The Role of Percutaneous Cricothyrotomy: Wire In Trachea Readiness Technique

April 21st, 2013

by reuben in airway
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There was a period in the history of emergency medicine when cricothyrotomy was the primary airway management strategy for all patients in cervical spine precautions. We have since learned that most of these patients can be intubated orally, but in the intervening years have lost our nerve when it comes to using the neck for airway access. Today, everyone agrees that the most important error around emergency cricothyrotomy is that it is performed too late [1, 2, 3]. An unsuccessful cricothyrotomy performed at the right time is defensible; a successful cricothyrotomy performed too late is indefensible. Both lead to terrible outcomes: one is good, defensible care, the other is poor, indefensible care. The pivotal element in emergency surgical airway decision-making is giving yourself permission to initiate the procedure before the patient is dead.

Guidewire

 

The Cricothyrotomy Menu

There are a variety of strategies for accessing the trachea via the neck and the terminology is confusing. Open cricothyrotomy, often referred to as surgical cricothyrotomy, is using a knife to cut a hole in the cricothyroid membrane and placing a tracheostomy tube or endotracheal through that hole. Several techniques have been described, including the no-drop technique, the rapid four-step technique, and the scalpel-bougie technique.

Percutaneous cricothyrotomy is a term usually used in distinction to surgical or open cricothyrotomy, implying a less invasive approach. Percutaneous cricothyrotomy facilitates the placement of a tracheostomy or endotracheal tube in the trachea by using either a Seldinger tube-over-dilator-over-wire technique, or a tube-over-trocar device [1, 2]. Most emergency physicians are referring to the Seldinger technique when they use the term percutaneous cricothyrotomy.

Though a needle is used in the Seldinger technique, the term needle cricothyrotomy usually refers to a less definitive procedure where a comparatively small cannula, such as a 14g angiocath, is placed into the trachea and oxygen is insufflated under pressure through the cannula; this is called transtracheal jet ventilation when a special high-flow device is used, though a bag-valve-mask is more likely to be available, if less effective, and several hard to remember maneuvers are commonly proposed that allow a BVM to be adapted for this purpose.

Wire In Trachea Readiness Technique

For patients who suddenly and unexpectedly cannot be intubated or oxygenated, the weight of evidence and opinion seems to favor an open technique [1, 2, 3, 4, 5], which appears to be faster than a percutaneous approach, more likely to be successful for those who don’t perform the procedure often (i.e. everyone), and would be used to rescue a failed percutaneous attempt. Smart people disagree on this point, however. Certainly, the goal in these scenarios is to establish oxygenation as quickly as possible by whatever means necessary, and that will differ based on provider, patient, and setting. Have a plan that works for you in your environment.

Many patients who cannot be intubated orally do not suddenly and unexpectedly crash, however. The need for a surgical airway can present itself as a land mine that explodes in front of you as you walk to your mailbox in your bathrobe, but also as a land mine that explodes as you carefully traverse a known minefield in a tank. Of course every emergency intubation is a minefield, and being cognitively and materially prepared for failure of intubation and failure of ventilation at the outset of every case is one of the characteristics of the airway expert. But while we have many options for plan A and plan B, there is still only one plan C – when intubation fails, and oxygenation fails, plan C is cricothyrotomy. Since it is clear that the most important surgical airway error is that it is delayed, several airway management paradigms [1, 2, 3] have recently emerged that explicitly encourage providers to prepare for and properly initiate cricothyrotomy.

In Scott Weingart’s CricCon taxonomy, the highest alert posture is to cut the skin and find the membrane, so that if the need arises, incising the membrane and placing the tube is simple. Most emergency practitioners, however, are uninterested in cutting the neck. On the other hand we are perfectly happy to put wires and tubes in the neck, and do it all the time in the internal jugular vein. Here lies the role of percutaneous cricothyrotomy: not as a crash technique, but as an alert posture, a readiness maneuver: when the likelihood of requiring a surgical airway is sufficiently high, place a wire in the trachea.

Placing a wire in the trachea feels more like inserting a central line than cutting the neck. Feel free to use ultrasound. [1, 2, 3] The strength of the wire-in-trachea approach is that it lures the practitioner into preparation and makes timely performance of cricothyrotomy more likely by breaking the procedure into agreeable steps. Inclination via incrementalism.

There are at least two scenarios in which wire-in-trachea readiness technique would be used:

a. An almost crash expected very difficult laryngoscopy, such as an angioedema patient who requires an airway not this very second but urgently.  If the patient is cooperative, wire is placed after rapid local anesthetic infiltration as preparations are being made for awake laryngoscopy vs. RSI. If uncooperative, wire is placed immediately after induction (concurrent with preoxygenation if using a delayed sequence strategy), just before laryngoscopy, or as laryngoscopy is beginning. This is basically an enhanced double setup.

b. In the midst of a can’t intubate, can ventilate situation. This occurs relatively commonly: laryngoscopy has failed, but LMA or bag-mask ventilation is effective, then the second laryngoscopy attempt fails, but ventilation remains effective, and then the third attempt fails, and you feel like you’re running out of tricks/tools. And you know that with every airway attempt, the glottis becomes a little more swollen, the airway gods–who have until now granted you the gift of ventilation–their patience is a little more tested, and the prospect of can’t intubate, can’t ventilate looms. So after a few failed oral attempts, while the patient is being ventilated, place the wire, then go on with as many further attempts as you want, knowing that if and when ventilation becomes ineffective (or if you have other patients to see and want to move on), cricothyrotomy is straightforward.

Logistics

Percutaneous cricothyrotomy kits are expensive and often stocked in small numbers. To utilize the wire-in-trachea readiness technique, use the needle/syringe/wire from a central line kit. Fill the syringe halfway with water/saline so that tracheal location of the needle can be confirmed by the bubbling of aspirated air.

Have your unopened percutaneous cric kit at the bedside, and when needed, 1) open the kit 2) stab the skin with the scalpel 3) slide the tracheostomy tube-over-dilator into the trachea 4) pull the wire and dilator 5) inflate the cuff 6) ventilate. Don’t forget to load the tracheostomy tube onto the dilator if not pre-loaded in your kit.

Step 2 is important: an aggressive stab must be made on the skin, along the path of the wire, similar to central line technique but larger, to accommodate a larger device.

Step 3, inserting the tube-over-dilator, is facilitated, like everything else, by the application of sterile lubricant. Use a firm twisting motion.

If oral or nasal access is successful and cricothyrotomy isn’t needed, simply pull the wire. Put a band-aid on the site; this will serve as evidence of a disarmed land mine.

emupdates ETI Plan ABC

 

Thanks to Rob and Scott for helping me develop this idea.

Emergency Department I&D Checklist

December 30th, 2012

by reuben in skin/soft tissue infection
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snippet

 

Vector image for screen viewing

Acrobat document for printing

 

References:

• 1 Fitch MT, Manthey DE, McGinnis HD, Nicks BA, Pariyadath M. Videos in Clinical Medicine: Abscess Incision and drainage (video). N Engl J Med 2077; 357:e20.

• 2 Danby FW, Margesson LJ. Hidradenitis suppurativa. Dermatol Clin. 2010Oct;28(4):779-93.

• 3 Orman, Rob. Perianal Abscess. ERCAST, Jan 2011.  http://ercast.org/perianal-abscess

• 4 Schwarz RJ, Shrestha R. Needle Aspiration of Breast Abscess. Am J Surg. 2001;l 182(2):117.

• 5 Kronfol R, Downey K. Technique of Incision and Drainage for Skin Abscess. UpToDate Online. May 2011.

• 6 Wilson W et al.  Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association and others. Circulation. 2007 Oct 9;116(15):1736-54.

• 7 Roberts, James R. Clinical Procedures in Emergency Medicine, 5th ed. 2009.

• 8 Liu C, Bayer A, Infectious Diseases Society of America, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylo- coccus aureus infections in adults and children. Clin Infect Dis. 2011;52(3):e18-e55.

• 9 O’Malley GF, Dominici P, Giraldo P, Aguilera E, Verma M, Lares C, Burger P, Williams E. Routine packing of simple cutaneous abscesses is painful and probably unnecessary. Acad Emerg Med. 2009 May;16(5):470-3.

• 10 Schmitz GR. How do you treat an abscess in the era of increased community-associated methicillin-resistant Staphylococcus aureus (MRSA)? J Emerg Med. 2011 Sep;41(3):276-81.

• 11 Walraven CJ, Lingenfelter E, Rollo J, Madsen T, Alexander DP. Diagnostic and therapeutic evaluation of community-acquired methicillin-resistant Staphylococcus Aureus (MRSA) skin and soft tissue infections in the emergency department. J Emerg Med. 2012 Apr;42(4):392-9.

 

Tetanus recommendations

 

For abscess I&D, most of us haven’t been thinking about antibiotic prophylaxis in patients at risk for infective endocarditis. According to my interpretation of table six of this guideline, we should be. “Antibiotic prophylaxis is reasonable for procedures on respiratory tract or infected skin, skin structures, or musculoskeletal tissue only for patients with underlying cardiac conditions associated with the highest risk of adverse outcome from IE (Table 3).”

The Emergency Department Double Setup

October 25th, 2012

by reuben in airway
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The double setup is an airway management strategy conventionally carried out in the operating room, in a stable or relatively stable patient who requires a definitive airway but is anticipated to be very difficult to intubate orally. An otolaryngologist or other surgeon fully prepares to perform a cricothyrotomy or tracheotomy–patient prepped, all equipment laid out, sterile gown and gloved, scalpel in hand–and then gives the anesthesiologist the nod, at which point the patient is induced and orotracheal intubation is attempted. If unsuccessful, anesthesia nods to surgery, who proceeds with a neck incision.

Emergency physicians are trained to manage difficult oral airways and perform cricothyrotomy–how does the double setup apply to our environment? Once the decision to intubate has been made and preoxygenation has been initiated (don’t forget the nasal cannula), ask two questions: How urgently must this patient be intubated? How difficult do I predict this airway to be?

 

Scenario 1: Must intubate immediately, very scary airway.

Some patients need to be intubated right now, and some patients who need to be intubated right now also are predicted to have difficult airways. The paradigmatic examples of this stressful situation are the dynamic airway insults: patients with bullets, bites or burns (neck trauma, anaphylaxis, airway burn or caustic exposure) who are already showing signs of airway embarrassment. The proper mentality in these cases is this patient is going to require cricothyrotomy, but I’m going to attempt orotracheal intubation, just to make sure. There is no time for a fancy airway assessment or fancy preparations, these patients are a test of your department’s, and your own, usual state of readiness. Patients with dynamic airways should be induced and paralyzed, because intubation will get harder with each passing minute–RSI gives you optimal conditions, as quickly as possible. Once the tools you need to perform cricothyrotomy are at the bedside, use the orotracheal technique that, in your hands, will give you your best shot at first pass success, as quickly as possible. Video laryngoscopy is a good choice. As soon as your first pass fails and not one second later, attempt ventilation (I suggest you move straight to an LMA), but you have accepted that there is a good chance that this is also unlikely to succeed and that the next step is to cut the neck. You must give yourself permission to initiate a surgical airway early in this group. An unsuccessful cricothyrotomy performed at the right time is defensible; a successful cricothyrotomy performed too late is indefensible. Both lead to terrible outcomes, one is defensible, one indefensible. Scenario 1 is an anesthesiologist’s technique compressed into an emergency physician’s timeline.

 

Scenario 2: Must intubate immediately, no difficult airway features. 

Lots of ED patients fall into this category, perhaps the most typical is the CNS catastrophe who presents with a GCS that can be counted on one hand. Like scenario 1, the airway attempt must proceed without extensive preparation, but both orotracheal intubation and ventilation are more likely to be successful, and this procedural reserve affords you a more measured approach. Be mindful, however, that your brief airway assessment may mislead you, and that you never know what you’re going to get when you put in the laryngoscope. You therefore have decided, before you push drugs and put in the laryngoscope, what you will do when laryngoscopy fails, and what you will do when ventilation fails, and you have the materials at the bedside to do it. Experienced emergency providers recognize procedural reserve as a luxury that the patient can revoke immediately and unpredictably, and are thus ready to transition to a scenario 1 type approach every time they push a paralytic.

 

Scenario 3: No urgency to intubate, very scary airway. 

When you have time to intubate, you are swimming in the anesthesiologist’s ocean and you need to use a different stroke; in fact swimming like an anesthesiologist is mostly about wearing several life jackets and surrounding yourself with lifeguards. This scenario might involve a patient with a fixed flexion deformity of the cervical spine who is slowly decompensating from a pneumonia, or a patient with an airway tumor who just took 20 long-acting diltiazem tablets and needs gastric lavage. Calling an anesthesiologist is reasonable in these cases and certainly is the right answer on an oral board exam, but an anesthesiologist may not be available (and certainly will not be available on the boards).

The approach for these patients centers on being cognitively and materially ready for plan A, B, C, and D and on awake technique. It’s also nice to have a few friends at the bedside. Exactly what is plan A-D is up to you, as long as these plans are carefully prepared, and one of them is cricothyrotomy, if the patient cannot be intubated or ventilated. This picture demonstrates an example plan A, B, C, and D and a variety of best practice points.

The patient has a variety of congenital cognitive and anatomic anomalies, was very uncooperative and required intubation for emergent MRI. He is known to be a very difficult laryngoscopy. Our plan was to use an awake technique using IM ketamine sedation to augment local anesthesia.

1. Plan A is video laryngoscopy. The intubator (in the middle) made his best attempt but could not visualize the vocal cords, so without removing the device, handed off the video laryngoscope to the assistant on the patient’s left, who was already performing suction.

2. Plan B is flexible endoscopy, which is ongoing. Note that the operators are at this point using both video screens (video laryngoscope and flexible endoscope) simultaneously.

3. The second assistant on the patient’s right has access to the equipment tray and is also the designated surgical airway operator.

4. The neck is marked, and the site has been infiltrated with lidocaine and epinephrine. The more likely is cricothyrotomy, and the more time you have to prepare, the more advanced your surgical airway preparation should be.

5. The second assistant is using his finger to pull on the right corner of the mouth. This under-utilized technique really opens things up.

6. The usual suction (in this case, the second suction) under the patient’s right shoulder is available to either the intubator or second assistant. The flexible endoscope used in this case does not have suction capability, which made the need for suction on either side more likely.

7. The head of the bed is at 30 degrees.

8. The bag-mask is on the patient’s abdomen. A common mistake is to leave the bag-mask behind the operators, hanging off the oxygen tubing, so that as the saturation is dropping, someone who is already freaking out and tangled in wires and tubes has to perform a complex dance move to get at the device.

9. The intubating LMA is ready to be inserted if emergency ventilation is required. This is our Plan C. Plan D is cricothyrotomy (either carefully if Plans A/B/C have failed but oxygenation is adequate, or quickly at any moment if intubation and oxygenation fail).

10. A variety of tubes and blades, as well as oral and nasal airways.

11. The medications and tools we used to anesthetize the airway.

12. Post-intubation equipment.

13. The ventilator is on standby, connected to end-tidal CO2 (not visible) and programmed with patient-appropriate settings.

14. This container holds our supply of bougies and is sadly empty. There is a bougie on a stand behind the video laryngoscope, not visible but easily accessible to the assistant on the patient’s left.

15. Don’t forget to use a checklist.

 

Scenario 4: No urgency to intubate, no difficult airway features. 

Here we’re talking about the slowly worsening guillain-barré patient, or the patient with the small subdural that the receiving hospital has asked you to intubate for transport. Seems like low risk, and it is low risk, for the patient. But these cases are actually higher risk for you, because when a patient arrives in extremis, your hand is forced and if it doesn’t go well, it’s harder to hold you responsible. In a well patient with normal anatomy who needs to be intubated, you are again in anesthesiologist territory, and you are potentially held to the higher standard of an anesthesiologist, who gets called into the chief’s office when the patient wakes up with a chipped tooth. These are great cases to practice your awake technique; you might find that you don’t mind swimming with a life jacket every once in a while.

 

 


The Usual State of Readiness

September 26th, 2012

by reuben in heuristic, resus
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Emergency providers are routinely called upon to react to complex scenarios that demand specific life-saving maneuvers, immediately and without warning.  The most important impediment to performing well in these situations is your own catecholamines, and the most important catecholamine reduction strategy is preparation. The extent to which you are prepared to immediately react is your usual state of readiness, and it has two parts: cognitive and material.

Cognitive readiness requires that you consider emergency scenarios and decide on a plan. This starts with a textbook (by textbook I of course mean the internet) and reading what others think you should do in a given emergency scenario. The hard part of cognitive readiness is keeping up with the endlessly changing, endlessly disagreeing opinions, and deciding how to shape them into a plan that you like and that works for you in your environment. Logistics are key.

As medical knowledge expands forever faster, perhaps the most important knowledge of all is knowing what you need to know, and knowing what you can look up. This is not an either/or so much as a spectrum of how close information needs to be to your brain. There are plans that have to live in your brain (management of a completely obstructing airway foreign body), facts that you can take 30 seconds to look up (weight-based dose of atropine), and lists that you can review at your desk (the differential diagnosis of anisocoria). Memory fails when catecholamines are high; planning for emergency scenarios involves the development and deployment of emergency references. Your emergency references must be instantly available, instantly familiar and navigable, and damn reliable. Your plan for emergency scenarios takes into account how close aspects of that plan need to be to your brain and incorporates your emergency references.

As you develop cognitive readiness, the plans you develop for emergency scenarios start with a textbook but proceed in your imagination. I call this invisible simulation, and I find that I do a lot of it in the shower. The more you invisibly simulate emergency scenarios, the more likely the demand to immediately act will be met with calm. It is the combination of recognizing when to act immediately, and doing so calmly, that is the defining characteristic of an emergency professional.

Material readiness is simpler than cognitive readiness but often neglected. Material readiness is having the equipment you need, when you need it, where you need it. Nurses and technicians are often charged with this responsibility, however, when you need suction and it’s not there, the technician being reprimanded later does not get the blood out of your patient’s airway. You will do well to make a habit, at the start of every shift, of verifying that the most important equipment is ready and in a location known to you.

It might seem like a daunting task to cognitively and materially prepare for all the scenarios that might call for immediate action, after all, anything could roll through the doors at any time, right? Well, yes, but not really.

Asphyxiation. We focus on airway preparation for good reason. The best time to go through your airway checklist is before the patient arrives. Of particular interest is the scalpel. It has been said (by me) that there are two kinds of emergency physicians: those who always carry a scalpel in their pocket, and those who will, later on in their career, always carry a scalpel in their pocket.

Suffocation. Your adrenals will appreciate it if you have a well-rehearsed plan for managing the severe asthmatic. Also, having the capability to immediately initiate noninvasive ventilation–without calling for a machine, mask, or respiratory therapist–is worth fighting for. When you are forced to intubate a patient who could have been managed with NIV, you have done your patient a disservice.

Exsanguination and serious trauma. Do you know how to get your hands on uncrossmatched blood immediately? Do you have a good sense of the key interventions to consider in the first few minutes of a trauma resuscitation?

Cardiac arrest. Do you know exactly how to use your defibrillator? What about if the paddles or pads are disconnected? Can you initiate emergency pacing? Do you have a command of ACLS pulseless arrest, or your own algorithm? Do you know how to lyse a diagnosed or strongly suspected pulmonary embolism in cardiac arrest? Do you have a plan for treating cardiac tamponade? For tension pneumothorax, all you need is your scalpel and your finger.

Difficult access. Do you know where your IO device is and how to use it?

The uncontrollably violent patient. Do you know how to activate the highest alert to hospital security? Do you know what drug to use if you only have one shot?

Anaphylaxis. Do you know exactly which preparation of epinephrine to use and how much? Also see asphyxiation, above.

Status epilepticus. Do you have a clear set of priorities when managing the seizing patient? Which drug are you going to reach for first, and what dose? What if you don’t have an IV/IO?

Contamination. Do you know where all your personal protective equipment is, including those fancy masks? How you will make a patient covered in something dangerous safe to bring into your department?

Poisoning. How do you access your antidotes (digoxin immune Fab, lipid emulsion, hydroxocobalamin, etc)?

There are other scenarios that require immediate action, but start with these ten. Be warned that spending too long in the shower will upset your roommate.

 

Emergency Department Intubation Checklist v13

July 8th, 2012

by reuben in airway
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vector image for screen viewing

acrobat document for printing

Changes in v13:

  • nasal cannula and preoxygenation sections beefed up
  • added airway management strategy section
  • removed incremental FiO2/PEEP chart
  • roc dose changed from TBW to IBW
  • added section on cricothyrotomy technique
  • ultrasound added to post-intubation complications assessment
  • added proviso, “pretreatment agents are always optional.”
  • added S to DOPES mnemonic (breath stacking)
  • added “function” to “verify cuff” for ETT
  • changed phenylephrine from post to peri intubation hypotension
  • fancy style enhancements

Bonus: personnel arrangement diagram

Hypertension and the Emergency Physician

May 27th, 2012

by reuben in .hypertension
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There are two kinds of hypertension encountered by emergency physicians: hypertensive emergencies, and hypertension. The term hypertensive urgency has minimal meaning, less than minimal utility, and should be abandoned.

Patients with a hypertensive emergency are critically ill. They need to be in a resuscitation area on intravenous antihypertensive drips. The hypertensive emergencies are acute pulmonary edema, aortic dissection, preeclampsia, subarachnoid hemorrhage, and hypertensive encephalopathy. Intravenous blood pressure reduction may also be indicated in acute coronary syndrome, acute ischemic stroke, and intracerebral hemorrhage. A patient with severe hypertension and arterial bleeding unable to be staunched using conventional means perhaps qualifies as a hypertensive emergency and it may be reasonable to use IV medications to lower blood pressure in these patients as well; however, if allowed to take its natural course, hypertension in these cases will surely be self-limited.

Acute renal failure is always included in the list of hypertensive emergencies, but no one knows what to do with this because while it is clear that longstanding hypertension can box your kidneys, the relationship of the elevated creatinine in the patient in front of you to the hypertension in the patient in front of you is usually impossible to determine. If an acutely ill patient has very high blood pressure and an elevated creatinine that is not known to be old, it is reasonable to treat that patient as a hypertensive emergency. A well patient with hypertension and an elevated creatinine needs to be in an internist’s clinic, not in the emergency department.

There are a variety of hyperadrenergic states such as cocaine intoxication, thyroid storm, autonomic hyperreflexia and pheochromocytoma that may resemble hypertensive emergency, but it is the hyperadrenergic state that is the therapeutic target in these instances, not the hypertension. Do not forget to actively cool patients hotter than 41°C (105°F).

Headache is not a hypertensive emergency, no matter how high the blood pressure. It is likely the headache that is causing the hypertension, not the other way around. Treat the headache and the pressure will come down. The same is true of epistaxis.

Lowering blood pressure quickly, for example with the infamous IV labetalol push, in a patient who does not have a hypertensive emergency, subjects the patient to risk of harm without chance of benefit. [ref] Many of these patients have been living with high blood pressure for a long time and quick reductions can cause quick problems, like stroke. You can bring the blood pressure down with IV meds, and this may make you feel powerful and may pacify the consultant/nurse/patient/family, but as soon as you turn around the pressure will go right back up. Fixing the number is a great pacifier but is bad for patients. The consultant/nurse/patient/family may not know better, but you are paid well to know better. It’s easier to write for 20 of IV labetalol than to explain to the consultant/nurse/patient/family, but you are paid well to explain.

All patients with hypertension, unless clearly secondary to pain or emotion (i.e. hypertension resolves with symptom resolution) should be told that they might have the disease of hypertension and their blood pressure should be rechecked in a primary care physician’s office. How strictly you arrange or recommend followup depends on how high the blood pressure is and how many other diseases the patient has. Shayne & Pitts suggest that patients who have diseases known to be caused by or worsened by hypertension (CAD, CHF, stroke, renal insufficiency, etc) are at higher risk and want to call these patients hypertensive urgency, but this is confusing and unnecessary. Just follow these patients up closely, as is consistent with basic emergency medicine principles. Even if the blood pressure were normal, you would still want these patients to follow up closely because having a lot of bad diseases is a risk factor for a bad outcome.

There is no evidence that initiating oral antihypertensive therapy in the ED makes any difference, but it’s not unreasonable and is an excellent patient satisfaction gambit. EMCREG recommends: “Consider oral antihypertensive therapy for patients with blood pressure > 180/110 mm Hg and initiate therapy in patients with blood pressure > 200/130 mm Hg.” I use amlodipine, because it has few contraindications and toxicities. Emergency physicians should not perform ancillary testing on patients with hypertension either to make sure this isn’t a hypertensive urgency, which is a disease that does not exist, or to attempt to tailor a daily antihypertensive prescription to the creatinine, or ECG, or urinalysis, or anything else. You do gunshot wounds and heart attacks and IV dilaudid seekers, let the primary care physician do hypertension.

The most common scenario where lowering blood pressure quickly makes a big difference is in acute hypertensive pulmonary edema; in this scenario it’s the blood pressure that’s the problem. The treatment is high dose nitroglycerine and noninvasive ventilation. For very distressed patients with very high blood pressure, start with a 1 mg IV push of nitroglycerine and start your drip at 200 mcg/min and stand at the bedside, watching closely, titrating the drip and giving additional boluses as needed. [ref 1, ref 2, ref 3] Patients with active myocardial ischemia and hypertension should also be on a nitro drip, titrated to relief of pain or untoward drop in blood pressure. Not patients with a positive troponin who are legs crossed reading a newspaper, not patients with undifferentiated chest pain waiting on their second enzyme, this applies to patients who are clutching their chest because their heart wants more oxygen than their coronary arteries can deliver.

The blood pressure isn’t the problem in aortic dissection, but we have good reason to believe that elevated blood pressure (and heart rate) makes things worse. If strongly suspected or confirmed, call a surgeon and aggressively dose opiates to abolish pain and anxiety as you bring heart rate down to 60 using IV esmolol (or diltiazem/verapamil if beta blockers are contraindicated); this will also reduce blood pressure. If at that point blood pressure isn’t as low as it could be, add a titratable vasodilator like nicardipine and bring pressure as low as possible while maintaining organ perfusion. [ref]

Preeclampsia is an important hypertensive emergency that is easy to overlook, especially postpartum–almost always within two weeks but possibly up to six weeks after delivery. Hypertensive pregnant or postpartum patients with signs of preeclampsia should be treated with high-dose magnesium (start with 6 g over 20 minutes). EMCREG recommends keeping blood pressure under 160/110 in the antepartum and intrapartum period and less than 150/100 if postpartum or if platelet count is < 100,000. Magnesium will have a salutary effect on blood pressure but if not at target, labetalol is the recommended agent. Other beta blockers and ACE inhibitors should be avoided in pregnancy. Delivery is the therapy of interest in most of these patients, they are therefore usually best managed on L&D.

Blood pressure management is key in subarachnoid hemorrhage, analogous to aortic dissection. Use nicardipine to keep SBP less than 160. [ref] Nimodipine, given orally, is to prevent vasospasm later on, not to lower blood pressure. There’s a lot to think about in SAH, so get some help, even if it comes from a dubious source.

Hypertensive encephalopathy is not headache, patients with hypertensive encephalopathy are encephalopathic and acutely ill. You are not going to diagnose hypertensive encephalopathy until after you’ve ruled out intracranial hemorrhage, because when a patient presents altered and looking bad with a very high blood pressure, it’s much more likely to be ICH, so that patient needs management of ABC’s and then a quick CT scan. If the CT scan is negative, and the patient continues to be altered and very hypertensive, start your nicardipine drip. If the patient’s mentation improves with lowering of blood pressure, you then say, aha, that was hypertensive encephalopathy.

Acute ischemic stroke and spontaneous intracranial hemorrhage patients often have very high blood pressure and medical science has not yet determined if patients with these conditions benefit from blood pressure reduction. For ischemic stroke, If you’re using thrombolytics, keep blood pressure under 180/105 using nicardipine or labetalol. Otherwise, the latest recommendations are to lower blood pressure above 220/120 by 15% within 24 hours. The AHA says it’s probably safe to lower systolic blood pressure to 140 in ICH patients. Otherwise they suggest blood pressure management according to this table, which isn’t confusing at all. In traumatic brain injury, leave hypertension alone; focus on preventing hypotension and teaching your consultants that ketamine does not raise ICP and is an appropriate RSI agent in this context.

Lastly, tell your patients who check their blood pressure at home and then come in for hypertension that checking blood pressure at home causes cancer.

The High Flow Nasal Cannula in the Emergency Department

March 1st, 2012

by reuben in airway
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Those of you who have adopted the strategy of Nasal Oxygen During Efforts at Securing A Tube know how powerful this technique is, and know that there is no reason not to take advantage of apneic oxygenation by applying nasal cannula oxygen during every airway management case. After observing the effect of this technique a few times, you may have shaken your head at all the unnecessary catecholamines released by you and your patients over the years as you or your trainee hunted around for cords as the saturation fell. But there’s also a small part of you that is glad to have been part of this earlier era, when intubating in the emergency department was a harrowing combination of skill, brute force, and luck. When intubating in the emergency department left providers drenched in sweat and epinephrine, hands trembling, wired and exhausted. When intubating in the emergency department felt like saving a life.

 

These days, with all the fancy airway tools and techniques, placing an endotracheal tube in the trachea often feels as dramatic as placing a foley in the urethra. Your hard-fought airway skills and intestinal fortitude seem wasted. You might find yourself obscuring your intern’s view by “applying cricoid pressure” just to watch him get that same panic-induced nausea you had to suffer day in day out, all those years, glidescope be damned. Intubation these days is too friggen easy. Well it’s about to get even easier.

The high flow nasal cannula is a device that has been used by neonatologists for some time, but is now making its way into adult medicine. By using special tubing, warming, and humidification, the device allows for the nasal adminstration of oxygen at upwards of sixty (60) liters per minute. This enables the delivery of 100% oxygen fraction and true positive pressure, up to around six centimeters water of PEEP. The apparatus itself has a relatively small footprint and is easier to set up than non-invasive ventilation. The oxygen hose connects to a seperate valve on the wall-mounted flowmeter, which liberates precious oxygen sources for the bag valve mask and face mask.

Being blasted with 60 liters per minute of oxygen through your nose isn’t a pleasure, but it’s much more comfortable than NIV, and of course allows the patient to talk, eat, vomit, whatever they want. Because so much water has to be added to the air, the HFNC should not be used in patients who cannot tolerate additional volume. We will see HFNC being used in the ED on many of the COPD and pneumonia patients who linger miserably on NIV, not sick enough to require ETI but not well enough to fly on simple supplemental oxygen.

But where HFNC really shines is during RSI. Put the big cannulae into your patient’s nose and let’r rip. Add a face mask or NIV or whatever your preoxygenation pleasure, then push your meds and laugh to yourself as the saturation rises during apnea. Whistle sweetly as the intern illuminates every inch of the soft palate with great determination. Hell, go see another patient and tell him to call you when he’s given up.* You remember, though, the days of the giants. When being regarded as a skilled laryngoscopist meant something. When the word airway made internists scatter like mice. When it wasn’t so easy to save a life.

 

 

*Note that hypercapnea is a consequence of apnea seperate from hypoxia. High CO2 levels are generally tolerated well, but now that we can seemingly oxygenate the apneic patient indefinitely, remember that patients with severe acidemia or intracranial insults require the expeditious establishment of ventilation as well as oxygenation.

When the patient can’t breathe, and you can’t think: The emergency department life-threatening asthma flowsheet

December 14th, 2011

by reuben in .dyspnea, asthma
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Another case report demonstrates the utility of dissociative-dose ketamine in the deteriorating asthmatic. Life-threatening asthma is uncommon and difficult to study; we may never have better evidence and it’s time to add ketamine to the kitchen sink. This flowsheet incorporates ketamine into a stepwise approach to the severe asthmatic for the emergency clinician who may not remember drip rates and vent settings when her own heart rate is 140.

Management of Life-Threatening Asthma in the Emergency Department (pdf)

Management of Life-Threatening Asthma in the Emergency Department (png)

Regarding nebulized epinephrine: 1:1000 L-epi is 0.1% = 1 mg/ML, so 5 mL = 5 mg. 2.25% racemic epi = 22.5 mg racemic epi per mL = 11.25 mg L-epi (the active isomer) per mL, and we’re using 0.5 mL, which is 5.625 mg L-epi, so roughly  the same dose.

Dexmedetomidine has found its home in the ED: Pediatric painless procedures

November 10th, 2011

by reuben in PSA & analgesia
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Dexmedetomidine (trade name Precedex) is an alpha-2 receptor agonist, similar to clonidine. Whereas clonidine provides a robust decrease in blood pressure with mild sedation, dexmedetomidine provides robust sedation with a mild decrease in blood pressure. It does not depress airway reflexes or respiration. It has a variety of potential uses in the emergency department, including procedural sedation, the facilitation of awake intubation or noninvasive ventilation, and the treatment of alcohol withdrawal. For these indications, however, we have agents that are at least as good, familiar, and a hell of a lot cheaper.

Sedation for painless procedures in children is the scenario that may push dexmedetomidine into the emergency physician’s toolkit. Kids who require sedation for CT or MR imaging would ideally be managed without placing an IV (nix etomidate), using an agent that does not cause significant cardiorespiratory depression (nix barbiturates), is otherwise safe (nix chloral hydrate, which is also unpredictable, untitratable, and lasts forever), and reliably causes kids to be still (nix ketamine).

This case series reports on 65 consecutive children sedated for CT or MRI with intramuscular dexmedetomidine, administered either once or twice at a dose of 1-4 mcg/kg, the exact dose left to provider discretion, to achieve a target Ramsay score of 4 (asleep but briskly responsive to a light stimulus). 4 patients out of 65 required a second IM dose to achieve a Ramsay score of 4. Once Ramsay 4 was achieved, no other agents were given for the duration of the procedure. The mean dose was about 2.5 mcg/kg.

All 65 children successfully completed the study. Though 9 out of 65 patients developed transient hypotension, there were no adverse events that required intervention. 65 patients is not enough to conclusively demonstrate safety, but 100% efficacy is hard to beat, and I suspect the safety profile will stand up in larger series.

Average time to sedation was 13 minutes. The average time from the end of the study to recovery was 22 minutes in the MRI group and 17 minutes in the CT group, with wide confidence intervals, i.e. there was no difference in recovery times. Since MRI is significantly longer than CT, and no sedatives were administered after the initial dose, how can this be?

Dexmedetomidine causes a different type of sedation than what we’re used to. It’s not a CNS depressant in the typical sense, it’s a powerful sympatholytic. Patients sedated with with dexmedetomidine will wake up with minimal stimulation, but when that stimulation is removed, they gently drift off to sleep. This is not a useful feature when trying to facilitate awake intubation, but it’s perfect for getting a 3 year old through the CT scanner.

 

Mason KP, Lubisch NB, Robinson F, Roskos R. Intramuscular dexmedetomidine sedation for pediatric MRI and CT. American Journal of Roentgenology 2011 Sep;197(3):720-5.