Intravenous (IV) fluids, especially crystalloids, are routinely used in hospitalized patients throughout the patients' stay. Intravenous fluids are a regular daily occurrence, so their importance is often overlooked. Many patients receive large volumes of fluid during resuscitation to aid in promoting tissue perfusion and regulating hemodynamics (Marik et al, 2017). Intravenous fluids are used also as maintenance or replacement fluids and as carriers of medications or nutrition (Malbrain et al, 2018; Silversides et al, 2020). Several studies have attempted to determine the optimal amount and type of fluid for patients, as well as the best time to infuse these fluids (Bartels et al, 2013; Marik, 2016; Vincent, 2019; Casey et al, 2020; Hammond et al, 2020). As nurses regularly administer IV fluids, either as part of maintenance infusions or as lifesaving therapies, they need to understand thoroughly how IV fluids impact their patients (Casey et al, 2020; Marik, 2016). Increasing amounts of new research demonstrate a direct link between IV fluid resuscitation, persistent hypervolemia, and patient outcomes and, therefore, the need to improve intravenous fluid stewardship (Monnet et al, 2016). To improve upon IV fluid management practices first it is necessary to gain a better understanding of nurses' existing perceptions regarding those practices, which is the primary aim of this study. The secondary purpose is to identify potential gaps in knowledge about IV fluid management practices.
Methods
Study design
This study used an online survey to gather information on nursing perceptions of IV fluids. This study was approved by the Fraser Health Research Ethics Board (Ethics #2022325). The survey platform, Qualtrics, was approved by the Research Ethics Board and, prior to the start of the survey, included an explanation that completion of the questionnaires constituted implied consent. No participant identifying data were collected.
Setting and sample
The Canadian publicly funded healthcare system covers all costs of IV fluids used in hospitals. Nurses working in acute care, including registered nurses (RNs), licensed practical nurses (LPNs), and student nurses from across Canada were invited to participate. The survey was open from May 2022 to August 2022. The invitation to participate was sent out by email through the primary investigator's network. The email contained a link to the online survey and an invitation to share broadly. Also, social media recruitment through Facebook and LinkedIn was used, with a request to share broadly.
Data collection and analysis
A survey involving three parts was designed for data collection. Part One presented 18 statements about IV fluid practices and nursing perceptions, which participants were asked to rate using a Likert scale from (1) strongly disagree to (5) strongly agree. Part Two was comprised of six multiple-choice questions to gather information about participants' understanding of patient assessment parameters concerning volume status. The participants were given multiple options and asked to choose all options that applied. Part Three had three multiple-choice questions evaluating the participants' understanding of volume status versus volume responsiveness and one open-ended question asking what resources or tools participants had access to in their current hospital units to help them assess a patient's volume status. Basic demographic data, including province or territory of employment, type of hospital, type of unit, professional role, age, gender, and years in health care were also collected. Descriptive statistics were used to analyze the results.
Results
Participant demographics
A total of 512 participants initiated the survey, with 462 completing the full survey (Table 1). The participants included RNs, LPNs, and students ranging in age from 21 to 66 years old, who had been in health care between 0.5 and 47 years. There were participants from nine provinces and two territories from a wide range of academic, tertiary, community, and rural hospitals. A considerable variety of nursing unit types and patient populations were represented as well.
Table 1. Demographics
| Demographics (n=462) | ||
|---|---|---|
| Province/Territory | British Columbia | 379 (82%) |
| Alberta | 10 (2.2%) | |
| Saskatchewan | 1 (0.2%) | |
| Manitoba | 3 (0.6%) | |
| Ontario | 57 (12.3%) | |
| Quebec | 4 (0.9%) | |
| Maritimes (Nova Scotia, New Brunswick, Newfoundland & Labrador) | 6 (1.4%) | |
| Territories (Northwest Territories, Nunavut) | 2 (0.4%) | |
| Hospital type | Academic | 119 (26%) |
| Tertiary | 196 (42%) | |
| Community | 138 (30%) | |
| Rural | 9 (2%) | |
| Unit type | Cardiology | 16 (3.6%) |
| Critical Care | 88 (19%) | |
| Emergency department | 86 (18.6%) | |
| Geriatrics | 3 (0.7%) | |
| Internal medicine | 9 (1.9%) | |
| Maternity | 16 (3.6%) | |
| Medical | 117 (25.3%) | |
| Oncology | 6 (1.3%) | |
| Operating room | 5 (1%) | |
| Palliative care | 6 (1.3%) | |
| Pediatrics | 9 (1.9%) | |
| Post-anaesthesia care unit | 14 (3%) | |
| Psychiatry | 5 (1%) | |
| Surgical | 59 (12.8%) | |
| Other | 23 (5%) | |
| Patient population | Adult | 337 (73%) |
| Mixed | 102 (22%) | |
| Neonates | 12 (2.6%) | |
| Paediatrics | 11 (2.4%) | |
| Nursing role | Registered nurse (RN) | 349 (76%) |
| Licensed practical nurse (LPN) | 103 (22%) | |
| Student nurse | 10 (2%) | |
| Age | Range | 21 to 66 years |
| Average | 38 years | |
| Gender | Female | 415 (90%) |
| Male | 39 (8%) | |
| Prefer not to answer | 8 (2%) | |
| Years in health care | Range | 0.5 to 47 years |
| Average | 12 years | |
IV fluid practices and nursing perceptions
In Part One, survey participants were asked to rate statements about IV fluid practices and nursing perceptions, using a Likert scale from (1) strongly disagree to (5) strongly agree. Overall, participants recognized the importance of IV fluids, including the type, amount, and potential impact fluid status can have on patient outcomes (Table 2). The majority of participants (91.8%) did not believe all hospitalized patients require IV fluids, and 95.6% recognize that IV fluid status can impact a patient's outcomes. Most also agreed that the type of IV fluid and the amount a patient received were important and that knowing a patient's accumulative fluid balance and overall fluid status is part of their role as a nurse. The results were consistent among the different groups of nurses when compared with specialty areas and healthcare experience.
Table 2. Perceptions about IV fluids
| Perceptions (n =462) | |
|---|---|
| All hospitalized patients require IV fluids | Agree: 9 (1.9%) |
| Neutral: 29 (6.3%) | |
| Disagree: 424 (91.8%) | |
| The type of IV fluids a patient is receiving is important | Agree: 457 (98.9%) |
| Neutral: 4 (0.9%) | |
| Disagree: 1 (0.2%) | |
| The amount of IV fluid a patient is receiving is important | Agree: 453 (98%) |
| Neutral: 6 (1.3 %) | |
| Disagree: 3 (0.7%) | |
| Measuring a patient's intake and output is important | Agree: 430 (93.1%) |
| Neutral: 28 (6.1%) | |
| Disagree: 4 (0.8%) | |
| Knowing a patient's accumulative fluid balance is important | Agree: 423 (91.5%) |
| Neutral: 35 (7.6%) | |
| Disagree: 4 (0.9%) | |
| Knowing a patient's fluid status is part of my roles and responsibilities as a nurse | Agree: 455 (98.5%) |
| Neutral: 6 (1.3%) | |
| Disagree: 1 (0.2%) | |
| A patient's acute medical diagnosis must be considered when determining the type of fluid and amount to be given | Agree: 460 (99.6%) |
| Neutral: 0 (0%) | |
| Disagree: 2 (0.4%) | |
| A patient's past medical history must be considered when determining the type of fluid and amount to be given | Agree: 429 (92.9%) |
| Neutral: 26 (5.6%) | |
| Disagree: 7 (1.5%) | |
| A patient's lab values must be considered when determining the type of fluid and amount to be given | Agree: 457 (98.9%) |
| Neutral: 5 (1.1%) | |
| Disagree: 0 (0%) | |
| A patient's !uid status impacts their overall outcomes | Agree: 442 (95.6%) |
| Neutral: 16 (3.5%) | |
| Disagree: 4 (0.9%) | |
Patient assessments and IV fluids
While Part One of the survey indicated that nurses perceived management of IV fluids to be an important part of their role in the care of hospitalized patients, Part Two revealed a wide variety of assessment parameters and practices. Nurses reported utilizing many different parameters to determine fluid status, including chest X-ray results, physical assessment findings, intake and output balance, vital signs, cardiac output, and central venous pressure (Figure 1). The most common parameters used to determine fluid status were assessment findings, followed by intake and output measurements, and vital signs. As with nursing practices and perceptions (Part One) above, patient assessment (Part Two) results were consistent among the different groups of nurses when compared with specialty areas and healthcare experience.
Nurses described a variety of assessment indicators they used to determine if a patient required fluids, including blood pressure, urine output, heart rate, cardiac index, central venous pressure (CVP), mucus membranes, and skin turgor (Figure 2). They also reported numerous factors they considered when assessing a patient's volume status and need for additional IV fluids (Figure 3). Overall, a wide variety of practices appeared to be employed when assessing volume status and the need for additional fluids. These results, too, were consistent among the different groups of nurses when compared with specialty areas and healthcare experience.
Volume status and volume responsiveness
Part Three of the survey asked participants to answer three questions regarding their knowledge of volume status versus volume responsiveness. Ninety-one percent of participants recognized a difference between volume status and volume responsiveness. However, there was no clear consensus on which assessment variable measured volume responsiveness. Forty-five percent of participants believed heart rate and blood pressure indicated volume responsiveness, whereas 13.4% indicated stroke volume, 9.3% indicated CVP, 1.7% indicated jugular vein distention, and 30.6% indicated they were unsure which parameter indicated volume responsiveness. When asked to determine if a patient's intake and output, weight, chest X-ray, and presence/absence of crackles and pitting edema were useful in determining fluid volume status or fluid responsiveness, 71% correctly identified fluid volume status, whereas 8.4% believed the factors represented fluid responsiveness and 20.6% were unsure.
The final question of Part Three allowed participants to share what resources they currently have for assessing patients' fluid status and responsiveness. Most participants indicated that basic vital sign machines (including heart rate, blood pressure, and oxygen saturation) were used. Many also indicated they used urine output, scales, and stethoscopes to assist in their assessments. Very few indicated they had access to or used advanced monitors. Participants that indicated access to advanced monitors described cardiac rhythm monitors, cardiac output monitors (most notably, pulmonary arterial lines), CVP, and arterial lines.
One participant indicated that point-of-care ultrasound (POCUS) was available for assessments if the physician could perform the bedside assessment.
Discussion
Intravenous fluid administration is a common occurrence among hospitalized patients. Patients often receive IV fluids for various reasons while in the hospital, including resuscitation, maintenance, and as carriers of medications and nutrition (Mitchell et al, 2015; Marik, 2016; Marik et al, 2017; Malbrain et al, 2018). Our study highlighted an ongoing knowledge gap among nurses concerning comprehending IV fluid management practices and assessments. This knowledge gap has been an issue among nurses and physicians (Iregui et al, 2003; Cannesson et al, 2011; Silversides et al, 2020). The figures presented in our findings provide an overview of the vast differences in knowledge and techniques being used by nurses to assess both fluid status and fluid responsiveness. These findings stress that more education and training are necessary for nurses to understand the difference between fluid responsiveness and fluid volume status.
Although there was a consensus that IV fluids were important to patient outcomes, there was a lack of awareness of how to appropriately assess both fluid status and responsiveness. This lack of awareness was similar to other published studies and the KIND study conducted by Toth et al (2022). Recent studies have started to highlight the importance of fluid balance, especially hypervolemia, as an indicator of patient outcomes (Mitchell et al, 2015; Schindler and Marx, 2016; Silversides et al, 2016; Marik et al, 2017; Casey et al, 2020; Silversides et al, 2020). Hypervolemia has been associated with worse patient outcomes (Mitchell et al, 2015; Marik et al, 2017; Casey et al, 2020; Silversides et al, 2020). Casey et al (2020) found that being fluid-overloaded was a significant risk for acute respiratory distress syndrome (ARDS). Marik et al (2017) found that patients who received greater than five litres of fluid on their first day in the intensive care unit (ICU) had a significantly higher mortality rate than those who received less than five litres. Other authors reported altered end-organ function, significant edema, prolonged mechanical ventilation, immobility, acute kidney injury, and increased mortality with hypervolemia (Mitchell et al, 2015; Marik, 2016; Monnet et al, 2016; Silversides et al, 2016; Vincent, 2019). As more evidence is amassed about the adverse sequelae of hypervolemia, more attention should be focused on intravenous fluid stewardship. Our study supports that more education and attention to fluid practices are necessary.
Overall, this study demonstrated that nurses continue to rely on traditional monitoring (eg, blood pressure, heart rate) and do not have access to more sophisticated technology designed to assess fluid responsiveness. While trending of vital signs is valuable and necessary, basic static measurements do not measure fluid responsiveness only volume status (Marik, 2016; Monnet et al, 2016; Schindler and Marx, 2016; Monge Garcia and Gonzalez, 2017). Although nurses recognized the difference between fluid status and responsiveness, by not understanding how to measure responsiveness nurses have demonstrated a need for further education. Providing additional education in nursing programs surrounding IV fluids, assessments, and responsiveness will benefit nurses and their patients.
Most participants did not have access to appropriate tools to help them adequately assess their patients' fluid responsiveness. Therefore, by using static rather than dynamic measurements, patients' fluid responsiveness cannot be sufficiently measured to determine if additional fluid is necessary. Without a proper understanding of the differences between fluid status and responsiveness and the proper education and technology to measure fluid responsiveness, many hospitalized patients may be receiving additional unnecessary IV fluids contributing to a state of hypervolemia, potentially leading to worse patient outcomes.
Strengths and limitations
The strengths of this study include the national representation of a diverse group of nurses. The sample represented a wide range of experience and practice areas. The sample size was a limitation of the study. Recruitment in the spring of 2022 may have influenced recruitment, as staffing and nurse fatigue post-pandemic were factors. However, a similar study conducted across the United States recruited 291 participants with similar findings.
Conclusion
In summary, our study supports improving nursing education to understand better the differences between fluid volume status and fluid volume responsiveness. Our study also provides evidence that nurses need access to more sophisticated tools to conduct dynamic assessments and better meet patients' needs.