Cough pathophysiology: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
 
(4 intermediate revisions by the same user not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Cough}}
{{Cough}}
Please help WikiDoc by adding more content here.  It's easy!  Click  [[Help:How_to_Edit_a_Page|here]]  to learn about editing.


{{CMG}}; {{AE}} {{CZ}}, {{MUT}} {{AMA}}
{{CMG}}; {{AE}} {{CZ}}, {{MUT}} {{AMA}}
Line 8: Line 7:
   
   
==Cough Reflex==
==Cough Reflex==
The cough reflex is constituted by 3 main components ie
The cough reflex is constituted by three main components ie
*'''The Afferent pathway:''' This is made up of [[sensory nerve]] [[fibers]] of the [[ciliated epithelium]] found in the upper airways. The afferent impulses are transmitted into the medulla.
*'''The Afferent pathway:''' This is made up of [[sensory nerve]] [[fibers]] of the [[ciliated epithelium]] found in the upper airways. The afferent impulses are transmitted into the medulla.


Line 20: Line 19:
*Slowly adapting stretch receptors (SARs)
*Slowly adapting stretch receptors (SARs)
*C-fibres.
*C-fibres.
 
[[image:Types of Cough Reflex.jpg|thumb|center|1200 × 1,140 pixels|Cough reflex-Brooks, S.M. Perspective on the human cough reflex.]]
==Cough Mechanics==
==Cough Mechanics==
For an effective cough to be produced, a sequence of timed mechanical events divided into 3 phases has to take place.<ref name="pmidPMID: 13542168">{{cite journal| author=BUCHER K| title=Pathophysiology and pharmacology of cough. | journal=Pharmacol Rev | year= 1958 | volume= 10 | issue= 1 | pages= 43-58 | pmid=PMID: 13542168 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=13542168  }} </ref>
For an effective cough to be produced, a sequence of timed mechanical events divided into 3 phases has to take place.<ref name="pmidPMID: 13542168">{{cite journal| author=BUCHER K| title=Pathophysiology and pharmacology of cough. | journal=Pharmacol Rev | year= 1958 | volume= 10 | issue= 1 | pages= 43-58 | pmid=PMID: 13542168 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=13542168  }} </ref>
Line 26: Line 25:
*'''The [[Compression]] Phase:''' The contraction of the [[muscles]] of the [[chest wall]], [[abdominal wall]], and the [[diaphragm]] against a closed [[glottis]] brings about a rapid increase in [[intrathoracic pressure]].The pressure developed in the [[glotts]] during this [[compression phase]] could be as high as 300mmhg.<ref name="pmidPMID: 16428691">{{cite journal| author=McCool FD| title=Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines. | journal=Chest | year= 2006 | volume= 129 | issue= 1 Suppl | pages= 48S-53S | pmid=PMID: 16428691 | doi=10.1378/chest.129.1_suppl.48S | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16428691  }} </ref>
*'''The [[Compression]] Phase:''' The contraction of the [[muscles]] of the [[chest wall]], [[abdominal wall]], and the [[diaphragm]] against a closed [[glottis]] brings about a rapid increase in [[intrathoracic pressure]].The pressure developed in the [[glotts]] during this [[compression phase]] could be as high as 300mmhg.<ref name="pmidPMID: 16428691">{{cite journal| author=McCool FD| title=Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines. | journal=Chest | year= 2006 | volume= 129 | issue= 1 Suppl | pages= 48S-53S | pmid=PMID: 16428691 | doi=10.1378/chest.129.1_suppl.48S | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16428691  }} </ref>
*'''The [[Expiratory]] Phase:''' At this last phase, the glottis is open and the large [[intrathoracic pressure]] that was developed in the [[compressive phase]] brings about a large [[expiratory]] airflow and the unique sound associated with coughing.<ref name="pmidPMID: 16428691">{{cite journal| author=McCool FD| title=Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines. | journal=Chest | year= 2006 | volume= 129 | issue= 1 Suppl | pages= 48S-53S | pmid=PMID: 16428691 | doi=10.1378/chest.129.1_suppl.48S | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16428691  }} </ref>
*'''The [[Expiratory]] Phase:''' At this last phase, the glottis is open and the large [[intrathoracic pressure]] that was developed in the [[compressive phase]] brings about a large [[expiratory]] airflow and the unique sound associated with coughing.<ref name="pmidPMID: 16428691">{{cite journal| author=McCool FD| title=Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines. | journal=Chest | year= 2006 | volume= 129 | issue= 1 Suppl | pages= 48S-53S | pmid=PMID: 16428691 | doi=10.1378/chest.129.1_suppl.48S | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16428691  }} </ref>
 
[[image:Cough Schematics.png|thumb|center|860 × 1,024 pixels|Cough Schematics-Milano, Politecnico di and Andrea Aliverti.VOLUNTARY COUGH MECHANICS IN HEALTH AND DUCHENNE MUSCULAR DYSTROPHY.” (2012).]]
==Dysfunction==
==Dysfunction==
The ability to [[cough]] efficiently and effectively is cannot be overstated and when patients have impaired ability to cough, they are at an increased risk of [[atelectasis]], [[pneumonia]], and other [[chronic airways diseases]] secondary to [[aspiration]] and retention of secretions. In patients with [[chest wall deformities]], [[abdominal wall deformities]] and other [[neuromuscular disorders]] may have problems generating the required flow pressure needed to clear respiratory secretions effectively.<ref name="pmidPMID: 22958367">{{cite journal| author=Polverino M, Polverino F, Fasolino M, Andò F, Alfieri A, De Blasio F| title=Anatomy and neuro-pathophysiology of the cough reflex arc. | journal=Multidiscip Respir Med | year= 2012 | volume= 7 | issue= 1 | pages= 5 | pmid=PMID: 22958367 | doi=10.1186/2049-6958-7-5 | pmc=3415124 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22958367  }} </ref><ref name="pmidPMID: 10836153">{{cite journal| author=Schramm CM| title=Current concepts of respiratory complications of neuromuscular disease in children. | journal=Curr Opin Pediatr | year= 2000 | volume= 12 | issue= 3 | pages= 203-7 | pmid=PMID: 10836153 | doi=10.1097/00008480-200006000-00004 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10836153  }} </ref>
The ability to [[cough]] efficiently and effectively cannot be overstated and when patients have impaired ability to cough, they are at an increased risk of [[atelectasis]], [[pneumonia]], and other [[chronic airways diseases]] secondary to [[aspiration]] and retention of secretions. In patients with [[chest wall deformities]], [[abdominal wall deformities]] and other [[neuromuscular disorders]] may have problems generating the required flow pressure needed to clear respiratory secretions effectively.<ref name="pmidPMID: 22958367">{{cite journal| author=Polverino M, Polverino F, Fasolino M, Andò F, Alfieri A, De Blasio F| title=Anatomy and neuro-pathophysiology of the cough reflex arc. | journal=Multidiscip Respir Med | year= 2012 | volume= 7 | issue= 1 | pages= 5 | pmid=PMID: 22958367 | doi=10.1186/2049-6958-7-5 | pmc=3415124 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22958367  }} </ref><ref name="pmidPMID: 10836153">{{cite journal| author=Schramm CM| title=Current concepts of respiratory complications of neuromuscular disease in children. | journal=Curr Opin Pediatr | year= 2000 | volume= 12 | issue= 3 | pages= 203-7 | pmid=PMID: 10836153 | doi=10.1097/00008480-200006000-00004 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10836153  }} </ref>


===Arnold's nerve cough reflex===
===Arnold's nerve cough reflex===

Latest revision as of 13:57, 27 August 2020

Cough Microchapters

Home

Patient Information

Overview

Classification

Historical perspective

Pathophysiology

Causes

Differentiating Cough from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Cough pathophysiology On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Cough pathophysiology

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Cough pathophysiology

CDC on Cough pathophysiology

Cough pathophysiology in the news

Blogs on Cough pathophysiology

Directions to Hospitals Treating Cough

Risk calculators and risk factors for Cough pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Cafer Zorkun, M.D., Ph.D. [2], M.Umer Tariq [3] Abiodun Akanmode,M.D.[4]

Pathophysiology

The act of coughing is a vital one that leads to the mucociliary clearance of excess secretions from the airway and other parts of the respiratory tree.Cough occurs via a complex neurophysiologic cough reflex arc.

Cough Reflex

The cough reflex is constituted by three main components ie

  • Central pathway: This is a central area located within the pons and brainstem. It coordinates the cough reflex arc.[1]

The Afferent sensory nerves

There are 3 major classes of afferent sensory nerves,this classification is based on there conduction velocity(A-fiber, > 3 m/s; C-fiber, < 2 m/s),origin ,myelination,neurochemistry etc.

  • Rapidly adapting receptors (RARs)
  • Slowly adapting stretch receptors (SARs)
  • C-fibres.
Cough reflex-Brooks, S.M. Perspective on the human cough reflex.

Cough Mechanics

For an effective cough to be produced, a sequence of timed mechanical events divided into 3 phases has to take place.[2]

Cough Schematics-Milano, Politecnico di and Andrea Aliverti.VOLUNTARY COUGH MECHANICS IN HEALTH AND DUCHENNE MUSCULAR DYSTROPHY.” (2012).

Dysfunction

The ability to cough efficiently and effectively cannot be overstated and when patients have impaired ability to cough, they are at an increased risk of atelectasis, pneumonia, and other chronic airways diseases secondary to aspiration and retention of secretions. In patients with chest wall deformities, abdominal wall deformities and other neuromuscular disorders may have problems generating the required flow pressure needed to clear respiratory secretions effectively.[6][7]

Arnold's nerve cough reflex

This is a very rare nerve disorder associated with chronic cough, in patients with this disorder, the stimulation of the external auditory meatus leads to the activation of the auricular branch of the vagus nerve(Arnold's nerve) thus stimulating the cough reflex. Treatment of patients with this condition and other sensory vagal neuropathy with chronic coughis with gabapentin.[8]

During Injections

Coughing during an injection can lessen the pain of the needle stick caused by a sudden, temporary rise in pressure in the chest and spinal canal, inhibiting the pain-conducting structures of the spinal cord.[9]

References

  1. Polverino M, Polverino F, Fasolino M, Andò F, Alfieri A, De Blasio F (2012). "Anatomy and neuro-pathophysiology of the cough reflex arc". Multidiscip Respir Med. 7 (1): 5. doi:10.1186/2049-6958-7-5. PMC 3415124. PMID 22958367.
  2. BUCHER K (1958). "Pathophysiology and pharmacology of cough". Pharmacol Rev. 10 (1): 43–58. PMID 13542168 PMID: 13542168 Check |pmid= value (help).
  3. Harris RS, Lawson TV (1968). "The relative mechanical effectiveness and efficiency of successive voluntary coughs in healthy young adults". Clin Sci. 34 (3): 569–77. PMID 5666883 PMID: 5666883 Check |pmid= value (help).
  4. Yanagihara N, Von Leden H, Werner-Kukuk E (1966). "The physical parameters of cough: the larynx in a normal single cough". Acta Otolaryngol. 61 (6): 495–510. doi:10.3109/00016486609127088. PMID 5963004.
  5. 5.0 5.1 McCool FD (2006). "Global physiology and pathophysiology of cough: ACCP evidence-based clinical practice guidelines". Chest. 129 (1 Suppl): 48S–53S. doi:10.1378/chest.129.1_suppl.48S. PMID 16428691 PMID: 16428691 Check |pmid= value (help).
  6. Polverino M, Polverino F, Fasolino M, Andò F, Alfieri A, De Blasio F (2012). "Anatomy and neuro-pathophysiology of the cough reflex arc". Multidiscip Respir Med. 7 (1): 5. doi:10.1186/2049-6958-7-5. PMC 3415124. PMID 22958367 PMID: 22958367 Check |pmid= value (help).
  7. Schramm CM (2000). "Current concepts of respiratory complications of neuromuscular disease in children". Curr Opin Pediatr. 12 (3): 203–7. doi:10.1097/00008480-200006000-00004. PMID 10836153 PMID: 10836153 Check |pmid= value (help).
  8. Ryan NM, Gibson PG, Birring SS (2014). "Arnold's nerve cough reflex: evidence for chronic cough as a sensory vagal neuropathy". J Thorac Dis. 6 (Suppl 7): S748–52. doi:10.3978/j.issn.2072-1439.2014.04.22. PMC 4222929. PMID 25383210 PMID: 25383210 Check |pmid= value (help).
  9. Usichenko, TI (2004). "Reducing venipuncture pain by a cough trick: a randomized crossover volunteer study". Anesthesia and Analgesia. 99 (3): 952–3. PMID 14742367. Unknown parameter |coauthors= ignored (help); |access-date= requires |url= (help)

Template:WH Template:WS