VOL: 101, ISSUE: 22, PAGE NO: 30
Jo Trim, MPhil, BSc, RN, is nurse adviser at University Hospital Birmingham Foundation Trust
Respirations can provide health care professionals with a wealth of information related to a patient’s condition, be it respiratory, cardiovascular or neurological. They are assessed to:
- Establish a baseline on admission;
- Monitor changes in respiratory status;
- Evaluate response to treatment.
Anatomy and physiology
Respiration supplies the body’s cells with oxygen and removes carbon dioxide, a by-product of metabolism. Respiratory drive is involuntarily regulated by the medulla, in the brain, or respiratory centre. The basic rhythm of respiration is generated by cyclical nerve impulses passing from the medulla to the principal inspiratory muscles, the diaphragm and external intercostals via the phrenic nerve (Hinchliff and Montague, 1991) (Fig 1).
A rate between 12 and 18 breaths per minute (bpm) is regarded the norm, although the literature on this subject shows some variation. A rate over 12bpm is termed tachypnoea or fast breathing; a rate less than 12bpm, bradypnoea or slow breathing (Bennett, 2003; Pritchard and Mallett, 2001).
Rhythm and depth
Alterations in the rhythm and depth of respiration may indicate a number of conditions. Hyperventilation, an increase in rate and depth, can be caused by anxiety, fear, hepatic coma, neurological complications or alterations in blood gas concentration. Alternatively, cheyne stokes respiration, which may be observed before a patient dies, is defined by an irregular rate and depth of breathing with periods of apnoea (absence of respirations) (Bennett, 2003).
Breath sounds can be heard during inspiration and expiration. By listening to these sounds, respiratory complications may be identified. For example, crackles - high pitched rustles - may be heard at the end of expiration and may indicate pulmonary oedema or, if heard during both inspiration and expiration, pneumonia (Adam and Osborne, 1997).
Effort to breathe
This is commonly known as work of breathing, and describes the effort needed to breathe. This is dependent on rate, depth and airway resistance. For example, an asthmatic patient may use the accessory muscles to assist with breathing, which is demonstrated by lifting the shoulders and using external intercostal muscles during inspiration. A patient’s breathing may also be shallow and rapid due to increased airway resistance associated with bronchospasm.
- Wash hands and put on clean gloves and apron if required.
- Prior to commencing any observations, obtain informed consent as appropriate. This is a useful time to undertake a general assessment of the patient’s respiratory status (Fig 3) including:
- Ability to speak without breathlessness;
- Restlessness or confusion;
- Sweating, or cool, clammy skin;
- Overall skin colour and signs of cyanosis;
- Whether the patient’s position is constricting their breathing.
- If there are any changes to the patient’s norm established at the baseline assessment, seek assistance and document the changes.
- Ensure a clock or watch with a second hand is easily visible (Fig 4).
- Count the respirations over 30 or 60 seconds, depending on the breathing rate.
- Simultaneously, or if preferred, after counting the respiratory rate, assess rhythm and depth.
- Document immediately (Fig 5).
- Check the patient’s breath sounds by using a stethoscope (Fig 6), ensuring all lung fields are assessed.
- If unsure at any stage during the assessment, seek guidance from a more experienced member of staff.
Patients may alter their breathing rate and pattern if they are aware their respirations are being counted. This can be avoided by continuing to maintain the same position following the manual pulse check and counting the patient’s respirations instead.
It is essential that all health care professionals undertaking respiratory assessments are competent to do so - in particular in assessing breath sounds. This technique is not widely used by general nurses and requires supervision if inexperienced. It is the responsibility of individual professionals to ensure they are up to date with both the theory and practice of this skill and practise in accordance with local trust policy.
- This article has been double-blind peer-reviewed.
For related articles on this subject and links to relevant websites see www.nursingtimes.net.