Can you use methadone to prevent opiate withdrawal?

The situation: a young woman with opiate use disorder comes into the hospital with a broken arm after a car accident. She tells you she has been been buying methadone off the street and taking 60 mg a day. How do you manage this patient’s pain regimen and what can you do to prevent opiate withdrawal?

Methadone is typically used for maintenance therapy for opiate use disorder (OUD) or chronic pain. If it is for OUD, they must receive their doses from a methadone clinic. You should always try to call the clinic to verify the correct dose. In this patient’s case, she was buying methadone on her own. Therefore, the first step is to do a urine tox test–if the patient has been using methadone in the past week, it should be positive. If she is negative, it is not a good idea to start methadone unless she’s having withdrawal symptoms.

A patient’s home methadone dose does not provide acute pain control. Patients undergoing surgery can continue their methadone perioperatively. A patient who comes in on methadone (or suboxone, for that matter) needs the same kind of pain management as everyone else. For the patient above with the broken arm, you should still start Tylenol, NSAIDs if possible, and opiates like oxycodone or dilaudid for severe breakthrough pain.

Methadone is effective for preventing withdrawal symptoms in the inpatient setting. This Cochrane review shows that compared to placebo, tapered doses of methadone helped prevent withdrawal symptoms. There is no universal methadone tapered dose protocol. This American Pain Society sheet states methadone can be safely and rapidly tapered in 7-14 days. This pamphlet created by Pain Topics (and written by a Univ. Iowa pharmacist) has helpful information on short and long tapers. In general, you want to get the patient to reduce their dose by at most 25% every few days, end on a dose of 10 mg daily, and then stop completely.

For management of symptoms like sweats, muscle cramps, and nausea, check out this sister post.

How long does this person have to be NPO for?

Being NPO for an add-on surgical case (only to be told at 5 PM that there’s no chance the case will happen today) is a low-grade form of torture, and patients are always anxious to know when and if they can even have a little bit of water for their parched mouths. The nurse wants to know what time Mr. Smith should get his aspirin with a little apple juice if the case is scheduled for 11 AM. What’s the answer?

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Nicely prepared table from the learning module “Anesthesia for Internists” from the Society of Hospital Medicine

How to manage chest tubes (5-minute version)

I am no expert in chest tubes, and will add the caveat that for this particular post I really hope everything is correct! If it’s not, let me know! See this post on the different kinds of chest tubes. This is a great but long nursing resource from RN.com.

You’ve placed a chest tube: great! Now you hook it up to some weird box thing that is called a drainage system…now what? Knowing how chest tubes used to work helps you understand the box thing.

This picture is taken from a truly excellent little video on how chest tube drainage works:

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ThScreen Shot 2017-01-26 at 6.01.21 PM.pngere used to be 3 separate bottles hooked up to the chest tube itself: Bottle #1 is where the patient’s empyema fluid or blood leaked into. Bottle #2 is the waterseal: air is forced to travel through water and can only move in one direction (it cannot move back into the patient). Bottle #3 sets suction power based on how much water is in the bottle–more water=less suction, less water=more suction, and you need to make sure the suction power is just right. You can see how the drainage system has evolved over time on the right.

Should patients be “placed to waterseal” or “placed to -20 suction?” 

“Place to waterseal”= don’t be too crazy with drainage, which is appropriate for most pleural effusions or a mild pneumothorax. If the lung is not fully expanded, you can “turn up the suction.”If you apply suction too aggressively, you put the patient at risk for re-expansion pulmonary edema.

How do I know if there is an “air leak” and what the heck does it mean? 

An air leak is present if there is bubbling in the waterseal chamber when the suction is clamped/on waterseal–this indicates there is still air flowing from the chest to the tube. Positive pressure coming from the pleural space=air getting into the pleural space. Intermittent bubbling with expiration (when pleural pressure is highest in the non-ventilated patient) may be normal, but a continuous air leak is pathological and means the patient is not ready to have their chest tube pulled! 

You can “clamp” the tubing, which should stop an air leak. If the air leak persists even with clamping, consider:

  • ruptured bleb (severe emphysema)
  • simple traumatic pneumothorax (from placing the chest tube)
  • a leak in the actual tubing system
  • mechanical ventilation (may see decreased tidal volumes, failure of PEEP increase)
  • bronchopleural fistula (usually more severe or continuous)
  • lung entrapment vs. trapped lung

NB: if your patient has a persistent air leak, think twice about pulling their chest tube because if you do, you may cause a recurrent pneumothorax.

What is “tidaling?” 

You may see movement in the waterseal chamber with respiratory variation. It’s the water being sucked back towards the lung with inspiration due to negative inspiratory pressure. (In mechanically ventilated patients, it’s the opposite.)

How do I know when the tube can be taken out? 

In a 2013 study out of Michigan State, the team found it is reasonable to remove chest tubes when drainage <200 ml/day, on waterseal, with no air leak. In stable patients on the floor, theoretically you don’t need a chest x-ray after removal, but given our litigious society, everyone gets one. In mechanically ventilated patients, you should get a chest x-ray 1-3 hours after removal. However there is no need for regular surveillance chest imaging while a patient has a chest tube in. 

What do I do if the tube falls out? 

Use common sense: cover the area and prepare to re-insert a chest tube. Maintain sterility. The patient is at risk of a tension pneumothorax, so someone should stay with them for close monitoring. More troubleshooting at this nursing website.

 

 

What is MAC anesthesia?

MAC (monitored anesthesia care) aims to put the patient in deep sedation–arousable only to painful stimuli. It may be useful in situations where the patient gets too agitated with just conscious sedation, i.e., a patient undergoing colonoscopy who has severe anxiety and “fights back” on the table. MAC utilizes a cocktail of choice of propofol, midazolam, ketamine, fentanyl, etc. to achieve deep sedation. Some studies have looked at the effect of dexmedetomidine (Precedex) and found favorable outcomes and side effect profiles. MAC requires the presence of an anesthesiologist in case of an emergency where the patient has to be intubated.

This is different from conscious sedation in that the patient is only sedated enough to stop moving around on the table–asleep, but arousable. This can be given by a trained nurse. The medications of choice are usually fentanyl/midazolam (versed).

What should I know before seeing a CABG?

CABG is an open-heart procedure that re-vascularizes the coronary arteries for people who have suffered a heart attack or are at high risk for having one. See this Medscape chart for indications for CABG.

This post is about some interesting tidbits that you might see during a CABG, or that help you understand exactly what the heck the surgeon is thinking about/doing.

What is the basic procedure?

  • Sternotomy (crack!)
  • Sewing catheters into the right atrium (a catheter pumps blood from here into the machine) and ascending aorta (a catheter pumps blood into this to perfuse the body).
  • blood flows from right atrium into the machine, and back into the ascending aorta. From: Tracy Lu, https://prezi.com/avhhcs0buz5m/cardiac-devices/
  • Usually, two surgeons will be working simultaneously to procure graft vessels. After stopping the heart, they will graft vessels onto the coronaries on the surface of the heart. (WHATTTT)
  • Test vessel flow and if everything’s good, close the patient up again.
  • 0-8 (steel cord) sutures are used to close the sternum. This is why CABG patients have metal that shows up on their chest x-rays.

Why does the patient get protamine?

  • The blood is constantly heparinized to prevent clotting during CPB. Therefore, give protamine to reverse the heparin effect. (But sometimes patients can have a reaction to protamine.)

Why are there cardioversion pads in the OR?

  • When tunneling the catheter into the right atrium, you may cause atrial fibrillation by irritating or breaking the pacemaker circuitry in that region of the heart. In the case I saw, the surgeon realized this was happening when he saw an afib rhythm on the monitor and the systolic blood pressure dropped 30 mmHg. The patient was cardioverted on the table with small pads.
  • If the surgeon decides the patient had “paroxysmal afib” the patient may be put on amiodarone or a beta-blocker after the surgery.

What will I see when cardiopulmonary bypass (CPB) is started?

A heart-lung bypass machine. From: http://www.firstheartnorth.com/
A heart-lung bypass machine. From: http://www.firstheartnorth.com/
  • CPB involves slowing the heart with potassium-loaded cardioplegia solution that is given every twenty minutes. During surgery, you can see the heart shrink in size as its pumping grows weaker and weaker. It’s humbling, really.
  • The heart rate will go to zero. The pulmonary artery pressure goes to zero. The EKG flatlines. But, the blood pressure is not zero. Why? There is steady flow determined by the CPB (BP stays around 30-50 depending on how high the flow rate is…there’s no systolic/diastolic). The central venous pressure is also not zero because you do have SOME blood flow.
  • The tubes are filled with plasmoid solution to prevent air bubbles from turning into air emboli, which could be very, very bad.

How do you pick which vessel grafts to use?

The places where grafts may come from. From: Cleveland Clinic
The places where grafts may come from. From: Cleveland Clinic
  • Classically, the great saphenous vein was used. These days, surgeons try to go with arteries if possible because they last longer and have better flow.
  • The LIMA and RIMA (left and right internal mammary) are often the arteries of choice. But you can’t take out both in a diabetic or an old person who might have a lot of complications.
  • In some younger people you can use the radial artery but again, not if they’re too old or diabetic. Furthermore you want to try to use the person’s non-dominant radial artery, but you can’t use an artery that was recently used for cath access or when the person might eventually require an AV fistula (if they have chronic kidney disease).

What complications should you be wary of?

  • MI
  • air embolism
  • atrial fibrillation
  • mediastinitis
  • tamponade
  • heart perforation (!)

When to clamp an NG tube?

Looks appropriately horrified (from youtube.com)
Looks appropriately horrified (from youtube.com)

“Clamping” an NG tube is done to determine if a patient can safely have an NG tube removed. Here’s how to decide:

When the patient has had less than 200 cc of output over an 8-hour shift, you can attempt the clamping trial!

Check on the patient in 4 hours, and release the clamp and turn on suction to see how much residue comes rushing out. If the output is less than 100-200 cc  then you can remove the NG tube and start the patient on clears.

From: Flashcard Machine