MITO: eMedicine - Diaphragm Disorders Article by M , DO

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Subject: eMedicine - Diaphragm Disorders Article by M , DO

eMedicine - Diaphragm Disorders : Article by M , DOThis is an

interesting article below. My Pain Management doctor believes that my

breathing problems may be diaphragm related. I asked my neurologist and he

wants me to have xrays done with breathing in and then breathing out to see

if the diaphragm moves. This article mentions that brainstem and cervical

spine disorders can cause problems with diaphragm function. Those of you

who have dysfunction, could you please let me know what kind of studies

identified your problems. Shjould I have more than the xrays? Thank You!

Maureen

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Diaphragm Disorders

Last Updated: March 7, 2004 Rate this Article

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Synonyms and related keywords: diaphragm dysfunction, phrenic

nerve injury, diaphragm, respiratory dysfunction, Bochdalek hernias

AUTHOR INFORMATION Section 1 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Author: M , DO, Staff Physician, Department of

General Surgery, Spartanburg Regional Medical Center

Coauthor(s): Sidney R Steinberg, MD, FACS, Program Director,

Department of General Surgery, Spartanburg Regional Healthcare System;

Consulting Surgeon, Department of Surgery, WG Hefner Veterans Affairs

Medical Center

Editor(s): Ryland P Byrd, Jr, MD, Chief of Pulmonary Medicine,

Medical Director of Respiratory Therapy, Quillen VA Medical Center;

Professor, Department of Internal Medicine, Division of Pulmonary Diseases

and Critical Care Medicine, Quillen College of Medicine, East Tennessee

State University; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor,

Pharmacy, eMedicine; Om Prakash Sharma, MD, Professor, Department of

Medicine, Division of Pulmonary and Critical Care Medicine, University of

Southern California; D Rice, MD, Associate Professor, Departments of

Internal Medicine and Pediatrics and Adolescent Medicine, Saint Louis

University School of Medicine; and Zab Mohsenifar, MD, Director, Division of

Pulmonary/Critical Care Medicine, Department of Medicine, Cedars-Sinai

Medical Center; Professor, Department of Internal Medicine, University of

California at Los Angeles School of Medicine

INTRODUCTION Section 2 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Background: The diaphragm is the major muscle of respiration and the

second most important muscle in the human body after the heart. Because the

body relies so much on the diaphragm for respiratory function, understanding

how many different disease processes ultimately result in diaphragm

dysfunction is important.

A concomitant respiratory dysfunction exists any time a decrease in

diaphragmatic function is present. The body has many inherent mechanisms of

compensation for decreased diaphragmatic function, but none of these

processes can successfully prevent respiratory compromise if excursion of

the diaphragm is moderately diminished or simply absent.

The easiest approach to diaphragmatic problems is to observe both the

neurologic and anatomic processes that result in decreased function.

Neurologic problems of the diaphragm occur when a traumatic injury or

disease process decreases or terminates the impulse of respiratory stimuli

originating in the brain. Anatomic disorders decrease the integrity of the

musculature of the diaphragm, thus decreasing its excursion. Both anatomic

and neurologic problems related to the diaphragm ultimately result in the

inability of the diaphragm to provide adequate negative intrathoracic

pressure, thereby decreasing the amount of oxygen provided to the alveoli.

Anatomy of the diaphragm

The diaphragm is a modified half dome of musculofibrous tissue that

separates the thorax from the abdomen. Four embryologic components make up

the formation of the diaphragm: the septum transversum, 2 pleuroperitoneal

folds, cervical myotomes, and the dorsal mesentery. Development begins

during the third week of gestation and is completed by the eighth week.

Failure in the development of the pleuroperitoneal folds and subsequent

muscle migration results in congenital defects (see Disorders of anatomy).

The muscular origin of the diaphragm is from the lower 6 ribs

bilaterally, the posterior xiphoid process, and from the external and

internal arcuate ligaments. A number of different structures traverse the

diaphragm, but 3 distinct apertures allow the passage of the aorta,

esophagus, and the vena cava. The aortic aperture is the lowest and most

posterior of the openings lying at the level of the 12th thoracic vertebra.

The aortic opening also transmits the thoracic duct and, sometimes, the

azygous and hemiazygous veins. The esophageal aperture is surrounded by

diaphragmatic muscle and lies at the level of the 10th thoracic vertebra.

The vena caval aperture is the highest of the 3 openings and lies level to

the disc space between the eighth and ninth thoracic vertebrae.

Arterial supply to the diaphragm comes from the right and left phrenic

arteries, the intercostal arteries, and the musculophrenic branches of the

internal thoracic arteries. Some arterial blood is provided from small

branches of the pericardiophrenic arteries that run with the phrenic nerve,

mainly where the nerves penetrate the diaphragm. Venous drainage occurs via

the inferior vena cava and azygous vein on the right and the adrenal/renal

and hemizygous veins on the left.

The diaphragm receives its sole muscular neurologic impulse from the

phrenic nerve, which originates primarily from the fourth cervical ramus but

also has contributions from the third and fifth rami. Originating around the

level of the scalenus anterior muscle, the phrenic nerve courses inferiorly

through the neck and thorax before reaching its end point, the diaphragm.

Because the phrenic nerve has such a long course before reaching its final

destination, any processes that disrupt the transmission of neurologic

impulses through the nerve directly affect the diaphragm.

Pathophysiology:

Disorders of innervation

During normal respiration, the brain stem sends a nervous impulse to

the third through fifth spinal levels, which then give off dorsal rami that

further convalesce to form the phrenic nerves bilaterally. The phrenic

nerves then traverse the neck and thorax and innervate the diaphragm. The

successful impulse of respiratory stimulus from the brain to the diaphragm

can be compromised by a myriad of entities.

Traumatic injury to the head and/or brain stem prevents nerve signals

from reaching the phrenic nerve. Generally, injuries that affect the brain

and brain stem are catastrophic, and the chances of survival are very low.

Injuries or disease processes that affect the respiratory nervous

impulse along its long course are widely described. Spinal cord disorders,

including trauma, syringomyelia, poliomyelitis, and motor neuron disease,

decrease the impulse of stimuli to the cervical spinal cord.

Peripheral phrenic nerve injuries result from damage to the nerve

along its path in either the cervical area or the thorax. A number of

clinical entities can affect the phrenic nerve directly, including trauma,

open heart or thoracic surgeries, chiropractic cervical spine manipulation,

radiotherapy, demyelinating diseases (eg, Guillain-Barré syndrome), tumors,

uremia, brachial plexus stretch injury or neuritis, lead neuropathy,

postinfectious neuropathies, and many other processes.

Disorders of anatomy

Anatomic disorders of the diaphragm are typically classified into 2

broad categories: congenital and acquired. Congenital diaphragmatic hernias

occur when the muscular entities of the diaphragm do not develop normally,

usually resulting in displacement of abdominal components into the thorax.

The most common cause of acquired diaphragmatic disorders is trauma;

however, consider several other important entities when observing anatomic

defects of the diaphragm in adults.

Bochdalek hernias represent the majority of congenital diaphragmatic

hernias. The major defects in Bochdalek hernias are posterolateral defects

of the diaphragm, which result in either failure in the development of the

pleuroperitoneal folds or improper or absent migration of the diaphragmatic

musculature. Patients with congenital diaphragmatic hernias generally

present in the neonatal period and have a mortality rate of 45-50%. The

morbidity and mortality associated with congenital diaphragmatic hernias

relate mostly to hypoplasia of the lung on the affected side. Thus, timely

diagnosis and proper management remains the key ingredient to survival.

Traumatic diaphragmatic rupture occurs secondary to both blunt and

penetrating trauma. Incidence of diaphragmatic rupture is 0.8-1.6% in

patients admitted to the hospital for blunt trauma. The major etiologies of

diaphragmatic rupture are motor vehicle accidents and penetrating trauma

from gunshot and stab wounds. Several theories have been postulated

regarding the mechanism of rupture due to blunt trauma, including shearing

of a stretched membrane, avulsion of the diaphragm from its points of

attachment, and sudden force transmission through viscera acting as a

viscous fluid. Left-sided rupture is more common than right-sided rupture

(68.5% vs 24.2%, respectively) because of both hepatic protection and

increased strength of the right hemidiaphragm. However, increased left-sided

hernias may also result from weaknesses in points of diaphragmatic

embryologic fusion.

Mortality/Morbidity: Morbidity and mortality associated with

diaphragmatic disorders lie in the etiology of the dysfunction. Individuals

with anatomic defects are much more likely to survive than individuals with

unresolving defective or absent neurologic impulses. Persons with unilateral

dysfunction are much more likely to remain asymptomatic than individuals

with bilateral involvement.

a.. Patients with neurologic involvement generally recover if

dysfunction is not due to neuropathic process. Recovery can take up to 2

years or longer.

a.. Patients with anatomic defects generally do well once the defect

is repaired. The outcome of neonates with congenital diaphragmatic hernias

generally relates to the pulmonary development after repair of the hernia.

a.. Patients with congenital diaphragmatic hernias generally present

in the neonatal period and have a mortality rate of 45-50%. The morbidity

and mortality associated with congenital diaphragmatic hernias relate mostly

to hypoplasia of the lung on the affected side. Thus, timely diagnosis and

proper management remains the key ingredient to survival.

CLINICAL Section 3 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

History: Background information is of prime importance when

considering dysfunctions of the diaphragm. An adequate history is essential

to help differentiate potential causes. Even so, an etiology for

diaphragmatic dysfunction is never found in 50-60% of patients.

a.. Congenital hernias

a.. Respiratory distress and/or cyanosis may occur within the

first 24 hours of life.

a.. If the defect is small enough, the patient may not be

diagnosed for several years.

a.. Traumatic rupture

a.. The acute phase manifests with abdominal pain, concurrent

injuries, respiratory distress, and cardiac dysfunction.

a.. Latent phase symptoms include upper GI symptoms, pain in the

left upper quadrant or chest, pain in the left shoulder, dyspnea, and

orthopnea.

a.. The GI obstructive phase manifests with nausea and vomiting

with unrelenting abdominal pain, prostration, and respiratory distress.

a.. Neurologic causes

a.. Fifty percent of patients with unilateral paralysis are

asymptomatic. Manifestations include mild exertional dyspnea, generalized

muscle fatigue, chest wall pain, and resting dyspnea while lying with

paralyzed side down. Symptoms generally are more severe in patients with

concomitant lung disease.

a.. Bilateral paralysis manifests with shortness of breath, severe

exertional dyspnea, and marked orthopnea.

Physical: Physical findings on examination vary depending on the

etiology.

a.. Congenital hernias

a.. Right-sided heart

a.. Decreased breath sounds on affected side

a.. Scaphoid abdomen

a.. Auscultation of bowel sounds in the thorax

a.. Traumatic rupture

a.. Marked respiratory distress

a.. Decreased breath sounds on affected side

a.. Palpation of abdominal contents upon insertion of chest tube

a.. Auscultation of bowel sounds in chest

a.. Paradoxic movement of abdomen with breathing

a.. Neurologic causes

a.. Decreased breath sounds

a.. Generalized or focal neurologic deficits

a.. Paralysis

Causes: The etiology of diaphragmatic dysfunction is most easily

separated into anatomic or neurologic causes.

a.. Anatomic defects

a.. Congenital defects - Bochdalek hernia, Morgagni hernia,

eventration of the diaphragm, and diaphragmatic agenesis

a.. Acquired defects - Traumatic rupture, penetrating injuries,

idiopathic etiologies, and iatrogenic responses to surgery or other invasive

procedures

a.. Innervation defects

a.. Cerebral stroke

a.. Spinal cord disorders - Trauma to the cervical spinal cord,

syringomyelia, poliomyelitis, and motor neuron disease

a.. Phrenic nerve neuropathy - Trauma to the phrenic nerve from

surgery, radiation, or tumor; Guillain-Barré syndrome; brachial plexus

neuritis; diabetic, nutritional, and alcoholic neuropathy; vasculitic

neuropathy; lead and poison neuropathy; and infection-related nerve injury

(eg, diphtheria, tetanus, typhoid, measles, botulism)

a.. Myasthenia gravis

a.. Muscular disorders - Myotonic dystrophies, Duchenne muscular

dystrophy, metabolic myopathies, and polymyositis

a.. Idiopathic etiologies

DIFFERENTIALS Section 4 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Macrocytosis

Other Problems to be Considered:

Fractures, Cervical Spine

Guillain-Barré Syndrome

Myasthenia Gravis

Cervical fracture

Cerebral hemorrhage or ischemia

Numerous neuropathies

Injury to phrenic nerve from trauma

Injury to phrenic nerve from neoplasm

Injury to phrenic nerve from surgery (most commonly from cardiac

surgery due to cold cardioplegia)

Quick Find

Author Information

Introduction

Clinical

Differentials

Workup

Treatment

Medication

Follow-up

Miscellaneous

Pictures

Bibliography

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WORKUP Section 5 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Lab Studies:

a.. Laboratory studies are limited to discovery of neuropathic

causes of diaphragmatic dysfunction.

Imaging Studies:

a.. Chest radiography

a.. Neurologic impairment manifests radiographically with

elevation of the diaphragm (unilateral or bilateral), mediastinal shift on

inspiration, and diminished, absent, or paradoxic movements on inspiration.

Chest radiographs may exhibit cervical or thoracic mass that encompasses the

phrenic nerve.

a.. Congenital defect or traumatic rupture is demonstrated

roentgenographically with abdominal contents in the thorax on the affected

side. A nasogastric tube in the thorax may be mistaken for a massive

hemothorax. Thus, palpation of lung parenchyma and/or abdominal viscus

within the thorax before insertion of a chest tube into the patient with

trauma is always important.

a.. Fluoroscopy

a.. Up to 6% of the healthy population has paradoxic movement of a

hemidiaphragm on a deep inspiratory effort against a closed airway (sniff

test) as a normal finding.

a.. The sniff test is considered positive if a 2-cm or longer

excursion is present and the whole leaf of the hemidiaphragm, in the oblique

view, is involved.

Other Tests:

a.. Pulmonary function tests, including maximum inspiratory

pressures, transdiaphragmatic pressure measurement, and vital capacity, in

both upright and supine positions help the clinician to determine whether

diaphragmatic dysfunction is present and/or to determine the degree of

respiratory compromise experienced by the patient in different positions.

a.. Phrenic nerve conduction studies are used to assess the latency

of conducting nervous impulses along the course of the nerve. This helps

localize lesions to one side or the other and helps the clinician to

decipher whether the condition is a bilateral phenomenon. This test is not

generally available and may require referral to a center that is able to

provide this service.

TREATMENT Section 6 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Medical Care: Focus medical care on the etiology of the dysfunction.

In anatomic causes and defects, the only treatment option is surgical

repair. Once a nontraumatic etiology is considered, the most important next

step is to discover the cause. Neurologic processes, depending on the

etiology, can generally be managed medically.

a.. Supportive management

a.. Many patients with severe dysfunction need ventilatory

support. Depending on the etiology of the disease, some patients only

require short-term support, while others may require life-long ventilatory

breathing.

a.. If the phrenic nerve is intact and the problem lies in

actually transmitting an impulse to the nerve, phrenic nerve or

diaphragmatic pacing may be useful modalities in the treatment of this

subset of patients.

a.. Neurologic

a.. Once a diagnosis of neurologic dysfunction is made, ordering

studies to determine the cause is vital.

a.. A number of neurologic etiologies can be managed medically,

but discovering the cause often becomes a challenge.

Surgical Care: Surgically manage anatomic defects in the diaphragm.

The type of surgical intervention depends on the anatomic defect or problem.

a.. Congenital defects: Manage congenital diaphragmatic defects

through transabdominal primary surgical repair.

a.. Acquired defects: Manage acquired diaphragmatic defects (ie,

traumatic rupture, late-onset congenital diaphragmatic defect) by

thoracoscopic plication of the hemidiaphragm.

a.. Phrenic nerve injury

a.. Primary repair of phrenic nerve damage from trauma can be

attempted but does not generally restore function. With expectant treatment,

few patients regain phrenic nerve function.

a.. Manage injury from a tumor by resection of the tumor encasing

the phrenic nerve, which yields good results. Most patients regain function

of the nerve.

a.. Cold phrenic nerve injury during cardiac surgery generally

resolves with expectant management.

MEDICATION Section 7 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Medication is limited to the etiology of neurologic involvement.

FOLLOW-UP Section 8 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Further Outpatient Care:

a.. Once an anatomic defect is corrected, the patient should undergo

periodic chest radiography and assessment of pulmonary function. Although

spontaneous recurrence of a repaired diaphragmatic hernia is low, small

defects in the repair site have been reported; therefore, surveillance is

important.

a.. If dysfunction was secondary to a tumor encroaching on the

phrenic nerve, maintaining close follow-up contact with the patient is

important to ensure that the mass has not recurred.

Complications:

a.. Anatomic defects may lead to respiratory failure, incarceration

or strangulation of bowel, or hypoplasia of the lung in congenital defects.

a.. Neurologic problems may lead to respiratory failure.

Prognosis:

a.. Patients with anatomic repairs

a.. Prognosis for patients with anatomic repairs from traumatic

rupture directly correlates with the extent of concomitant injuries.

a.. Neonates generally have a good prognosis after repair of

congenital diaphragmatic hernias, but it is directly related to the

development of the lung on the affected side.

a.. Patients with neurologic conditions

a.. Prognosis for patients with neurologic conditions generally

correlates with etiology.

a.. Persons with high cervical spine fractures generally fare

worse than individuals with transient neuropathies such as Guillain-Barré

syndrome.

MISCELLANEOUS Section 9 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Medical/Legal Pitfalls:

a.. Failure to conduct periodic chest radiography and assessment of

pulmonary function once an anatomic defect is corrected

a.. Failure to maintain close follow-up contact if dysfunction was

secondary to a tumor encroaching on the phrenic nerve

PICTURES Section 10 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

Caption: Picture 1. Diaphragm disorders. Radiograph of a man who

fell 45 feet from scaffolding, through plate glass windows, and onto the

ground. Intraoperatively, he had a completely avulsed diaphragm on the left

side. The patient subsequently recovered after a 45-day hospital course of

treatment.

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BIBLIOGRAPHY Section 11 of 11

Author Information Introduction Clinical Differentials

Workup Treatment Medication Follow-up Miscellaneous Pictures Bibliography

a.. Baum GL, Crapo JD, Celli BR: Textbook of Pulmonary Diseases. 6th

ed. Boston, Mass: Little Brown and Co; 1995.

b.. Brander PE, Jarvinen V, Lohela P, Salmi T: Bilateral

diaphragmatic weakness: a late complication of radiotherapy. Thorax 1997

Sep; 52(9): 829-31[Medline].

c.. Efthimiou J, J, Woodham C, et al: Diaphragm paralysis

following cardiac surgery: role of phrenic nerve cold injury. Ann Thorac

Surg 1991 Oct; 52(4): 1005-8[Medline].

d.. Fell SC: Surgical anatomy of the diaphragm and the phrenic

nerve. Chest Surg Clin N Am 1998 May; 8(2): 281-94[Medline].

e.. Fitting JW, Grassino A: Diagnosis of diaphragmatic dysfunction.

Clin Chest Med 1987 Mar; 8(1): 91-103[Medline].

f.. Grmoljez PF, JE Jr: Congenital diaphragmatic hernia:

Bochdalek type. Am J Surg 1976 Dec; 132(6): 744-6[Medline].

g.. Heffner JE: Diaphragmatic paralysis following chiropractic

manipulation of the cervical spine. Arch Intern Med 1985 Mar; 145(3):

562-4[Medline].

h.. Iverson LI, Mittal A, Dugan DJ, Samson PC: Injuries to the

phrenic nerve resulting in diaphragmatic paralysis with special reference to

stretch trauma. Am J Surg 1976 Aug; 132(2): 263-9[Medline].

i.. Lemons VR, Wagner FC Jr: Respiratory complications after

cervical spinal cord injury. Spine 1994 Oct 15; 19(20): 2315-20[Medline].

j.. Murray JF, Nadel JA: Textbook of Respiratory Medicine.

Philadelphia, Pa: WB Saunders and Co; 1997.

k.. Rees JR, Redo SF, Tanner DW: Bochdalek's hernia. A review of

twenty-one cases. Am J Surg 1975 Mar; 129(3): 259-61[Medline].

l.. Shah R, Sabanathan S, Mearns AJ, Choudhury AK: Traumatic rupture

of diaphragm. Ann Thorac Surg 1995 Nov; 60(5): 1444-9[Medline].

m.. Sharma OP: Traumatic diaphragmatic rupture: not an uncommon

entity--personal experience with collective review of the 1980's. J Trauma

1989 May; 29(5): 678-82[Medline].

n.. van Vugt AB, Schoots FJ: Acute diaphragmatic rupture due to

blunt trauma: a retrospective analysis. J Trauma 1989 May; 29(5):

683-6[Medline].

o.. Wiseman NE, MacPherson RI: " Acquired " congenital diaphragmatic

hernia. J Pediatr Surg 1977 Oct; 12(5): 657-65[Medline].

p.. Zifko U, Auinger M, Albrecht G, et al: Phrenic neuropathy in

chronic renal failure. Thorax 1995 Jul; 50(7): 793-4[Medline].

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