HOW TO DIAGNOSE SEPTIC ARTHRITIS

The biggest challenge in diagnosing septic arthritis is to think of it. Once you think of it, there is a diagnostic process that you activate. The second biggest challenge is that that diagnostic process we learn in training is flawed. We have no alternatives right now, so I will share with you my thoughts on how we should use our judgment as clinicians.

 

Triggers to consider septic arthritis essentially are the same triggers as infection anywhere. Celsus’ cardinal signs of inflammation are dolor (pain), calor (warmth), rubor (redness), tumor (swelling). Some authors have written that fluor (flow) should be the 5th cardinal sign and in this case the effusion is one of the most important clinical signs.

 

The detection of effusion at the bedside has been covered elsewhere but includes inspection, palpation, and milking. Smaller volumes of fluid are harder to detect. Ultrasound can be utilized to improve our accuracy.

 

The clinician generates hypotheses at the bedside and then circles back to revisit risk factors. This is an underappreciated process that deserves more attention. The following risk factors have high specificity:

 

-diabetes

-joint surgery (mainly recent)

-joint prosthesis (at any time)

 

There are others but those are the main ones. You might think of it as “compromised immune system” and “compromised joint.” If it helps you in remembering this, recall that the synovium is a vascular tissue. It lacks a basement membrane (which tends to filter out bacteria in other tissues, like the cornea). The joint relies on the immune system to protect us from bacterial translocation. Recall also that bacteria love to find crevices to hide in. A disrupted joint, or a compromised immune system creates the setting for septic arthritis.

 

They don’t all have to have those high risk features though. Often the clinician is left with enough suspicion to pursue a risk stratification process before considering a tap. In low risk patients that process can involve inflammatory markers (traditionally WBC, CRP, ESR, with emerging roles for procalcitonin and perhaps other markers) to lower your suspicion back below the threshold of further testing. I recommend you use as many of these as you need to reassure you in a low risk patient that there is no infection. All of them have limitations but if the results are normal, you are greatly reassured.

 

For patients where doubt continues to exist, the diagnostic pathway for septic arthritis ends in arthrocentesis, though its results may be less clear than we realize. Common practice is to use synovial blood counts (often 50K) as disease-defining, which does not actually work very well. Synovial WBC cutoffs at all levels will both miss and overcall septic arthritis. Even if you use the cutoff as 25K, it still misses as many as 1/4 of all cases, one prospective study said it would miss more than 1/3 of all cases (Margaretten JAMA2007). Meanwhile there will continue to be patients with WBC above 50K who have other causes (gout for example).

 

The gram stain sensitivity is as low as 40% (Ross Infect Dis Clin North Am2017). If you have strong suspicion based on risk factors, drain the joint and have them follow up in 24 hours, giving antibiotics while awaiting culture results.

 

Summary:

-Septic arthritis is considered when the patient has an inflamed joint (effusion, warmth, pain).

-Inflammatory markers, if all normal, can lower your concern enough in a low risk patient to rule out disease.

-Risk factors (compromise of joint, compromise of immune system) may be more important than the other tests.

-Synovial WBC has significant limitations in sensitivity and specificity, and is not a disease-defining reference standard.

 

Selected References:

 

Septic Arthritis of Native Joints.

Ross JJ.

Infect Dis Clin North Am. 2017 Jun;31(2):203-218. doi: 10.1016/j.idc.2017.01.001. Epub 2017 Mar 30.

 

Does this adult patient have septic arthritis?

Margaretten ME, Kohlwes J, Moore D, Bent S.

JAMA. 2007 Apr 4;297(13):1478-88. Review.

PMID: 17405973

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SOFT TISSUE FOREIGN BODY: PAIN WITH MANIPULATION

A patient presents with redness and swelling. There had been a wound there 2 weeks before and the patient is worried about retained foreign body. Xrays are negative for foreign body. The student tells the patient “Good news! The xrays show there is no foreign body there!”

 

You wince a bit. Every mature clinician must know the limitations of the tools they use. I want to take a divining rod to the beach and see if it knows which direction is the ocean. If it doesn’t, that doesn’t mean the ocean is a mirage. It means the tool doesn’t work perfectly.

 

You clarify the student’s comments. The xrays do not show there is no foreign body. Instead they merely are negative. You manipulate the swelling and it reproduces pain. That is the hallmark of an infected foreign body (or any sharp foreign body, infected or not). Alas, anything infected hurts when you manipulate it, so this rule is not very specific.

 

You tell the patient there could be a foreign body there. You ask more about the history and it turns out there could be some plastic in there. Ultrasound is suggestive enough that you choose to dissect, and indeed uncover a broken piece of plastic.

 

Summary:

-Always acknowledge the limitations of imaging studies (or any studies)

-Foreign bodies are suggested by pain with manipulation

REAPPROXIMATING MID FOREARM FRACTURES THROUGH ANGULATION

A patient presents with a mid forearm fracture. Reduction is tough because it is 100% displaced. Unlike distal fractures, you can not grab the bone as it is surrounded by muscle. It is hard to pull enough traction to reapproximate. Now what?

 

Try angling more during your reduction, exaggerating the angulation. Now it is slack enough you can put the distal piece on the proximal piece. Use your other hand to guide it on manually. Once the two pieces touch each other, simply straighten the bone out.

 

You try this and are able to secure adequate reduction. The patient now has a better chance of receiving adequate reduction without surgery.

 

TAKE HOME POINTS

If you can not pull traction to reapproximate fractures, try angling the fracture to give it slack, then fit the fragments together before restoring alignment.

AIRWAY VISUALIZATION – EXTERNAL “CEPHALIC” MANIPULATION

Here is a potential airway technique that may help with visualization: hold the laryngoscope in the left hand (the usual) but the right hand, instead of being at your side, is behind the patient’s head. You then move it around until you get the best view. Then you have an assistant hold the head in that spot.

 

A hospital in Southern California started doing that. The technique deserves some exploration. The work of Richard Levitan reminds us that the airway is most patent in the sniffing position. Extension does not really help but true sniffing position does. Sometimes you think you have enough and you need more.

 

I have not seen this technique studied but it probably deserves some attention.

 

TAKE HOME POINTS

-Consider external cephalic manipulation as an analogy to “external laryngeal manipulation” as a way of fine tuning the visualization during a tough intubation

INDIRECT LARYNGOSCOPY

A patient presents with severe sore throat. You wonder about epiglottitis. You know that using a mirror to look at the epiglottis is a great way to check this but are not confident in your skills. What do you need?

 

Dental mirror – they are cheap, have your ED stock them

 

Light – can use a headlamp, the kind that are sold in outdoor stores. Get one with a spot beam rather than a flood light. Nice to have regular AAA batteries instead of the medical ones with cords that are always getting lost or damaged

 

Relaxed patient – explain to them what you are doing and rehearse it once first

 

Anatomy – have them lean forward, chin out

 

View – wrap gauze around their tongue. Don’t pull it out but hold it so they don’t have to sustain muscle contraction to keep the tongue out

 

No gag – not sure topical anesthetics really work. Try to avoid hitting their pharynx with the mirror until you are ready to lift the uvula and look. Have the patient fix vision in the distance. Have them say “eeeeeee.” Have them do slow panting style shallow breathing.

 

No fog – hydrogen peroxide or hot water will help prevent fogging

 

You look and it is hard to see. That reminds us the final thing you need – practice!

 

TAKE HOME POINTS

-Indirect laryngoscopy is a complex hand-eye skill that you can learn

-Get the right supplies and start doing this now. It may really help you one day.

FINGER TEST FOR NECROTIZING FASCIITIS

A patient presents with a deep muscle abscess. Is this necrotizing fasciitis? All too often I see the deliberation focus on things like the laboratory score or the imaging. The role of those things are being debated but what is beyond debate is to have the bedside skills for recognizing necrotizing infections.

 

Childers in 2001 and 2002 described the finger test as a diagnostic intervention at the bedside. It does not get enough attention. The instructions are to make a 2 cm incision down to fascia. “…if the tissues dissect with minimal resistance, the finger test is positive”

 

Other signs:

-lack of bleeding

-grey necrotic tissue

-dishwater purulence

 

There is no reason ED physicians should not know this and perform it. We are already making incisions to check for abscess. Know the 4 surgical signs of necrotizing fasciitis.

 

TAKE HOME POINTS

The 4 surgical signs of necrotizing fasciitis are:

-lack of resistant to finger spread

-lack of bleeding

-grey necrotic tissue

-dishwater purulence

 

Childers BJ Necrotizing fasciitis: a fourteen-year retrospective study of 163 consecutive patients. Am Surg. 2002;68:109-16.

 

Andreasen TJ, Green SD, Childers BJ. Massive infectious soft-tissue injury: diagnosis and management of necrotizing fasciitis and purpura fulminans. Plast Reconstr Surg. 2001;107:1025-35.

BLADDER STIMULATION TECHNIQUES FOR NEWBORN CLEAN CATCH URINE COLLECTION

An infant presents with fever. The parents do not want a catheter placed in his penis. You want to check for urine infection. The resident suggests placing a bag. Are there any other options?

 

In 2013 Herreros-Fernendez described a technique of coaxing the child to urinate. She would tap the bladder at a rate of 100 taps per minute, and massage the low back. 86% of the time the child would urinate, with a median of 45 seconds. The population was strictly those less than 30 days of age, so it may not apply to older babies. The idea was inspired by bladder stimulation techniques used in adults with neurological diseases. There may be some element of a frontal lobe “release” reflex involved in the phenomenon.

 

The original study stacked the odds in their favor by feeding the babies, but follow-up studies all showed a greater than 50% success rate within 5 minutes. Thus, this technique is well worth trying in a low risk population.

 

Of note, the bladder tapping was 100 taps per minute. It is supposed to be gentle but the parents may quickly throw in the towel and ask for the catheter.

 

Take Home Points

-For the infant with a low suspicion of urinary tract infection, consider massage and bladder tapping to elicit a urination reflex

 

Herreros Fernández ML et al. A new technique for fast and safe collection of urine in newborns. Arch Dis Child. 2013;98:27-9.

JAW THRUST MASK GRIP

You are intubating a critically ill patient. The first intubation attempt fails and the patient experiences rapid oxygen desaturation. The respiratory therapist tries to ventilate the patient but air leaks out around the mask with each breath, spraying bloody froth on those nearby. The chest does not rise and the saturation is dropping. You want to help. Let’s address some questions that come up on this topic:

 

What is the problem when air leaks in face mask ventilation?

When airway pressure (A) is greater than mask pressure (M), air will leak at the mask. Of course, mask friction is part of it. Beards, blood, and secretions will all lubricate the seal and make leakage happen at lower pressure.

 

Why would mask pressure be too low?

Usually it isn’t that the mask pressure is too low but that airway pressure is high. That being said we do have a problem with mask pressure. The classic C grip puts the forces at the wrong angle, and can end up closing the airway at the submandibular soft tissues.

 

Why would airway pressure be too high to begin with?

Airway pressure is higher in the supine position because the soft tissues fall back with gravity.

 

Should we just sit patients up?

Yes, if we can. That would help.

 

Why do you say the C grip can raise airway pressure?

Any grip that relies on fingers on the submandibular area will occlude the airway. Perhaps this is too graphic but as a teaching device I tell students not to strangulate the patient, but rather to do the opposite, pull their airway open.

 

How do you open the airway?

Put your hands in a praying position, thumbs together. Now tip the hands forward.  This is your hand position. Stand at the head of the bed and put the thumbs on the mask. Your fingers go not in the submandibular space but behind the angle of the jaw.  This is the same as the jaw thrust maneuver.

 

Why does the jaw thrust mask grip work better?

First of all your muscles there are massively strong. The jaw thrust uses more than your fingers but actually uses your back, shoulders, and arms. This is the position you would use if you were picking up a 40 pound dumbbell. You would not grab it with a C grip on top, expecting friction to allow you to suction it up. You would get your fingers under it and use your biceps to lift. You could literally lift their head off the bed with it. This makes a tremendous jaw thrust and lowers A, airway pressure.

 

Second, your thumbs are working against the mask holding it tight. If you held a soda can in your hands with this grip you could probably crush it. This means M, mask pressure will be higher.

 

In summary, the jaw thrust grip lowers A (airway pressure) and raises M (mask pressure).

 

I can’t find anything about the jaw thrust grip. Is this new?

No. It is starting to be used under this more descriptive name. It is also called the TE (thenar eminence) hold as well as modified 2 handed and the EV grip. In my opinion those are all terrible names because they don’t tell you what it does. Look up on google the proper way to do jaw thrust. The fingers are behind the angle of the jaw and the thumbs are resting astride the nose. Add a mask to those images and you know how to do this. So calling this the jaw thrust maneuver is a better name for this.

 

Some studies say CE grip or jaw thrust grip are equally effective. So why do you say jaw thrust is better?

Any study that looks at people who are not sick is going to find that there is no difference between the optimal technique and the suboptimal technique. In well people in the OR, airway resistance (A) is lower than mask resistance (M). Anything will work in that situation. What really matters is what happens when A is greater than M. That isn’t addressed in most of these studies.

 

What happens when A is higher than M?

When airway resistance is higher than mask resistance, the operator grips harder to raise mask pressure. The fingers then unwittingly compress the submandibular space. This presses the tongue against the posterior airway, and raises airway pressure further. The harder you grip, the more you close off the airway. Any grip with fingers on the submandibular space is inherently inferior and subject to this vicious cycle.

 

Hey, that isn’t fair. The C grip is supposed to be on the bone, not on the soft-tissue, so if done properly it isn’t as bad as you say.

I agree. But I am talking about what happens in actual practice. The C grip is not an ergonomic grip, and it does not provide enough strength. So people do it improperly, to strengthen their grip. The jaw thrust doesn’t have that problem.

 

Is there anything else that will help?

#1 Sit them up. This takes away the gravity compression of the soft tissue, as well as the abdominal resistance that adds to airway pressure

#2 Place two nasal airways as well as an oral airway. This splints open the airway and lowers airway pressure

 

Let’s go back to the case. You put the thumbs pointing forward on the mask and pull jaw thrust with digits 2-5. The leak is gone and the patient is re-oxygenated before your second attempt.

 

TAKE HOME POINTS

-Mask ventilation skill could make the difference between life and death.

-Jaw thrust mask grip raises mask pressure through a stronger grip

-Jaw thrust lowers airway pressure by pulling the jaw and attached structures forward

-Sit the patient up

-Place nasal and oral airways

 

Suggested references:

Efficacy of facemask ventilation techniques in novice providers.

Gerstein NS, Carey MC, BraudeDA, TawilI, Petersen TR, Deriy L, Anderson MS.

J Clin Anesth. 2013;25:193-7

UNLOCKING SHOULDER DISLOCATIONS

A patient presents with a recurrent anterior shoulder dislocation. Milch fails but Spaso works. The next month she is back and the procedure feels different, with more resistance. This time Spaso fails and Milch works. Same shoulder, so what is different? Why did the efficacy reverse?

 

Milch’s 1938 article started with a question: why do some reductions seem impossible and then under general anesthesia they become very easy, almost going in spontaneously? It was the muscle and tendon opposition, he concluded, so his technique focused on putting the patient in the muscle neutral position overhead (hanging from a limb position). The various shoulder muscles would share equal stress and equal angles.

 

Milch’s idea has probably not yet been fully fulfilled – it was the idea that shoulder reduction is not about overcoming force but about untangling the humeral head from the adjacent muscles, tendons, and soft-tissues. That was the same idea that inspired Kocher.

 

We have all had the tough shoulder that would not go in with technique A, but after trying technique B, a second attempt with A yielded an effortless reduction. There seems to be an unlocking of the soft structures that occurs.

 

Now as to the unlocking. I suspect there is advantage in the difficult shoulder to running through a variety of techniques. Ideally we would know which soft structures are causing the locking, but the literature lacks consensus and I do not know to resolve that. So I run though a variety of techniques.

 

This is reductionistic but you can think of all techniques as the application of external rotation in different positions.

 

Kocher is external rotation in the adducted humerus, as are all the derivative techniques.

 

Milch is external rotation in the abducted elevated humerus (technically he advocated doing the external rotation on the way up).

 

Spaso is external rotation in the forward flexed shoulder.

 

Back to the bedside. Its your next shoulder attempt. The shoulder is locked in internal rotation. Your goal is to get it into external rotation. You try Kocher but there is too much resistance to external rotation. You laterally abduct to Milch and you came close but did not fully reduce the shoulder. Finally, you perform forward flexion (Spaso) which also does not work. You then go back to Kocher, which this time was successful.

 

Take Home Points:

-The obstruction to shoulder reduction is not bone position but soft structures

-The obstruction can apparently be unlocked through applying external rotation in various positions through the range of motion

-If your favorite technique does not work, range the shoulder, externally rotate, and try it again.


Check out medicalclassics.com for more on Milch. If the link does not work, here is the location.  https://medicalclassics.com/2016/09/05/1938-milchs-shoulder-reduction-techniqueabduction-external-rotation-and-pulsion/

 

KOCHER INTENDED FOR SUBCORACOID DISLOCATIONS, NOT SUBGLENOID

The Kocher technique, one of the oldest and most popular techniques, was developed for the subcoracoid anterior dislocation. Review Neil Cunningham’s resources at shoulderdislocation.net for insight on this, as well as his translation of the original Kocher article.

 

The goal of Kocher’s method, which was worked out on cadavers in 1870, is to roll the greater trochanter of the humeral head on the glenoid rim. It might have been named the “shoulder rim roll.” Here are the steps:

 

1) Adduct the elbow all the way to get the greater trochanter right next to the glenoid rim.

2) Externally rotate to roll the greater trochanter on the glenoid rim.

3) Forward flex the shoulder (sagittal plane) to tip the humeral head back toward the socket.

4) Internally rotate to complete the reduction.

 

Kocher’s words:

“Pressing the arm bent at the elbow towards the body, turning outward until resistance is felt, lifting of the outwardly rotated upper arm in the sagittal plane as far as possible, and finally slowly turning it inward” (translation by Cunningham)

 

DON’T USE THE SHOULDER RIM ROLL IF YOU AREN’T ROLLING ON THE RIM

The subglenoid dislocation will not be resolved with the Kocher technique because the external rotation phase will not latch onto anything. Kocher himself in his article specified that this was for subcoracoid dislocations, and said “the more therefore the head has departed from the coracoid process toward the interior … the less can be expected from the method.”

 

PITFALLS

-Make sure you fully adduct the elbow first.

-Avoid traction, which is what creates the need for sedation(Chitgopar Injury 2005).

-Avoid sedation. This is the best way to avoid too much force. Kocher’s method excluded the use of force. Perpendicular forces of opposing muscles can lead to fracture. If you get resistance, use another technique.

 

TAKE HOME POINTS:

-Kocher’s shoulder reduction was originally intended for subcoracoid dislocations, not for subglenoid.

-Do not use force with Kocher’s method.

 

References:

shoulderdislocation.net (see the lectures and translation of the original Kocher article)

Chitgopkar SD, Khan M. Painless reduction of anterior shoulder dislocation by Kocher’s method. Injury. 2005;36:1182-4.