Tachypnea

Tachypnea is defined as rapid breathing. The younger the child, the faster the average respiratory rate, and the wider the acceptable range of normal. The average newborn may breathe anywhere between 30 and 80 respirations per minute, a 2-year-old at 20–40, and older children at rates close to adult averages (16–28). Minute ventilation (Ve) is measured in liters per minute; a rapid respiratory rate with a smaller tidal volume (Vt) may lead to little change in Ve. Airway obstruction in infants may lead to tachypnea instead of expiratory prolongation. Rather than forcing air out (increasing Vt), the baby may breathe rapidly at a high lung volume, keeping airways open (airway caliber is greater at higher lung volumes).

Differential Diagnosis

• Consider tachypnea using a compartmental, anatomic model; recall that causes are usually multifactoral and that the CNS ultimately drives RR

• CNS
  –Increased “respiratory drive” usually affects rate, not just Vt
  –Physiologic variables that drive up RR are those found in respiratory failure (hypoxia, hypercapnea, acidosis); thus, hypoxia for any reason (e.g., high altitude or pneumonia) increases RR
  –Other “CNS” factors that may increase respiratory rate include dehydration, fever, and anxiety

• Obstruction
  –Airway obstruction may lead to an increased work of breathing, expiratory prolongation, increased Vt, or dyspnea, but may cause tachypnea as well
  –Upper airway: Laryngomalacia, choanal atresia, macroglossia, micrognathia, subglottic stenosis, web, or laryngospasm
  –Lower airway: Tracheal stenosis, rings, slings, asthma, or FB

• Parenchymal disease
  –Decreased lung volume (e.g., atelectasis, pneumonectomy), poor compliance (e.g., pulmonary edema, pneumonia, pulmonary fibrosis)
• Chest wall disorders
  –High or low chest wall compliance (e.g., kyphoscoliosis or flail chest)
• Pulmonary vascular disease is often due to hypoxia and other mechanisms
  –Pulmonary edema (altered compliance and hypoxia)
  –Pulmonary hypertension (hypoxia), V/Q mismatch (e.g., pneumonia), shunt such as CCHD
• Lymphatic system
  –Lymphangiectasia (altered compliance)
  –BALT (airway obstruction and hypoxia)
  –Chylothorax (altered chest wall mechanics and hypoxia)
• Other inflammatory mediators (e.g., cytokines or eicosanoids) may affect respiratory rate through uncertain mechanisms

Workup and Diagnosis

• Remember, tachypnea may be normal
• History is directed at logical associations with tachypnea
• Setting of onset: History of acute onset and associated with a viral illness might suggest temperature or mild acidosis as relevant factors, whereas a sudden onset associated with a sudden-onset cough in a toddler may suggest FB
• What makes it better (O2 or antipyretics)?
• Related signs and symptoms: Look for evidence of CCHD, sepsis (e.g., GBS sepsis), toxic ingestion (e.g., aspirin)
• Physical exam
  –Look for agitation, anxiety, mental status changes, or other signs of CNS dysfunction
  –Auscultate over all of airways to find potential source of obstructive disease
  –Inspect for evidence of chest wall disease or increased work of breathing (e.g., retractions or use of accessory muscles of respiration)
• Radiology is effective in demonstrating parenchymal or pleural disease; less helpful with airways
• Other radiographic tools targeted at suspected cause: CT for empyema, congenital lesions of lung; MRI/MRA for vascular anomalies in chest; and nuclear medicine (V/Q scan); Echo/ECG for CCHD
• Pulmonary function tests: Measure volumes and flows
• Blood work for miscellaneous (ABG, CBG)

Treatment

• Treat underlying etiology
• Prevent impending respiratory failure aggressively with O2, fluids, intubation, and mechanical ventilation
• Severe metabolic acidosis may need correction with bicarbonate and therapy targeted at the cause (e.g., antibiotics for sepsis)
• Relieve obstruction medically or surgically depending on site and cause; severe upper airway obstruction may require intubation to bypass obstruction; severe lower airway obstruction may need bronchoscopy (e.g., FB, mucus plug) or asthma therapy
• If the demands of respiration are excessive, respiratory muscle failure may ensue, requiring mechanical ventilation; severe lower airway obstruction may even preclude mechanical ventilation
• Tachypnea in well babies is often physiologic and may require no intervention, but one must first exclude pathology

Book Source Details

• Book Title: In A Page: Pediatric Signs and Symptoms
• Author(s): Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan
• Year of Publication: 2007
• Copyright Details: In A Page: Pediatric Signs and Symptoms, Copyright © 2007 Lippincott Williams & Wilkins.

Other Book Chapters Related to Rapid breathing

Read excerpts from these other book chapters related to Rapid breathing:

Copyright Details: In A Page: Pediatric Signs and Symptoms, Copyright © 2008 Williams & Wilkins.

More About Causes of Rapid breathing

• Back to symptom: Rapid breathing: Introduction (review 336 causes)
• Next Book Extract About Rapid breathing: DYSPNEA, TACHYPNEA, AND ORTHOPNEA (Differential Diagnosis in Primary Care)
• All Book Extracts: All Online Book Extracts for Rapid breathing

More About This Book: Title: In A Page: Pediatric Signs and Symptoms Authors: Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan Publisher: Lippincott Williams & Wilkins Copyright: 2007 ISBN: 1-4051-0427-9

 » Next page: DYSPNEA, TACHYPNEA, AND ORTHOPNEA (Differential Diagnosis in Primary Care)

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• DYSPNEA, TACHYPNEA, AND ORTHOPNEA (Differential Diagnosis in Primary Care)
• DECREASED RESPIRATIONS, APNEA, AND CHEYNE–STOKES BREATHING (Differential Diagnosis in Primary Care)
• SLEEP APNEA (Differential Diagnosis in Primary Care)
• STRIDOR AND SNORING (Differential Diagnosis in Primary Care)
• Accessory muscle use (Handbook of Signs & Symptoms (Third Edition))

Tools & Services:

• Bookmark this page
• Related medical articles for Tachypnea:
• Take a survey relating to Rapid breathing
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City