Term
| What does an aneurysm usually result from? |
|
Definition
| *Atherosclerosis which causes a degeneration of the medial layer of the artery (collagen/elastin imbalance) |
|
|
Term
| Where are aneurysms most frequently occurring? |
|
Definition
| *65% occur in the Abdomen |
|
|
Term
| What are the three types of aneurysms? |
|
Definition
*Fulsiform (narrow cylinder)
*Saccular (Berry)
*Dissection |
|
|
Term
| List etiology/causes of aneurysm formation |
|
Definition
*Familial Incidence/Genetic Predisposition
*Atherosclerosis
*Trauma
*Iatrogenic
*Aortitis d/t SLE (lupus), Rheumatoid or Syphilis
*Marfans Syndrome
*Ehlers-Danlos Syndrome |
|
|
Term
| How many individuals do ruptured aortic aneurysms kill before they reach the hospital or during open surgery? |
|
Definition
| *Four out of five victims |
|
|
Term
| Where in the vascular system to aortic aneurysm usually occur? |
|
Definition
| *90% occur infrarenal and may extend into the iliac region |
|
|
Term
| How many AAA are asymptomatic and discovered incidentally? |
|
Definition
|
|
Term
| How are known AAA medically managed? |
|
Definition
*Antihypertensive medication
*Careful monitoring of aneurysm growth |
|
|
Term
| When is surgical repair necessitated for AAA? |
|
Definition
*When aneurysm becomes >5cm in cross sectional dimension
*When painful, leaking or ruptured |
|
|
Term
|
Definition
*Occur predominantly in white males >60 years old
*Back/flank pain
*vomiting
*Collapse
*Shock symptoms
*Ischemic limb
*Paraplegia of neuropathy
|
|
|
Term
| What is the Classic Triad that often indicates impending dissection or rupture of AAA? |
|
Definition
*Back/Flank Pain
*Pulsatile mass in abdomen
*Hypotension |
|
|
Term
| What are some diagnostic tests that can detect a AAA? |
|
Definition
*Echocardiogram
*TEE
*Chest X-ray
*Chest MRI
*CT Scan of Chest
*Aortic Angiography
*Doppler Ultrasonography |
|
|
Term
| What are the steps in traditional surgical repair of an AAA? |
|
Definition
*Transperitoneal or Retroperitoneal incision
*Abdominal Aorta and iliacs are exposed
*AFTER HEPARIN administration, the aorta is clamped, distally then proximally
*Aorta is incised, lumbar vessels oversewn and the aorta is transected to allow for the graft to be sewn into place.
*Aorta is unclamped sequentially and the incision is closed |
|
|
Term
| What is the anesthetic goal for elective repair of a AAA? |
|
Definition
| *Preservation of myocardial function |
|
|
Term
| What is the anesthetic goal for emergent repair of AAA? |
|
Definition
*Control of blood loss
*Reverse hypotension |
|
|
Term
| What are emergent repair mortality rates for AAA directly proportional to? |
|
Definition
| *Time it takes to gain control of the proximal aorta |
|
|
Term
| *List some preoperative considerations for the patient undergoing elective AAA |
|
Definition
*Thorough pre op
*Cardiac work up including EF%, stress test
*Labs-CBC, Lytes, BUN, Cr, Glucose
*Type and Cross for 4-6 units
*Bowel prep?
*PFTs if applicable
*Results of MRI, ultrasound or CT of aneurysm
*Arterial line
*Pulmonary artery catheter or other central access
*Two large bore IVs
*+/- epidural for post op pain?
*Foley (after induction)
*Cardiac clearence
*CT of aneurysm (where it is, it will dictate room set up)
|
|
|
Term
| List items needed for room set up |
|
Definition
*Standard monitors
*5 Lead ECG (II, V5 with ST segments)
*Arterial/PA cath (or other central line)
*Warming devices
*Rapid infusion devices available/cell saver
|
|
|
Term
| List drugs that should be available and ready for repair of AAA |
|
Definition
*Drugs to get blood pressure up and down quickly
*Epi, levophed, dopamine, neosynephrine, beta blockers, NTG/SNP, NaHCO3, heparin, protamine
*Muscle relaxants
*Induction drugs dictated by patient status |
|
|
Term
| What should absolutely be avoided intra op prior to AOX? |
|
Definition
| *Avoid HYPERTENSION before AOX is placed so you do not inadvertently cause aneurysm rupture! |
|
|
Term
| Important notes on induction and interop monitoring of the AAA repair pt |
|
Definition
*Aggressive control of hypertension
*Controlled induction with avoidance of swings in MAP and HR
*Close monitoring of blood loss and fluid replacement
*Careful monitoring of U/O
*Record AOX (aortic cross-clamp) times |
|
|
Term
| After induction what is the goal for pts undergoing AAA? |
|
Definition
*Keep them warm
*Keep HR normal
*Avoid anemia |
|
|
Term
| What are the goals/ tasks for preclamp dynamics? |
|
Definition
*Keep MAP slightly lower than normal
*Give Heparin (20,000-30,000 units) when about to clamp
*Keep slightly hypovolemic
*PCWP 5-12mmHg
*Give renal and spinal protective agents if indicated
*Infrarenal clamping will decrease renal flow
|
|
|
Term
| During repair of AAA the higher the clamp....... |
|
Definition
| The higher the clamp the harder it is on the heart! |
|
|
Term
| If able where should heparin be administered? |
|
Definition
| *Centrally via a central line |
|
|
Term
| When is renal protection indicated during repair of AAA? |
|
Definition
*In aneurysms that are located super renally
*Pts with possible renal disease
*In the presence of dehydration |
|
|
Term
| What agents are given for renal protection? |
|
Definition
*Maintain adequate vascular volume
*Mannitol 0.5g/kg
*Renal dose dopamine
*loop diuretics
*renal plegia solution
|
|
|
Term
| What occurs hemodynamically when clamping occurs? |
|
Definition
*Sudden impedance to flow, blood gets redistributed to upper half of body
*Increased SVR, Preload, LVEDV, myocardial demand and contractility
*Rapid increase in BP- need vasodilators
*Oxygen consumption decreased- SVO2 increases
*Increase in lactate production --> Metabolic acidosis
|
|
|
Term
| Where if clamped is there large changes in hemodynamics during AAA repair? |
|
Definition
| *Clamping above the celiac artery |
|
|
Term
| Why is notification (ideally 15 minutes) prior to unclamping useful? |
|
Definition
*To volume load
*To decrease anesthetic agents
*To decrease use of vasodilators
*all in anticipation of decreased BP |
|
|
Term
| What are changes that occur with Unclamping? |
|
Definition
*Decreases in BP, CO, and CVP
*Reactive hyperemia (max effect is in 15 minutes)
|
|
|
Term
| What can be done to combat drastic hemodynamic changes post unclamping? |
|
Definition
*Volume loading- PCWP 10-20mmHg
*Increase ventilation
*Check labs/ABG's and correct if needed
*Gradual clamping and unclamping
*CaCl and NaHCO3 may be useful
*Have vasopressors ready! |
|
|
Term
| What is the major M&M post op for AAA repair? |
|
Definition
| *Myocardial Infarction leads to ~55% of post op deaths |
|
|
Term
| What other concerns should be monitored in ICU post AAA? |
|
Definition
*Massive fluid shifts
*Renal failure
*Pulmonary failure
*colon ischemia
*Keep BP within normal range for the patient! |
|
|
Term
| What is the priority for the Ruptured Aneurysm Patient? |
|
Definition
*Get to OR, Prep and Drape and get patient to sleep so the bleeding can be controlled!
*lines come secondary |
|
|
Term
| What should be ordered immediately for the ruptured AAA pt? |
|
Definition
*Get blood ASAP- may need O- 10-12u
*Tell blood bank to stay ahead! |
|
|
Term
| What medication should not be given during ruptured AAA repair? |
|
Definition
|
|
Term
| What is the selection criteria for patients with a AAA who want an endovascular aortic graft? |
|
Definition
*Infrarenal
*Length of aorta below renal arteries at least 1.5cm long |
|
|
Term
| Traditional vs. Endovascular AAA repair |
|
Definition
Traditional vs. Endovascular
Incision: Long, Midline abdominal incision vs. bilateral groin incisions
Anesthesia: GA required Vs. local, regional, or GA
Length of surgery: 3-5 hours vs 2-3 hours
EBL: 1500-3700mL vs 150-300mL
Post op: Mechanical ventilation post-op vs. spontaneous respiration or extubate in OR
*Length of stay: 5-10 days vs. 1-3 days
*Cost: Less expensive vs. More expensive |
|
|
Term
| Pre-op consideration for Endovascular repair |
|
Definition
*Location: operating room, radiology department, catheterization lab, endovascular suite
*Always prepare patient and room set up for open repair and be ready for worst case scenario
*if out of department have emergency and induction drugs, drips (pressors), induction equipment
*Have OR room on hold |
|
|
Term
| What are the intra op goals for endovascular AAA repair? |
|
Definition
*Maintain cardiac output
*Minimize myocardial depression |
|
|
Term
| *What anesthetic techniques/lines are needed for endovascular AAA repair |
|
Definition
*Local, regional, or general
*Arterial line- absolute!
*Possible central line
*16-18g PIV |
|
|
Term
| What are some intraop considerations for endovascular AAA repair management? |
|
Definition
*Possible apnea during stent deployment
*Possible induced hypotension/bradycardia
*possible avoidance of lines in left upper extremity
*Temperature regulation
*Restraints if under regional! |
|
|
