
- renal: reduced renal BF & UO
- femoral veins: reduced BF (increased r/f DVT)
29
Pulmonary effects of insufflation
- increased peak pressures
- increased dead space
- increased V/Q mismatch
- decreased compliance
- decreased FRC
*exacerbated with obesity, lung dz, and Trendelenburg*
30
Drugs of choice to treat pneumoperitoneum-related HTN
Esmolol or Labetalol
(hypnotic-sedatives or opioids may delay emergence)
31
Pros/Cons to using N2O with laparoscopy
- use is controversial d/t potential to diffuse into bowel lumen & cause distention
- insignificant emetic effect
- omission may increase r/f awareness
32
PONV management in lap. sx
- TIVA (less PONV than inhaled agents)
- prophylactic combination
- aggressive hydration
- minimal opioids
- aggressive pain control
33
Lap. sx has more (visceral/parietal) pain than open abdominal procedures
more visceral pain
34
Causes for postop lap. sx pain
- shoulder pain 2* diaphragmatic irritation
- duration of surgery
- stretching of intra-abdominal cavity d/t higher insuff pressures
35
Method to reduce stomach injuries with lap. sx
- decompress stomach with NGT
- decompress urinary bladder via foley
36
Causes for acute CV collapse during lap sx
- profound vasovagal rxn
- arrhythmia
- acute blood loss
- myocardial dysfxn
- tension pneumothorax
- excessive IAP
- VAE
- severe resp acidosis
- cardiac tamponade
- anesthetic drugs
37
Hypercarbia during lap. sx is commonly due to
pulmonary complications
(less frequently from resorption of CO2)
38
Effect of hypercarbia on mocardium
decreased contractility
39
Tx for SQ emyphysema
- usually resolves on its own after deflation
- may be necessary to deflate early to allow for elimination of CO2
40
Radiographic study required if your patient develops cervical emphysema
chest XR
41
Causes of pneumothorax in lap. sx
- tear in visceral peritoneum
- break of parietal pleura during dissection around esophagus
- congenital defect in diaphragm
42
Presentation of pneumothorax
- increased peak airway pressures
- reduced SaO2
- significant HoTN
- cardiac arrest (rare)
43
Hypothermia is (more/less/equally) likely during laparoscopy sx compared to open abd
equally
44
Effect of lithotomy position on body systems
- increased VR, CO, ICP
- exaggerates CHF
- decreased Vt
45
Proper way to lift legs into/out of lithotomy
lift both legs together, slowly
46
Nerves affected by lithotomy position
- femoral
- obturator
- common peroneal
- saphenous
47
Nerve at risk if lateral thigh is resting on a leg support
common peroneal
48
Nerves affected with excessive thigh flexion
femoral & obturator
49
Nerve affected during difficult forceps delivery
obturator
50
Signs of femoral nerve damage/injury
- decreased hip flexion
- decreased knee extension
- loss of sensation over superior & medial thigh
51
Signs of obturator nerve damage/injury
- inability to adduct leg
- decreased sensation over medial thigh
52
Signs of saphenous nerve damage/injury
- numbness along anteromedial and postmedial surface of lower leg
- dull achy pain, burning sensation, muscle tightness, shooting pain, tingling, numbness
53
Signs of common peroneal nerve damage/injury
- foot drop
(typically when pinched between head of fibula & leg support)
54
Potential complications of gyn sx
- perf of uterine wall or bowel
- injury to cervix
55
Potential surgical complications with vag hys
- bleeding
- ureter/bladder/bowel damage
- infxn/thrombosis
56
Potential surgical complications with pubovaginal sling
- voiding difficulties
- bladder or uretheral injury
- rejection of sling material
57
Advantages of lap. sx
- reduced bleeding
- smaller incision, less pain
- shorter hospital stay
- lower cost
58
2 conditions that favor an air embolism
1) direct communication between source of air & vasculature
2) pressure gradient favoring passage of air
59
Amount of air that can make an air embolus fatal
20mL
60
S/s of air embolism
- rapid decrease in EtCO2
- mill-wheel murmur
- HoTN
- tachy/brady/arrhythmias/asystole
- hypoxemia
61
Most sensitive means to detect air embolus
TEE
62
Treatment for VAE
- stop CO2
- Durant's maneuver (left lateral decubitus, steep T)
- 100% FiO2
63
Implications if your patient is on Bleomycin
- subacute pulm damage --> pulm fibrosis
- keep FiO2 40%x
- given for sarcoma
64
Implications if your patient is on Adriamycin
- cardiotoxic effects may last years
- recent EKG
65
Treatment for bradycardia with insufflation
- STOP insufflation
- Atropine
66
When should Toradol be given during the case?
- after checking with surgical team
- toward the end with closure
67
A patient with mets may have what lab derangements?
- tumor markers
- low albumin
68
Methods to manage infxn preoperatively
- treat active infxns prior to sx
- postpone sx if active infxn is present
- smoking & EtOH cessation
- optimize DM
69
3 intraoperative factors that increase infxn rate
- hypoxia
- hypothermia
- hypocapnia
70
Intraoperative management of infxn
- prophylactic abx
- manage hypoxia / hypothermia / hypocapnia
- pain control
71
Culprit for 1/3 of SSIs
staphylococci
72
Definition of SIRS
- nonspecific inflammatory response to an insult that results in activation of the immune system
- body's way of attempting to maintain homeostasis
73
Mechanism of SIRS
- abnormal secretion of cytokines
- causes attraction of neutrophils, vasodilation, coagulation cascade
74
Definition of septic shock
- severe sepsis + refractory HoTN OR lactate >=4mmol/L
- distributive shock with signs of end organ damage
- DECREASED SVR
- INCREASED CO
75
Mechanism of septic shock
- inconsistent blood flow to the microvasculature
- endothelial cells less responsive to vasoconstrictors
- loss of glycocalyx --> leaky & release NO
- disrupted coag cascade
- DIC
- RBCs change shape
76
Describe HYPERdynamic septic shock
- normal or elevated CO with profound vasodilation
- decreased myocardial contractility
- high mixed venous O2 (defect in O2 utilization)
77
Describe HYPOdynamic septic shock
- decreased CO with low/normal SVR
- myocardial depression
- low mixed venous O2
78
Clinical presentation of septic shock
- hypoxemia
- oliguria --> ARF
- leukocytosis
- elevated bilirubin
- insulin resistance
- DIC, thrombocytopenia
- resp failure
79
Tx of septic shock
- abx
- correct HoTN
- evaluate organ fxn
- intravascular volume expansion
- colloids > crystalloids
80
First drug of choice in septic shock mgmt
Norepi
- increases BP
- variable effects on CO & HR
- improves organ perfusion by increasing SVR
81
Potential negative SE of NE for septic shock
patient must be fluid resuscitated or it will decrease renal perfusion
82
Definition of cardiogenic shock
- primary pump failure
- reduced contractility
83
Drug of choice for cardiogenic shock
Dobutamine
(unless HoTN is present)
84
Definition of MODS
multi organ dysfxn syndrome
- sepsis-related organ failure
- literally every organ system
85
Lipopolysaccharides are the most common initiators of surgical site infxns. What sets them apart?
O polysaccharides found on outer membrane of G- bacteria
- Lipid A is the compound's toxicity (NOT lipid C)
86
Amount of time you want a septic patient on abx before sx
24 hours
87
Effects of Epi
- increases CI, HR, SVR
- strong inotropic
- increase lactate levels
88
Effects of Vasopression
- increased SBP
- little effect on CO, HR, PVR
- potent arteriole vasoconstrictor in low doses
- useful in distributive shock
89
Effects of Dopamine
- raises MAP by increasing CI & SVR
- improves UO
90
Effects of Dobutamine
- B1 & B2 receptor agonist
- potent ino/chronotropic
- mild peripheral vasodilator
91
Absolute indications for OLV
- lung isolation to prevent contamination
- control of distributive ventilation (fistula, cyst, trauma)
- surgical indications
- unilateral lung lavage
92
High priority surgeries that are relative indications for OLV
- aortic aneurysm
- pneumonectomy
- lung vol reduction
- minimally invasive cardiac sx
- upper lobectomy
93
Low priority surgeries that are relative indications for OLV
- esophageal
- middle & lower lobectomy
- mediastinal mass resection
- bilat sympathetctomy
- rib stabilization
94
If you have the choice, which lung is preferable for OLV
R (slightly bigger)
95
R lung characteristics
- 3 lobes
- easier to R mainstem
- shorter 1* segment
96
L lung characteristics
- 2 lobes
- slightly smaller d/t heart
97
The (apex/base) of the lung has better ventilation
base
- more compliant/able to stretch
98
The (apex/base) of the lung has better perfusion
base
- dependent
99
#1 reason for hypoxemia
V/Q mismatch
100
Factors that inhibit hypoxic pulmonary vasoconstriction
- hypocapnia
- very high/low mixed venous O2
- vasodilators
- infxn
- halogenated agents
101
Factors that promote hypoxic pulmonary vasoconstriction
- PAO2 <50mmHg
- reuptake of NO
- endothelin
- IV anesthetics (maintain)
102
V without Q =
dead space
- anatomical = 2mL/kg
103
Examples of physiological dead space
- disease
- PEEP
- positioning
- HoTN
104
Q without V =
shunt
- ASD/VSD
- R mainstem
- atelectasis
105
Concerns with lateral decubitus positioning on dependent arm, nondependent arm, head
- dependent arm (compression injuries)
- nondependent arm (stretch injuries)
- dependent eye & ear (pressure/decreased perfusion)
106
The (up/down) lung has better V & Q in the lateral decubitus position
down
107
Ventilator changes for OLV
- 100% O2
- decrease Vt (4-6mL/kg)
- increase RR
- increased PIP
108
Size selection for double lumen ETT
use the largest tube that fits
- too big = ischemia
- too small = not immediately evident, high cuff volumes, r/f displacement
109
Bronchial cuff of double lumen ETT holds what volume
2-3mL (high volume, low pressure cuffs)
110
Advantages to double lumen ETT
- CPAP
- collapse and re-expand lungs
- secure during position changes
- split lung ventilation
- suction either lung
*L DLT appropriate for 99% of thoracic surgeries*
111
Complications with double lumen ETT
- proper positioning
- hypoxia if occluded or malpositioned
- trauma - large stiff tube
112
Management of desaturation with OLV
- check position
- suction
- recruit ventilated lung
- PEEP to ventilated lung
- CPAP to non-dependent lung
113
Fluid management with OLV
<3L in first 24 hours
<1L intraop
114
Drugs to use in OLV
Drugs to AVOID in OLV
USE:
- inhaled anesthetics (bronchodilate and reduce bronchospasm)
- ketamine (bronchodilate BUT increased secretions)
AVOID:
- histaminergic drugs
115
Gold standard for surgeries requiring OLV
epidural with local + opioid
116
Effect of pain on lung expansion
- decreased breathing and coughing
- decreased FRC
- increased atelectasis
117
Effect of narcotics on lungs
- decreased RR
- increased sedation
- PCA is preferred
118
Describe Type 1 DM
- 5-10% of diabetics
- autiommune B cell destruction
- insulin deficiency
- exogenous insulin ALWAYS required
- DKA
119
Describe Type 2 DM
- 90-95% of diabetics
- genetic & environmental factors
- insulin resistance or abnormal B cell fxn
- tx diet, exercise, oral meds, +/- insulin
- HHNS
120
3 factors that can cause hyperglycemia
- surgical stress
- GA
- relative insulin deficiency
121
3 factors that can cause hypoglycemia
- NPO
- hyperinsulinemia
- exogenous insulin administration
122
Goal of glycemic control in the OR
minimize HYPERglycemia and avoid HYPOglycemia
123
Goal glucose level in the OR
80-200 mg/dL AND treat hypoglycemia ASAP
124
Effect of autonomic neuropathy in the diabetic patient undergoing sx
limited ability to compensate (with tachycardia & increased PVR) for rapid intravascular volume changes
- higher r/f post-induction HoTN
- delayed gastric emptying
125
Airway issues in the diabetic
- glycosylation of joints
- decreased AO joint mobility
126
What % of type 1 diabetics have a difficult airway?
30%
127
DM med with a r/f lactic acidosis
biguanides (Metformin)
128
3 DM drug classes to be d/c'ed before sx
- biguanides (Metformin) x>48hrs
- sulfonylureas (-zide, -amide) 24-48hrs
- SGLT2 inhibitors (-agliflozin) 72hrs
129
2 DM drug classes w/ r/f aspiration
- glucagon-like peptide-1 receptor antagonists (Exenatide)
- dipeptidyl-peptidase-4 inhibitors (-gliptin)
130
4 DM drug classes with r/f hypoglycemia
1) sulfonylureas
2) meglitinides
3) glucagon-like peptide-1 inhibitors
4) dipeptidyl-peptidase-4 inhibitors
131
3 DM drug classes that do NOT cause hypoglycemia
1) biguanides
2) thiazolidinediones
3) a-glucosidase inhibitors
132
DM drug class with r/f dehydration, hypovolemia, HoTN, ketoacidosis
SGLT2 inhibitors
133
DM drug class that results in ECF expansion & edema
thiazolidinediones
134
General oral antidiabetic medication guidelines:
- continue usual routine until morning of sx
- hold oral meds on AM of sx
- EXCEPT: metformin & sulfonylureas (24-48hrs) & SGLT-2s (72hrs)
135
Peak action of short, intermediate, & long acting insulin
short: 1hr (regular 2-4hr)
intermediate: 6-8hr
long: no peak
136
Insulin guidelines on day of sx
omit short/rapid-acting insulin on AM of sx
if they take 2 types of insulin in the AM: 1/2 to 2/3 of total intermediate/long-acting
if they take 2 types of insulin 2+ times/day: 1/3 to 1/2 total intermediate/long-acting AM dose
137
Preop insulin mgmt in diabetics depends on 3 things:
1) type of DM
2) insulin regimen
3) predisposition to hypoglycemia
138
Recommendation for insulin administration in type 2 DM the evening before sx
- 75-80% long-acting
- 75-80% intermediate
- normal regular/rapid
- normal pump
139
Recommendation for insulin administration in type 2 DM the AM of sx
- 50% long-acting
- 50% intermediate (unless AM glucose <120)
- HOLD regular/rapid
- 60-80% pump, HOLD short-acting
140
When does the mild correction scale begin for DM type 1
>=180mg/dL
141
When does the moderate correction scale begin for DM type 2
>=140mg/dL
142
Typical basal insulin dose via continuous pump
0.5-1.0 units/hour of rapid acting insulin
increased/decreased at various times of day d/t activity levels
143
Perioperative insulin pump guidelines
- <2hr px - continue basal rate
- >2hr px - IV insulin in fusion AM of sx
- glucose check Q1h
- follow institutional algorithm
144
Typical intraop IV insulin infusion goal range
140-180mg/dL
145
Nerve that runs along the lateral border of each thyroid lobe
recurrent laryngeal nerve
146
3 hormones secreted by the thyroid
- T3
- T4
- calcitonin
147
Thyroid hormone synthesis depends on...
hypothalamic-pituitary-thyroid axis
148
Ratio of T3:T4
1:10
149
T3 / T4
More directly released from thyroid:
More protein bound:
More potent:
Longer half-life:
More active:
- directly released = T4
- protein bound = T4
- potent = T3
- half-life: T4
- active: T3
150
Effect of thyroid hormones on the body
- increased BMR
- increased O2 consumption
- increased CO2 production
151
Most common form of HYPERthyroidism & presentation
Grave's disease (autoimmune); presents as hypermetabolism
152
Most common form of HYPOthyroidism & presentation
Hashimoto's thyroiditis (autoimmune); presents as decreased BMR
153
Hyperthyroidism presentation
- heat intolerance
- weight loss
- diarrhea
- muscle weakness/fatigue
- tremors
- tachydysrhythmias (AFIB!)
154
Hypothyroidism presentation
- cold intolerance
- weight gain
- constipation
- fatigue
- mood swings
- pericardial effusion
155
Meds to treat hyperthyroidism & MOA
- thionamides (inhibit thyroid synthesis)
- BB (reduce SNS stimulation, prevent T4-T3 conversion)
- K+ or Na+ iodide (inhibits synthesis & release)
- radioactive iodine (destroys thyroid tissue
156
Anesthetic considerations for hyperthyroid patient
- euthyroid state is ideal
- tracheal deviation?
- r/f corneal abraisons
- avoid ketamine, pancuronium, paralysis
- no change in MAC
157
4 major complications of thyroid surgery
- RLN injury (hoarseness, stridor, obstruction)
- hemorrhage
- hypoCa2+ (inadvertent removal of PT glands)
- thyroid storm
158
When does post-thyroidectomy hypoCa2+ develop? How is it treated?
- 24-48 hours postop
- airway management & Ca2+ administration
159
Thyroid storm is most likely to trigger...
- during times of stress
- 18 hours after sx
160
4 Bs of treating thyroid storm
- block thyroid hormone production
- block thyroid hormone release
- block conversion of T4 --> T3
- block adrenergic effects of thyroid hormones
161
Anesthetic implications for patients with HYPOthyroidism
- mild/moderate acceptable for sx
- large tongue/goiter --> airway obstruction
- delayed gastric emptying
- prone to hypodynamic circulation
- sensitive to anesthetics, benzos, narcs
- may not respond to catecholamines
- monitor for myxedema coma
162
Myxedema coma typically occurs..
Symptoms?
Treatment?
- rare, but postoperatively d/t infxn, cold, sedatives
- AMS, coma, sz, brady, HF
- MEDICAL EMERGENCY --> urgent administration of Levothyroxine
163
Location of catecholamine secretion
adrenal medulla
164
Ratio of Epi:NE secretion
4:1
(80% Epi, 20% NE)
165
Location of steroid hormone secretion
adrenal cortex
(cortisol, aldosterone, testosterone)
166
Adrenal cortex layers and the hormone they secrete
(outermost)
- glomerulosa (mineral corticoids - aldosterone)
- fasciculata (glucocorticoids - cortisol)
- reticularis (sex hormones - androgens)
167
Aldosterone:
- effects
- stimulated by
- location it acts on
- effects: responds to salt and water loss to maintain intravascular volume (Na+ retention, K+ secretion)
- stimulated by: angiotensin II
- acts on: distal tubule & collecting duct
168
Hormone required for vasculature to respond to the vasoconstrictive effects of catecholamines
cortisol
169
Effects of cortisol
- gluconeogenesis
- protein catabolism
- FA mobilization
- anti-inflammatory
- improves myocardial performance via increasing # & sensitivity of B receptors on heart
170
Effect of stress on daily cortisol production
normal = 8-30mg/day
stress = 150mg/day
171
HPA axis is potently stimulated by...
surgery/stress
172
What patients should receive stress dose steroids?
- at r/f HPA suppression
- >20mg/day for >3weeks within last year
173
Hydrocortisone dose for:
superficial surgery
minor
moderate
major
- superficial = normal AM dose
- minor = normal AM dose + 25mg
- moderate = normal AM dose + 50-75mg + taper
- major = normal AM dose + 100-150mg + taper
174
Steroid equivalent doses
0.75mg Dexamethasone
4mg Methylprednisolone
5mg Prednisone
20mg Hydrocortisone
175
8mg Dexamethasone = ____mg Hydrocortisone
200mg
176
Most potent steroid
Dexamethasone
177
Least potent steroid
Cortisone
178
Steroid with highest mineralcorticoid effect
Fludrocortisone
179
Steroids with NO mineralcorticoid effect
- Triamcinolone
- Dexamethasone
- Betamethasone
180
DOA of long-acting glucocorticoids
36-72 hours
181
Cause & effect of primary adrenal insufficiency
- cause: adrenal gland disorders; lack of (-) feedback by cortisol
- effect: deficiency in both mineral- and glucocorticoids --> volume depletion & HoTN
182
Cause & effect of secondary adrenal insufficiency
- cause: pituitary gland or hypothalamus disorders (regulatory centers)
- effect: deficiency in GLUCOcorticoids only --> decreased vascular tone & HoTN
183
Example of 1* adrenal insufficiency
Addison's dz - autoimmune destruction of adrenal glands
184
Cortisol deficiency s/s
- weakness
- fatigue
- weight loss
- N/V
185
Exogenous steroid administration can lead to what disorder?
secondary adrenal insufficiency
186
Patients with 2* adrenal insufficiency are at risk for ________
adrenal crisis
187
S/S of adrenal crisis under anesthesia
- hemodynamic instability
- refractory HoTN
188
Tx of acute adrenal crisis
- steroid replacement (hydrocortisone 300mg/day)
- ECF volume expansion
- hemodynamic support
189
Final metabolite of NE and Epi
vanillylmandelic acid (VMA)
190
Primary sites of catecholamine metabolism
kidneys & liver
5% NE excreted unchanged in urine
191
Pheochromocytomas secrete more ___ than ___
NE > Epi
192
Triad of symptoms for pheo
1) diaphoresis
2) palpitations
3) headache
193
5Ps of pheo
pain
pallor
palpitations
perspiration
pressure
194
Preop mgmt of pheo patients should include...
- assess CV system for dysfxn
- assess effectiveness of HTN tx.
- a-adrenergic blockade (phenoxybenzamine)
- B-blockade after a-blockade
- CCB
- tyrosine hydroxylase inhibitor
- correct hypovolemia
195
Which patients require an awake art line?
pheochromocytoma
196
Things to avoid in pheo patients
- stimulation of catecholamine release
- indirect release of catecholamines
- histamine release
- vagolytics/sympathomimetics
- succs
- DA receptor antagonists
- glucagon
197
What happens during phase I of pheo surgery? What should we watch for?
- tumor dissection & location of vascular supply
- HTN/arrhythmias
198
What happens during phase 2 of pheo surgery? What should we watch for?
- effluent vein clamped
- HoTN
199
3 events likely to cause hemodynamic instability in pheo patients
- insufflation
- tumor manipulation
- ligation of tumor blood supply
200
Goal of anesthesia for pheo patient
avoid stimulation
201
Gold standard HTN treatment for intraop pheo
clevidipine (CCB)
1-2 mg/hr; doubled at 90sec intervals
reduces SBP 2-4mmHg per 1-2mg/hr
202
Alternative HTN options for intraop pheo
- Na+ nitroprusside
- phentolamine
- nicardipine
- labetolol
- esmolol
- Mg
203
Besides HTN, what other side effects can occur during pheo surgery
arrhythmias (lido, esmolol, amiodarone)
HoTN (fluids, phenyl, vaso, methylene blue)
hypoglycemia
204
Why might pheo patients develop hypoglycemia postop?
rebound hyperinsulinemia d/t sudden reduction in circulating catecholamines
205
Highest risk patients to develop intraop renal failure
- >56 years old
- male
- HTN
- heart or liver failure
- aortic cross clamp sx
- emergency
- intraperitoneal sx
- renal insuff
- DM
206
4 major functions of the renal system
- maintain ECF composition
- maintain ECF volume
- endocrine fxns
- arterial BP regulation
207
4 components to regulation of ECF composition by the kidneys
1) ions (Na, K, Ca, Mg, Cl, H+, HCO3)
2) osmolality (ADH)
3) plasma (AA, glucose, proteins, vitamins)
4) metabolic products & toxins
208
How is regulation of ECF volume managed by the kidneys?
aldosterone
209
What system is responsible for arterial BP maintenance in the kidneys?
RAAS
210
3 hormones secreted by the kidneys
- EPO
- vit D
- renin
211
EPO production is stimulated by...
decreased PO2 stimulates RBC formation in bone marrow
deficiency in BRF = anemia
212
Definition of normal UO, oliguria, and anuria
- normal = >0.5mL/kg/hr
- oliguria = <20mL/hr
- anuria = none
213
Kidneys get __% of CO
25%
(80% cortex, 20% medulla)
214
Renal O2 consumption = ____ mL/min
18 mL/min
215
Best overall measure of renal fxn
GFR
(normal = 90)
216
Renal lab value that changes with diet, dehydration, co-existing dz, fever
BUN
(normal = 10-20 mL/dL)
217
Renal lab value that is a product of muscle mass, high protein meals, and is affected by Cimetidine
serum creatinine
(normal = 0.7-1.5 mg/dL)
218
Most reliable measure of GFR
creatinine clearance
(normal = 110-150mL/min)
219
CrCl values and associated impairment
- normal = 95-100 mL/min
- mild = 50-80
- moderate = <25
- ESRD = <10
220
Indirect effects of anesthesia on renal fxn
- CV depression, vasodilation
- neural = increased renal vascular resistance
- endocrine d/t stress response
221
Direct effects of anesthesia on renal fxn
- volatiles decrease renal vascular resistance, compound A
- IV agents inhibit prostaglandin activity
- surgical stimulation
222
Auto regulation effect of BP on renal perfusion
- low BP = vasodilates afferent arteriole, increase renal BF
- high BP = vasoconstriction of afferent arteriole, decreased renal BF
- needs MAP 50-180
223
Hallmark sign of acute renal failure
retention of nitrogenous waste products (azotemia)
224
Pre-renal causes of ARF
- decreased renal BF
- hypovolemia
- blocked afferent arteriole
225
Intrarenal causes of ARF (acute tubular necrosis)
- renal tubular damage
- ischemia
- nephrotoxins
- myoglobinuria
226
Postrenal causes of ARF
- obstruction of urinary outflow tract
227
Area of kidney most vulnerable to ischemia
inner strip of outer medulla
- less blood flow but higher O2 demand
228
Strategies to prevent ARF
- MAINTAIN RENAL PERFUSION
- maintain adequate intravascular vol
- maintain O2 transport
- use diuretics or dopamine
229
How to distinguish between pre-renal and renal failure
fractional excretion of Na+ (FENa+) is 90% specific & sensitive
pre-renal = <=1%
renal failure = 1-3%
230
Characteristics of chronic renal failure
- chronic anemia (Hgb 5-8)
- electrolyte disturbances (hyperK, hyperMg, hyperPhos, hypoCa)
- HTN (80% of CRF)
- chronic metabolic acidosis
- nervous sytem probs
- infxn
231
#1 COD of patients with CRF
sepsis
232
Drugs to avoid in CRF
- Diazepam
- Lorazepam
- Meperidine
- Pancuronium
- Doxacurium
233
Avoid which fluid in patients with hyperK+
LR
234
Reversal agents rely on the ___ for elimination
renal system
235
Predictors of RA severity
- corticosteroid use
- hands and feet involvement
- high BMI
236
Important anesthesia consideration for RA patients
- positioning of extremities
- reduced neck mobility
- unstable atlantoaxial joint
237
Considerations for ortho trauma cases
- r/f aspiration
- closed head injuries
- C-spine involvement
- internal bleeding
- pneumothorax
- pelvic fx = blood loss, DVT
238
Possible complications with arthroscopc procedures
- pneumothorax
- pneumomediastinum
- tourniquet pain
- fluid volume overload
- pulm edema
239
Considerations regarding irrigation fluid with arthroscopic cases
- airway edema
- pulmonary edema
- fluid overload
240
Indications for interscalene block
- shoulder
- arm
- elbow
(spares branches of the lower FA)
241
Most proximal regional block
interscalene
242
Describe Horner syndrome & when it may appear
- RLN paralysis
- mild ipsilateral ptosis & miosis
- nasal congestion
*may occur with interscalene block*
*self-limiting*
243
Major potential complications with interscalene block
- Horner syndrome
- diaphragmatic paralysis
- intravascular injection
- avoid in severe COPD
244
Indication for supraclavicular block
- shoulder
- arm
- elbow
- FA
- hand
245
Primary risk associated with supraclavicular block
pneumothorax
246
Indication for infraclavicular block
- elbow
- FA
- hand
- tourniquet pain
247
Risks associated with infraclavicular block
- intravascular injection (into axillary and subclavian arteries)
- pneumothorax
248
Indication for axillary block
(not popular)
- FA
- hand
249
Limitations to axillary blocks
- positioning
- tourniquet pain
- spotty
250
Major downside of a femoral block
no weight bearing
251
An adductor/saphenous nerve block will provide ____
analgesia to knee and medial leg
252
Major benefits to adductor/saphenous nerve block
- allows for WB
- spares quadriceps muscle
- faster ambulation postop
- lasts 12-16 hours
253
Which block has the highest rate of complications
psoas compartment block
254
Ankle blocks are used for...
- foot surgery, amputation
255
5 nerves included in an ankle block
- saphenous
- deep peroneal
- superficial peroneal
- posterior tib
- sural
256
Indications for spinal anesthesia
- hip & knee sx
- hernia
- C-section
257
Symptoms of a sympathetic blockade with spinal anesthesia
- vasodilation
- unopposed parasympathetic tone
- intercostal muscle paralysis
258
LAs in order of length of procedure
Procaine
Lido/Mepivacaine
Bup/Tetra/Ropivacaine
259
First and last nerves blocked
sympathetic = first
motor = last
260
Ortho cases from most to least painful
joint scope > TKA > THA
261
LAST has a worse prognosis when which LAs are used
Bupivacaine, Levobupivacaine, Ropivacaine
262
Risk factors for LAST
- extreme ages
- liver disease/low plasma protein
- metabolic or respiratory acidosis
- conduction abnormalities
- renal failure
263
Management of LAST
- stop injection
- treat hypoxia, hypercapinia, acidosis
- intralipid 20%
- Midazolam for sz
- fluids
- lower Epi dose
- Amiodarone for arrhythmias
264
Drugs to avoid in LAST
- CCB
- BB
- vasopressin
- LA
- propofol
265
Most common position for ortho surgeries
dorsal / supine
266
Proper arm position on armboard
supine
(palms in if tucked)
267
Things to remember about lateral decubitus positioning
- used for hip, shoulder, extremity sx
- r/f brachial plexus injury
- no BP cuff on dependent arm
- V/Q mismatch
268
Cons to beach chair position re: perfusion
- cerebral hypoperfusion
- HoTN & brady events
269
HBEs are common with which procedure set-up
- GETA
- interscalene block
- beach chair position
270
Cons to beach chair position re: safety
- potential for extubation
- r/f neck stretching
- r/f c-spine injury
- r/f embolism
271
SAFE bed movements while in beach chair position
- Tburg/reverse Tburg
- table up/down
- L or R tilt
- Leg up/down
272
UNSAFE bed movements while in beach chair position
- flex/reflex
- back up/down
273
Describe tourniquet pain
- localized pain and distal ischemia
- dull pain (C-fibers)
- lasts 45-90min
- r/f sympathetic surge
274
Tourniquet associated nerve damage can occur...
TTT > 2 hrs
275
Tourniquets are contraindicated in what paitent population
vaso-occlusive crisis (RBC sickling)
276
Tx for tourniquet pain
- intermittent deflation
- double tourniquets
- deepen anesthetic
- beta blockade
277
Expected complications associated with tourniquet deflation
- venous return (acidotic, hypothermic, hyperK)
- acute dysrhythmias
- acute HoTN (rapid SVR reduction, direct myocardiac depression)
278
Tx for tourniquet deflation issues
- fluid resuscitation
- pressors
- hyperventilation
- IV Ca2+ or HCO3
- cardioversion / defib
279
First sign of bone cement implantation syndrome
fall in EtCO2
(along with dyspnea)
280
Describe BCIS
- intramedullary HTN
- BM and air embolization
- inflammatory response
- pulm HTN, R heart strain
281
Management of BCIS
- hyperventilation
- fluid resuscitation
- treat HoTN
- bronchodilators
- turn off N2O
282
3 parts of the brain affected by drug use
- basal ganglia
- extended amygdala
- prefrontal cortex
283
Tx for anxiety r/t stimulant use
- benzos
- barbiturates
- haldol
284
Tx for tachycardia / HTN r/t stimulant use
- a & B blockers
- direct vasodilators
285
How to promote secretion of stimulants
- IV hydration
- gastric lavage
- ammonium chloride to acidify urine
286
Effect of ACUTE stimulant use on MAC
increases MAC
287
Effect of CHRONIC stimulant use on MAC
decreases MAC
288
HoTN associated with stimulant use should be treated with...
direct acting vasopressors
(poor response to indirect acting)
289
2 drugs to avoid in patients on stimulants
ketamine & pancuronium
(increase HR)
290
The analgesic and pulm depressant effects of opioids are (shortened/prolonged) in patients on halluginogens
prolonged
291
Effects of barbiturates, ketamine, and opioids are (shortened/prolonged) in patients on weed
prolonged
292
Most frequently abused legal drugs according to poison control
1. Hydromorphone
2. Oxycodone
3. Methadone
293
Drugs to avoid in patients on chronic opioids
opioid antagonists
294
Methadone half-life
15-25 hours
295
Effect of acute depressant intoxication on MAC
decreases MAC
296
Effect of chronic depressant use on MAC
increases MAC
297
Promotion of depressant drug secretion
- IV hydration
- gastric lavage
- ammonium chloride to acidify urine
298
Most widely consumed psychoactive substance
caffeine
299
Tx for pre-op caffeine-related headache
IV narcotics
300
Dose of caffeine to reduce withdrawal symptoms
100mg IV
no adverse HR or BP rxn
301
Effect of ACUTE ETOH intoxication on MAC
decreases MAC
302
Major thing to remember with acutely ETOH intoxicated patients
- prone to gastric regurg
- no LMA
- decompress stomach
- less IV and volatile required
303
Acute ETOH leads to increased incidence of 2 things
- hypoglycemia
- hypothermia
304
Effect of chronic ETOH use on MAC
increases MAC
305
Effect of chronic ETOH use on coagulation
- increased INR
- decreased PLT
306
Chronic ETOH and liver fxn r/t anesthesia
- decreased albumin production
- decreased coagulation factors
- more free drug
307
Med for esophageal verices
octreotide
308
Acute intox with amphetamines & cocaine has what effect on MAC
increases MAC
309
Airway plan for lumpectomy
GA with LMA
310
Pain plan for lumpectomy
- fentanyl
- LA
311
Airway plan for mastectomy
GETA
TIVA +/- N2O
312
Pain plan for mastectomy
- Tylenol & Celebrex preop
- Dilaudid
- 3x antiemetics
313
DIEP flap =
deep inferior epigastric perforator
- fat, skin, & BV
- NO MUSCLE
- done s/p mastectomy
314
Airway plan for DIEP flap
GETA
+/- art line
2 PIV
NO PRESSORS
315
Pain plan for DIEP flap & gender reassignment
long-acting narcotics
316
Airway plan for gender reassignment
GETA
+/- art line
2 PIV
317
Contraindications to liposuction
- CV disease (d/t Epi component)
- severe coagulation disorder
318
Airway plan for liposuction
GETA or LMA
*very stimulating
319
Airway plan for face lift
GETA - sx suture to teeth/blenderm tape
2 PIV
320
Face lift patients need judicious administration of what
IVF to decrease swelling
321
Drug to avoid in face lift surgeries
Toradol
322
Airway plan for blepharoplasty
GA with LMA or ETT
**PONV prophylaxis**
323
2 things to remember with blepharoplasty
- oculocardiac reflex can be elicited
- avoid bucking d/t increased intraorbital pressure
324
Rhinoplasty/septoplasty has high r/f...
PONV - consider TIVA/dirty TIVA, always 3x antiemetics
- decompress stomach at end
- NO MASK post-extubation
325
Liver receives ___% of CO
25-30%
326
Describe the hepatic blood supply
- portal vein = 75% BF, 50% O2 delivery
- hepatic artery = 25% BF, 50% O2 delivery
- venous return to the IVC by the R, L, and middle hepatic veins
327
Impact of portal HTN
- end result of hepatic injury/fibrosis
- portosystemic shunts develop
- bypass liver's detox capabilities
- buildup of nitrogenous waste
--> hepatic encephalopathy
328
3 issues that develop from portal HTN
- varices & variceal hemorrhage
- ascites
- hepatorenal syndrome
329
Cardiac effects of liver dz
- hyperdynamic circulation
- decreased SVR & MAP
- increased CO
- volume up but severely intravascularly dry
- prolonged QT
- decreased response to catecholamines
- AV shunting
- looks like sepsis
330
What fraction of the liver can be removed and the organ still be able to regenerate
2/3
331
T/F: the liver is the largest internal organ in the body
True
332
Avg hepatic venous pressures
- what venous pressure constitutes portal HTN?
- average = 4-5mmHg
- portal HTN = pressure gradient >5mmHg
333
What causes portal HTN?
injured hepatocytes are replaced by fibrous tissue which impedes BF
334
Equation for hepatic BF
mean arterial (portal venous pressure) - hepatic vein pressure
335
Impact of stress on hepatic BF
Impact of increased CVP on hepatic BF
BOTH decrease flow
336
Liver functions:
- protein metab
- cholesterol/lipid metab
- drug metab & detox
- glucose maintenance/buffer
- bilirubin excretion
- blood reservoir (1L)
- pro & anti-coag production
- vitamin storage
337
Describe the stages of liver damage
healthy liver --> fatty liver --> liver fibrosis --> cirrhosis
338
T/F: AST and ALT assess liver fxn
False
- ALT does NOT assess liver fxn - it assesses hepatocellular injury & necrosis
- ALT is localized primarily to the Liver
- AST present in many tissues
339
Clotting factors synthesized by the liver:
- all of them EXCEPT: III, IV, VIII
340
2 coag labs indicative of severe hepatic dysfxn
- PT & INR
*prolonged PT is non-specific for liver dz
341
Hepatic dz causes thrombocytopenia. What are some effects of that?
- liver is 1* site of thrombopoietin
- direct BM suppression
- DIC
- splenic sequestration of up to 90% of PLT
342
Main players in hepatic drug metab
smooth ER of hepatocytes
343
Bilirubin is a byproduct of what? What are the 2 fractions?
- byproduct of Hgb from RBCs
- lipid soluble / indirect / unconjugated
- water soluble / direct / conjugated
344
#1 cause of acute liver failure
drug related (50% acetaminophen)
345
4 characteristics of acute liver failure
1. encephalopathy
2. coagulopathy (INR >1.5)
3. no hx of liver dz
4. illness <26 wks
346
2 vascular abnormalities unique to setting of portal HTN
1. hepatopulmonary syndrome
2. portopulmonary syndrome
347
% of patients with hepatic dz with SOB
50-70%
348
Hepatopulmonary syndrome (HPS) triad:
1. liver dysfxn
2. unexplained hypoxemia
3. intrapulm vascular dilation
349
Define orthodexia
positional oxygen change; IPVDs predominate in the base of the lungs
- standing worse, supine better
350
Tx for type 1 HPS
increase FiO2
351
Mechanism of reduced metab of drugs by liver
- reduced protein binding
- decreased fxnl mass of hepatocytes
- portocaval shunts
352
Compare drugs with high/low hepatic extraction ratios
- high: significantly affected by changes in hepatic BF
- low: not significantly affected by BF, but are affected by protein binding, induction/inhibition of enzymes, age, liver dz
353
Cause of hepatic encephalopathy
hyperammonemia
- body can't get rid of ammonia so it synthesizes glutamine
- glutamine is osmotically active --> edema
- systemic inflammatory response
354
Increased mortality from hepatic sx associated with:
- albumin <4
- pre-existing lung dz
- intraop transfusion / high blood loss
- concurrent intra-abd op
- prolonged OR time
355
Describe the pringle maneuver
- portal vein & hepatic artery temporarily occluded via clamping of the portal triad
356
Liver sx complications
- BLEEDING
- air embolism
- post-op (coagulopathy, liver dysfxn, neurologic, cardiac, resp)
357
Periop risk assessment for liver dz sx
Child-Turcotte-Pugh
Albumin, Ascites
Bilirubin
Encephalopathy
PT/INR
358
Labs included in the MELD score
- INR
- Creatinine
- Bilirubin
359
Score that allocates organs for liver tx
- what score has an acceptable risk?
MELD
- score <11 = low postop mortality and acceptable risk
360
How to optimize a liver pt for sx
- treat active infxns
- minimize vasoactive infusions
- optimize central blood bolume
- minimize ascites
- improve encephalopathy & coagulopathy
361
Effect of liver dz on NMBAs
prolonged succs, vec, roc, pan
362
Reasons to give albumin to cirrhotics
- after large volume paracentesis
- presence of SBP to prevent renal impairment
- presence of hepatorenal syndrome
363
Indication for TIPS procedure
decompress portal HTN in setting of esophageal varices/intractable ascites
