Fluid Management in the Elderly

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Current Anesthesiology Reports e-ISSN 2167-6275 Curr Anesthesiol RepDOI 10.1007/s40140-017-0243-4

Fluid Management in the Elderly

David G. A. Williams, Aaron J. Sandler,Elena Koepke, Erin L. Manning,Timothy E. Miller & MichaelW. Manning

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GERIATRIC ANESTHESIA (S AKHTAR, SECTION EDITOR)

Fluid Management in the Elderly

David G. A. Williams1 & Aaron J. Sandler1 & Elena Koepke1 &

Erin L. Manning2 & Timothy E. Miller1 & Michael W. Manning1,3

# Springer Science+Business Media, LLC 2017

AbstractPurpose of Review As the population ages and more numbersof surgeries are performed in the elderly, little thought hasbeen given to the proper fluid management for the aging pa-tient. This presents a unique challenge in perioperative man-agement due to the normal physiologic changes that occur asorgan systems age.Recent Findings Despite our current understanding of cardio-vascular and renal aging, appropriate fluid management re-mains poorly understood. Current trends in goal-directed ther-apy demonstrate favorable postoperative outcomes; however,little is known as to the best application of fluid managementin the elderly.Summary By using minimally invasive cardiac output moni-tors to guide fluid therapy and maximize tissue perfusion,patient-specific individualizedmanagement is achieved whichmay be beneficial to the elderly population as fluid-handlingorgan systems diminish. Perioperative fluid management ofelderly surgical patients must be considered in the context ofthe reduced organ-specific functional reserve associated withnormal aging.

Keywords Perioperative fluid management . Elderlyphysiology . Goal-directed therapy

Introduction

It is projected that there will be 83.7million people in the USAaged 65 and older by the year 2050, according to the USCensus Bureau [1]. This estimated elderly population repre-sents almost double the estimated elderly population in 2012.The baby boom that occurred in the USA after World War IIhas been shaping the age structure of the USA since their birthand is projected to continue to influence the characteristics ofthe nation as they continue to age. More than 20% of the totalUS population will be over the age of 65 by 2029, and by2056, the population 65 years and over is projected to becomelarger than the population under 18 [1]. As the number ofelderly patients who will require surgical procedures in-creases, a significant proportion of these patients are likelyto be high-risk elderly patients with multiple comorbidities.

Perioperative fluid management is a major component ofperioperative optimization pathways, and the optimal periop-erative fluid strategy selected is an important determinant ofclinical outcome. Despite the association between fluid imbal-ance and impaired postoperative recovery, increased morbid-ity, and prolonged hospital stay [2, 3], there is no consensus onevidence-based standardized perioperative procedure-specificguidelines for fluid management.While most clinicians acceptthat perioperative management should achieve and maintainadequate fluid balance to guarantee tissue perfusion and oxy-genation, “restrictive,” “liberal,” and “balanced” fluid thera-pies have all been advocated as the most beneficial for patientoutcomes [4].

Goal-directed therapy (GDT) has shown favorable patientoutcomes in colorectal and abdominal surgeries through its

This article is part of the Topical Collection on Geriatric Anesthesia

* Timothy E. [email protected]

1 Division of General, Vascular, and Transplant Anesthesiology, DukeUniversity Medical Center, Box 3094, 2301 Erwin Rd,Durham, NC 27710, USA

2 Division of Regional Anesthesiology, Duke University, Box 3094,2301 Erwin Rd, Durham, NC 27710, USA

3 Division of Cardiothoracic Anesthesiology, Duke University, Box3094, 2301 Erwin Rd, Durham, NC 27710, USA

Curr Anesthesiol Rephttps://doi.org/10.1007/s40140-017-0243-4

Author's personal copy

use of colloid administration to optimize cardiac output andtissue perfusion based on real-time assessment of stroke vol-ume and stroke volume variation [5, 6••]. When combinedwith crystalloid administration to replace basal fluid require-ments and extracellular losses, GDT may prove similarly ad-vantageous as a strategy for perioperative fluid managementin the elderly population as their age-related organ changesrequire a more individualized approach to fluid therapy. Age-related changes in cardiovascular hemodynamics, such as re-duced cardiac output, systemic hypertension, and diastolicdysfunction, may increase the risk for worse patient outcomeswhen faced with generous fluid burdens [7]. This is furthercompounded by a progressive reduction in renal perfusion,filtration, and maximal free water clearance, therefore predis-posing the elderly patient to fluid retention [8]. Changes in theactivity or responsiveness of the renin-angiotensin system(RAS) occur with aging and may also predispose the elderlyto various fluid and electrolyte imbalances, as well as acutekidney injury and chronic kidney disease [9, 10]. Thesechanges in the organ system function occur with aging, withsome slight, individual variations within this population.

It is important that the distinction is made between thenormal progressive decline of function occurring in all olderpersons and the loss of function that represents pathologicalchanges resulting from diseases which are encountered withincreased prevalence in the older population. In this review,we will discuss some of the physiological changes that occurwith natural aging in multiple organ systems and their conse-quence for various therapeutic approaches to perioperativefluid management of the aging patient.

Restrictive vs. Liberal Perioperative FluidAdministration

There has been a long debate over the appropriate volume offluid that should be administered during the perioperative pe-riod [11–13]. A randomized, controlled trial by Brandstrupet al. investigated 141 patients undergoing major colorectalsurgery [14]. Compared to the liberal group, intra- and post-operative fluid restrictions (mean ~ 2.7 vs. ~ 5.4 L per day)significantly reduced the incidence of major and minor com-plications, including pulmonary edema, pneumonia, anasto-motic leakage, and wound infection, while preserving renalfunction [14]. Similarly, Nisanevich et al. studied 152 patientsundergoing various major intra-abdominal procedures whointraoperatively received either restricted or liberal fluid regi-mens. Decreased postoperative morbidity and a shortenedhospital stay were observed in the restrictive group [15].Moreover, in a small, randomized, double-blind small studyof 23 patients undergoing fast-track colon surgery, Holte et al.demonstrated that restrictive (~1.6 L) intraoperative fluid ad-ministration showed an improvement in pulmonary function

and postoperative hypoxemia when compared with liberal(~5 L) fluid administration [12].

Several studies, however, have demonstrated that liberalfluid administration improves outcomes after major abdomi-nal surgery [16, 17]. Using tissue oxygenation as an outcomeparameter, Arkilic et al. reported that liberal perioperative flu-id administration (~ 3.8 vs. 2 L) increased tissue oxygenationin 56 patients undergoing elective colon resection [16]. Thisincrease in tissue oxygenation is suggestive of lower woundinfection rates [18]. However, the study did not measureweight gain, development of tissue edema, cardiopulmonarycomplications, anastomosis healing, length of hospital stay,and bowel function, which are known effects of excessivefluid administration [11, 14]. Interestingly, MacKay et al.found no statistical difference in the time to return of gastro-intestinal function and length of hospital stay between thestandard and restrictive fluid regimens in a study of postoper-ative fluid administration in 80 patients undergoing colorectalsurgery [19]. A careful analysis of the study design, however,reveals that both groups were treated with a relative restrictionof fluid administration (mean 2.6 vs. 2 L per day) and nopatient received more than 3 L of fluid a day [19]. This sug-gests that even the standard group was treated too restrictivelyfor the manifestations of excessive fluid administration to be-come apparent [19].

More recently, researchers have been able to use big datawhen analyzing electronic medical records comparing differ-ent perioperative fluid regimes. By reviewing a large databaseof patients within an enhanced recovery program (ERP), it hasbeen shown that each additional liter of fluid administeredintraoperatively is associated with a 16% increase in the riskof postoperative symptoms and a 32% increase in the proba-bility of postoperative complications [20].

While the studies reviewed above lack consistency withregards to the definitions of liberal and restrictive therapiesin terms of milliliters per kilogram per hour and differ in theperioperative period studied and the type of fluids adminis-tered, most experts believe that avoiding fluid excess is asso-ciated with improved outcome [11, 20]. A much larger trialcomparing restrictive and liberal fluid regimes, the RELIEFstudy, has just finished enrollment. The study recruited 2800patients undergoing major abdominal surgery, with the prima-ry endpoint of disability-free survival 1 year after surgery [21].Results are expected in 2018 and should further informclinicians.

Goal-Directed Therapy

With the understanding that perioperative fluid administrationcontributes to patient outcomes, it becomes necessary to find amore reliable way to guide fluid therapy that is individualizedto the type of patient and procedure. GDT is a patient-specific

Curr Anesthesiol Rep


individualized technique that utilizes cardiac output monitor-ing to guide fluid titration in order to optimize tissue perfusion[22]. The fundamental principle of GDT is based on theFrank-Starling physiology, such that a dynamic assessmentis made by administering a 3 mL/kg intravascular fluid chal-lenge and directly observing the heart’s ventricular response.If the stroke volume or cardiac output increases by at least10%, this is highly predictive of significant cardiac outputincrease with additional intravascular fluid administration, asthe patient is likely hypovolemic and is on the steeper part ofthe Frank-Starling curve. A response of less than 10% is pre-dictive that the patient is unlikely to increase perfusion withadditional fluid [22]. Typically, fluid loading is with colloid,and the optimization strategy can also include administratinginotropes (i.e., dopamine/dobutamine/norepinephrine/epi-nephrine) to optimize physiology when needed.

Mayer et al. investigated the impact of an optimizationprotocol on outcome in 60 high-risk patients scheduled formajor abdominal surgery [23]. The GDT protocol consistedof dobutamine, norepinephrine, and colloid boluses to main-tain a cardiac index of at least 2.5 L/min/m2 and resulted in asignificant reduction of the length of hospital stay and periop-erative complications compared with a standard managementwith pressure-based goals [23].

A Cochrane meta-analysis of 24 studies with a combinedtotal of 2677 patients demonstrated that GDT was associatedwith a reduction in both the duration of hospital stay andcomplications, including those of renal and respiratory failuresas well as wound infection [24]. Although they concluded thatthere was limited evidence to support the widespread imple-mentation of GDT, they did suggest that the greatest benefitmay be found in high-risk patients.

This leads to the more recent Optimization of CardiovascularManagement to Improve Surgical Outcomes (OPTIMISE) studywhich was a multicenter, randomized, observer-blinded trial of734 high-risk patients comparing GDT with usual care [6••].Although the difference did not achieve statistical significance(p = 0.07), it showed a strong trend for patients receiving GDT toexperience fewer complications in the first 30 postoperative days(36.6%) compared to control patients (43.4%). Unfortunately,the complication was lower than expected from prelimi-nary data used to calculate the sample size for the trial(complication rate 68%) and hence, the study was under-powered. Unfortunately, this study did not provide a de-finitive answer; however, the OPTIMISE II trial, with anincreased sample size of 2800 is starting recruitment andshould provide more definitive answers.

Aging Cardiac Physiology

Aging is associated with structural changes in the heart. Thesechanges include an increasing myocardial thickness and wall

stress, owing to increased cardiomyocyte size and fibrosiswithin the interstitial space of the myocardium. With the pro-gressive stiffening of the arteries that occurs with age, partic-ularly in the thoracic aorta, afterload increases over time andresults in adaptive changes such as increased left ventricular(LV) wall thickness and alters myocardial contractile efficien-cy [25, 26]. Increasing sympathetic nervous system (SNS)activity is also observed in older persons. Hypertension andcoronary artery disease are the two most common causes ofheart failure in all ages, including older adults [27]. In patientswith no history of cardiac disease, cardiac output (CO) de-creases linearly after the third decade of life at a rate of about1% per year [28]. However, the aging patient may compensatewith an increased ejection fraction and typically produces astroke volume, cardiac output, and overall systolic functionthat are adequate to meet their resting physiologic require-ments [25, 29–31].

In the absence of heart failure, stroke volume (SV) isthought to be maintained throughout life such that the declinein CO is likely due to impaired maximal heart rate. The agingmyocardium has a decreased inotropic response to catechol-amines, both endogenous and exogenous, as well as a de-creased response to cardiac glycosides. Compared to youngerhealthy individuals, the senescent heart has an increasedisovolumetric relaxation time and a decrease in passive ven-tricular filling during the early diastolic phase [26, 32, 33].Interestingly, the end-diastolic volume remains unchanged orincreases somewhat with rest- and low-level exercises. This islargely the result of a slower heart rate typically seen in aginghearts, which allows for longer filling times. Substantial def-icits are uncovered in the older population when the peakfilling rate at maximal exercise is compared to younger indi-viduals [30]. [Typically] an increase in tissue oxygen demand(by exercise or surgical stress) induces an increase in SV andheart rate in order to increase overall cardiac output. Thisincreased heart rate also increases the rate of isovolumetricrelaxation and produces a “suction” effect which contributesto ventricular filling in the early phase of the diastole.However, these responses are diminished with aging as a re-sult of impaired relaxation, reduced β-adrenergic responsive-ness, and alterations in the pattern of relaxation [34, 35].

Impairment of LV relaxation has clinical implications onthe aging heart’s ability to handle increases in preload.Myocardial relaxation was initially considered not to be af-fected by preload conditions [36]; however, Gilbert demon-strated that in a patient with reduced LV diastolic function, aleg elevation maneuver can result in a substantial increase inend-diastolic pressure [37]. This case report suggests that anyexcess in fluid can induce a dramatic and potentially detrimen-tal increase in LVend-diastolic pressure (LVEDP). Moreover,since LV filling mainly depends on the pressure gradient be-tween the left atrium (LA) and LV, impairment of LV compli-ance (decreased LA-LV pressure gradient) or the loss of atrial



contraction will directly impair diastolic filling. With increas-ing LV diastolic dysfunction, the diastolic portion of thepressure/volume loop (compliance curve) is shifted to the leftand upward (Fig. 1). Consequently, for a given LV end-diastolic volume (LVEDV), LVEDP is increased and mayresult in pulmonary congestion.

Aging Renal Physiology

A gradual decrease in renal mass is observed with advancingage. Diminished glomerular lobulation and glomerulus scle-rosis tend to reduce the surface area available for filtration.This, in conjunction with increased hyalinization of afferentarterioles and tubulointerstitial fibrosis, contributes to the ob-served age-related decline in the filtration coefficient and glo-merular filtration rate (GFR) [9]. There is a concomitant re-duction in creatinine production such that serum creatinineremains relatively constant despite the age-related decreasein creatinine clearance (CrCl) and GFR.

Total body renin and aldosterone levels fall during aging,due to decreased renin production and release [38, 39].Decreased responsiveness of the RAS leads to decreased reninrelease when appropriate stimuli are present [40]. This maypredispose elderly patients to low circulating blood volumes,especially during periods of fasting [8]. Contrarily, there maybe an exaggerated physiologic response to renin and aldoste-rone when present due to their prolonged low levels [41].Moreover, there is a pathologic decrease in nitric oxide (NO)

[42] with aging, which leads to increased renal vasoconstric-tion, sodium retention (with resultant worsening hyperten-sion), and increased matrix production and mesangial fibrosis.

Renal blood flow declines by about 10% per decade afterthe fourth decade of life [43]. The decrease in renal blood flowand maximal free water clearance may decrease the renal sys-tem’s ability to handle excess fluid loads. This is further ex-emplified by the observation of an increased incidence of bothmicroalbuminuria and overt proteinuria that occurs with ad-vancing age in population studies, even in the absence ofdiabetes, hypertension, or CKD, predisposing this populationto cardiopulmonary circulatory fluid overload [44].

Perioperative Implications

Preoperative Fluid Management

Total body fluid content is inversely proportional to age. Tocompensate for insensible perspiration, urine, and fecal out-put, the daily basal fluid requirements for elderly patients are25–30 mL/kg, compared to about 40 mL/kg for young adults.Preoperative correction of fluid and electrolyte imbalances isimportant in the elderly to optimize postoperative outcomes.Elderly patients receiving bowel preparation prior to colorec-tal procedures can be moderately dehydrated (1–2 L) and mayhave a significant electrolyte imbalance [45, 46]. Impairmentof the RAS, paired with reduced sense of thirst and a deficit inurinary concentrating ability [47], may exacerbate their pre-operative dehydration and place them on the steeper part ofthe Frank-Starling curve. This fluid responsiveness state hasimplications for intraoperative hypotension, as their reducedability to increase their maximal heart rate makes their cardiacoutput become SV-dependent. Postoperative adverse cardiacevents have been associated with even brief periods of intra-operative hypotension in the general population [48], and theelderly patient may be especially susceptible due to the reduc-tion in cardiac reserve that occurs as we age. Perioperativehypotension is also a risk factor for postoperative cognitivedysfunction (POCD) in the elderly, and GDT may be protec-tive in this vulnerable population against the subsequenthealth and financial burdens. Encouraging a clear liquid oralintake up to 2 h prior to surgery is recommended [49] and issupported by the American Society of Anesthesiology (ASA)consensus guidelines on preoperative fasting [50]. In addition,oral intake of a maltodextrin carbohydrate drink before sur-gery has been shown to improve patient satisfaction, reducethirst, and improve insulin sensitivity [51••].

Intraoperative Fluid Management

It has been shown that both under-and over-resuscitationslead to increased morbidity, resulting in a characteristic U-

Fig. 1 Pressure/volume loop. The solid line represents a normal LVfunction. The dotted line represents LV diastolic dysfunction. Asdiastolic dysfunction increases with age, the main alteration in the P/Vloop is a shift in the end-diastolic pressure/volume relationship (EDPVR),whereas the end-systolic pressure/volume relationship (ESPVR) remainsunaltered. LVEDP, left ventricular end-diastolic pressure; MVO, mitralvalve opening; MVC, mitral valve closure; AVO, aortic valve opening;AVC, aortic valve closure



shaped curve [52, 53]. For induction of general anesthesia,consider infusing 3–5 mL/kg of crystalloid to counteractthe negative effects of anesthetic agents on cardiovascularstability. For major surgery (such as colorectal, vascular,orthopedic), a background crystalloid infusion should beadministered to replace fluid loss due to insensible perspi-ration and urine output, with maintenance requirementstypically 1–3 mL/kg/h (Table 1). Fluid boluses should beadministered to replace fluid deficits caused by acute bloodloss. Colloid solutions are frequently used for fluid bolusessince microvascular blood flow is enhanced by infusion ofa solution that remains mainly in the intravascular com-partment [3, 54]. Although there are no outcome studiessupporting the use of colloids for fluid boluses, colloid-based fluid regimens have been shown to enhance tissueblood flow and oxygen tension while crystalloid-basedfluids will rather impair tissue perfusion and oxygenation[55]. Due to the age-related functional decline in fluid han-dling, it is reasonable to use GDT for fluid management inthe elderly, as it evaluates hemodynamics in real time andallows for a patient-specific individualized therapy.

Postoperative Fluid Management

Adequate fluid resuscitation to maintain tissue perfusionshould be continued in the postoperative period. Urineoutput may not be a reliable marker of reduced intravas-cular volume or organ perfusion [56]. Oliguria, defined as< 0.5 mL/kg/h, may be a normal physiologic response tostress and surgery. A recent meta-analysis showed thatalthough postoperative fluid restriction increases the riskfor oliguria, it does not increase the incidence of acutekidney injury (AKI) [57]. Whereas traditionally, oliguriawould be treated with intravenous fluid boluses, this

additional fluid burden may actually be detrimental tothe patient [57].

Enhance recovery protocols (ERPs) advocate beginningoral intake early in the postoperative period. This greatly di-minishes the need for postoperative intravenous fluid admin-istration [58]. However, intravenous fluid administration com-bined with vasopressors may be required to treat postoperativehypotension, considering that a recent observational studysuggests that mean blood pressure (MBP) < 65 mm Hg forgreater than or equal to 15 min was associated with higherrates of myocardial and kidney injuries [48]. A goal-directedapproach, with titration of fluids and vasopressor guided byhemodynamic monitoring, is reasonable in this case.Moreover, patients with postoperative ileus or PONV mayalso require intravenous fluids and a basal rate of 1.5 mL/kg/h may suffice until oral intake can be initiated in these cases.These patients may also benefit from opioid-sparing analgesiaand early mobilization.

Summary and Conclusions

Amajor component of perioperative optimization pathways isperioperative fluid management, and the exact approach tofluid therapy has consequences on patient outcome.Perioperative fluid management of the elderly must be con-sidered in the context of the declining organ-specific function-al reserve associated with normal aging. These changes in-clude reduced cardiac and renal reserves, which make theelderly more vulnerable to water and electrolyte imbalanceswith a resulting increase in morbidity and mortality. A sug-gested strategy for optimizing perioperative fluid managementin the elderly is a combination of continuous crystalloid ad-ministration combined with individualized goal-directed

Table 1 Strategy for the optimization of perioperative fluid management in the elderly

Considerations when planning for the appropriate perioperative fluid therapy in the elderly

Preoperative period Encourage clear liquids until 2 h before induction of anesthesia; consider a preoperative carbohydrate drink

Intraoperative period Immediately prior to or during induction bolus 3–5 mL/kg (IBW) (to counteract myocardialdepressant effect of anesthetics).

Infuse 1–3 mL/kg/h (IBW) of crystalloid (to compensate for procedure-specific insensible losses,urine output, and basal requirement)

For major surgery, use GDT to optimize SV/SVV using cardiac output monitoring. Infuse 3 mL/kg ofcolloid over < 15 min when SVV is > 10%. If SV increases by > 10%, repeat bolus. If SVincreases < 10%, the patient does not require further bolus. Give further colloid bolus whenSV drops 10% from the peak value.

Measured blood loss should be compensated with an equal volume of colloid until the predeterminedcritical Hb level for blood transfusion is reached.

Postoperative period Encourage early oral intake where indicated. Provide basal fluid requirements 1.5 mL/kg/h (IBW),and compensate measured ongoing losses with a mixture of crystalloid and colloid.

The use of fixed crystalloid administration to replace basal fluid requirements and extravascular losses paired with individualized goal-directed colloidadministration guided by flow-based hemodynamic monitors to optimize cardiac stroke volume and tissue perfusion



colloid administration. By doing so, basal fluid requirementsand extravascular losses are replaced, while utilizing flow-based hemodynamic monitors to maintain an adequate intra-vascular volume to optimize cardiac stroke volume, tissueoxygenation, and oxygen delivery. With the increasing num-ber of elderly patients who will require perioperative care,further prospective studies are needed to deliver evidence-based fluid administration protocols for this population andimproved perioperative management.

Compliance With Ethical Standards

Conflict of Interest David G.A.Williams declares that he has no con-flict of interest.

Aaron J. Sandler declares that he has no conflict of interest.Elena Koepke declares that she has no conflict of interest.Erin L. Manning declares that she has no conflict of interest.Timothy E. Miller has received research funding through a grant from

Edwards Lifesciences and has received compensation from EdwardsLifesciences and Cheetah Medical for service as a consultant.

Michael W. Manning declares that he has no conflict of interest.

Human and Animal Rights and Informed Consent This article doesnot contain any studies with human or animal subjects performed by anyof the authors.

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Fluid Management in the Elderly