1. Pneumothorax- a pneumothorax is a potential medical
emergency wherein air or gas is present in the pleural cavity.
Type of pneumothorax:
o
o
o
Primary spontaneous pneumothorax (PSP) occurs in
people without underlying lung disease and in the
absence of an inciting event. Many patients whose
condition is labeled as primary spontaneous
pneumothorax have subclinical lung disease.
Secondary spontaneous pneumothorax (SSP) occurs in
people with a wide variety of parenchymal lung diseases.
Iatrogenic pneumothorax results from incursion into
the pleural space secondary to diagnostic or therapeutic
medical intervention.
o
Traumatic pneumothorax results from injury, typically
blunt or penetrating trauma.
o
Tension pneumothorax develops when air is trapped
in the pleural cavity under positive pressure.
EtiologyIt most commonly arises:
-Spontaneously (more commonly in tall slim young males and in
Marfan syndrome)
2. -Following a penetrating chest wound
-Following barotrauma to the lungs.
It may also be due to:
-Chronic lung pathologies including emphysema, asthma
-Acute infections
-Chronic infections, such as tuberculosis
-Lung damage caused by cystic fibrosis
-Lung Cancer
Rare diseases that are unique to women such as Catamenial
pneumothorax (due to endometriosis in the chest cavity) and
lymphangioleiomyomatosis (LAM).
Pneumothoraces are divided into tension and non-tension
pneumathoraces.
A tension pneumothorax is a medical emergency as air
accumulates in the pleural space with each breath. The
increase in intrathoracic pressure results in massive shifts of the
mediastinum away from the affected lung compressing
intrathoracic vessels.
A non-tension pneumothorax by contrast is of lesser
concern because there is no ongoing accumulation of air and
hence no increasing pressure on the organs within the chest.
3. The accumulation of blood in the thoracic cavity (hemothorax)
exacerbates the problem, creating a hemopneumothorax.
PathophysiologyThe inner surface of the thoracic cage (parietal pleura) is
contiguous with the outer surface of the lung (visceral pleura);
this space contains a small amount of lubricating fluid and is
normally under negative pressure compared to the alveoli.
Determinants of pleural pressure are the opposing recoil forces
of the lung and chest wall.
Primary spontaneous pneumothorax (PSP) is typically observed
in tall young people without parenchymal lung disease and is
thought to be related to increased shear forces in the apex.
PSP is associated with the presence of apical pleural blebs lying
under the visceral pleura, but the exact anatomic site of air
leakage is often uncertain. Fluorescein-enhanced
autofluorescence thoracoscopy (FEAT), a novel method to
examine the site of air leak in PSP, shows FEAT-positive lesions
that are normal when viewed under normal white-light
thoracoscopy.
Blebs and bullae (sometimes called emphysematous-like
changes or ELCs) are related to the occurrence of primary
spontaneous pneumothorax.
4. While patients with PSP do not have overt parenchymal
disease, more than 90% of them are smokers. The relative risk
of PSP increases as the number of cigarettes smoked per day
increases. This incremental risk with increasing number of
cigarettes smoked per day is much more pronounced in female
smokers.
Lung inflammation and oxidative stress are hypothesized to be
important to the pathogenesis of PSP.Current smokers, at
increased risk for PSP, have increased numbers of inflammatory
cells in the small airways. Bronchoalveolar lavage studies in
patients with PSP associated the degree of inflammation with
the extent of ELCs. One hypothesis is that ELCs result from
degradation of lung tissue due to imbalances of enzymes and
antioxidants released by innate immune cells.In one study,
erythrocyte superoxide dismutase activity was significantly
lower and plasma malondialdehyde levels higher in patients
with PSP than in normal control subjects.
A growing body of evidence indicates that genetic factors may
be important in the pathogenesis of many cases of primary
spontaneous pneumothorax. Familial clustering of this
condition has been reported. Genetic disorders that have been
linked to primary spontaneous pneumothorax include Marfan
syndrome, homocystinuria, and Birt-Hogg-Dube (BHD)
syndrome.
5. Birt-Hogg-Dube syndrome is an autosomal dominant disorder
that is characterized by benign skin tumors (hair follicle
hamartomas), renal and colon cancer, and spontaneous
pneumothorax. The spontaneous pneumothorax occurs in
about 22% of patients with this syndrome. The gene
responsible for this syndrome has been identified and is a
tumor suppressor gene located on chromosome 17p11.2. The
gene encoding folliculin has been identified and is thought to
be the etiology of Birt-Hogg-Dube syndrome.
Secondary spontaneous pneumothoraces (SSP) occur in the
presence of lung disease, primarily in the presence of chronic
obstructive pulmonary disease (COPD). Other diseases that may
be present when SSPs occur include tuberculosis, sarcoidosis,
cystic fibrosis, malignancy, and idiopathic pulmonary fibrosis.
Pneumocystis jiroveci pneumonia (previously known as
Pneumocystis carinii pneumonia [PCP]) was a common cause of
secondary spontaneous pneumothorax in patients with AIDS
during the last decade. With the advent of highly active
antiretroviral therapy (HAART) and widespread use of
trimethoprim-sulfamethoxazole prophylaxis, the incidence of
PCP and associated SSP has significantly declined.
PCP is now primarily seen in patients who are noncompliant
with HIV therapy or trimethoprim-sulfamethoxazole
prophylaxis or those taking inhaled pentamidine for PCP
6. prophylaxis (probably related to nonuniform distribution of the
medication aerosol). PCP in other immunocompromised
patients is seen only when trimethoprim-sulfamethoxazole
prophylaxis is withdrawn prematurely. For practical purposes, if
the immunocompromised patient has been taking
trimethoprim-sulfamethoxazole prophylaxis reliably, PCP is
reasonably excluded from the differential diagnosis.
Iatrogenic pneumothorax is a complication of medical or
surgical procedures. It most commonly results from
transthoracic needle aspiration. Other procedures commonly
causing iatrogenic pneumothorax are therapeutic
thoracentesis, pleural biopsy, central venous catheter insertion,
transbronchial biopsy, positive pressure mechanical ventilation,
and inadvertent intubation of the right mainstem bronchus.
Traumatic pneumothoraces can result from both penetrating
and nonpenetrating lung injuries. Complications include
hemopneumothorax and bronchopleural fistula. Traumatic
pneumothoraces can create a 1-way valve in the pleural space
(only letting in air without escape) and can lead to a tension
pneumothorax.
Tension pneumothorax typically occurs in the intensive care
setting in patients who are ventilated. With air trapping in the
pleural space, positive pressure rises. This pressure compresses
the mediastinum, decreasing venous return to the heart and
7. reducing cardiac output. In addition, owing to ipsilateral lung
collapse and contralateral lung compression, gas exchange is
compromised, leading to hypoxemia.
Clinical
History
-Acute onset of chest pain - Severe and/or stabbing pain,
radiating to ipsilateral shoulder and increasing with inspiration
(pleuritic)
-Sudden shortness of breath, dry coughs, cyanosis (turning
blue)
-Anxiety, and vague presenting symptoms (eg, general malaise,
fatigue) are less commonly observed
-Dyspnea tends to be more severe with secondary spontaneous
pneumothoraces (SSPs) because of decreased lung reserve.
-Bilateral pneumothorax - Primary bilateral spontaneous
pneumothorax (PBSP) was significantly more common in
patients with lower BMI and among smokers.
-In penetrating chest wounds, the sound of air flowing through
the puncture hole may indicate pneumothorax, hence the term
"sucking" chest wound. The flopping sound of a punctured lung
is also occasionally heard. Subcutaneous emphysema is another
symptom.
8. -If untreated, hypoxia may lead to hypercapnia, respiratory
acidosis, and loss of consciousness. In a tension pneumothorax,
shifting of the mediastinum away from the site of the injury can
obstruct the superior and inferior vena cava resulting in
reduced venous return. This in turn decreases cardiac preload
and cardiac output.
Physical
1.General appearance
-Diaphoretic
-Splinting chest wall to relieve pleuritic pain
-Cyanotic (with tension pneumothoraces)
-Vital signs
-Tachypnea
-Tachycardia (most common finding) - If faster than 135 beats
per minute (bpm), tension pneumothorax is likely
-Pulsus paradoxus
-Hypotension (often with tension pneumothorax)
-Asymmetric lung expansion - Mediastinal and tracheal shift to
the contralateral side with a large tension pneumothorax
-Distant or absent breath sounds
9. -Hyperresonance on percussion
-Decreased tactile fremitus
2.Cardiovascular - Jugular venous distension (tension
pneumothorax)
3.Neurologic - Altered mental status
If patients who are mechanically ventilated are difficult to
ventilate during resuscitation, high peak airway pressures are a
clue to an impending pneumothorax. A tension pneumothorax
causes progressive difficulty with ventilation as the normal lung
is compressed. On volume-control ventilation, this is indicated
by marked increase in both peak and plateau pressures, with
relatively preserved peak and plateau pressure difference. On
pressure control ventilation, tension pneumothorax causes
sudden drop in tidal volume. However, these observations are
neither sensitive nor specific for making the diagnosis of
pneumothorax or ruling out the possibility of pneumothorax.
Causes
1.Risks factors for primary spontaneous pneumothorax (PSP)
-Smoking
-Marfan syndrome
-Pregnancy
10. -Familial pneumothorax
-A primary spontaneous pneumothorax may occur without
either trauma to the chest or any kind of blast injury. This type
of pneumothorax is caused when a bleb (an imperfection in the
lining of the lung) bursts causing the lung to deflate. The lung is
reinflated by the surgical insertion of a chest tube. A minority of
patients will suffer a second instance. In this case, thoracic
surgeons often recommend thorascopic pleurodesis to improve
the contact between the lung and the pleura. If multiple and/or
bilateral occurrences continue, surgeons may opt for a far more
invasive bullectomy and pleurectomy to permanently adhere
the lung to the interior of the rib cage with scar tissue, making
collapse of that lung physically impossible. Primary
spontaneous pneumothorax is most common in tall, thin men
between 17 and 40 years of age, without any history of lung
disease. Though less common, it also occurs in women, usually
of the same age and body type. The tendency for primary
spontaneous pneumothorax sufferers to be tall and thin is not
due to weight, diet or lifestyle, but because the genetic
predisposition toward those traits often coincides with a
genetic predisposition toward high volume lungs with large,
burstable blebs. A small portion of primary spontaneous
pneumothoraxes occur in persons outside the typical range of
age and body type
11. 2.Diseases and conditions associated with secondary
spontaneous pneumothorax
Chronic obstructive pulmonary disease (COPD),
Asthma.
HIV/AIDS with Pneumocystis jiroveci (PCP) infection.
Necrotizing pneumonia,
Tuberculosis, Cystic fibrosis (CF)
Bronchogenic carcinoma, Metastatic malignancy
Inhalational and intravenous drug use such as marijuana and
cocaine has been implicated as etiology of SP as well.
Interstitial lung diseases associated with connective tissue
diseases(Ankylosing spondylitis)
Idiopathic pulmonary fibrosis,
Sarcoidosis
Lymphangioleiomyomatosis (LAM),
histiocytosis
Langerhans cell
Acute respiratory distress syndrome (ARDS) and positive
pressure ventilation in ICU
Severe acute respiratory syndrome (SARS) ,
endometriosis
Thoracic
3.Causes of iatrogenic pneumothorax
Transthoracic needle aspiration biopsy of pulmonary nodules,
Transbronchial biopsy
.
12. Thoracentesis, Tracheostomy
Central venous catheter insertion, Intercostal nerve block
Cardiopulmonary resuscitation
Positive pressure ventilation and ARDS in the ICU
Nasogastric feeding tube placement, Acupuncture
4.Causes of traumatic pneumothorax
Trauma - Penetrating and nonpenetrating injury
Rib fracture
High-risk occupation (eg, diving, flying)
Differential diagnosis
Esophageal Spasm
Pericarditis, Acute
Pleurodynia
Pulmonary Embolism
Acute Myocardial Infarction: presents with shortness of breath
and chest pain, though MI chest pain is characteristically
crushing, central and radiating to the jaw, left arm or stomach.
Whilst not a lung condition, patients having an MI often happen
to also have lung disease.
13. Emphysema: here, delicate functional lung tissue is lost and
replaced with air spaces, giving shortness of breath, and
decreased air entry and increased resonance on examination.
However, it is usually a chronic condition, and signs are diffuse
(not localised as in pneumothorax).
Diagnosis
1.The absence of audible breath sounds through a stethoscope
can indicate that the lung is not unfolded in the pleural cavity.
This accompanied by hyperresonance (higher pitched sounds
than normal) to percussion of the chest wall is suggestive of the
diagnosis. The "coin test" may be positive. Two coins when
tapped on the affected side, produce a tinkling resonant sound
which is audible on auscultation.
2. If the signs and symptoms are doubtful, an X-ray of the chest
can be performed, but in severe hypoxia, or evidence of tension
pneumothorax emergency treatment has to be administered
first. An x-ray can illustrate the collapse of the lung as extra
black space, indicating the presence of air, will be seen in the xray around the lung. The lung shrivels up away from the
affected side and the mediastinum (trachea and other
components) will shift towards the unaffected side.
In a supine chest X-ray the deep sulcus sign is diagnostic, which
is characterized by a low lateral costophrenic angle on the
affected side. In layman's terms, the place where rib and
14. diaphragm meet appears lower on an X-ray with a deep sulcus
sign and suggests the diagnosis of pneumothorax.
3. CT scan is not recommended for routine use but can help to
accomplish the following:
-Distinguish between a large bulla and a pneumothorax
-Indicate underlying emphysema or emphysemalike changes
-Determine the exact size of the pneumothorax, especially if it
is small
-Confirm the diagnosis of pneumothorax in patients with head
trauma who are mechanically ventilated.
4. Ultrasonography is increasingly used in the acute care setting
as a readily available bedside tool, especially in ICU and
emergency departments.
Traumatic pneumothorax in the ICU setting can be followed
accurately and early (initial 24 hours) with ultrasonography
alone for resolution of the lesion.
Lung sliding is the terminology for normal pleural movement in
patients without pneumothorax. One study showed absent lung
sliding from an anterior approach indicated pneumothorax.
Management
15. Chest wound- Penetrating wounds (also known as 'sucking
chest wounds') require immediate coverage with an occlusive
dressing, field dressing, or pressure bandage made air-tight
with petroleum jelly or clean plastic sheeting. The sterile inside
of a plastic bandage packaging is good for this purpose;
however in an emergency situation any airtight material, even
the cellophane of a cigarette pack, can be used. A small
opening, known as a flutter valve, may be left open so the air
can escape while the lung reinflates. Any patient with a
penetrating chest wound must be closely watched at all times
and may develop a tension pneumothorax or other
immediately life-threatening respiratory emergency at any
moment. They cannot be left alone.
Blast injury or tension- If the air in the pleural cavity is due to a
tear in the lung tissue (in the case of a blast injury or tension
pneumothorax), it needs to be released. A thin needle can be
used for this purpose, to relieve the pressure and allow the lung
to reinflate.
Pre-hospital care- Many paramedics can perform needle
thoracocentesis to relieve intrathoracic pressure. Intubation
may be required, even of a conscious patient, if the situation
deteriorates. Advanced medical care and immediate evacuation
are strongly indicated.
16. An untreated pneumothorax is an absolute contraindication of
evacuation or transportation by flight.
Small pneumothoraces- Small pneumothoraces are often
managed conservatively as they will resolve on their own.
Repeat observation via chest X-rays and oxygen administered.
Pneumothoraces which are too small to require tube
thoracostomy and too large to leave untreated, may be
aspirated with a small catheter.
Larger pneumothoraces- Large pneumothoraces may require
tube thoracostomy, also known as chest tube placement. If a
thorough anesthetizing of the parietal pleura and the
intercostal muscles is performed, the only major pain
experienced should be either the injury that caused the
pneumothorax or the re-expanding of the lung. Proper
anesthetizing will come about by the following procedure: the
needle should be inserted into the chest cavity and a negative
pressure created in the syringe. While air bubbles rise into the
syringe, the needle should be slowly pulled out of the cavity
until the bubbles cease. The tip of the syringe that contains the
anesthetic is now in the intercostal muscles just next to the
parietal pleura. A proper and sizable injection should ensue (5
to 10 ml). This will allow the patient to be fairly comfortable
despite a hemostat or finger being inserted into the chest
cavity. A tube is then inserted through the chest wall into the
17. pleural space and air is extracted using a simple one way valve
or vacuum and a water valve device. This allows the lung to reexpand within the chest cavity. The rate of re-expansion will
vary widely. It is important not to connect the chest tube to
suction right away, as rapid expansion may lead to pulmonary
edema. The pneumothorax is followed up with repeated X-rays.
If the pneumothorax has resolved and there is no further air
leak, the chest tube is removed. If, during the time that the
tube is still in the chest, the lung manages to sustain the reexpansion, but once suction is turned off, the lung collapses, a
Heimlich valve may be used. This flutter valve allows air and
fluid in the pleural cavity to escape the pleura into a drainage
bag while not letting any air or fluid back in. This method was
developed by the military in order to get soldiers with lung
injuries stable and out of the battlefield faster. It is a rarely
used medical device in the treatment of patients these days,
but may be used in order to allow the patient to leave the
hospital.
It is critical that the chest tube be managed in such a way that it
does not become kinked or occluded with clot or other
fibrinous material. Chest tube clogging can result in build up of
air in the pleural space. At the very least, this will lead to a
recurrent pneumothorax. In the worse case, the patient can
have a tension pneumothorax if the air builds up under
pressure and impairs venous return to the heart. This can be
18. fatal. The tubes have a tendency to form clot from blood and
other fibrinous material that can occlude them. To keep them
open they must be stripped, milked or even replaced if they
totally occlude. Smaller tubes are less traumatic, but more
prone to clogging, although this can also occur with larger
tubes. One sign the chest tube is clogged is subcutaneous
emphysema. Another is a loss of respiratory variation in the
fluid level at the water seal valve in the drainage canister.
In the situation that the chest tube is not sufficient in healing of
the lung (for example, a continued air leak despite chest tube
drainage), or if CT scans show the presence of large "bullae" on
the surface of the lung, thoracoscopic surgery, or video assisted
thorascopic surgery (VATS), may be done in order to staple the
leak shut and to irritate the pleura to promote adhesions
between the lung and pleura (pleurodesis). Two or three small
incisions are made in the side of the chest and back, one for a
small camera and the other (s) for tools used to seal the lung
and abrade or remove the pleura. When finished the wound is
covered with a steri-strip and bandaged up.
In case of penetrating wounds, these require attention, but
generally only after the airway has been secured and a chest
drain inserted. Supportive therapy may include mechanical
ventilation.
Surgical Care
19. Indications for surgical assistance:
1.Persistent air leak for more than 7 days. 2.Recurrent
ipsilateral pneumothorax. 3.Contralateral pneumothorax.
4.Bilateral pneumothorax. 5.First-time presentation in a
patient with a high-risk occupation (eg, diver, pilot).
6.Patients with AIDS often need this intervention because
of extensive underlying necrosis. 7.The risk of recurrent
pneumothorax may also be unacceptable for patients with
plans for extended stays at remote sites.
8.Lymphangiomyomatosis, a condition causing a high risk
of pneumothorax39
Video-assisted thoracoscopic surgery (VATS)
VATS is appropriate for recurrent primary spontaneous
pneumothorax (PSP) or secondary spontaneous pneumothorax
(SSP).
VATS with resection of large bullous lesions is associated with a
recurrence rate of 2-14%.
VATS is done under general anesthesia using a camera and 2
trocar ports.
Thoracotomy
Insufflation of talc and thoracotomy has a recurrence rate of 07%.
20. Talc is the preferred agent for pleurodesis. It can be
administered by insufflation or as a slurry.
Complications of surgical procedures include the following:
1.Failure to cure the problem. 2.Acute respiratory distress or
failure. 3.Infection of the pleural space, 4.Cutaneous or
systemic infection 5.Persistent air leak 6.Reexpansion
pulmonary edema 7.Prolonged tube drainage and hospital
stay 8.Increased risk of post-operative bleeding after lung
transplantation (for medical pleurodesis and surgery; not found
to affect the length of hospital stay)
Prevention of recurrent pneumothorax
Observation: Observation is appropriate for iatrogenic
pneumothorax in an individual with normal lungs who has
responded to treatment with observation or simple aspiration.
Simple aspiration or chest tube drainage of pneumothorax does
not prevent recurrence. A recent study showed that a Heimlich
valve with small-caliber catheter was less effective in
preventing recurrence than closed thoracostomy. In another
study, the recurrence rate after 1 year with Heimlich valve vs.
chest tube placement was not significantly different. Recurrent
spontaneous pneumothorax requires more definitive treatment
to prevent recurrence. Recurrence rates are higher with SSP
than PSP; hence, observation is less often chosen as an
approach in SSP.
21. Pleurodesis: A patient treated with surgical pleurodesis has a
recurrence prevention rate of greater than 90%. Talc is the
preferred agent for pleurodesis. It can be administered by
insufflation or as a slurry. Practice variation depends on local
practitioner experience, resources, and success with
approaches ranging from video-assisted thoracotomy
(recommended by the American College of Chest Physicians) to
surgical thoracotomy and pleurectomy (recommended by the
British Thoracic Society because of the absolute lowest
recurrence rates).
Nonsurgical pleurodesis: "Medical" thoracoscopy requires only
local anesthesia or conscious sedation, in an endoscopy suite,
using nondisposable rigid instruments. Thus, it is considerably
less invasive and less expensive, but also less effective,
particularly in inexperienced hands. Patient comorbidity plays a
role in selection of appropriate intervention. The main
diagnostic and therapeutic indications for medical
thoracoscopy are pleural effusions and pneumothorax.
-Tetracycline and talc are well-studied effective agents for
medical pleurodesis; the latter was 5% more effective in 1
randomized study. Success rates for chemical are up to 91% vs.
95-100% in surgical techniques. Chemical pleurodesis resulted
in a significant reduction of recurrence compared to chest tube
drainage alone in an early study.
22. -Chemical pleurodesis and surgery were equally effective and
were both superior to conservative therapy in preventing the
recurrence of pneumothorax in LAM.
Medication
The goals of pharmacotherapy are to reduce morbidity and to
prevent complications. In addition to the medications listed
below, talc may be used as a sclerosing agent for pleurodesis by
mixing 2-5 g in 250 mL of sterile isotonic sodium chloride
solution to form a slurry or poudrage. Acute respiratory distress
syndrome (ARDS) has been reported after use of talc as a
pleural sclerosing agent but is considered to be a rare
complication.
Local anesthetics- Used for thoracentesis and chest tube
placement.
Lidocaine hydrochloride (Xylocaine, Dilocaine, Anestacon)Local anesthetic used as 1% solution. Onset of action is within
45-90 seconds. Duration of anesthesia is 10-20 min. Dose varies
with the procedure, local vascularity, and condition of patient;
applied locally, not to exceed 4.5 mg/kg; do not repeat within 2
h. Adverse effects with use as local anesthetic include allergic
reactions.
Opiate analgetics- Used for pain control.
23. Fentanyl citrate (Sublimaze, Fentanyl Oralet)- Onset of
analgesia is immediate with IV use. Duration of analgesia is 3060 min. Respiratory depressant effect may last longer than
analgesia. 0.5-1 mcg/kg/dose IV for minor procedures; may
repeat dose at 30- to 60-min intervals.
Meperidine hydrochloride (Demerol)- Onset of analgesia occurs
within 5 min. Titrate dose to effect. Half-life of the parent drug
is 2.5-4 h, prolonged in patients with liver disease. Half-life of
the active metabolite, normeperidine, is 15-30 h. Accumulates
with high dose and renal insufficiency. 50-150 mg/dose IV; can
repeat in 3-4 h prn
Benzodiazepine- Used for conscious sedation.
Midazolam hydrochloride (Versed)-Benzodiazepine used for
sedation component of conscious sedation protocol. Onset of
action occurs within 1-5 min. Half-life of 1-4 h. Prolonged with
liver cirrhosis, congestive heart failure, obesity, and old age.
Initial dose: 0.5-2 mg IV over 2 min; slowly titrate to effect by
repeating doses every 2-3 min; usual total dose is 5 mg;
decrease initial dose in the older population to 0.5 mg IV;
administer no more than 1.5 mg in a 2-min period, to a total
dose of 3.5 mg.
Complications
-Respiratory or cardiac arrest
