Vital signs to monitor hospital patients: a systematic review

Reviewers Primary reviewer: Sandeep Moola Secondary reviewer: Yifan Xue Third reviewer: Craig Lockwood Fourth Reviewer: Tim Schultz Background Vital signs are an important component of monitoring the adult or child patient's progress during hospitalisation, as they allow for the prompt detection of delayed recovery or adverse events.1 Vital signs are measured to obtain basic indicators of a patient's health status. If outside of a normal range of values they may point to dysfunction or a disease state. The most common intervention performed in hospital medicine is measurement of vital signs and these traditionally consist of blood pressure, temperature, pulse rate and respiratory rate. In relation to vital sign collection and post-operative monitoring, the literature provides little guidance as to what constitutes best practice.2 Most patients will have had their vital signs measured by a nurse or health care assistant before a doctor sees them. Vital signs are termed ‘vital’ as they influence clinical-decision making, but such monitoring is expensive and even inaccurate at times.3 The initial assessment of vital signs frequently dictates the hospitalisation decision.4 Similarly, resolution of vital sign abnormalities is an important determinant of discharge decision.5 It has been suggested that, in relation to vital signs collection, there “is little empirical evidence for existing regimes and, whenever regimens are recommended in the literature, the suggestions appear to be based on current clinical practice”.6 Vital signs are collected based on traditional - some would say almost ritual patterns - rather than on evidence-based nursing practice. They are collected routinely and are not determined by the clinician or the individual patient. One survey of nurses demonstrated that vital signs were undertaken as a routine procedure, irrespective of patients' needs.7 There is only limited information regarding the frequency with which vital signs should be monitored and much of this is based on surveys, clinical practice reports and expert opinion.1 This review will seek to find evidence supporting an optimal frequency of vital sign measurements and also to determine if the frequent collection of regulated routine vital signs has a positive impact on patient outcomes. Finally, the issue of accuracy of measurement will be considered in the light of advanced medical technologies being developed for the purpose of determining vital signs. For example, although vital sign measurement is quicker using automated techniques, the accuracy of these measurements in many cases is unknown. A study found in the original systematic review compared vital sign measurements by conventional methods versus automated measurements and found that the latter saved 20 seconds per person, which according to the researchers represented a significant saving when viewed in terms of all hospital patients over a 1-year period.8 However, the study did not provide accurate data on the accuracy of vital signs taken using machines and monitors. Additionally, currently used automated blood pressure measurement devices seem to be less accurate at increasing blood pressure levels.9 In updating this review, databases will be searched for studies addressing advanced technology and vital signs measurement. This review is an update of a previously published systematic review.1 The original review highlighted the lack of research on many important issues concerning vital sign measurement. Little research has been done on the general issues relating to vital signs, such as the need for vital signs and what parameters should be used. The purpose of this review is to identify, appraise and summarise the best available evidence regarding the vital signs utilised by nurses to monitor hospital patients. This systematic review aims to provide important information and benefits for patient safety, nursing practice and education of health professionals. Question / Objectives The primary objective of this review is to find the best available practices and information in relation to the monitoring of patient vital signs in hospitals and also to summarise the findings of relevant studies. The specific objectives of the review are to determine: the purpose of monitoring patients' vital signs; how to measure vital signs (methods); accuracy of the methods used; the optimal frequency for monitoring vital signs; and limitations of vital signs measurements. In addition to this, the review will seek to identify additional issues of importance such as the value of vital signs as indicators of serious illness and the role of new technology in patient monitoring. This review will also seek to find whether the traditional four vital signs can be extended to include a fifth vital sign, such as pulse oximetry or pain. Criteria for considering studies for this review Types of studies The review will consider any quantitative or qualitative studies addressing some aspect of vital sign measurements to ensure all issues of importance are identified. Types of participants Studies that include neonatal, paediatric and adult hospital patients will be included in the review. Types of intervention Interventions of interest are those related to the determination of: the optimal frequency of vital sign measurement; the limitations of vital signs; and the measurements needed to ensure patient safety or adequate monitoring. Types of outcome measures Outcomes of interest include accuracy, the required frequency of or the need for vital signs. Search strategy The search will seek to find both published and unpublished studies written in the English language. A three-step search strategy will be used. An initial search of Medline and CINAHL databases will be undertaken to identify optimal search terms, followed by a second search using all identified key words and index terms. The updated search strategy incorporates the period October 2003 to December 2007. Initial search terms: vital and sign* patient and observation* patient and monitoring Second search terms include: heart rate AND (determin* OR measure*) blood pressure AND (determin* OR measure*) body temperature AND (determin* OR measure*) respiratory rate AND (determin* OR measure*) vital signs AND (determin* OR measure*) fifth vital sign AND (determin* OR measure*) monitoring AND physiological AND/OR nursing pulse AND evaluat* pulse oximetry AND (determin* OR measure*) patient oxygenation AND (determin* OR measure*) pain AND vital sign (determin* OR measure*) blood and pressure in ti respirat* in ti pulse in ti temperature in ti vital and sign* in ti observation* in ti. The following databases will be searched: CINAHL (October 2003 - December 2007); Medline (October 2003 - December 2007); Current Contents (October 2003 - December 2007); Cochrane Library (October 2003 - December 2007); Embase (October 2003 - December 2007); Academic Search Premier (October 2003 - December 2007). . The third and final search for unpublished studies or grey literature will include: Dissertation Abstracts International (October 2003 - December 2007) Grey Literature Report: The New York Academy of Medicine Library (October 2003 - December 2007) GoogleScholar (October 2003 - December 2007) Assessment of methodological quality Methodological quality of all articles and study reports will be assessed for relevance to the review using the inclusion criteria developed by JBI (Appendix 1). Data collection/ extraction Data will be extracted from studies using a data extraction tool developed by JBI (Appendix 2). Data synthesis As the topic is conceptually broad and the review will address many different aspects to it, statistical pooling of results from different studies will not be attempted. Results will be summarised in narrative form, identifying emerging themes, issues of importance, limitations or gaps in the available research (Appendix 3). Potential conflicts of interest None Acknowledgements This protocol is an updated version of a previous systematic review.1