Grand Rounds Recap 11.7.2018

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Ultrasound Grand Rounds: Cardiac Tamponade WITH DR. MINGES

Background

Tamponade Definitions

  • Accumulation of fluid in the pericardial sac that impairs diastolic filling

  • The speed of accumulation is often more important than the volume of accumulation as the pericardium can stretch with time to accommodate small amounts of fluid

Beck’s Triad

  • Hypotension, Muffled Heart Sounds, JVD

  • Inadequate for diagnosing Tamponade, as it has poor sensitivity

Incidence

  • Single center study by Blaivas found 7/103 ED patients with undifferentiated dyspnea after traditional diagnostics had effusion requiring admission

High Risk Patients

  • Hypotensive patients

  • Any cardiac surgery

  • Dialysis patients

  • Cancer patients

  • Trauma

  • Patients with rheumatologic disease

Ultrasound in Tamponade

US Findings of Tamponade

  • RV collapse during diastolic filling

  • Consider alternative effusions as effusion can be confused with a pericardial fat pad or pleural effusion

    • Fat pads are isoechoic to heart, adherent to the right heart

    • Pleural effusions are typically posterior to the descending thoracic aorta and are not circumferential

  • Measurement

    • Measure during diastole at the widest point

    • Small effusion <0.5 cm

    • Large effusion >2 cm

  • IVC Collapsibility

    • >50% collapsibility with respiration suggestive of no right heart strain and against tamponade

    • Ensure you have hyperechoic IVC wall, which assures you are measuring the IVC in the widest dimension

  • Right Atrial Systolic Collapse

    • Early finding of tamponade, but difficult to detect in the ED with accuracy 

  • Value of M-Mode

    • Directing your M-mode line through RV free wall and anterior leaflet of mitral valve

    • Look for collapse when the mitral valve is open  

  • False Negatives

    • Patients with Pulmonary HTN tend to not have RV collapse due to high filling pressures

    • Similar for patients with other reasons for RV hypertrophy

  • Pericardiocentesis

    • Assess with US to see the largest window possible for pericardiocentesis

    • Best view to do the procedure should be assessed on a patient-by-patient basis, prompted by precipitous hemodynamic compromise

Taming the SRU: Carotid Blowout WITH DR. SCANLON

The Case:

The patient is and elderly gentleman with history of SCC of the oropharynx who has a tracheostomy. Transferred from outside facility due to coughing up 200cc of blood from his tracheostomy. Vital signs are stable aside from a BP of 91/59. He has rust colored oral secretions without overt hemorrhage on initial evaluation. He clinically declines and begins to experience frank hemoptysis. The trach was exchanged for a cuffed trach. Following this, ENT placed oropharyngeal packing with temporary hemostasis, until the patient experiences recurrence of brisk hemorrhage out of both the oropharynx and the sidewall of the neck. Direct pressure helps stop the hemorrhage, and his hemorrhagic shock is managed with large volume transfusion. He is taken immediately to the operating room. Intraoperatively they find he has extensive tumor necrosis with external carotid blowout.

 Learning Points

Know Your Anatomy:

  • Laryngectomy isolates the trachea from the oropharynx during cancer resection

    • CANNOT BE INTUBATED FROM ABOVE

  • Tracheostomy is a stoma into the trachea that still shares a connection with the oropharynx

Inserting a Tracheostomy Tube

  • Number of trach tube refers to the diameter of inner cannula (I.D)

  • Obturator is placed within the inner cannula to give you a blunt tip to place the tube, can also replace with nasal cannula or bougie in the trach to maintain the tract, however the obturator cannot be used if this is done.

Carotid Blowout Syndrome.

  • Sequela of oropharyngeal malignancy eroding into the vasculature, most commonly SCC

  • Associated with 40% mortality and significant morbidity

  • Tumor recurrence and radiotherapy are risk factors

  • Gold standard for diagnosis is Digital Subtraction Angiography, but CT angiography is an adequate alternative

  • Treatment in the ED is largely supportive (packing, resuscitation with hemorrhagic shock)

  • Treatment in the OR is surgical ligation of the vessel, though endovascular therapy such as balloon occlusion are possible

  • 15-20% rate of cerebral ischemia after operative management

R4 Clinical Capstone: SCIWORA WITH DR. BAEZ

 Case:

Middle aged patient presents after an MVC. He is tachypneic, but hemodynamically stable. His exam is remarkable for diminished strength in the LUE and LLE. He has no tone or movement in the RUE and RLE. He has no rectal tone. He becomes hypotensive and he gets crystalloid due to likely neurogenic shock. He is taken to CT and found to have no acute fractures with a negative pan-scan. He regains his movement briefly while the trauma team is examining him. However, one hour later, he re-experiences his deficits. MRI is ordered which reveals cord edema at C4-C5 consistent with central cord syndrome and cord contusion. He is taken emergently to the OR for decompression.

Learning Points 

SCIWORA- Spinal Cord Injury Without Radiographic Abnormality

  • Spinal Cord Injury without evidence of injury on CT or x-ray imaging

  • Can be due to Spinal Concussion

    • This is defined as a transient loss of neurologic function from spinal cord up to 3 days

    • This is a clinical diagnosis

    • 15% have abnormal MRI when imaging

  • Risk Factors

    • Hyperextension injuries are common causes of this

    • Diving and wrestling have higher rates than other sports

  • Diagnosis

    • Arm weakness is often > leg weakness due to component of central cord syndrome when cervical

    • Any persistent neurologic deficit should prompt further investigation (paresthesias, reflex changes)

  • ED Management

    • Brace

    • Limit re-injury

    • Surgery is for ligamentous injury or cord compression on MRI

    • Steroids are controversial, no benefit has been able to be demonstrated however difficult to study given rarity

AirCare Grand Rounds WITH DRS. WHITFORD, BERNARDONI, harty, HAM, KLASZKY, AND HINCKLEY

Refractory Hypoxia on the Ventilator - Rodney Wise, RN and Mike Klaszky, MD

Recruitment Maneuvers: Background

  • Maneuvers to increase the area of gas exchange within your lungs

  • Evidence is controversial due to unclear mortality benefit

  • ~50% of people respond to these maneuvers

  • Complications include barotrauma and hemodynamic compromise

    • Hemodynamic compromise is due to decreased filling of the RA, and decreased preload

Maneuvers

  • Stair-Step Maneuver

    • Start with a low PEEP (5), maintaining the delta as you slowly increase the PEEP

    • Increase by PEEP of 2 every 1-2 minutes until getting to a high PEEP (~30)

    • Decrease at the same rate by 2 of PEEP every 1-2 minutes, ending on your target PEEP

  • Inspiratory Hold

    • Hold their inspiratory pressure for 10-15 seconds

    • This will recruit extra alveoli for oxygenation

    • Consider increasing their PEEP if this is needed to improve their oxygenation

    • On our HEMS vent (IMPACT), hold the exhalation port and it will cause an inspiratory hold

Transporting Patients with Refractory Hypoxia

  • Consider keeping on the ventilator at the outside hospital until correcting oxygenation before loading into the helicopter vent as their ventilators can be more versatile and you save your O2.

  • Briefly clamp your ET tube prior to transferring to our ventilator to not lose any lung recruitment gained

V-Scan Ultrasound on AirCare with Drs. Ham and Harty

Indications on AirCare

  • E-FAST (identification of hypoxia / hypotension in trauma)

  • Limited Pericardial View

    • Pericardial effusion vs. no pericardial effusion

    • Cardiac activity vs. no cardiac activity

  • Peripheral IJ

    • For use in stable patients who can cooperate with placement (not in trauma when an IO is faster and safer)

    • Use sterile gloves, as well as chlorhexidine swabs

    • Place a 14g or alternatively 18g

    • Ensure you encourage providers at destination hospital know to swap it out as soon as possible

Postpartum Hemorrhage with Dr. Whitford

AirCare Logistics

  • For patients in labor, get a second helicopter on standby to transport the infant

  • The infant and mother should go to the same facility

  • Stay at the outside hospital for delivery if cm >6cm dilated (G1), >5cm dilated (G2), or if contractions <5 minutes apart

What to ask to patients in labor

  • Any evidence of meconium staining

  • Previous complications of delivery

  • Number of infants (twin vs triplet pregnancy)

  • Gestational age

  • Whether they have broken their water or had any vaginal bleeding

Postpartum Hemorrhage

  • Causes

    • Lack of uterine tone is the cause of 70% of the cases

    • Alternative causes include retained placental products, trauma, coagulopathy, or products within the cervical os

  •  Management

    • Bimanual uterine massage is a temporizing maneuver

      • This involves putting suprapubic pressure while a fist is inserted into the vaginal canal to tamponade the uterus

    • Consider Pitocin 10U IM

    • There are commercially available devices such as a Bakri Balloon to inflate in the uterus beyond the cervical os and tamponade bleeding

      • A Blakemore tube is a suitable alternative on the aircraft.

    • Manage the hemorrhagic shock

      • TXA

      • Transfusion of blood products as needed