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Current Anaesthesia & Critical Care 21 (2010) 108–113

Contents lists avai

Current Anaesthesia & Critical Care

journal homepage: www.elsevier .com/locate/cacc

FOCUS ON: ENHANCED RECOVERY

Targeted fluid administration for major surgery

Daniel Conway a,*, Stuart Gold b,1

a Department of Anaesthesia, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UKb Department of Anaesthesia, Derby Royal Hospital, Uttoxeter Road, Derby DE22 3NE, UK

Keywords:Cardiac output monitoringIntravenous fluid administrationOesophageal Doppler monitoringMajor surgery

* Corresponding author. Tel.: þ44 1612764551; faxE-mail addresses: drdconway@aol.com, Daniel.Conw

stuart.gold@nhs.net (S. Gold).1 Tel.: þ44 1332 783430.

0953-7112/$ – see front matter � 2010 Elsevier Ltd. Adoi:10.1016/j.cacc.2010.01.001

s u m m a r y

Targeted Fluid Adminstration (TFA) is a technique using less invasive cardiac output monitors to guideindividualised intra-operative fluid therapy. Typically, the anaesthetist administers boluses of approxi-mately 200–250 ml of colloid solution whilst measuring changes in stroke volume or another measure offluid responsiveness, such as stroke volume variation. When the stroke volume measurements indicatethat the cardiovascular system is no longer fluid responsive, the patient is assumed to be close to theupper flat phase of the Frank–Starling Curve. Research using TFA suggests that post-operative compli-cations such as ileus and length of hospital stay are reduced when fluid therapy is managed in this way.Most of the positive evidence for TFA has been achieved using the oesophageal Doppler (CardioQ, DeltexMedical, Chichester UK), although other cardiac output monitors are available, there are few clinicaloutcome studies that justify their use in routine practice. Widespread adoption of TFA for patientsundergoing major surgery will help achieve the goals of enhanced recovery.

� 2010 Elsevier Ltd. All rights reserved.

1. Introduction

Adequate tissue perfusion during the peri-operative period isa key determinant of post-operative outcomes, complications,length of stay and even survival. Standard cardiovascular monitorsavailable to the anaesthetist include pulse, non-invasive bloodpressure and urine output in addition to clinical observation. Thesephysiological observations are not rapid or sensitive indicators ofhypovolaemia: it is possible to have a 15% reduction in circulatingvolume without any effect on heart rate or blood pressure. Similarlyurine output is assessed over at least 1 h before any effect of fluidresuscitation can be interpreted. Unfortunately standard moni-toring does not detect occult hypovolaemia or respond to large fluidshifts rapidly. This prevents the anaesthetist from giving fluids totreat hypovolaemia and provide optimal perfusion conditions.More invasive estimates of cardiac pre-load such as central venouspressure and pulmonary artery pressure have been advocated asperi-operative monitors. Extensive investigation of invasive pres-sure monitoring has consistently demonstrated that these devicespoorly predict the response of the cardiovascular system to changessuch as fluid challenge, fluid loss, changes in PEEP or changes in

: þ44 1612768027.ay@cmft.nhs.uk (D. Conway),

ll rights reserved.

patient position.1–3 Furthermore pressure-based monitoring isinvasive, time consuming, expensive and associated with signifi-cant clinical complications.

Studies in very high risk surgical patients have demonstratedthat targeting oxygen delivery using the pulmonary artery catheterto guide fluid and vasoactive drugs could improve post-operativepatient outcomes.4,5 However the benefits suggested by thesepromising early studies failed to materialise when repeated inlarger multi-centric randomised controlled trials.6,7 The use of thepulmonary artery catheter during major surgery has diminished asa result of the published evidence and the emergence of lessinvasive monitoring systems.

Less invasive cardiac output monitors have been developed inresponse to the desire of anaesthetists to offer optimal tissueperfusion using blood flow based monitors to guide fluid and drugtherapy. In order to gain widespread acceptability, these monitorshave demonstrated reliability and validity in estimating cardiacoutput and other cardiovascular parameters. They also need to beuser friendly, suitable for the theatre environment, minimallyinvasive and cost effective. These monitors can then be integratedinto a technique of ‘Targeted Fluid Administration’ (TFA): a pro-active, individualised approach to intravenous fluid therapy.Crucially, peri-operative techniques such as TFA should optimisetissue perfusion and improve the post-operative experience forpatients undergoing major surgery.

In this article, we will review the various monitors, fluids anddrugs which can be used to apply TFA for major surgical patients.

Measure Stroke Volume

200ml fluid over 5 minutes

Stroke Volume up > 10%? No Yes

No

Yes

Stroke Volume down > 10%?

Monitor Stroke Volume

Fig. 1. Targeted Fluid Administration. Clinical Algorithm.

Fig. 2. The characteristic waveform of oesophageal Doppler representing the velocitychange over time of blood pulsating in the descending aorta.

D. Conway, S. Gold / Current Anaesthesia & Critical Care 21 (2010) 108–113 109

2. Fluid therapy during major surgery: achieving a balancein unknown quantities

Major surgery presents a number of significant challenges to theanaesthetist such as producing adequate ventilation, oxygenation,hypnosis, muscle relaxation and pain relief (nociception) bothduring and after surgery. All these require a careful balance of thebeneficial and unwanted effects of drugs and mechanical inter-ventions during surgery which itself involves significant tissuedamage over a prolonged period of time. Perhaps the mostcontroversial area of anaesthetic management is intravenous fluidtherapy where advocates of liberal or restrictive administrationtechniques; different fluid formulations and various vasoactivedrugs can all claim to have supporting evidence. Below we willoutline the challenge and propose a rational fluid replacementtechnique, which is practical and associated with improved patientoutcomes. We believe that this technique should be fully integratedinto Enhanced Recovery Services.

2.1. Measuring tissue perfusion

One of the greatest challenges during and after major surgery ismaintaining adequate tissue perfusion to allow optimal delivery ofoxygen and nutrients whilst helping eliminate metabolic wasteproducts. Optimal tissue perfusion has been shown to reduceexcessive pro-inflammatory states and hence complicationsfollowing surgery. Adequate perfusion is very difficult to measureat the tissue beds in routine clinical practice, and so the anaes-thetist must rely on surrogate cardiovascular markers such as bloodpressure, stroke volume and cardiac output.

2.2. Measuring fluid status

Although fluid losses during surgeryare to be anticipated, the stateof hydration before and during surgery is unknown and measuringblood volume directly, whilst possible in principle, is invasive andsufficiently complex to prohibit use in day-to-day practice. Measuringfluid loss relies on careful measurement of surgical swabs and crudeestimation of evaporative and other insensible losses of perhaps up to1 mL/kg/h. Fluid overload is equally difficult to assess yet is associatedwith complications related to excessive tissue oedema such as ileusand respiratory distress. Again the anaesthetist has to rely on surro-gate markers to assess volume status yet commonly adoptedpressure-based surrogates: pulmonary capillary wedge pressure andcentral venous pressure, consistently fail to predict fluid responsive-ness.1–3,8 Dynamic surrogate measures of fluid responsiveness such asstroke volume variation, pulse pressure variation and to a lesserextent corrected flow time have all been shown to be superior topressure-based surrogates.9,10

3. Targeted fluid administration

‘Targeted Fluid Administration’ is a technique that utilises lessinvasive cardiac output monitors such as oesophageal Doppler toguide fluid boluses with the intention of maximising stroke volume(Fig. 1). These devices also display flow based surrogates of volumestatus. Whilst there is no proof that maximised stroke volume isequivalent to either optimal tissue perfusion or euvolaemia, it isclear that this technique particularly when instituted in a timelymanner at the start of anaesthesia is associated with a reduction inthe production of pro-inflammatory cytokines.11 Whilst these aremerely surrogate markers, using this technique has reduced post-operative complications leading to enhanced recovery anda reduction in length of hospital stay for patients undergoing majorsurgery in a number of randomised controlled trials.12,13

4. Using cardiac output monitoring to guide intravenous fluid

Targeted Fluid Administration has been demonstrated mostreliably with less invasive cardiac output monitors. Of these, theoesophageal Doppler is the most popular device, used in 7 rando-mised controlled trials; quality improvement projects and routineclinical practice around the world. For the purpose of this reviewarticle, we will concentrate on the use of the oesophageal Doppler.

5. Oesophageal Doppler monitoring (ODM)

ODM measures the velocity of blood flowing down thedescending aorta with each heartbeat. This is achieved by carefulplacement of a soft, flexible probe in the mid-oesophagus via thenose or mouth. The probe tip is gently manoeuvred until theultrasound beam is directed at the descending aorta. The Dopplershift principle then allows measurement of blood velocity in theaorta. This is can be represented by a typical triangular waveform(Fig. 2) and characteristic sound. By integrating the velocitywaveform to derive the average velocity and making assumptionsabout aortic cross- sectional area (based on weight, height and age)

D. Conway, S. Gold / Current Anaesthesia & Critical Care 21 (2010) 108–113110

and the proportion of cardiac output that flows to the head andupper body, the ODM will estimate stroke volume and cardiacoutput. ODM will also provide continuous measures of other vari-ables such as corrected flow time.

ODM has been shown to have reasonable validity, with no biasand high clinical agreement when compared to cardiac outputmonitoring with the invasive pulmonary artery catheter. Thisagreement is maintained during periods of significant haemody-namic change which occur in patients on intensive care or intheatre when techniques such as Targeted Fluid Administration areemployed.14 These changes can be quantified in terms of change inflow time, peak velocity as well as stroke volume (Fig. 3). Someexperienced anaesthetists will use the changes in the characteristicsound to judge subtle haemodynamic change during surgery.

ODM has been shown to have a short learning curve with mostusers competent with a programme of classroom and theatretraining. Whilst some commentators claim that this device is easyto use compared with invasive devices, we would advocate that anexperienced anaesthetist will be able to achieve Targeted FluidAdministration during major surgery most effectively. This isbecause intra-operative haemodynamic changes should be inter-preted in the context of the effects of anaesthesia, analgesia,surgery and the signal from the ODM probe which frequentlyrequires re-adjustment. Post-operatively ODM can facilitate nurse-led fluid therapy on the Intensive Care Unit.15

The ODM has a number of significant drawbacks which preventit from being the ideal monitor for Targeted Fluid Administration inall patients who could benefit. ODM cannot be used in patients withoesophageal pathology. ODM use in head and neck, oesophagealand gastric surgery is limited due to the proximity of the probe tothe surgical field. Despite attempts to design and promote nasalprobes for use in patients who are awake, these have failed to gainpopularity. Thus the ODM is rarely used in patients having proce-dures under regional anaesthesia or retained for post-operative usein the High Dependency or Post-Anaesthesia Care Units.

Despite these limitations, a recent report from the Centre forEvidence Based Purchasing concluded that the ODM had significantpotential to improve care for patients undergoing high risksurgery.16 This report reviewed all the relevant research intopatient outcome following ODM guided management and stated

Fig. 3. Predictable changes in the shape of the oesophageal Doppler waveform occurduring changes in the haemodynamic state of an individual. The most commonabnormality seen during Targeted Fluid Administration is hypovolaemia, usually at thestart of surgery which is represented by the narrow triangular waveform ‘Pre-loadreduction’.

that the addition of ODM should result in fewer post-operativecomplications with the cost of ODM being compensated for bya reduction in length of stay. A 2007 report from the US FederalAgency for Healthcare Research and Quality came to similarconclusions.17

The National Institute for Health Research Health TechnologyAssessment Programme have performed an economic evaluation ofODM compared with standard care with or without CVP moni-toring. The HTA modelled the impact of ODM on Quality AdjustedLife Year (QALY) calculations. This assessment revealed ODMguided Targeted Fluid Administration during major surgery to becost effective under almost all potential circumstances. The HTAestimated that between £581 and £11 600 extra would have to bespent on each survivor of surgery receiving ODM guided fluidbefore ODM would no longer be regarded as cost effective.18

5.1. Targeted fluid administration with oesophagealDoppler – a practical guide

Where possible the ODM probe should be inserted as soon aspracticable following induction of anaesthesia. Some prefer to dothis in the anaesthetic room before moving into the operatingtheatre. To avoid connecting and disconnecting the probe andmoving the monitor, it is feasible to move into the operating roomand insert the probe while the surgical team are preparing thepatient for surgery, for example by inserting the urinary catheter.

The probe can be inserted orally or nasally, there are markings toguide average depth of insertion for either of these sites. Manyanaesthetists find the nasal route provides the easiest route into theoesophagus and seems to hold the probe in a more stable positionintra-operatively.

The initial signal can be very difficult to pick up – this is likely tobe the lowest stroke volume the patient has during the whole case,making the signal difficult to find. If unable to find an adequateaortic signal we would advocate giving a small fluid bolus whichoften increases the stroke volume enough for the signal to besufficient for continuous monitoring.

Fluid boluses are given and stroke volume is assessed prior to,and following each bolus, The ODM signal should be optimisedeach time a fluid boluses are given. Newer ODM monitors have thefacility to graph, save and analyse changes in stroke volume whichmakes this process much easier to follow and record during theoperation.

Essentially the process of fluid boluses is continued as long asfluid boluses increase stroke volume by at least 10%. This processmakes physiological sense as we are attempting to constructa Frank–Starling curve for each individual patient by administeringfluid challenge until the peak of the individual’s particular Frank–Starling curve is reached (Fig. 1).

Clinicians who have extensive experience of using this monitortend to give more fluid at the beginning of the case than they wouldhave without ODM monitoring. Sudden changes in SV are often theresult of probe displacement and an attempt should be made torefocus the probe, however if the probe cannot be refocused toa better signal, alternative causes should sought; bleeding andmyocardial dysfunction being the two commonest causes.

As the operation comes to an end, the need for ODM guided fluidboluses has usually ceased for most uncomplicated elective surgery.Some ODM users attempt to leave the probe in while anaesthesia isreversed and the patient is woken up. There are significantadvantages to being able to use ODM in the recovery room tofurther guide fluid therapy in the conscious patient. In our expe-rience the signal is often too unstable to interpret in a recoveringpatient. However a study in post-operative cardiac surgical patients

D. Conway, S. Gold / Current Anaesthesia & Critical Care 21 (2010) 108–113 111

suggested that ODM guided fluid therapy in the intensive care unitmay be beneficial.15

5.2. Disadvantages of applying targeted fluid administrationwith ODM

Using TFA can be distracting for a single anaesthetist providinganaesthesia to the patient and interacting with the rest of the theatreteam. The noise of ODM can be distracting to surgeons while it isbeing focused. Surgical diathermy and harmonic scalpels causeelectrical interference which impairs the signal. If a nasogastric tubeis placed, the air inside the tube can interfere with the ODM signal.This can sometimes be rectified by filling the tube with fluid.

The ODM can be quite user dependent and requires regular re-adjustment to achieve an optimal signal. Ideally the probe shouldbe re-focussed prior to any clinical decision such as administeringa fluid challenge. This is particularly important when multipleanaesthetists are involved in a case.

The ODM is less reliable when the heart rate is high, or when therhythm is irregular. The readings in patients with atrial fibrillationcan be difficult to interpret and we suggest that the ODM is pro-grammed to average the stroke volume measurement over a longerperiod of time in these circumstances.

6. Alternative cardiac output devices

Other less invasive cardiac output monitors have been advo-cated for Enhanced Recovery Programmes and there is some data tosupport their use. It is even possible that by using measures of fluidresponsiveness, such as pulse pressure variation during mechanicalventilation, occult hypovolaemia can be detected and eliminated.

6.1. Pulse contour analysis less invasive cardiac output monitors

The potential for the arterial waveform to estimate the cardiacoutput has been recognised for some time. Devices using pulsecontour analysis techniques (PCA) are commercially available.Unfortunately, these devices have not been investigated in clinicaltrials of Targeted Fluid Administration to the same extent as ODM.However they may still have an important role to play, particularlyin situations where ODM use is precluded. Continuous monitoringof stroke volume with PCA was described by Wesseling, Lange-wouters and colleagues. Their calculations identified three keyfactors which will affect the interpretation of PCA based on theWindkessel (German for ‘Air Chamber’) phenomena, namely aorticimpedance, peripheral vascular resistance and aortic compliance.19

Interpretation of PCA when rapid changes in haemodynamicchanges occur can lead to inaccuracy. The devices become lessreliable at extremes of cardiac output. As a result, most PCA devicesutilise a second cardiac output measurement technique in order tocalibrate continuous PCA. Examples of calibration include trans-pulmonary thermodilution (PiCCO) and Lithium dye dilution(LiDCO). Auto calibrating PCA such as Flotrac Vigileo have beendeveloped using mathematical techniques which avoid the needfor time consuming calibration during surgery.

6.2. LiDCO

LiDCO� plus system employs two technologies. Initial cardiacoutput calibration is performed by lithium indicator dilution wherelithium chloride is injected ivand then detected bya lithium-sensitiveelectrode attached to an arterial cannula. The technique requiresarterial and venous cannulation; a central venous catheter is prefer-able. Although some patients receiving Targeted Fluid Administrationrequire invasive arterial and central venous monitoring, many do not

and so LiDCO would require additional invasive cannulation. LiDCOcalculates change in stroke volume by power analysis of the firstharmonic of the arterial pressure waveform looking for changes instroke volume rather than absolute values. This means that calibra-tion may be necessary during TFA. Only one clinical trial has reportedthe use of LiDCO in surgical patients. This study used a combination ofTFA and the vasoactive drug dopexamine after the end of surgery toachieve a target oxygen delivery of 600 mL/min/m2. This studydemonstrated less post-operative complications and a 3 day length ofstay reduction.20

6.3. PiCCO

PiCCO� differs from other PCA devices in that it utilizes onlythe area under the systolic portion of the curve. It is calibrated bythe transpulmonary thermodilution technique, which requires theplacement of a 5-French (Fr) thermistor-tipped arterial catheter. Itis necessary that the catheter is inserted into the femoral artery,making the PiCCO relatively invasive and therefore at increased riskof bleeding complications. Usually a central venous catheter isrequired as the injection point for thermodilution. As with LiDCO,these requirements are more invasive than would often be requiredfor patients undergoing elective colorectal surgery for example.

The authors are unaware of any clinical studies or randomisedcontrolled trials which evaluate the use of the PiCCO device forTargeted Fluid Administration.

6.4. Autocalibrating PCA (Edwards Vigileo�)

One drawback of PCA with PiCCO and LiDCO, is that it relies ona relatively simple, three-parameter model and needs recalibrationduring haemodynamic change, such as occurs during TargetedFluid Administration. The Edwards Flotrac Vigileo system incor-porates a more complex model to account for other phenomena,such as the pattern of pressure wave reflections due to impedancemis-matches. Vigileo attempts to improve PCA by estimating SV asa function of the ratio between the area under the entire pressurecurve and a linear combination of various components of imped-ance. In attempting to account for pressure reflections, the Vigileosystem relies not only on accurate estimates of pressure function,but also on mathematical adjustments of the mean pressure value.

Although initially disappointing validation studies of the Flo-Trac/Vigileo device were reported, more encouraging results aftersoftware updates have been published which demonstrateimprovements in a variety of patient groups including those withobesity.21 However, even with these software upgrades, manystudies investigating Vigileo continue to report cardiac outputmeasurement outside of the acceptable clinical range whencompared to other less invasive devices.22 The authors are unawareof any clinical studies or randomised controlled trials which eval-uate the use of the Vigileo device for Targeted Fluid Administration.

6.5. Bioimpedance cardiac output monitoring

Bioimpedance describes the passive electrical properties of bio-logical materials. When a current is passed between electrodesattached to the body, the ability to oppose current flow is termedimpedance (Z) which is measured in Ohms. Bioimpedance can act asan indirect transducing mechanism for monitoring physiologicalphenomena. For example, the rapid changes in bioimpedance thatoccur following the opening of the aortic valve probably relate tovolumetric changes in the aorta. Tetrapolar systems have beendeveloped which estimate the velocity of blood in the aorta. Thesenewer techniques use either four electrodes – two electrodes aroundthe neck, one electrode around the apex of the heart, and the fourth

D. Conway, S. Gold / Current Anaesthesia & Critical Care 21 (2010) 108–113112

further in caudal direction (ICON, Osypka Medical, Berlin) or eightspot electrodes arranged as four double electrodes which are placedon the upper and lower chest wall on each side (NICOM, CheetahMedical, Tel Aviv) (Fig. 4). These systems allow the amplitude of theimpedance change (dZ) to be measured as well as the frequency. ThedZ waveform is similar to the characteristic aortic velocity curvedisplayed by the ODM. The first time derivative dZ/dt is called theimpedance cardiographic curve. The Cheetah system claims toreduce the signal to noise ratio further by analysing phase shiftbetween the injected current and the measured voltage. By addinginformation about patient age, sex, and weight, it is possible toestimate the heart stroke volume and cardiac output.22

Bioimpedance devices are yet to be fully evaluated in terms ofbeing used to guide Targeted Fluid Administration techniques.

6.6. Pulse pressure variation monitoring

The superiority of dynamic measures of fluid responsivenessover static measures such as central venous pressure are wellestablished in the literature.1–3,8–10 Unfortunately most patientmonitoring systems do not display modalities such as pulse pres-sure variation (PPV) and the anaesthetist has hitherto relied ona visual inspection of the arterial pulse pressure trace colloquiallyreferred to as the ‘swing’. A pilot study which used a calculated PPVfrom the arterial pressure wave to guide fluid therapy foundsignificant improvement in clinical outcomes.23

It is likely that the manufacturers of patient monitoring systemswill incorporate the relatively simple software to calculate and displayPPV in the future. However, larger randomised controlled trialsare needed to establish the place of PPV guided Targeted FluidAdministration.

7. Peri-operative fluid administration. Ongoing controversyand the place of targeted fluid administration

Most anaesthetists and surgeons with an interest in improvingthe care for the high risk surgical patient will be very aware of theintense controversy that surrounds the use of peri-operative fluid.

Fig. 4. A tetrapolar Bioimpedance device which is entirely non-invasive, relying onfour double electrodes placed on the chest wall. Change in electrical impedance toa current passed between the electrodes, represent the movement of blood during theaortic pulse wave.

All protagonists agree that inappropriate fluid management islikely to lead to clinical complications and adverse patientoutcomes. The evidence from research papers and review articlesas to what constitutes inappropriate fluid management can oftenappear conflicting, as management regimes using different types offluids, with or without cardiac output monitoring, at differentpoints of the surgical patients pathway have all been reported.

7.1. Targeted fluid administration: liberal, restrictive or neither?

The complexity of peri-operative fluid management is com-pounded by the fact that both over-administration and under-administration of fluid is likely to result in sub-optimal care.However based on the evidence outlined above, a consensus isemerging that at least in the intra-operative period, Targeted FluidAdministration is a reasonable method to minimise the harm causedby over-administration or under-administration of fluid. The keyfeatures of Targeted Fluid Administration that enable safe care are:-

i. Fluid therapy is started early, before tissue injury or majorfluid losses occur.

ii. Early fluid challenge and continuous review of stroke volumeminimise the occult hypovolaemia which has resulted fromstarvation and anaesthetic techniques.

iii. Fluid administration is individualised and curtailed as soon asthe patient is no longer fluid responsive.

iv. By achieving adequate perfusion at the start of surgery, thereappears to be an attenuation of the burst of pro-inflammatorycytokines. This may lead to a reduction in capillary leak post-operatively and the development of tissue oedema which isoften exacerbated by inappropriately excessive fluid therapyfollowing surgery.

v. Continuous monitoring of cardiac output intra-operativelyallows the anaesthetist to rapidly detect when sudden hae-modynamic changes occur during surgery when compared tostandard monitoring modalities.

7.2. Targeted fluid administration and the choice of fluid

Another great source of controversy and debate is the choice ofintra-operative fluid. It is essential to acknowledge that intravenousfluids are drugs with indications, contraindications, and side effects.With this in mind the anaesthetist must carefully choose the type offluid used intra-operatively. This choice is based on a large numberof factors. The evidence for Targeted Fluid Administration suggeststhat early administration of colloid provides benefit. However nohead-to-head trials of crystalloid versus colloid or colloid versuscolloid during Targeted Fluid Administration have been performed.Likewise all the clinical trials of Targeted Fluid Administration usedsaline-based fluids. The development and widespread availability of‘balanced’ colloid solutions have led many to advocate their useduring Targeted Fluid Administration, based on evidence supporting‘balanced’ intra-operative fluids such as Hartmanns solution.24,25

In our clinical practice, the authors have used colloids (hydroxyl-ethyl starch) suspended in both balanced and saline-based solu-tions, to perform fluid challenges as part of Targeted FluidAdministration.

8. Targeted fluid administration – a practical guide totechnology adoption

Introducing TFA into practice requires adequate resources,comprehensive training, local protocols, robust data collection andquality assurance of the whole process.

D. Conway, S. Gold / Current Anaesthesia & Critical Care 21 (2010) 108–113 113

The fiscal constraints affecting healthcare mandates thata business case is made to justify the purchase of monitors andongoing consumable costs. Training in the use of the monitors isusually provided by the manufacturer upon agreement of a servicelevel agreement for the product. This will usually take the form ofclassroom theoretical explanation of the principals involved inusing the monitors followed by in theatre, practical training in theuse of ODM to maximise stroke volume. In this way, users can bedemonstrated to be competent in the use of the monitor and able tofollow the locally agreed protocol to maximise stroke volume.

When introducing a change in practice such as this, it isnecessary to collect data regarding use of equipment andconsumables, case selection, intra-operative use, fluids adminis-tered and patient outcomes. Outcome data are necessary to ensuresafe use of the monitor and TFA protocol, as well as demonstrateimprovement in patient outcomes.

Practical difficulties encountered introducing TFA include;Organisational difficulties: most hospitals have a complex

committee structure making authorisation of the project laboriouse.g. Trust and directorate management board, equipmentcommittee, audit committee, clinical practice committee.

Short term management aims: demonstrating improvedoutcomes and efficiency gains will probable take 2 years fromcapital outlay. This is a long time for a medical manager to wait tojustify investment, bear in mind their performance will be assessedeach financial year.

Silo budgeting: in many hospitals, monitors and consumableswill be purchased using theatre budgets, however it is the surgicalward that will benefit from the efficiency saving of reducedcomplications and length of stay.

The practical solution to these administrative difficulties is to engagewith a senior manager who has responsibility for theatres and wards.They will be able to take a high level view and support the project.

9. Conclusion

Targeted Fluid administration using less invasive cardiac outputmonitors such as oesophageal Doppler is an effective strategy thatcan be employed by the anaesthetist during major surgery toimprove tissue perfusion, reduce post-operative complications andenhance the patient’s recovery from surgery which will lead toreduced length of hospital stay. The oesophageal Doppler isa minimally invasive device that can be widely and rapidly imple-mented by committed clinicians, with the support of healthcaremanagers. The ODM is not suitable for all cases and thereforealternative devices will also need to be available. The benefits ofwidespread implementation of TFA should be integral to anyenhanced recovery programme for major surgical patients.

Conflict of interest

None.

Acknowledgements

Images in Figs. 2 and 3 were provided by Deltex Medical Ltd.Image in Fig. 4 was provided by PROACT Medical Ltd.

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