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Three part screencast covering the essentials of procedural sedation and analgesia for emergency clinicians.

Part one covers how to think about and prepare for PSA, including a discussion of fasting guidelines. 13 minutes.

Part two describes how patients are harmed during PSA and how to prevent patients from being harmed during PSA. 29 minutes.

Part three discusses contemporary PSA pharmacology. 16 minutes.

 

References

Slideset

Emergency Department PSA Checklist

 

airway-breathing-aes-during-psa

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Designed to be used as a single, double-sided page. 

pdf for printing

pdf vector image for screen viewing

for PSA mastery, see the PSA screencast trilogy

If you’d like to modify the checklist for your institution, I can send you the original layout (omnigraffle format) and tables (excel format).

Update: Egg and soy allergy is NOT a contraindication to propofol.

Update: ACEP’s procedural sedation clinical policy stipulates “Do not delay procedural sedation in adults or pediatrics in the ED based on fasting time. Preprocedural fasting for any duration has not demonstrated a reduction in the risk of emesis or aspiration when administering procedural sedation and analgesia.” See the harms of fasting.

Awake Intubation: A Very Brief Guide

July 7th, 2013
by reuben in airway

 

 

Awake intubation is placing an endotracheal tube in the trachea while the patient continues to breathe. The principle advantage over RSI is that you do not take away the patient’s respirations or airway reflexes, which makes the process safer in many circumstances. The disadvantages are that the patient’s personality and movements, as well as the patient’s airway reflexes, must be managed, which takes time, and even when done well, the view you get won’t be as good as in a paralyzed patient.  Instrumenting the back of the throat may cause gagging and possibly vomiting, though this is quite unlikely to lead to clinically significant aspiration (because the patient is awake).  The more difficult airway features, and the less urgent the intubation, the more likely you should intubate awake. Patients who are at high risk to vomit are not good candidates for an awake technique.

The two arms of awake intubation are local anesthesia and systemic sedation. The more cooperative your patient, the more you can rely on local; perfectly cooperative patients can be intubated awake without any sedation at all. More commonly in the ED, patients will require sedation. Ketamine is the agent of choice in most circumstances, as it sedates without depressing respiration or airway reflexes. In somewhat cooperative patients, 20 mg boluses, titrated to effect, work very well. In very uncooperative/agitated patients, a full dissociative dose (1.5 mg/kg) is an effective strategy though a brief period of apnea is usual if dissociative doses are delivered as a bolus, and laryngospasm is a possible complication. For those patients where raising heart rate or blood pressure is undesirable, benzodiazepine sedation will have a less effective but still salutary effect. Dexmedetomidine is probably a better agent in these scenarios, but is a little tricky to use and not available in most EDs.

Even if using full dissociative dose ketamine, do your best to anesthetize the airway, using the steps listed in the box above, excerpted from the ED intubation checklist. Local is much facilitated by a dry mucosa, so the first step, if possible, is to dry the mucosa with glycopyrolate or atropine, followed by suction and dabbing with gauze. Once this is done, anesthesia is delivered by nebulization, atomization (ideally using a purpose-built atomizer like a MAD device), and drip techniques.

Once the patient is adequately anesthetized/sedated, you gently proceed with your intubation method of choice. When you see the cords, you can pass the tube without paralysis, place the bougie and then paralyze, or paralyze before placing the bougie/tube. I recommend the second option, and I also recommend that you prepare to do a full RSI, with whatever equipment and drugs you would use in an RSI case.

When done well, awake intubation is quite anticlimactic, as the patient simply continues to breathe, and saturation is maintained, for as long as needed. While RSI is terrific and will work very well in most cases, if you perform RSI on a patient who was a good candidate for an awake technique, and it doesn’t go well, you have made a consequential mistake. Awake technique requires little additional skill; it is under-utilized in emergency medicine because it requires what emergency providers often lack: patience. In this case, however, patience is well rewarded.

Hypotension: Differential Diagnosis

June 22nd, 2013
by reuben in .shock

hypotensionDdx.001

 

It’s an important differential. For emphasis, and in case you need to paste it somewhere, here it is again, in text form.

vasodilatory
sepsis
anaphylaxis
neurogenic

obstructive
tension pneumothorax
cardiac tamponade
pulmonary embolism
abdominal compartment syndrome (thanks GW)

cardiogenic
arrhythmia
ischemia
valvulopathy
myopathy

 

hypovolemic (hemorrhage)
chest
abdomen
retroperitoneum
GI tract
thigh
street

hypovolemic (not hemorrhage)
vomiting, diarrhea
inadequate fluid intake
diuresis, hyperglycemia
diaphoresis, hyperthermia
cirrhosis, pancreatitis, burn

 

toxicologic
calcium channel blocker
beta blocker
clonidine
digoxin
opiates
sedatives
valproic acid
TCA
phenothiazine
CO, CN-

metabolic
hypoadrenalism
hypo/hyperthyroidism

spurious
(equipment or technique failure)

A few other considerations:

auto-PEEP if intubated

hypocalcemia

Ectopic Algorithm Snippet

Key Points

In hemodynamically stable patients, the history and physical are insufficiently accurate to either rule in or rule out ectopic pregnancy.  The threshold should be very low to enter a patient with early pregnancy and symptoms or signs potentially referable to ectopic pregnancy into a rule out ectopic process.

In contrast to what most of us were taught, the index beta HCG measurement does not discriminate among ectopic pregnancy, failed/failing intrauterine pregnancy, and early/healthy intrauterine pregnancy with sufficient accuracy to guide decision-making. Put more simply, the beta does not help you. If the ultrasound shows no IUP or ectopic, do not be reassured by a low beta and do not be alarmed by a high beta. The patient may have a healthy IUP, she may have a nonviable IUP that is miscarrying or will miscarry, or she may have an ectopic pregnancy; the beta doesn’t make any of these three diagnoses more or less likely enough to be a useful test to us, on the index visit. This is not controversial, the evidence is plentiful [1, 2, 3, 4, 5, 6, 7], and ACEP’s recent clinical policy states at a Level B recommendation, “Do not use the beta-hCG value to exclude the diagnosis of ectopic pregnancy in patients who have an indeterminate ultrasound.” If the beta is a million zillion, feel free to diagnose molar pregnancy.

If IUP is confirmed by ultrasound, measurement of quantitative beta is unnecessary. If ultrasound shows no evidence of IUP or ectopic, a quantitative HCG level should be sent but the result is not important for this visit–it is useful in comparison to the beta drawn in followup.  A low beta should never be used as a reason to forgo pelvic ultrasound, and a high beta should never be used as a reason to initiate treatment for ectopic pregnancy (in a stable patient). The concept of the discriminatory zone is obsolete and has no value to emergency clinicians [1, 2, 3].

There are a variety of abnormal early pregnancy conditions, and the terminology is confusing. Threatened abortion refers to a patient with a confirmed IUP who has bleeding or pain; these patients are not at risk for ectopic pregnancy and threatened abortion should not be used as a diagnosis for patients with pregnancy of undetermined location. Similarly, patients with missed, inevitable, incomplete, and complete abortion by definition to do not have ectopic pregnancy, and, like threatened abortion, these conditions are generally not dangerous to mom. Often, these diagnoses can only be made after repeat ultrasound and beta measurements. I liken these diagnoses to migraine, tension, cluster, and other primary headaches: the role of the emergency clinician is not to diagnose a benign headache syndrome, it is to exclude dangerous causes of headaches. Confident as you may be that your patient without a sonographic IUP is having some variant of miscarriage and not an ectopic, to make that diagnosis prior to the beta falling to zero (or the passing of what is unequivocally products of conception, i.e. has a human form or characteristic features under a microscope) is unwise. Septic abortion, while not an ectopic pregnancy, is dangerous, and patients with early pregnancy and fever, unwell appearance, or significant uterine tenderness should be managed with this condition–which generally requires prompt surgical uterine evacuation in addition to parenteral antibiotics–in mind.

Most patients who present to the ED with bleeding or pain in early pregnancy are primarily concerned about the viability of their pregnancy, while the emergency clinician’s priority is excluding the presence of a dangerous condition–in this case, mainly ectopic pregnancy. It is important to recognize and address this discordance.  Attempting to determine if the pregnancy is likely to succeed or fail on the index visit is imprudent in most cases, but not acknowledging your patient’s concerns is equally imprudent.

“Using the ultrasound, I don’t see where your pregnancy is. Most likely, you have either a normal pregnancy that I can’t see, or you’re having a miscarriage; we can’t tell, and there’s nothing you or anyone can do to change your course other than having a healthy lifestyle and taking care of yourself. But neither of these situations is dangerous to you and our role in the emergency department is to make sure that your symptoms aren’t caused by a problem that is dangerous to you, most importantly, a pregnancy in the wrong location such as the fallopian tubes. And since I don’t see where your pregnancy is today, we need to repeat the ultrasound the day after tomorrow. If you have more bleeding, or more pain, or feel faint or pass out, or develop a fever, come back immediately, we’re here 24/7.”

 

Who does the ultrasound?

Much practice variability exists around who performs the ultrasound–the emergency clinician, obstetrician, or radiologist–in different rule out ectopic scenarios. Emergency physician-performed ultrasound has been demonstrated to be accurate in this context, and it is reasonable and appropriate for emergency physician-performed ultrasound to be used as the primary imaging modality in a rule out ectopic paradigm, especially when the emergency physician has demonstrated proficiency in pelvic ultrasound and the study is performed under a structured departmental ultrasound QA process. But sometimes an ectopic pregnancy can look like an IUP, and calling what isn’t an IUP an IUP is a very dangerous mistake (don’t neglect to evaluate the myometrial mantle all around what you think is an IUP).  Also, we generally rule out ectopic by ruling in IUP, and when an IUP is definitively identified in a patient not at high risk for ectopic or heterotopic pregnancy, ectopic pregnancy has been reasonably excluded. However, in a patient without sonographic IUP, the second goal of imaging is to look for evidence of ectopic pregnancy, and these findings, often in the adnexa, require more ultrasound skill.

As usual, the most important strategy to manage physician risk is to decide as a department and institution how these patients will be managed. Reasonable approaches include, in order of decreasing emergency clinician risk (and increasing patient inconvenience):

a. Discharge the patient after emergency physician-performed ultrasound either with a diagnosis of intrauterine pregnancy and routine followup, or with a diagnosis of pregnancy of undetermined location, strict ectopic precautions and urgent followup, based on the results of the emergency physician-performed ultrasound.

b. Discharge patients who do not have ectopic risk factors and have PUL after emergency physician-performed ultrasound with ectopic precautions and urgent followup; arrange immediate specialist-performed ultrasound for patients with ectopic risk factors who do not have an IUP identified by the emergency clinician. This is the strategy I use.

c. Arrange immediate specialist-performed ultrasound for all patients who do not have IUP identified by the emergency clinician.

d. Arrange immediate specialist-performed ultrasound for all patients who enter into the rule out ectopic flow.

There are other approaches and gradations within these approaches; for example, if you usually discharge a rule out ectopic patient after your bedside ultrasound but have a patient you are more concerned about than usual, but don’t have access to specialist ultrasound or assessment, have the patient return for repeat assessment not in 48 hours but in 24 or 12 hours.

 

Rhogam

The use of Anti-D rhesus prophylaxis in early pregnancy is controversial, because “There are insufficient data available to evaluate the practice of anti-D administration in an unsensitised Rh-negative mother after spontaneous miscarriage. Thus, until high-quality evidence becomes available, the practice of anti-D Immunoglobulin prophylaxis after spontaneous miscarriage for preventing Rh alloimmunisation cannot be generalised and should be based on the standard practice guidelines of each country.”

The use of Rhogam for threatened abortion or pregnancy of undetermined location is even less likely to be beneficial than in cases of diagnosed miscarriage, which was the subject of the quoted Cochrane review. ACOG recommends it “after a first-trimester pregnancy loss” and suggests it “be considered” in cases of threatened abortion, while British guidelines state, “Do not offer anti-D rhesus prophylaxis to women who receive solely medical management for an ectopic pregnancy or miscarriage, or have a threatened miscarriage, or have a complete miscarriage, or have a pregnancy of unknown location.” ACEP chimes in with their Level B recommendation “Administer 50 μg of anti-D immunoglobulin to Rh-negative women in all cases of documented first trimester loss of established pregnancy” and Level C “Consider administration of anti-D immunoglobulin in cases of minor trauma in Rh-negative patients.”  See SMART-EM‘s treatment of the subject for details. If you don’t use Rhogam routinely in threatened abortion, most of these patients can return home to their loved ones immediately if IUP is identified, without bloodwork, and even, some say, without a pelvic exam [1, 2].

 

Followup

Ideally all patients with pregnancy of undetermined location would be seen by an obstetrician within 48 hours for repeat exam, ultrasound, and serum beta. If the only option in your environment is for the patient to return to the ED, if IUP is not identified on the repeat visit, have a low threshold to at least discuss the case with an obstetrician. Interpreting beta trends and deciding on therapies like methotrexate, or uterotonic agents, or dilation and curettage, is ideally in the domain of obstetrics and not emergency medicine.

 

Rule Out Ectopic Algorithm (Screen Version)

Rule Out Ectopic Algorithm (Print Version)

 

Thanks to Sigrid Hahn and Phil Andrus for their erudition.

 

Bonus: amazing/bewildering vaginal bleeding algorithm I created as a medical student many years ago, demonstrating outdated strategies for rule out ectopic, among many other outdated strategies.