Study help

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mcrr

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I'm having trouble knowing when an arterial line would be indicated. I know: during CPB, when wide swings in blood pressure are expected, when rigorous control of BP is necessary, and when there is a need for ABG measurements throughout the surgery. But I don't have enough OR experience to really apply that. Given the following scenarios, I need to determine whether or not an art-line is indicated.
1. healthy 23 yo s/p MVA with closed head injury for ORIF of acetabulum.
-- My thoughts: ORIF of acetabulum typically results in extensive bloodloss. With a closed head injury, you'd want to maintain the BP in a narrow range so as not to develop BP that is too high and may cause further damage or too low which may cause hypoxemia and further damage. Thus, I would think an A-line is indicated. I'm thrown off by the "healthy 23 yo," though.

2. 74 yo with stable angina for sigmoid colectomy.
--- Continuous intra-arterial pressure monitoring can reduce the risk of hemodynamic events by early identification of problems. Rapid changes in hemodynamics can quickly lead to cardiac arrest. With that in mind, I would think yes, it is safer to place an A-line. But, a colectomy is not typically associated with great amounts of blood loss, so maybe he does not need it.

3. 34 yo with morbid obesity for partial gastrectomy
--- Gastrectomy surgery may result in great blood loss and variation in electrolytes. Additionally, the pt is morbidly obese so he/she likely already has chronic resp acidosis. Thus, I think to measure ABGs and monitor BP continuously, an A-line is indicated.

4. Healthy 18 yo for lumbar fusion with expected EBL of 1000 cc.
--- Significant amount of blood loss, but patient is young and healthy and likely can tolerate brief hypotension. As the hypotension is anticipated, the patient can be given fluid pre-operatively and if necessary blood during the surgery. Because we would follow his/her hematocrit to guide whether or not to give blood products, an A-line may be indicated.

Surely an A-line is not needed in all of these procedures. I would appreciate any and all guidance on determining whether or not an A-line is indicated in those situations.
 
I'm having trouble knowing when an arterial line would be indicated. I know: during CPB, when wide swings in blood pressure are expected, when rigorous control of BP is necessary, and when there is a need for ABG measurements throughout the surgery. But I don't have enough OR experience to really apply that. Given the following scenarios, I need to determine whether or not an art-line is indicated.
1. healthy 23 yo s/p MVA with closed head injury for ORIF of acetabulum.
-- My thoughts: ORIF of acetabulum typically results in extensive bloodloss. With a closed head injury, you'd want to maintain the BP in a narrow range so as not to develop BP that is too high and may cause further damage or too low which may cause hypoxemia and further damage. Thus, I would think an A-line is indicated. I'm thrown off by the "healthy 23 yo," though.

2. 74 yo with stable angina for sigmoid colectomy.
--- Continuous intra-arterial pressure monitoring can reduce the risk of hemodynamic events by early identification of problems. Rapid changes in hemodynamics can quickly lead to cardiac arrest. With that in mind, I would think yes, it is safer to place an A-line. But, a colectomy is not typically associated with great amounts of blood loss, so maybe he does not need it.

3. 34 yo with morbid obesity for partial gastrectomy
--- Gastrectomy surgery may result in great blood loss and variation in electrolytes. Additionally, the pt is morbidly obese so he/she likely already has chronic resp acidosis. Thus, I think to measure ABGs and monitor BP continuously, an A-line is indicated.

4. Healthy 18 yo for lumbar fusion with expected EBL of 1000 cc.
--- Significant amount of blood loss, but patient is young and healthy and likely can tolerate brief hypotension. As the hypotension is anticipated, the patient can be given fluid pre-operatively and if necessary blood during the surgery. Because we would follow his/her hematocrit to guide whether or not to give blood products, an A-line may be indicated.

Surely an A-line is not needed in all of these procedures. I would appreciate any and all guidance on determining whether or not an A-line is indicated in those situations.

From a private practice standpoint, I can tell you that none of your examples (as you've described them) would get an A-line in our place. In an academic center, you'd probably get a totally different answer. We put A-lines in all of our major vascular procedures (AAA, TEVAR, CAE, etc.), most open chest cases (but probably only 2/3 of the thoracoscopies), and big spine cases only if we expect extended procedures +/- major blood loss. Obviously the sicker the patient, the more likely they are to get an A-line with a bigger procedure, but that's really where the difference in PP/academia comes in. A "big case" to you isn't necessarily a "big case" to us. A sigmoid colectomy takes less than 90 minutes, and many of our bariatric procedures are under an hour. We stand sick old ladies on their heads for friggin DaVinci hysterectomies and they do fine - but they only take an hour now as opposed to six hours when we first started doing them.
 
#4, any case where we do MEP/SSEPs for a spine they get an A-line.
 
I don't think you're wrong to put an a-line in any of them. Easy low risk procedure.

1 - Depends on the severity of the head injury. You don't need an a-line to track blood loss in a trauma patient, a cuff and the sound of the suction is all you need.

2 - Probably not, it's just a colectomy. Sometimes the surgeons want them lined up for postop care though.

3 - No. I don't think there's a need to run any ABGs intraop just because he's obese.

4 - Like #1, not interested in blood loss tracking with a-line for this guy. I don't think it's truly essential given MEP/SSEPs but it's totally reasonable to put an a-line in.


Also, for acute blood loss, hematocrit won't guide your transfusion decisions, or at least it shouldn't. Vital signs, the suction bucket, and your awareness of blood loss will. I could stab you in the liver with a pruning saw and watch you bleed 2 liters into your abdomen and your hct wouldn't change much, at least not immediately. Relying on hct changes to manage acute blood loss is wrong.
 
Thank you all very much for all of your responses! I can't tell you how much I appreciate them! This is from the ASA site-- it helps me to justify #4, but not the others necessarily:
Arterial Catheter (CPT code 36620) - Placement of a small catheter, usually in the radial artery, and connection of the catheter to electronic equipment allow for continuous monitoring of a patient's blood pressure. Unstable patients undergoing surgery as a result of trauma or for intra-abdominal pathology frequently need this form of monitoring. Patients having cardiac, vascular, chest, spine and brain surgery are subject to rapid changes in blood pressure. Continuous monitoring greatly helps the anesthesiologist manage these patients safely. Arterial catheters also provide a reliable method for obtaining arterial blood samples frequently, thus facilitating proper management of blood gas, blood chemistry and coagulation abnormalities.


One more question:
7. 70 kg adult just undergone a total colectomy and is in the recovery room. He is still intubated and breathing on a t-piece. RR is 12 with TV of 600 cc. He is sleeping but will wake up and respond to commands. O2 sat is 97%. Would you extubate? If not, why not?
My thoughts: Yes, because he is taking adequate tidal volumes at an adequate respiratory rate, thus maintaining adequate MV. His oxygen saturation is adequate. Though drowsy, his mentation is intact; he is able to follow commands and should be able to protect his airway. With a t-piece, the work of breathing is higher than through a normal airway. Since he is tolerating this, the chances of successful intubation are high. BUT: the wording of the if not, why not makes me think the answer is no. Additionally I have unresolved questions in my mind: why does he have a T-piece? Should I get an ABG first? Should I discuss weaning him first? Effect of what his FiO2 is. Do I need to calculate Aa gradient or anything? Am I missing something?
 
Smoking plastic in PACU for 30 min isn't gonna kill the guy. Just let him wake up a little more and do something purposeful, then extubate.
 
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