It's been identified that in most cases of Cardiac or Respiratory arrest, and other episodes of patient deterioration, predictors will be present up to 24 hours prior to the event.[1,2]
In Australia Recognising and Responding to Clinical Deterioration in Acute Health Care is a national standard in acute care facilities. Standard 9 in fact. The Australian Commission for Healthcare Standards found that ICU admission were often precipitated abnormalities in vital signs [3]. This finding led to the recommendation that Track and Trigger observation charts be implemented. Track and Trigger observation charts use coloured shading to represent normal vital sign values, vital sign values that warrant a medical review and vital sign values that require the activation of an Rapid Response Team (RRT) or Medical Emergency Team (MET). Track and Trigger charts have been shown to effective at intervening in deterioration and decreasing cardiac and respiratory arrest events on wards [4]. The standard track and trigger charts used public hospitals in Australia (Variations of the above linked image) is based off the 'Between the Flags' (BTF) system developed by the New South Wales Department of Health's Clinical Excellence Commission.
It is widely recognised that increasing respiratory rate is a precursor to deterioration. It's also recognised as the most commonly omitted vital sign.
Some of the cited reasons include time constraints, lack of confidence in performing the assessment and perceived lack of importance. Education is documented as the best method to combat all of these barriers [5,6,7].
So, Let's get into some education.
Respiration actually refers to the processes of both internal and external respiration, that is the gas exchange that occurs in the lungs (external*) and in tissue (internal). When we measure 'Respiratory rate' we're actually counting Ventilation rate. However, semantics are semantics and there are somethings that won't ever change - reference to Respiratory rate (RR) is likely one of them.
We know about the respiratory system's anatomy. That's basic A&P. we've got mouth/nose pharynx, larynx trachea, bronchi, bronchioles, alveoli. The action of breathing stems from a vacuum style system, requiring the movement of the diaphragm to draw air in and out of the lungs.
*External respiration - the source of respiration is the atmosphere external to the body.
We know that respiration (that is actual respiration) occurs at the alveoli, where the gases CO2 and O2 are exchanged, and blood is re-oxygenated, and we know that this occurs again in the tissues, supplying organs with oxygen. [8]
We count one breath as a full inhalation and exhalation. Some people do this for a full minute, others for 30 seconds and multiple the result by two, either way a RR should reflect the breaths per minute.
According to our Track and Trigger chart the safe RR is between 10 and 24 breaths per minute. This rate will alter depending on the source, however most sources will be close to these figures. Like any other vital sign, we can see more information in a trend than we can in a single sign, but that's not to say a single incidence of brady or tacypnoea shouldn't trigger an escalation of care.
What causes brady or tachypnoea?
whilst the physical causes of brady or tachypnoea are often extremely evident e.g. pain, exercise, sleep etc. The mechanism the causes this rise and fall in RR - Acid-Base Balance.The body's blood pH sits somewhere between 7.35 and 7.45
Standard CO2 levels (pCO2) are 35-45mmHg. It's an acidic substance, it's presences will skew blood pH further towards 1 on the other hand Hydrogen Carbonate (HCO3-) is very alkaline (base) it will send the pH towards 14. Standard Hydrogen Carbonate is 22-26mmol/L
with these values, your respiration rate will remain within acceptable limits.
The body will deal with alterations in pH in two ways - by the respiratory system or by the renal system. Typically, the respiratory system can manage pH imbalances (to a degree) momentarily, where as the renal system requires a period of hours or days.
Alterations in respiratory rates is the manifestation of this process.
When CO2 is high in presence, the RR increases in order to expel excess CO2. When CO2 is low in presence, the RR decreases. Whilst this mechanism is effective, it's only viable for a short period of time[8].
Ian Miller over at The Nurse Path has a great write up on Acid-Base Balance and Arterial Blood Gasses, with terrible puns to boot.
When to get help... and where?
The standard Track and Trigger chart should guide practice and escalation of care, however it's also been recognised that there are times when the reliance on a RRT or MET isn't an option - Rural hospitals for example. In this case, often Registered Nurses in Urgent Care Centres or on the ward act as both the clinical staff and RRT, whilst the skills mix usually includes at least one RN trained in Advanced Life Support there are cases where the deterioration is beyond the ability of the service to manage for reasons of staffing skills or available resources[7]. The use of retrieval services such as Adult Retrieval Victoria or PIPER (Paediatric, Infant & Perinatal Emergency Retrieval) is indicated. Early activation of these services is vital, as response time can be hindered by any number of factors.
Early Liaison with a retrieval service can provide staff with management advice and can at times assist in organising local resources to assist in resuscitative efforts if required (e.g. Local Ambulance). [10]
If you are in a hospital with a RRT or MET system, activate it early, if your service has an ICU liaison service, engage it's use any time you're concerned. At the very least you'll be able to access some education. - As a Graduate Nurse I learned what I consider to be the biggest piece of advice in assessment from an ICU liaison nurse; "The Resp Rate is at the top of the chart, because it's most important. If you see it heading up and you don't step in, it won't be me you'll be calling."
In terms of education - Simon Cooper of Monash University Melbourne and his team developed an online simulation program aimed at collecting data around the management of a deteriorating patient, it's free and highly worth checking out. First2Act
Trauma Victoria also recently launched their online learning programs, whilst the information in the program is directed around trauma there is a lot of general information that can be applied to day-to-day nursing. It does however, require an Australian Health Practitioner Regulation Agency Registration number, or Ambulance Victoria ID to sign up, it's free too. Trauma Victoria
Beyond the typical causes of tachy and bradypnoea, we then need to consider that any condition that has the potential to cause respiratory or metabolic acidosis or alkalosis will cause alterations in respiratory rates[9]. Most conditions requiring presentation to an Emergency Department or admission to a ward or ICU have the potential to cause an acidosis or alkalosis, so it's fair to say that respiratory rate is certainly the most vital of the signs.
Key points to take home
- Always take a respiratory rate - every set of vital signs.
- Inhalation and exhalation count as one breath.
- Patients will alter their breathing if they know you're counting it - so get sneaky.
- Respiratory rate will be the first sign of deterioration - Act on it!
References
[1] Felton, M. (2012). Recognising signs and symptoms of patient deterioration. Emergency Nurse: The Journal Of The RCN Accident And Emergency Nursing Association, 20(8), 23-27.
[2] Rattray, J. E., Lauder, W., Ludwick, R., Johnstone, C., Zeller, R., Winchell, J., & ... Smith, A. (2011). Indicators of acute deterioration in adult patients nursed in acute wards: a factorial survey. Journal Of Clinical Nursing, 20(5/6), 723-732.
[3]Australian Commission for Safety and Quality in Health Care (2009) Recognising and Responding to Clinical Deterioratoin: Use of Observation charts to identify clinical deterioration
[4]Wolfenden, J., Dunn, A., Holmes, A., Davies, C., & Buchan, J. (2010). Track and trigger system for use in community hospitals. Nursing Standard (Royal College Of Nursing (Great Britain): 1987. 24(45) 35-39
[5] Jonsson, T., Jonsdottir, H., Moller, A.D., & Balsursdottier, L. (2011) Nursing Documentation prior to emergency admissions to the intensive care unit. Nursing in Critical Care. July 2011;16(4) 164-169
[6]Felton M. Recognising signs and symptoms of patient deterioration. Emergency Nurse: The Journal Of The RCN Accident And Emergency Nursing Association . December 2012;20(8):23-27.
[7]Cooper, S., Cant, R., Sparkes, L. (2012) Respiratory rate records: the repeated rate? Journal of Clinical Nursing[8]Widmanier, E. Et al (2008) Vander's Human Physiology. (11th ed) New York, NY, McGrathHill Parkes, R. (2011). RATE OF RESPIRATION: THE FORGOTTEN VITAL SIGN. Emergency Nurse, 19(2), 12-18.
[9]O'Donnell, A. (2008)ABG...Easy as...123 (poster, sourced from the Agency for Clinical Innovation.) New South Wales Department of health
[10] Victorian Department of Health (2015) The deteriorating trauma patient. Trauma Victoria. http://trauma.reach.vic.gov.au/guidelines/the-deteriorating-trauma-patient/key-messages
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