Lung Ultrasound WITH Visiting lecturer DR. vicki Noble
Utilizing ultrasound in the evaluation of the patient with shortness of breath can help make you a more accurate diagnostician. Many providers rely on the chest Xray as their imaging modality of choice; however, ultrasound has many advantages that may be overlooked. Ultrasound is often faster and in the hands of the trained provider can be very accurate in the diagnosis of multiple different conditions.
Ding et al. (2011) performed a meta-analysis showing that bedside ultrasonography performed by clinicians had higher sensitivity and similar specificity compared with chest Xray in the diagnosis of pneumothorax.
Lung sliding is a sonographic finding often described as ‘‘ants marching’’ or ‘‘shimmering’’.
It is indicative that the parietal and visceral pleura are in contact without air between them.
The presence of lung sliding can help to rule OUT a pneumothorax.
Absence of lung sliding does not rule IN a pneumothorax. For example if you see B-lines these can suggest another process entirely.
Lung pulse is the rhythmic movement of the visceral pleura along the stationary parietal pleura with each cardiac contraction.
Lung point is the transition point where the visceral pleura begins to separate from the parietal pleura.
The presence of a lung point can help rule IN a pneumothorax.
A-lines: horizontal lines seen on ultrasound that are indicative of no fluid present in the lung due to reverberation artifact.
B-lines: vertical lines seen on ultrasound that are indicative of fluid in the lungs.
Technique for evaluating for B-lines.
Use a low frequency probe
Presence of more than three B-lines is pathologic
The differential for the presence of B-lines is broad; however, in a standard medical patient it often relates to pulmonary edema. In a trauma patient it may be due to pulmonary hemorrhage.
CPC: Dengue WITH DR. Mand and dr. lagasse
An otherwise healthy male in his 20’s presents to the emergency department with abdominal pain and lethargy for two days. He describes he also has associated nausea and vomiting, headache, and diffuse achy joints. He has no known medical issues, takes no daily medications, has no prior surgeries, and denies tobacco, alcohol, or illicit substance use.
The patient describes that he just returned from Guatemala yesterday. He states that prior to the development of the abdominal pain and lethargy symptoms which brought him to the ED today he had four to five days of fever and rash.
Vital Signs: Temp 37.5 HR 125 BP 94/67 RR 24 SpO2 98% on room air
Physical exam was notable for an ill appearing male with diminished breath sounds at bilateral bases, a palpable liver edge three centimeters below the costal margin, scattered petechiae in the upper and lower extremities, 2+ pitting lower extremity edema to the mid calf, and a diffusely tender abdomen that was distended with a positive fluid wave.
His laboratory studies were notable for leukopenia, thrombocytopenia, acute kidney injury, anion gap metabolic acidosis, transaminitis, and elevated INR. His EKG showed sinus tachycardia. His chest Xray showed bilateral pleural effusions without a consolidation. Additional testing showed a negative acute hepatitis panel, negative HIV and syphilis testing, negative cerebrospinal fluid analysis, and a normal blood smear.
The patient received 30cc/kg bolus IV fluids and broad spectrum antibiotics but his clinical condition worsened necessitating the initiation of pressors.
And then a diagnostic test was ordered …
Test: Dengue PCR in the United States OR tourniquet test in Guatemala
Diagnosis: Dengue Hemorrhagic Fever
Single stranded RNA virus which is part of the flavivirus genus
Transmitted by the female Aedes aegypti mosquito
Typically found in tropical climates; however, there have been cases in the United States
50 to 390 million infections occur annually. It is difficult to track due to the overlap of clinical picture with other tropical diseases and the lack of available serological testing in developing countries.
500,000 severe cases occur annually with 22,000 recorded deaths.
75% are asymptomatic
Dengue fever: fever + 2 of the following: nausea, vomiting, rash, aches and pains, leukopenia, capillary fragility
Dengue hemorrhagic fever: Dengue fever + any of the following: persistent vomiting, clinical fluid accumulation, mucosal bleeding, lethargy, liver enlargement
Treatment: supportive care.
r1 clinical diagnostics: PERC and Wells criteria WITH DR. pulvino
Check out Dr. Pulvino’s excellent post: PERCs of the Wells Score
r1 clinical knowledge: high altitude sickness WITH DR. connelly
Most symptoms occur at altitudes greater than 2500 meters (8200 ft)
High altitude decreases the availability of oxygen transfer into the tissues.
To compensate there is an increase in the respiratory rate
The increased respiratory rate leads to a respiratory alkalosis
Renal bicarbonate excretion is increased to compensate in an effort to normalize pH
Acute Mountain Sickness
Headache + GI symptoms, fatigue/weakness, dizziness/lightheaded, insomnia
The symptoms are fairly non-specific and therefore any symptoms outlined above in the setting of high altitude should be considered a manifestation of acute mountain sickness.
Incidence and severity increase with altitude
10 to 25% will experience some symptoms at 2500 meters
50 to 85% will experience some symptoms at 4500 to 5500 meters
Stop ascent. Most patients symptoms will improve in 24 hours. If improved they can continue the climb. If symptoms persist or worsen they must descend.
Mild symptoms: symptomatic treatment with NSAIDs and antiemetics
Acetazolamide: carbonic anhydrase inhibitor helping to facilitate the renal excretion of bicarbonate
Most patients will improve in 24 hours
High Altitude Cerebral Edema
Considered on a continuum with Acute Mountain Sickness
Truncal ataxia, confusion, severe lassitude, decreased level of consciousness
Finger to nose testing is typically preserved but tandem gait is often abnormal
Progression can lead to coma and death
Incidence: 0.5 to 1% at 4000 meters
Descend rapidly to at least 1000 meters
Can consider administering steroids, oxygen etc; however, the patient must descend.
High Altitude Pulmonary Edema
Cough (can progress to include frothy pink sputum), progressive dyspnea, hypoxemia.
Though to occur due to hypoxic pulmonary vasoconstriction which is exaggerated and leading to V/Q mismatch and increased microvascular pressure.
Most common cause of death among the high altitude illnesses.
Descent is the mainstay of management
Supplemental oxygen and bed rest can in mild cases be sufficient; however, persistent hypoxia or concomitant High Altitude Cerebral Edema makes descent non-negotiable. Can dive patients if descent not possible and portable chamber present.
Pediatric rashes WITH lipshaw
75% have a petechial rash (usually sparing the palms and soles)
11% have purpuric/ecchymotic lesions (purpura fulminans)
Rapidly progressive often presenting in septic shock/DIC
Rock Mountain Spotted Fever
Tick-borne rickettsial infection
Mortality 30% when untreated
Starts as macular rash on wrists and ankles progressing to petechiae and then spreading to the rest of the body
Doxycycline is the antibiotic treatment for all ages
Usually post-viral, post-mycoplasma, or post-HSV and less commonly medication related
Rash involves the hands, feet, extensor surfaces.
Appears as dusky target lesions with a central bluish hue and can also have mild oral mucosal involvement.
Stevens Johnson Syndrome
Type 4 immune hypersensitivity reaction often related to drug administration
Rash appears as areas of painful blisters with mucosal desquamation
Staphylococcal Scalded Skin Syndrome
Usually a prodrome of fever and malaise
Erythematous or scarlatiniform rash with erythema and tenderness over the whole body and crusting around the mouth
Superficial infection of the dermis by staph or strep
Initially a vesicle that erupts into a honey-colored crusted lesion
Often on the face, arms, or legs
Highly contagious exanthema
Greater than 90% of unimmunized people that come into contact will develop the disease
Rash begins at the scalp and then descends over the face and rest of the body
Most common complications include acute otitis media, pneumonia, and croup
1 in 1000 will develop encephalitis
1 in 100,000 with develop subacute sclerosing panencephalitis seven to ten years later.
Usually occurs in the first one to two weeks of life
Frequently no maternal history
Rash appears pustular/vesicular which can rupture and leave an ulcer.
Can appear anywhere but often around the eyes
Erythema Toxicum Neonatorum
Presents at 2 days to 2 weeks as erythema with some central yellow pustule that can wax and wane (even hourly)
Occurs in 50% of neonates and is a benign condition