Patellofemoral anatomy and disease (part 1)

During normal knee flexion, the patella slides within the trochlear grove. Both (patella and the trochlear groove) are lined with articular cartilage at the patellofemoral articulation.

https://www.stvincentsboneandjoint.com.au/images/patellofemoral-joint2.jpg

Multiple forces act on the patella which can affect proper tracking:  Proximately, by the quadriceps tendon, distally, by the patellar tendon, medially, by the medial retinaculum/vastus medialis and laterally by the lateral retinaculum and the vastus lateralis.

Patellofemoral OA can occur when this cartilage starts to wear and can be seen in skyline/sunrise/notch or equivalent views. OA here rarely occurs in isolation (<10%) and is usually part of medial or lateral knee OA.

https://www.stvincentsboneandjoint.com.au/images/patellofemoral-joint3.jpg

Patellofemoral pain is usually from overuse/training overload or malalignment.

Contributors to overuse involve total joint load which may have influence from training volume (total miles), intensity (competitive sports) in addition to BMI (>25) in addition to overall fitness level.

Malalignment aka abnormal patellar tracking involves both static (leg length discrepancy, hamstring tightness, etc.) and dynamic components (hip weakness, gluteus medius weakness, excessive foot pronation, etc.).

Patients with anterior knee pain should have activity modification, ice, NSAIDs (not steroids) and long-term engagement in physical therapy (>6 months) with a focus on flexibility and strengthening of lower extremity kinetic chain including the vastus medialis, gluteus medius, hip external rotators and core.

Also, consider looking for hyper supination or pronation. Foot orthotics can be of help with this.

Things to Consider for Persistent or Worsening Septic Shock

• Septic shock is one of the most common critical illnesses in emergency medicine and critical care.
• Norepinephrine is recommended as the initial vasopressor of choice for patients with septic shock, with vasopressin or epinephrine commonly added as a second vasopressor for patients with refractory shock.
• While vasopressors are being added and titrated, it is important to consider additional diagnoses in patients with worsening or persistent septic shock.  Some of these diagnoses include:
  • Undetected infection that requires emergent source control
  • Concomitant causes of shock: cardiogenic, PE, abdominal compartment syndrome, tamponade, adrenal insufficiency
  • Severe acidosis
  • MAP underestimation by a radial arterial line

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Predicting the need for a mass hemorrhage protocol (MHP) activation is important both for individual patient outcome as well as for proper utilization of critical resources such as blood products and healthcare workers time and effort. These two studies look at using the RABT score to predict the need for mass transfusion. The RABT score is:

A 4-point score

blunt (0)/penetrating trauma (1),

shock index (hr/SBP)≥ 1 (1),

pelvic fracture (1)

FAST positive (1)

With a score >2 predictive of needing MHP.

These studies (one in Canadian trauma centers, the other in US trauma centers) validate the use of this score to predict the need for activation of a mass hemorrhage protocol.

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This study from Sweden looked at 2397 trauma patients and identified 768 with thoracic injury. Those with thoracic injury had a 30-day mortality of 11% whereas those without thoracic injury had a 4% 30-day mortality. Patients over age 60 had higher mortality and were more likely to have rib fractures. Those under 60 with thoracic injury were more likely to have thoracic organ injury than rib fracture.

Bottom line: Rib fractures were more common over age 60 and there was a higher mortality for those with thoracic vs non-thoracic trauma.

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Title: Electrocardiographic Changes at the Early Stage of Status Epilepticus: First Insights From the ICTAL Registry.

As the song goes: “the thigh bone is connected to the hip bone, the hip bone is connected to the back bone.” It turns out that the brain electrical activities are also connected to the heart conduction activities.

In a multi-center (23 French ICUs) retrospective analysis of 155 critically ill patients with status epilepticus, ECGs were done within 24 hours of onset of status epilepticus, and were independently reviewed by cardiologists showed abnormalities in 145 (93.5%) of patients.

Below is a list of events that occurred more than 10% of events.

Abnormal rate (<60 or > 100 beats/min         64 (44%)

Negative T-waves                                           61 (42%)

Flattened T-waves                                           18 (12%)

ST elevation                                                    24 (16.6%)

ST depression                                                 26 (17.9%)

Left axis deviation                                          22 (15.9%)

Discussion:

Major ECG abnormalities were not associated with 90-day functional outcome in multivariable logistic regression.

The brain-heart axis could be affected by antiseizure medication. For example, phenytoin, lacosamide are sodium channel blockers while benzodiazepines, propofol, barbiturates with their GABAnergic effects will also display cardiac side effects.  This current study was not able to tease out whether the cardiac effects were from medication. Therefore, further studies are needed to figure out the cardiac effect for patients with status epilepticus.

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Applying a cervical collar to all patients involved in motor vehicle collisions and mechanical falls has been shown to add to patient discomfort, unwarranted imaging studies and prolonged on scene time for emergency medical services. This study adds further evidence that paramedics can use validated algorithms to clinically clear cervical spine injuries without any bad outcomes including spinal cord injuries. EMS medical directors and all of us who interact with EMS providers should be proactive in developing protocols to use cervical immobilization in appropriately selected patients only.  This study used the Modified Canadian C-Spine Rule. 

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Non-dihydropyridine calcium channel blockers, verapamil and diltiazem, can induce hypotension when administered intravenously (IV) in approximately 4% of patients.  It has previously been taught that administering IV calcium before administering these medications may prevent the hypotension.  Previously, this theory was tested for verapamil and found success with reducing hypotension.  Only one study has been done exclusively with diltiazem and it found no benefit. 

In a new multicenter retrospective cohort study of adults in the ED, patients were randomized into two groups: those who received diltiazem alone and those who received calcium with diltiazem for atrial fibrillation/atrial flutter (AF/AFL) with a HR ≥ 120 bpm. Patients were excluded if they required electrocardioversion, had other agents prior to diltiazem, incomplete information, were pregnant or incarcerated. The primary outcome was change in SBP 60 minutes (+/-30 minutes) after diltiazem administration.

Baseline characteristics: 73 year old, equal male:female, predominantly white patients.  40% had new onset AF/AFL and the initial HR was 140 in both groups. There were 198 patients in the diltiazem group and 56 patients in the combination group.  Notably, patients in the combination group had a lower presenting SBP 109 (101-121) vs 123 (114-132) P<0.0001 which matches classical teaching for when to consider calcium use. Additionally, patients in the combination group received a lower diltiazem dose of 10mg vs 15mg in the monotherapy group p=0.004 with both group receiving doses lower than the standard 0.25 mg/kg dosing recommendation.

Outcomes:

• Median change in SBP was not different between the monotherapy and combination therapy groups: (-2 mmHg vs -1.5 mmHg, p= 0.642)
• There was no difference in:
  • Time to rate control (1.4 vs 1.8 hours, p= 0.141)
  • Time to sustained rate control (7.9 vs 7.7 hours, p=0.570)
  • Change in HR at 60 minutes: (-33 vs -34 bpm, p=0.428)
• A subgroup analysis looking at timing of calcium (i.e. before or with diltiazem administration) also found no difference.

Take Home Point:

Administration of IV calcium may not be as beneficial as previously thought to prevent hypotension induced by diltiazem administration.  This particular study is confounded by the relatively low doses of diltiazem overall, but utilizing a lower dosing strategy in patients with low SBP is a reasonable safety strategy.

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Background: 

There have been a few studies that suggested that there may be some neuroprotective effect with a higher MAP goal in post-arrest patients. However, these studies were small and/or observational. 

Intervention:

-The BOX trial was a double-blind, dual-center (Denmark), randomized trial 

-Study population: >18 yo, OHCA of presumed cardiac cause

-Pts randomized to higher (77 mmHg) vs. lower (63 mmHg) MAP goal

-double-blinded by attaching a module that reported a BP that was 10% higher or lower than the pt’s actual BP

-Notable exclusion criteria:

-unwitnessed asystole or suspected intracranial bleeding/stroke

Results/Primary outcome:

-No sig difference in composite of death + Cerebral Performance Category of 3 or 4  (3= severe disability, 4= coma) within 90 days

-133 patients (34%) in the high-target group vs 127 patients (32%) in the low-target group (hazard ratio, 1.08;95%CI, 0.84 to 1.37; P=0.56)

Caveats/Takeaways:

-Mean difference in BP was 10.7 mmHg (95[CI], 10.0 to 11.4) which is still relatively clinically significant, but was lower than their goal difference of 14 mmHg

-They used IVF to target a CVP of 10 mmHg prior to initiation of norepi and used dopamine "if necessary"

-Consider generalizability given study population was patients with presumed cardiac cause of arrest

-Keeping a lower MAP goal of >65 mmHg is reasonable in post-arrest patients

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In a small study at a single level one trauma center, ? of patients screened positive for illicit fentanyl use prior to violent or intentional injury. Those who screened positive were more likely to require ICU admission and had a higher rate of previous trauma center admission. The authors concluded: 

“Exposure to illicit fentanyl was common among victims of violence in this single-center study. These patients are at increased risk of being admitted to intensive care units and repeated trauma center visits, suggesting fentanyl testing may help identify those who could benefit from violence prevention and substance abuse treatment.”

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Question

21-year-old college softball player presents for evaluation of Left hand/wrist pain following batting practice.

She states her pinky is “tingly”

On exam, there is tenderness over her volar ulnar wrist.

You obtain an X-ray.

https://prod-images-static.radiopaedia.org/images/52314027/a662d8f338ec08ba56178463638d25_jumbo.jpeg

What’s the diagnosis?

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Given my previous post on APRV (11/6/2022) and while I take issue with many of the author's statements, I wanted to share a very well referenced article with an excellent discussion on the current gaps in the knowledge around APRV and its use.

One statement I do agree with is the need for a well-designed and adequately powered trial of this mode in an admittedly difficult-to-study population.

Fortunately, this article has an invited rebuttal pending from Dr. Habashi which I am sure will appear in the Educational Pearls in short order. 

Good luck to the residents on the ITE!

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This study looked at 69,321 head injured patients over age 65 in a health care database for delayed intracranial hemorrhage (within 90 days of visit). 58,233 patients were not on oral anticoagulants, 3081 (4.4%) were on warfarin and 8007 (11.6%) were on direct oral anticoagulants. One percent of patients not on anticoagulation and those on oral direct anticoagulation had a delayed hemorrhage while those on warfarin had a 1.8% delayed hemorrhage rate.

Bottom Line: Direct oral anticoagulants do not increase the risk of delayed intracranial hemorrhage in patients over age 65 from baseline but warfarin does. 

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Sympathetic Crashing Acute Pulmonary Edema (SCAPE) (also known as flash pulmonary edema) is an extreme form of hypertensive acute heart failure where a surge of high blood pressure from catecholamine surge and sudden vascular redistribution causes sudden onset decompensated heart failure hallmarked by rapid pulmonary edema and symptoms of hypoxia and dyspnea.

This is treated by systolic blood pressure control and venous vasodilation with IV nitroglycerine, bilevel positive airway pressure (BPAP), and diuretics if needed. A common error in treatment is administration of the traditional IV nitroglycerine infusion dosing protocol in which the nitroglycerine infusion is started at 5 mcg/min and slowly increased by 5 mcg/min increments until the clinical response is seen. However, in this syndrome, rapid blood pressure control and correction of vascular redistribution is critically important to reverse the central factor for patient decompensation. Lack of blood pressure control places the patient at risk of further cardiac decompensation or respiratory failure ultimately requiring intubation.

Increasing literature has been published on the concept of high dose or push dose IV nitroglycerine for the treatment of this syndrome. Many of these studies show decreased rates of intubation, decreased ICU admissions, and shorter hospital length of stays with high dose or push dose nitroglycerine, while also demonstrating low risk of hypotension.

The actual dose of the high-dose nitroglycerine administered in these trials is variable, with some trials administering nitroglycerine 1-2 mg IV pushes every 3-5 minutes, and other trials using a nitroglycerine infusion at a much higher starting rate (between 200-400 mcg/min) with rapid down-titration as blood pressure is controlled.

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In December 2022, The American College of Surgeons released a practice guidine discussing screening trauma patients for mental health disorders and substance use disorders. There is a very high likelihood that your acute trauma patient has a pre-existing disorder.

"Over 50% of hospitalized trauma patients report an alcohol and/or drug use diagnosis during their lifetime. At the time of admission, one in four trauma victims meet diagnostic criteria for an active alcohol use problem and 18% meet diagnostic criteria for a drug use problem".

Screening, Brief Intervention and Referal to Treatment (SBIRT) programs have a major impact on injury recidivism and future mortality. Trauma patients should be screened for mental health disorders and substance use disorders. 

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Background: The use of sodium bicarbonate in the treatment of out-of-hospital cardiac arrest (OHCA) has been longstanding despite conflicting data regarding its benefit, outside of clear indications such as toxic ingestion or hyperkalemic arrest.

Study: A recent retrospective cross-sectional study by Niederberger et al.¹ examined prehospital EHR data for ALS units responding to nonpregnant adults with nontraumatic OHCA, noting use of prehospital bicarb and the outcomes of 1) ROSC in the prehospital encounter and 2) survival to hospital discharge. They created propensity-matched pairs of bicarb and control patients, with a priori confounders: age, sex, race, witnessed status, bystander CPR, prearrival instructions, any defibrillation attempt, use of CPR feedback devices, any attempted ventilation, length of resuscitation, number of epi doses.

There were 23,567 arrests (67.4% asystole, 16.6% PEA, 15.1% VT/VF), 28.3% overall received sodium bicarb. 

Results: 

In the propensity-matched sample, survival was higher in bicarb group (5.3% vs. 4.3%; p=0.019).

• Asystole (bicarb 3.3 vs 2.4%; p = 0.020)
• PEA (bicarb 8.1% vs 5.4%; p=0.034)

There were no differences in rate of ROSC overall, but looking at the different rhythms, ROSC was higher in the bicarb group with asystole as the presenting rhythm (bicarb 10.6 vs 8.8%; p=0.013) but not PEA or VT/VF.

*There is no indication by the authors as to the dosing of bicarb most associated with survival to hospital discharge (or ROSC in asystole) in the study, however a previous study has indicated that a single amp of bicarb is unlikely to significantly improve severe metabolic acidosis (pH <7.1),² so the general recommendation of at least 1-2mEq/kg should be employed.

Bottom Line: The use of sodium bicarb may increase survival in OHCA with initial PEA/asystole. The recommended initial dose is 1-2mEq/kg; giving at least 2 amps of bicarb (rather than the standard 1) should achieve this in many patients.

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Question

The classic teaching regarding penetrating neck trauma is violation of the platysma muscle in zones 1 and 3 requires angiography, endoscopy and bronchoscopy.  Injury to zone 2 is an automatic operative evaluation. Now, more anatomic and physiologic signs dictate operative management and those not meeting these hard signs get evaluated with Ct angiography. 

Neck zones and hard vs soft signs available by clicking link

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ACE-inhibitor (ACEi) induced angioedema is mediated by bradykinin and there are no proven medications for the treatment of this disease. Theoretically, a C1-esterase inhibitor (C1INH) could be beneficial; however, data has not demonstrated any efficacy for these agents.  

Strassen et al. recently published a double-blind, randomized, controlled, multicenter trial of 30 patients comparing C1NH (Brand Name: Berinert) to placebo. In addition to standard treatment, a dose of C1INH (Berinert) 20 IU/kg or placebo (0.95% NaCl) was administered intravenously.

The primary endpoint was the time to complete resolution of signs and symptoms of edema (TCER). When compared to placebo, the original primary analysis demonstrated that the placebo arm (15 hours) resolved faster than the C1INH arm (24 hours, p=0.046).

This study is further evidence against the use of C1INH for ACE-inhibitor induced angioedema. The primary focus in the treatment of ACEi induced angioedema should continue to be airway management.

For reference, at our institution we have both C1INH (Berinert) and icatibant on formulary and they are restricted to only being used for acute hereditary angioedema attacks and cannot be used for ACEi induced angioedema.

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