Case 5.3

Case Presentation by Dr. Frankie Civitarese


57 year old female with a history of COPD, DM, HTN, mitral stenosis presented with shortness of breath and was made a medical code for severe dyspnea and hypoxia.  After initial evaluation and attempts at stabilization she required intubation.

ROS:  Unable to be obtained.

PMH:  DM type 2, HTN, COPD, Mitral stenosis

PSH: colonoscopy 2009, EGD 2009, cholecystectomy, tubal ligation, L oophorectomy

Medications:  acetamenophen, tiotroprium bromide, albuterol, azithromycin, amoxicillin, prednisone, isosorbide

Allergies: iodine

Social History:  smokes cigarettes and marijuana.  Denies any other drug use. Denies use of alcohol.

FH:  DM, HTN

INITIAL EXAMINATION:

VS: 157/117, HR 102, RR 20, T 37.9, pulse ox 90% RA.

GEN: Acute respiratory distress. Alert and oriented times 3, extremely anxious.

CV:  Regular rhythm.  Tachycardia.  S1, S2.  No murmurs rubs or gallops.

PULM:  Severely tachypneic. Using accessory muscles and having substernal retractions. Speaking in brief words. No crackles/rhonchi.  Prolonged expirations with coarse expiratory nonmusical wheezes.

EXT:  Peripheral pulses are 2+ and symmetric bilaterally.

SKIN:  Warm to the touch and very diaphoretic.

The rest of examination was within appropriate limits

ED COURSE and STUDIES:

On presentation to the ED, her vital signs were 157/117, HR 102, Temp 37.9.  RR 20 pulse ox 90%.  She was brought to the resuscitation bay from triage as a medical code and was given nebulized breathing treatments.

Labs and Studies:

CXR post intubation:  good tube placement, no infiltrates

CBC, electrolytes, initial troponin were within normal limits.

BNP was 1526.

ABG results returned that revealed:  7.02/61/98/12.3.

The patient was sent to the CT scanner from resuscitation to evaluate for a possible pulmonary embolism.  On the way to the CT scanner, the patient was found to be in PEA, and immediately brought back to resuscitation.  After several rounds of CPR as well as doses of epinephrine and atropine, the patient had return of spontaneous circulation with sinus tachycardia in the 140s.

Subsequently, despite being intubated and maintained on a ventilator, the patient then became increasingly difficult to oxygenate.  A repeat chest xray was done that revealed:

.

Questions:

1.  What is the initial evaluation or procedure that should be performed on this patient?

A) needle decompression

B )bedside thoracotomy

C) immediate OR for thoracotomy

D) bedside ultrasound

E) tube thoracostomy 26F tube

F) tube thoracostomy 32F tube

.

2.  A chest tube was placed on the patient’s right side.  Where should the tube be placed?

A) anterior axillary line at the level of the nipple or inframammary angle

B) behind the lateral edge of pectoralis minor at nipple or inframammary angle

C) mid axillary line at the 6th intercostal space

D) posterior axillary line at the 5th intercostal space

.

3.  In the case of a hemopneumothorax, what is an indication for the patient to undergo urgent thoracotomy?

A) initial chest tube output of >1000cc after placement

B) consistent chest tube output of 50-100cc/hour for 2-4 hours after placement

C) minimal resolution of pneumothorax on repeat chest xray

D) evidence of tension pneumothorax

E) bronchi/bronchiole occlusion with secretions

F) large bronchus tear or tear of lung parenchyma

Answers and Discussion

1) A

2) A

3) A

Pneumothorax is defined as an accumulation of air in the pleural space, and can be spontaneous or as a result of chest trauma.  It is divided into three different classifications depending on whether or not air has direct access to the thoracic cavity:  simple, communicating, or tension.

A simple pneumothorax is defined when there is no open communication with the thoracic cavity and the atmosphere.  A simple pneumothorax has no mediastinal or tracheal shift.  “small” is defined as 15% or less, “moderate” is 15-60%, and a large pneumothorax is >60%.  Severe symptoms of pneumothorax become evident at a pneumothorax occupying 40% or more of the hemithorax, with a tension pneumothorax, or in a patient with underlying cardiopulmonary disease.

Simple Pneumothorax:

Traumatic pneumothorax can occur with direct penetrating trauma such as a gunshot or stab wound without direct communication with the atmosphere or with blunt trauma.  Chest compressions can fracture ribs that may result in a pneumothorax.  It can also occur without a fracture when the impact or force of the trauma occurs with a closed glottis at full inspiration.

A communicating pneumothorax, or a “sucking chest wound”, is associated with a defect in the chest wall after combat injuries.  This is generally associated with shotgun wounds in the civilian sector.  The loss of chest wall integrity leads to paradoxical collapse of the lung during inspiration.

 

Tension pneumothorax is defined as the accumulation of air under pressure in the pleural cavity with shift of the mediastinum to the opposite hemithorax and compression of the contralateral lung and great vessels.  A tension pneumothorax occurs when an injury acts as a one way valve, preventing free bilateral communication of air from inside the pleural cavity with the atmosphere.  The increased pressure in the intrapleural cavity results from the air’s inability to exit with expiration.  This results in a shift of the mediastinal structures that can compress the vena cava and may ultimately result in decreased diastolic filling of the chambers of the heart and thus decreased cardiac output.

Patients with tension pneumothorax will present with rapid onset of progressing and severe symptoms such as hypotension, hypoxia, jugular venous distension, tracheal deviation, and shock.  They become rapidly agitated, dyspneic, cyanotic, and display changes in mental status.  Classic physical exam signs of a tension pneumothorax are tachycardia, JVD, and absent breath sounds on the ipsilateral side.  The intubated patient in the emergency department is particularly at risk for developing tension pneumothoracies because they may be receiving positive pressure ventilation thus increasing the intrapleural pressure.  A resistance to ventilation may be the first clinical clue that a tension pneumothorax has developed in such a patient.  Also, those receiving CPR are at risk secondary to the possibility of fractured ribs from the cardiac compressions can puncture the lung parenchyma .

The most common clinical presenting symptoms suggesting pneumothorax are shortness of breath, pleuritic chest pain, and tachycardia.  Severity of symptoms can vary depending on the type of pneumothorax as well as the percentage of the hemithorax involved.  Physical exam will show decreased breath sounds and hyperresonance to percussion on the side of the pneumothorax.

1)  Clinical work up of a pneumothorax also varies depending on the type.  If presenting symptoms suggest that a tension pneumothorax may be the diagnosis, no further workup is required before intervention.  Pressure within the intrapleural cavity should be relieved immediately with needle decompression.  A large bore (14 gauge or larger) catheter, at least 5cm in length (adjusted for those with larger body habitus) should be inserted through the second intercostal space anteriorly in the mid clavicular line, in order to avoid the inframammary vessels that are positioned approximately 3cm on either side lateral to the sternum.  This can also be performed in the 4th or 5th intercostal space laterally on the involved side.  A follow up chest x ray can be then taken to ensure expansion of the lung.

In the case of suspected pneumothorax that does not appear to be a tension pneumothorax, initial diagnositic studies typically begin with an upright full inspiratory film.  To enhance a film if a small pneumothorax is suspected, an expiratory film can be taken that will decrease the lung volume, thus making smaller pneumothoracies more apparent.

In addition to a chest xray, an ultrasound examination as a part of the initial evaluation of the patient can be an important tool during the initial workup.  Some studies compare the accuracy of the bedside ultrasound in the experienced practitioner’s hands to that of a CT scan in detecting occult pneumothoracies.  Sensitivity has been evaluated at 92% (in comparison to 52% in the upright chest xray) with a specificity of 100%.  The clinical clue that a pneumothorax is present is the absence of the “sliding lung” sign.  If both ultrasound and chest xray are unable to detect a pneumothorax, occasionally they can also be revealed on CT scan.

Video from NY Presbyterian US Director on ultrasound of pneumothorax

http://www.youtube.com/watch?v=Xxdedx1HtHo

A good ACEP resource for Ultrasound Pneumothorax:  http://www.acep.org/Content.aspx?id=43362

Occult pneumothorax can be absent from initial chest xray.  Studies have found that pneumothoracies picked up serendipitously on abdominal or chest CT have required tube thoracostomy in 2/3 of cases.  In patients who have experienced penetrating chest trauma, but who are clinically stable, asymptomatic, and have an initial chest xray that is negative, the patient can be observed for a period of 4-6 hours with a chest xray repeated after this time period.  If the repeat chest xray remains negative, the patient can be safely discharged.  Recent data suggest that a period of 3 hours observation is probably effective and safe for reevaluation via chest xray and subsequent discharge of a patient if negative.  If the patient received a CT scan that was negative, a follow up chest xray is unnecessary.

TREATMENT STRATEGIES:

Simple pneumothorax can be treated with a chest tube to relieve respiratory compromise.  However, asymptomatic and small simple pneumothoracies can be safely observed with a  hospital admission.  Pneumothoracies of less than 25% in the hemodynamically stable patient may be observed in patients with penetrating trauma, however this approach is not recommended for multisystem trauma.  Any moderate to large sized pneumothorax should be treated with a chest tube.

2)  Indication for tube thoracostomy:

traumatic cause of pneumothorax

moderate to large size pneumo

symptomatic pneumo regardless of size

increasing size of pneumo

recurrence of pneumo following removal of initial chest tube

pt requires ventilatory support

associated hemothorax

bilateral pneumos regardless of size

tension pneumothorax

Preferred site for chest tube insertion is the fourth or 5th intercostal space at the anterior or midaxillary line at the level of the nipple in males and the inframammary crease in females.  The chest tube position will be beneath the lateral edge of pectoralis major.  The tube should be positioned posteriorly and towards the apex for pneumothorax, and can be positioned posteriorly and laterally for isolated hemothorax.

STEPS:

An oblique incision 1-2cm below the 4th or 5th intercostal space should be made in order to ensure that upon removal of the chest tube, the oblique tunnel that was created will seal, in order to decrease risk of recurrent pneumothorax.  A clamp should then be inserted through the initial skin incision into the intercostal muscles just above the rib and inserted through the intercostals fascia to create a 1.5cm to 2cm space.  A finger should then be inserted into the space to confirm placement within the thorax and to ensure that the lung is not adherent to the chest wall.  Chest tube should be 36-40F in adults and 16-32F in children, especially in trauma when hemothorax is likely to occur simultaneously with pneumothorax.  If the diagnosis is simple pneumothorax, some resources suggest that a 24 or 28 F will suffice.  The vent holes in the chest tube should all be completely positioned well within the chest cavity.  Guidelines suggest that a length of tube at least 2.5cm past the final vent hole should be inserted.  The chest tube should then be placed to water seal and placement confirmed on chest xray.

The chest tube SHOULD NOT be clamped if there is an air leak, and the water seal should be placed 1-2 feet below the level of the patient’s chest.  Chest tubes should be left in place a minimum of 24 hours after all air leaks stop OR if drainage becomes serous and <200cc/24 hours.  All chest tubes should remain in place in the intubated patient.  Recent studies suggest that empiric antibiotics during chest tube placement can be beneficial and can decrease the chances of incurring complications of empyema and pneumonia by 6% and 12% respectively, however there are no guidelines or consensus as to duration or antibiotic choice.

TROUBLE SHOOT YOUR CHEST TUBES:

If the chest tube is not functioning properly and the lung has not completely reexpanded, a replacement tube may be placed through the same incision site or another site may be chosen on the affected side.  It is not recommended to irrigate the tube or attempt to recannulate the chest tube with a Fogarty catheter as it will increase the risk of infection.  The practitioner can attempt to “troubleshoot” the chest tube by checking the chest tube’s position on a chest xray, correct any disrupted connections with the water seal, or have a bronchoscopy performed to look for bronchi/bronchiole occlusion secondary to secretions, a tear in the large bronchi, or a tear of the lung parenchyma itself.

 

3)  Thoracotomy is indicated if there is greater than 1000-1500cc of drainage (or >20cc/kg) after chest tube placement, or if there is 150-200cc/hour for a period of 2-4 hours after initial placement. Persistent bleeding at a rate of >7cc/kg/hr is also an indication for thoracotomy.

Also, other indications include:

the patient requires continuous transfusions to maintain hemodynamic stability

increasing hemothorax on chest xray

patientx remains hypotensive despite adequate blood replacement

patient decompensates after initial response to resuscitation.

PEARLS OF WISDOM:

1)  Always initially determine sick versus not sick.  If the patient is hemodynamically unstable, anxious, is difficult to oxygenate, and you have suspicion for tension pneumothorax secondary to mechanism, perform a needle thoracostomy immediately.  You do not need an initial chest xray.

2)  Occult pneumothoracies can often be picked up better on CT scan or bedside ultrasound.  Look for the sliding lung sign and comet tail artifacts to be absent on ultrasound.

3)  Tube thoracostomy is indicated for traumatic, large, increasing, tension, symptomatic, or bilateral pneumothoracies.

4)  Emergent thoracotomy is indicated with >1,000 cc of initial drainage from your chest tube or greater than 150cc per hour for 2-4 hours.  Also, thoracotomy is indicated if the patient decompensates, remains hypotensive despite adequate replacement, or a patient requiring continued transfusions.

5) If central venous access is required, placement should occur on the same side as the pneumothorax.

9 Responses

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  4. 1. A 2. A 3. A

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  6. 1A, 2A, 3A

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