What term would you use to document a respiratory rate greater than 25 per minute in an adult?

The fourth article in our series on respiratory rate is a guide to the assessment of breathing rhythm and chest movement, which provide important information on a patient’s condition

Breathing rhythm and chest movement provide key information on a patient’s condition. The fourth article in this five-part series on respiratory rate expands on the procedure to measure respiratory rate outlined in part 3 and provides a guide to the assessment of respiratory rhythm and chest movement.

Citation: Wheatley I (2018) Respiratory rate 4: breathing rhythm and chest movement. Nursing Times; 114: 9, 49-50.

Author: Iain Wheatley is nurse consultant in acute and respiratory care, Frimley Health Foundation Trust.

• This article has been double-blind peer reviewed
• This article is open access and can be freely distributed
• Scroll down to read the article or download a print-friendly PDF here (if the PDF fails to fully download please try again using a different browser)
• Click here to see other articles in this series
• This article is funded by an unrestricted educational grant from Hillrom

A changing respiratory rate (RR) measurement is cited as an early indicator of patient deterioration (Dougherty and Lister, 2015), but there are other respiratory signs that can be observed in conjunction with it.

In normal breathing a fairly steady rate, inspiratory volume and depth of chest movement are maintained, with equal expansion and symmetry. In the resting state normal breathing is relaxed, regulating the gas exchange in the lungs to maintain homoeostasis and balance pH changes and metabolism.

When there is an increased demand on the respiratory system from an acute episode, such as a chest infection, or long-term conditions, such as chronic obstructive pulmonary disease, the respiratory rhythm and chest movement change. These changes are compensatory mechanisms as a direct result of a chemical imbalance; and the primary cause may be mechanical, metabolic or neurological. The changes result in an increase or decrease in RR, depth of breathing and pattern of breathing.

Changes in rhythm and chest movements are made through feedback mechanisms to the central respiratory control centres of the brain. A range of receptors provide information that is interpreted in the higher respiratory centre, modulating RR and chest movement (Feldman and Del Negro, 2006); these receptors are:

• Peripheral chemoreceptors found in the carotid artery detect changes in PaO2 in the blood as well as PaCO2 and pH;
• Central chemoreceptors in the ventral medullary surface of the medulla oblongata in the brain detect pH changes;
• Mechanoreceptors are stretch receptors located in the smooth muscle of the main airways and parenchyma. They respond to excessive stretching of the lung during inspiration and send signals to the apneustic centre of the pons (located in the brain stem); the pons controls inspiration and expiration.

Respiratory rhythm and chest movement

Normal

In relaxed normal breathing the RR is 12-20 breaths per minute (bpm) (Royal College of Physicians, 2017). Chest expansion on inspiration should be the same or similar on each breath. The chest wall is symmetrical, accessory (neck and shoulder) muscles are not used, diaphragm muscles are functioning, and there is no paradoxical movement – the chest and abdomen move in the same direction on inspiration and expiration.

Abnormal

There are several reasons why respiratory rhythm and chest movement may change. Abnormality in respiratory rhythm may be related to changes in the patient’s metabolic state; for example, a patient with diabetic ketoacidosis may exhibit signs of rapid, deep breaths. Such breathing (often called Kussmaul’s breathing) aims to reduce the level of CO2 in the blood to maintain a normal pH and re-establish a homoeostatic state.

Patients with chest pain may have rapid but shallow breaths because deep breaths cause discomfort; in patients with rib fractures adequate pain relief is paramount to restore a normal depth and rate of breathing. Table 1 outlines common rhythm patterns, while Table 2 details key respiratory changes and possible causes.

The procedure

Observation of respiratory rhythm and chest movement can be incorporated into Wheatley’s (2018) procedure for assessing RR. The key principles of chest observation are outlined below. It is important to have a clear view of the chest so the chest area should be exposed. Protect the patient’s dignity at all times by screening the bed.

1. Chest symmetry – standing in front of and facing the patient, observe whether the movement of both sides of the anterior chest is symmetrical.
2. Chest and abdominal movement – the chest and abdomen should move in the same direction during a normal tidal breath (Fig 1) but it can be difficult to observe this. Positioning the patient in a semi-recumbent position and observing the movement from the side gives the best view.
3. Depth of chest movement – in normal tidal breathing the inspiratory and expiratory movement is fairly constant. Monitor for tachypnoea (>25bpm) or bradypnoea (<12bpm) and assess whether the tidal breath is very deep or shallow (RCP, 2017).
4. Accessory muscle use – observe the patient from the front and note whether there is increased work of breathing at rest, which includes the use of the sternocleidomastoid (neck), scalene (shoulder), pectoral and abdominal muscles (Tulaimat and Trick, 2017). The patient may sit forward with their hands on their knees or resting on a table to relieve respiratory muscles and increase inspiratory capacity.
5. Rhythm – breathing rhythm is usually constant and regular; a rhythm with abnormally long pauses between breaths or cessation of breaths and then rapid breathing is abnormal (Table 1).

Conclusion

It is important to observe RR and to examine the rhythm of breathing and movement of the chest when conducting a respiratory assessment. This observation can aid rapid diagnosis and treatment particularly in patients who are acutely ill.

Also in this series

Dougherty L, Lister S (2015) The Royal Marsden Manual of Clinical Nursing Procedures. Oxford: Wiley-Blackwell.

Feldman JL, Del Negro CA (2006) Looking for inspiration: new perspectives on respiratory rhythm. Nature Reviews Neuroscience; 7: 3, 232-241.

McCool FD, Tzelepis GE (2012) Dysfunction of the diaphragm. New England Journal of Medicine; 366: 10, 932-942.

Royal College of Physicians (2017) National Early Warning Score (NEWS) 2.

Tulaimat A, Trick WE (2017) DiapHRaGM: a mnemonic to describe the work of breathing in patients with respiratory faialure. PLoS One; 12: 7: e0179641.

Wheatley I (2018) Respiratory rate 3: how to take an accurate measurement. Nursing Times; 114: 7, 21-22.

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Respiratory rate (RR) is a non–invasive and useful assessment tool and abnormalities in respiratory rate have been shown to indicate patient deterioration and should be managed accordingly.[1]

Respiration is a vital process for humans, supplying oxygen to the mitochondria for ATP production (our bodies energy currency). The main byproduct of this process, carbon dioxide which goes through a process to finally be exhaled form our lungs.

The respiratory rate, i.e., the number of breaths per minute, is highly regulated to enable cells to produce the optimum amount of energy at any given occasion.

1. Our nervous system regulates the rate of oxygen inflow and carbon dioxide outflow. It adjusts it accordingly in conditions that tend to derange partial gas pressures in blood.
2. Respiration is a process involving the brain, brainstem, respiratory muscles, lungs, airways, and blood vessels. All these structures have involvement structurally, functionally, and regulatory to respiration[2].
3. Recording a full set of vital signs (pulse rate, blood pressure, respiratory rate and temperature) at least daily is considered standard for monitoring patients on acute hospital wards.[3]

Image 1: Animation of a diaphragm exhaling and inhaling

Norms - Respiratory Rates[edit | edit source]

RR is measured by counting the number of breaths a person takes in a one-minute period. The rate should be measured at rest, not after someone has been up and walking about.

• Newborn: 30-60 breaths per minute
• Infant (1 to 12 months): 30-60 breaths per minute
• Toddler (1-2 years): 24-40 breaths per minute
• Preschooler (3-5 years): 22-34 breaths per minute
• School-age child (6-12 years): 18-30 breaths per minute
• Adolescent (13-17 years): 12-16 breaths per minute
• The average respiratory rate in a healthy adult is between 12 and 18 breaths per minute.
• Normal respiratory rates in elderly people tend to be higher than those of younger adults, especially among older adults who are in long-term care facilities[4]

Recent evidence suggests that an adult with a respiratory rate of over 20 breaths/minute is probably unwell, and an adult with a respiratory rate of over 24 breaths/minute is likely to be critically ill.[3]

Best Practice Procedure[edit | edit source]

Points to remember:

• Take into consideration the importance of how the person is breathing, as well as the rate at which they are breathing
• Respiratory rate, depth and symmetry are indicative of different types of conditions. eg Pneumothorax: Asymmetrical chest expansion, use of accessory muscles; Exacerbation of asthma: Dyspnoea, difficulty breathing, wheeze, tachypnoea (RR above 20 breaths per minute); Exacerbation of chronic obstructive pulmonary disease: Dyspnoea, wheeze, tachypnoea (RR above 20 breaths per minute)
• The ideal length of time to take a respiratory rate measurement is 60 seconds, without patient awareness that they are being monitored.
• Oxygen saturation measurement (eg oximetry) is not a replacement for respiratory rate measurement
• Accurate documentation and interpretation of accurately taken observations help improve patient outcomes[1]

Importance[edit | edit source]

Changes and anomalies in RR are not simply associated with respiratory conditions, they are a good indicator that a patient is struggling to maintain homeostasis. Respiratory rate is an early, extremely good indicator of physiological conditions such as hypoxia (low levels of oxygen in the cells), hypercapnia (high levels of carbon dioxide in the bloodstream), metabolic and respiratory acidosis. Conditions in altered RR include:

• Metabolic acidosis states increase the tidal volume
• Metabolic alkalosis decreases the RR.
• Interstitial diseases that change the mechanical input to the respiratory centre lead to a rapid breathing rate.
• Congestive heart failure activates a neural circuit leading to stimulation of the respiratory centre resulting in an increase in breathing rate.
• Higher cortical centres can be affected by an increase in intracranial pressure, e.g., in a patient with head trauma or by pain in a patient with a rib fracture, resulting in an increased respiratory rate.
• The opposite effect on higher centres will be observable in an individual who has taken CNS depressant substances[2].
• Dehydration: Dehydration alone can result in a rapid rate of breathing.
• Fever: An increased rate of breathing with a fever is the body's attempt to lose heat by breathing faster. This is important both because a rapid respiratory rate can be a sign of a worsening infection, and because a fever needs to be taken into account in interpreting the respiratory rate.
• Hyperventilation: People may breathe more rapidly in response to stress, pain, anger or during a panic attack.[4]

Image 2: Researchers at University College London have developed new algorithms that make it possible to use low-cost thermal cameras attached to mobile phones to track how fast a person is breathing. This type of mobile thermal imaging could be used for monitoring breathing problems in elderly people living alone, people suspected of having sleep apnea or babies at risk for sudden infant death syndrome (SIDS).

Terminology[edit | edit source]

Terms to describe abnormal respiratory rate include:

• Bradypnea is the medical term used to define breathing that is abnormally slow.
• Tachypnea is the medical term used to define an elevated respiratory rate. This rapid respiratory rate is usually shallow, versus hyperpnea which can be rapid and deep.
• Dyspnea refers to the sensation of shortness of breath and can occur with an elevated, a normal, or a decreased respiratory rate.
• Hyperpnea refers to breathing that is abnormally deep and appears laboured. It may occur with or without rapid breathing.
• Apnea means literally “no breath” and refers to the absence of breathing[4]. eg sleep apnea

References[edit | edit source]