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Principles of intravenous fluid therapy. Jonathan Paddle Consultant in Intensive Care Medicine Royal Cornwall Hospitals NHS Trust 3 rd September 2007.
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Principles of intravenous fluid therapy Jonathan Paddle Consultant in Intensive Care Medicine Royal Cornwall Hospitals NHS Trust 3rd September 2007
"On the floor lay a girl of slender make and juvenile height, but with the face of a superannuated hag... The colour of her countenance was that of lead - a silver blue, ghastly tint; her eyes were sunk deep into sockets, as though they had been driven an inch behind their natural position; her mouth was squared; her features flattened; her eyelids black; her fingers shrunk, bent, and inky in their hue… In short, Sir, that face and form I can never forget, were I to live beyond the period of man's natural age."
WILLIAM BROOKE O’SHAUGHNESSY Edinburgh graduate, age 22 from Limerick • Investigated cholera outbreak in Sunderland: • Noted blood “..has lost a large part of its water content.. and.. a great proportion of its neutral saline ingredients..”, leading to venalisation (“blue, thick and cold”); established that the stools contained the missing elements in proportion • Therapeutic conclusions: “1. To restore the blood to its natural specific gravity; 2. To restore its deficient saline matters… … by the injection of aqueous fluid into the veins.”
“She had apparently reached the last moment of her earthly existence and now nothing could injure her... Having inserted a tube into the basilic vein, cautiously, anxiously, I watched the effects; ounce after ounce was injected but no visible change was produced. Still persevering, I thought she began to breathe less laboriously, soon the sharpened features, the sunken eye and fallen jaw, pale and cold, bearing the manifest impress of death’s signet, began to glow with returning animation; the pulse, which had long ceased, returned to the wrist; at first small and quick, by degrees it became more distinct, fuller, slower and firmer, and in the short space of half an hour, when six pints had been injected, she expressed in a firm voice that she was free from all uneasiness, actually became jocular, and fancied all she needed was a little sleep; her extremities were warm and every feature bore the aspect of comfort and health. This being my first case, I fancied my patient secure, and from my great need of a little repose, left her in charge of the Hospital surgeon” Thomas A Latta, Leith Physician. Lancet June 18th 1832
“.. But I had not been long gone, ere the vomiting and purging recurring, soon reduced her to her former state of disability … and she sunk in five and a half hours after I had left her… …I have no doubt, the case would have issued in complete reaction, had the remedy, which had already produced such effect, been repeated.”
Dr Latta’s Saline solution • Two to three drachms of muriate of soda (NaCl), two scruples of the bicarbonate of soda in six pints of water and injected it at temperature 112 Fah • ( approx 58mmol/l Na, 49 mmol/l Cl, 9 mmol/l bicarbonate) • Ten of the first fifteen patients died
Current controversies in fluid therapy • How much fluid to give • Which fluid to use
Assessment of volume status Look at the patient: • Pulse • Blood pressure • Capillary refill • Mucous membranes • Peripheral circulation • Thirst
Assessment of volume status Try a more invasive approach: • Urine output • Arterial line • Central venous line • PA catheter • Oesophageal doppler
Assessment of volume status How about blood tests? • U&Es • Haematocrit • Plasma/urine osmolality • Arterial blood gases • Lactate
Assessment of volume status OK, so the patient needs fluid… How much should we give?
P=0.04 Trauma • 598 adults with penetrating torso injuries • Randomised to standard care or no fluids until time of operation Bickell WH et al. Immediate versus Delayed Fluid Resuscitation for Hypotensive Patients with Penetrating Torso Injuries. NEJM 1994; 331: 1105-9
Trauma • Cochrane Database of Systematic reviews • Six randomised controlled studies • No evidence in support or against early aggressive fluid resuscitation • 52 animal trials hypotensive resuscitation reduced risk of death
Peri-operative • 138 patients undergoing major elective abdominal surgery • Randomised to one of three groups (one control and two goal directed therapy groups Wilson J et al. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery. BMJ 1999; 318: 1099-103
Peri-operative • Goal-directed therapy was aimed at optimising oxygen delivery to tissues with: • Fluids • Inotropes • Guided by invasive PA catheter monitoring Extra 1500 ml fluids pre-op Wilson J et al. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery. BMJ 1999; 318: 1099-103
Peri-operative Wilson J et al. Reducing the risk of major elective surgery: randomised controlled trial of preoperative optimisation of oxygen delivery. BMJ 1999; 318: 1099-103
However… • RCT 172 patients undergoing elective colorectal resection • Restrictive fluid regime (to maintain neutral body weight) vs. standard post-op fluids Complications: 33% versus 51% (P = 0.013) Brandstrup B et al. Effects of intravenous fluid restriction on postoperative complications: comparison of two perioperative fluid regimens: a randomized assessor-blinded multicenter trial. Ann Surg. 2003; 238(5): 641-8.
Sepsis and the critically ill Early Goal-Directed Therapy in the Treatment of Severe Sepsis and Septic ShockEmanuel Rivers, M.D., M.P.H., Bryant Nguyen, M.D., Suzanne Havstad, M.A., Julie Ressler, B.S., Alexandria Muzzin, B.S., Bernhard Knoblich, M.D., Edward Peterson, Ph.D., Michael Tomlanovich, M.D., for the Early Goal-Directed Therapy Collaborative Group Volume 345: 1368-1377 November 8, 2001
Sepsis and the critically ill Rivers E et al. Early Goal-Directed Therapy in the Treatment of Severe Sepsis and Septic Shock. NEJM 2001; 345: 1368-77 • 263 patients presenting with severe sepsis • Single-centre: large American Emergency department • Randomised to standard therapy or goal-directed therapy
The take-home message! • Resuscitate with fluids early and aggressively • They won’t get overloaded • They won’t get pulmonary oedema • They will be less likely to need ICU • Be guided by markers of tissue perfusion • Urine output • Lactate • Consider central venous oxygen saturations
FACTT Study • Comparison of two fluid management strategies in acute lung injury • Randomised controlled trial • 1001 patients with ARDS or ALI • Conservative v liberal fluid therapy • Also compared PAC or CVC • Mortality at 60 days, vent free days, organ failure free days National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wiedemann HP, Wheeler AP, Bernard GR, et al. Comparison of two fluid-management strategies in acute lung injury. N Engl J Med. 2006;354:2564-2575
FACTT • Fluid restriction 43 hrs post admission • 24 hours post ALI/ARDS • Renal failure pts excluded • Volume replete patients National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wiedemann HP, Wheeler AP, Bernard GR, et al. Comparison of two fluid-management strategies in acute lung injury. N Engl J Med. 2006;354:2564-2575
FACTT • No significant difference in mortality • Restrictive fluid group had: • Better oxygenation indexes • More ventilator free days • Less renal failure in conservative group • Recommendations: Conservative fluid approach without PAC • But………….. National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wiedemann HP, Wheeler AP, Bernard GR, et al. Comparison of two fluid-management strategies in acute lung injury. N Engl J Med. 2006;354:2564-2575
FACTT • Increase in cardiovascular failure days in patients in conservative group • Caution in fluid depleted patients. • Relative young age of patients • ? Realistic study population National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network; Wiedemann HP, Wheeler AP, Bernard GR, et al. Comparison of two fluid-management strategies in acute lung injury. N Engl J Med. 2006;354:2564-2575
What is the choice? • Crystalloids Colloids • Saline Albumin • Dextrose Gelatins • Hartmann’s Starches
Cell membrane Capillary wall Fluid distribution
Practical differences Roberts I, Alderson P, Bunn F, P Chinnock, K Ker and Schierhout G. Colloids versus crystalloids for fluid resuscitation in critically ill patients (Cochrane Review). The Cochrane Library, Issue 4, August 24th, 2004
“There is no evidence from randomised controlled trials that resuscitation with colloids reduces the risk of death compared to crystalloids in patients with trauma, burns and following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patient types can be justified outside the context of randomised controlled trials”
A Comparison of Albumin and Saline for Fluid Resuscitation in the Intensive Care Unit The SAFE Study Investigators 2004; 350: 2247-2256
Study design • 16 centres in Australia and New Zealand • Randomised, double-blind, trial of 4% albumin compared to 0.9% Saline for fluid resuscitation in the ICU • Study fluid given until death, discharge or 28 days
Study design • 6997 Patients enrolled • 90% power to detect 3% difference in mortality from baseline of 15% mortality • A priori sub-groups identified: • Trauma • Severe Sepsis • ARDS
What about starches? • Starches are polymers of glucose • α1,6 linkages produce branched chains called amylopectins • Hydroxyethyl radicals can be substituted on glucose units, hence HYDROXYETHYL STARCH
Why might they be useful? • Large molecules, so retained in the plasma • Stable molecules, so have a sustained effect • Some evidence of specific anti-inflammatory properties that may be therapeutic
Endothelial properties • Prospective RCT, single centre • 66 patients >65 years old • Major abdominal surgery • Ringer’s lactate (n=22) • Normal saline (n=22) • HES 130/0.4 (n=22) • From induction of anaesthesia until 1st post-op day to keep CVP 8-12mmHg Boldt J. Int Care Med 2004; 30: 416-22
Endothelial properties Boldt J. Int Care Med 2004; 30: 416-22
Why might they be bad? • Potential risk of anaphylaxis • Some starch solutions cause coagulation disorders • Risk of renal impairment • Known incidence of pruritis
Incidence of anaphylaxis • French multicentre study • 49 hospitals • 19593 patients • Overall 1 in 456 had an anaphylactoid reaction Laxenaire MC. Ann Fr Anesth Reanim 1994; 13: 301-10