Presentation on theme: "Problems with Solutions GUIDANCE FOR IV FLUID AND ELECTROLYTE PRESCRIBING IN FIFE Fluid Prescription Working Group May 2012."— Presentation transcript:
Problems with Solutions GUIDANCE FOR IV FLUID AND ELECTROLYTE PRESCRIBING IN FIFE Fluid Prescription Working Group May 2012
WHY HAVE WE PRODUCED THIS GUIDANCE? Fluid prescribing is done poorly. Certain problems can arise:
Please dont write up fluids on patients you know nothing about without looking at various parameters (to be explained below)
The background National reports Recent national guidelines National meetings Doctors level of knowledge and application Observation of practice Local audits
Abnormal Saline Is there a problem nationally?
1999 Patients are dying as a result of infusion of too much or too little fluid by inexperienced staff. New doctors have inadequate knowledge and sub-optimal prescribing skills Fluid prescription must be given the same status as drug prescription.
Poor fluid management contributed to around half of the deaths SASM Report 2008 Errors in fluid prescription are common in hospital practice and are dangerous Shaifee et al QJM % of postoperative patients develop morbidity directly related to fluid prescription Walsh et al Ann Roy Coll Surg Engl 2005 Has anything changed since 1999?
Fluid Prescribing Left to the most junior member of the team Wide variability in prescribing practices About 26% prescribed > 2L 0.9% saline/day Lobo et al Clin Nutr 2001
Fife 2012 Brief survey of juniors in HDU and anaesthesia Poor knowledge of maintenance requirements Poor knowledge of Na/K requirements No system for calculating peri-operative fluid requirements Fluid therapy is often poorly taught, poorly understood and poorly done
Some examples 75 year-old lady Post Hartmanns, 55kg Not well 5 days post-op: SOB, oedematous On TPN AND IV fluids : >3L/day Na 130 Lungs wet Ileus Gross peripheral oedema Needs fluid restriction; stop IV fluids Gentle diuresis
Overload in Orthopaedics 80 year-old man: Mild angina and mild aortic stenosis, independent, N U&Es, 60kg Op delayed for 6 days, fasted on and off for 6 days. Minimal food intake litres IV fluid in 6 days (requirement approx 1800ml/day = 10.8l), Na day 5 =128 Day 7 – surgery – still fasting, more IV fluid, D 8 Na 123 – cardiac failure, pulmonary oedema, angina. Frusemide++ D 9 creatinine 300, urea 10. All iatrogenic PREVENT!
Excess loss/ Inadequate provision 80 yrs, post-Hartmanns – developed high NG losses, 4 litres/day for 1 week Fluid balance on ward not properly addressed Developed severe alkalosis on the ward: pH 7.61 and severe dehydration, low Na/K Admitted to ICU for two days for correction before he could go back to theatre: anastomotic leak discovered Orthopaedics 80 yr old, 60kg with Alzheimers: #NOF 3 litres/5days (maintenance: 9 litres)
4 Audits in Fife Lots of patients not getting much fluid, especially in orthopaedics Some got far too much, especially in surgery Not enough potassium – all areas Far too much sodium – all areas BUT: Education improves practice
SHDU Results 2/3 of patients got too much sodium, in some cases excessively so (> 800mmol Na on one occasion) On 1/3 of patient–days roughly (+/- 500ml) the right volume of fluid was given, on 1/3 too much, and on 1/3 too little Fewer than 1/2 patients received enough potassium. Excess losses were generally not replaced
Anaesthetic audit: Results Patients with higher intra-operative fluid volumes experienced more post-op complications as well as more PONV (chest infections, arrhythmias, ileus, low BP, confusion) High volumes of Hartmanns are given peri-operatively and it is often used as a maintenance fluid post-op – it is not one
What should we do? Lessons from physiology
The right amount of the right fluid at the right time
Moderation FD Moore & GT Shires, Ann Surg 1967 The objective of medical care is restoration to normal physiology and normal function of organs, with a normal blood volume, functional body water and electrolytes. This can never be achieved by inundation.
In the distant past... Wounded/sick animal or person No food or water may be available for hours until he drags himself to the waterhole Retains fluid by oliguria and anti-diuresis, trying to maintain blood volume Stress response to trauma mediated by Renin angiotensin aldosterone system (RAAS), ADH and catecholamines
Catabolic Response to Injury/Illness Sodium and water retention (ADH, RAAS, catecholamines) Capacity of kidneys to excrete water and Na is impaired Increased potassium excretion (due to RAAS activity and protein catabolism) Decreased urine output Sicker patients have poor concentrating ability – poor excretion of Na and Cl load Catabolic patients produce more urea which is excreted in preference to Na and Cl and this increases water retention
What do we often do? We give lots of fluid, lots of sodium chloride Kidneys cant excrete sodium load Chloride causes renal vasoconstriction and exacerbates fluid retention and oedema Leaky capillaries in sick patients exacerbate RAAS/ADH activity and oedema worsens We dont give much potassium Potassium depletion reduces ability to excrete sodium We dont give many calories Calories help the cells to maintain fluid homeostasis
Salt & Water overload: Physiological Consequences Decreased renal blood flow and GFR Intra-mucosal acidosis Prolongation of gastric emptying time Ileus (+ low K+, opioids, poor mobility, pain) Hyperchloraemic acidosis Weight gain Low serum sodium - ? More given Cellular dysfunction
Salt & Water Overload: clinical Peripheral oedema Gastro-intestinal oedema: N & V Impaired cardiac function: Pulmonary oedema/ARDS CCF/arrhythmias Confusion Delayed mobilisation Pressure sores Increase in DVT
Salt & Water Depletion Reduced stroke volume – poor organ perfusion, hypotension, falls Impaired renal perfusion - ARF Increased viscosity of mucus Reduced saliva - discomfort Increased blood viscosity - clots
Problems with Solutions PROBLEMS WITH SALINE
The Origins of 0.9% Saline Not a physiological fluid – based on a mistake by a physiologist called Hamburger in 1830s He thought concentration of salt in blood was 0.9% but it is nearer 0.6% 0.9% NaCl is not a maintenance fluid It has certain specific uses
The Abuse of Normal Salt Solution George H. Evans, JAMA 1911 One cannot fail to be impressed with the danger of the utter recklessness with which salt solution is frequently prescribed, particularly in the postoperative period… One cannot fail to be impressed with the danger of the utter recklessness with which salt solution is frequently prescribed, particularly in the postoperative period… …the disastrous role played by the salt solution is often lost in light of the serious conditions that call forth its use.
The Times, 28 January 2000
Hartmanns solution/Ringers Lactate Discovered independently by Hartmann and Ringer Balanced solution i.e. More like the composition of plasma, has lactate as a buffer Less Na and Cl load and the Na load is more effectively excreted with less fluid retention (there still is some), less acidosis and less effect on albumin and Hb than saline It is a good REPLACEMENT fluid when a patient has lost body fluids
Evidence Experiments have shown that in healthy volunteers, infusion of 2 litres of saline results, after 6 hours, in weight gain due to fluid retention, a drop in albumin and Hb, acidosis, poor uop and retention of sodium. 2 litres of Hartmanns is better than saline for all of these parameters, and dextrose is the best in terms of lack of fluid retention and uop. This fluid retention is worse in sick patients. Dextrose-containing maintenance fluids are best but ensure not too much is given – the right amount!
Post -op Other studies have shown that patients having significant amounts of unnecessary fluid peri- operatively have more complications e.g. poor wound healing, chest infections, slow mobilisation, nausea and vomiting The fluid given must be tailored to each patients situation.
There is a very narrow range for optimal fluid load
NHS Fife Guidelines for intravenous fluid and electrolyte prescription in adults Group: M.McDougall, S. Oglesby, S. Bennett, A. Doyle, K. Buck, A. Sengupta, L. Clark, J. Hadoke, A. Timmins, K. Spurgeon, M. Clark, A. Rahman, L. Reekie. Based on GIFTASUP guidelines
British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients GIFTASUP Jeremy Powell-Tuck (chair), Peter Gosling, Dileep N Lobo, Simon P Allison, Gordon L Carlson, Marcus Gore, Andrew J Lewington, Rupert M Pearse, Monty G Mythen BAPEN Medical, the Association for Clinical Biochemistry, the Association of Surgeons of Great Britain and Ireland, the Society of Academic and Research Surgery, the Renal Association and the Intensive Care Society.
1.Balanced salt solutions e.g. Ringers lactate/acetate or Hartmanns solution should replace 0.9% saline when crystalloid resuscitation or replacement is indicated except in hypochloraemia 1b 2.Solutions such as 4%/0.18% dextrose/saline and 5% dextrose are important sources of free water for maintenance. Excessive amounts may cause hyponatraemia, especially in the elderly 1b
Recommendation 3 To meet maintenance requirements, patients should receive sodium mmol/day, potassium mmol/day in litres of water by the oral, enteral or parenteral route (or a combination of routes). Additional amounts should be given to correct deficit or continuing losses. Careful monitoring should be undertaken using clinical examination, fluid balance charts and regular weighing, when possible. Evidence level 5
Questions to ask before prescribing fluid Does my patient need intravenous fluid? Why does my patient need intravenous fluid? How much and which fluid does he need?
Does he need fluid? May be drinking May be on NG feed/TPN – both of these contain fluid which counts as maintenance May be receiving many drug infusions e.g. antibiotics/paracetamol – can amount to 1+ litre/day He may only need a bit of maintenance fluid This calculation should be done for each patient
Why does he need fluid? Maintenance –water and electrolytes To supply the daily needs – (e.g. 4% dextrose/0.18%saline/KCl) Replacement To replace ongoing losses know the content of the fluid! Resuscitation - e.g.colloid/blood To correct an intravascular or extracellular volume deficit
MAINTENANCE If you were on a desert island, would you drink from the sea or a stream? 0.9% saline is not a maintenance fluid
Daily Requirements (GIFTASUP) Water25-35 ml/kg (30) Sodiumapprox 1 mmol/kg Potassiumapprox 1 mmol/kg Caloriesminimum 400 Calories (i.e. 100 g dextrose) (calories help to deal with electrolytes normally)
Average Daily Requirements 70 kg man needs: 2100 ml H2O 70 mmol Na + 70 mmol K + 70 mmol Cl - 50kg man needs1500 ml H2O 50 mmol Na + 50 mmol K + 50 mmol Cl -
Properties of Commonly Used Crystalloid Solutions Solution Electrolyte Content (mmol/l) Osmolality (mOsm/kg) pH 0.9% NaCl Na Cl Dextrose (4%)-Saline (0.18%) Na + 31 Cl % Dextrose NilNil Hartmanns solution Na K + 5 Ca + 2 Cl HCO
MAINTENANCE Prescribe maintenance if not drinking >6hrs 4%/0.18% dextrose/saline with 20mmol potassium in 500ml, or 40mmol in 1 litre (1 litre is cheaper). Or no potassium Prescribe in ml/hr (see table) via a pump. The correct volume of this by weight per day for maintenance will provide roughly the correct amount of sodium and potassium for each patient. Maximum 100ml/hr to avoid hyponatraemia. Do not prescribe x hourly
PUMPS At present there are just about enough but distribution is a big problem We are hoping to get more and distribute them better in the hospital Each ward will have their own so it is important to keep hold of them and get them back if they leave If a patient is on dex/saline they really should have a pump to ensure the correct rate is given. If a patient is on fluids of any kind for >6 hours they should have a pump
Potassium A normal serum potassium is not an indication that the patient does not need potassium – it just means that their stores havent run out yet. A low potassium means that losses are high and body stores very low. A high potassium may be drug related but commonly is due to acute renal failure – monitor U&Es and do not give extra K. Remember that TPN, NG feed and food contain K
Sodium We all need some. However most drugs contain sodium so we dont need to give a lot in fluids unless the patient is losing it. Causes of a low Na – too much fluid (commonest cause in hospital!) – fluid restrict SIADH inappropriate antidiuretic hormone secretion– pneumonia, brain pathology High Na loss – usually upper GI losses – tend to be obvious
Fluid overload Recognise clinical signs May need fluid restriction Careful fluid balance and monitoring Gentle diuresis – beware of precipitating ARF in a patient whose kidneys may not be working efficiently
REPLACEMENT Losses should be accounted for with replacement fluid: balanced solution: Hartmanns (Plasma Lyte 148 – may become available, has Mg, no Ca, acetate not lactate) Work out how much patient is losing and replace this with Hartmanns – better to calculate retrospectively and replace. Fluid prescriptions for losses must be reviewed regularly and updated.
LOSSES Upper GI loss: stomach, small bowel ileostomy/fistula/bile leak: high Na and Cl content – may become hypochloraemic and alkalotic – appropriate to use 0.9%NaCl Lower GI loss: diarrhoea - lose lots of water and potassium: Hartmanns is appropriate to replace + extra potassium (guide in booklet)
How much fluid does he need? Weight for maintenance 30ml/kg/24hrs History, fasting, losses, sepsis, fluid balance charts Clinical status, current losses, fluid intake, urine output Electrolytes, Hb (may be raised in dehydration)
Exclusions Paediatric patients: consult paediatrician Diabetic patients: follow diabetic guidelines Head injury patients: avoid dextrose Renal failure patients: consult senior doctor Obstetrics: consult obstetric team in complex patients
Resuscitation Fluid For severe dehydration, sepsis or blood causing circulatory hypovolaemia and hypotension Use Hartmanns or colloid, blood/O Negative in emergencies May need critical care referral for inotropic support/ invasive monitoring Criteria for Critical Care Referral – on guidance Algorithm for fluid challenges
Fluid challenge 250ml colloid or Hartmanns over 2-5 mins Dont go away! Looking for improved UOP, improvement in perfusion/BP/HR Can be repeated – if patient still looks hypovolaemic after 2 litres senior help is required – may need inotropes and ICU Very few patients will go into LVF with 250ml fluid (less than a can of coke!)
Colloids Gelofusine – currently in 0.9%NaCl but will soon be in a balanced solution Albumin 4.5% Starch – for specialised use in theatre/ICU Some controversy about which is best For your purposes dont worry about this!
Summary Remember the three questions Doctors should take time and consult senior if unsure Patients on IV fluids need regular U&Es Patients should be allowed food and drink as soon as possible
The right amount of the right fluid at the right time