1832
Robert Lewins
1855
Sidney Ringer
8 mg NaCl, 0,3 g KCl, 0,33 g CaCl
1l di H
2O
Alexis Hartmann
1941
Albumina
Elettrolit
i ECF / ICF mEq/l ECF
Fabbisog no mEq/k/d Na ECF 135 - 146 1.5 K ICF 3.1 – 4.2 1.0 – 1.5 Mg ICF 0.85 – 1.25 8 – 20 Ca ECF 2 – 2.6 10 PO43- ICF 2.7 – 4.5 20 – 40 Cl ECF 97- 107 H2O ECF/ICF 20 – 30 ml/d
I cristalloidi sono soluzioni che
contengono soluti di peso
molecolare inferiore ai 30 kDa :
generalmente sali o glucosio.
Essi passano con facilità
attraverso la membrana dei
capillari. Possono essere
Solution Osmolality Ph Na + K + HCO3 Cl Plasma 295 7.4 140 3.6-5.1 30 100 0,9% Saline 308 5.0 154 0 0 154 3% Saline 1026 513 0 0 513 7.5% Saline 2400 1250 0 0 1250 Ringer Lactate 273 6.5 130 4 28 109 Ringer Acetate 270 6 130 4 30 110 Plasmalyte A 294 7.4 140 5 50 98 5% glucose D5W 253 4 0 0 0 0
HES solutions
are produced by hydroxyethyl substitution of amylopectin obtained from
sorghum, maize, or potatoes.
A high degree of substitution on glucose molecules protects against hydrolysis by non specific amylases in the blood, thereby prolonging intravascular expansion, but this action increases the potential for HES to
accumulate in reticuloendothelial tissues, such as skin (resulting in pruritus), liver, and kidney.
Succinylated gelatin, urea linked gelatin
Dextran solutions.
I colloidi sono soluzioni di molecole ad
elevato peso molecolare che passano
con difficoltà l’endotelio.
L’interesse nei loro confronti è legato
alla maggiore efficacia come effetto
volume oltre che ad interessanti
propietà reologiche ed
antiinfiammatorie.Comunque, in ampi
studi randomizzati,i colloidi non si sono
dimostarti superiori in termini di
misuredi outcome di elevato profilo
come la mortalità.
Solution Osmolality (mOsm) Na + (mM) (kDa)Mw Initial volume expansion (%)
Plasma half life (Hr) /
dosage limit
Plasma 295 140 Varying Low
Albumin 4%,5% 300 130-160 69 70 -100 16 – 24;no limit Albumin 20%,25% 1500 125 69 200 -300 16 – 24;no limit
Hespan 6 in ns 309 154 600 100 – 160 20 ml/Kg/die Hestend 6%
in lactate electrolite solution 307 143 670 100 -160 1.4 hr;20 ml/kg/d
Voluven6% in ns 296 140 130 1 :1 50 ml/Kg/die
Volulyte 6%
in balanced salt solution 296 140 130 1 :1
50 ml/Kg/die
Gelofusin 4% in ns 274 154 30 1:1 No upper limits
Rheomacrodex 10%
Dextran 40 in ns 350 154 40 175 1.5 gr/kg/die
Macrodex 6%
Dextran 70 in ns 300 154 70 100
HES solutions (10%)
with a molecular weight of more than 200 kD and a molar substitution ratio of more than 0.5
with a molecular weight of 130 kD and molar substitution ratios of 0.38 to 0.45.
HES is 33 to 50 ml per kilogram of body weight per day.
I Generazione GenerazioneII GenerazioneIII GenerazioneIV 450/0.7 HMW/HMS 70/0.5 200 - 260/0.5 200/0.62 130/0.4 130/0.42 Balanced 130/0.42 Hetastarch Pentastarch Tetrastarch Voluven Venofundin Tetraspan
The observed ratio of
HES to crystalloid
in
these trials was approximately 1:1.3,
which is consistent with the ratio of
albumin to saline reported in the SAFE
study.
The selection and use of resuscitation fluids is based on physiological principles, but clinical practice is determined largely by clinician preference, with marked regional variation.
Despite what may be inferred from physiological principles, colloid solutions do
not offer substantive advantages over crystalloid solutions with respect to hemodynamic effects.
Although albumin has been determined to be safe for use as a resuscitation fluid
in most critically ill patients and may have a role in early sepsis, its use is associated with increased mortality among patients with traumatic brain injury. The use of hydroxyethyl starch (HES) solutions is associated with increased rates of renal-replacement therapy and adverse events among patients in the intensive care unit (ICU).
There is no evidence to recommend the use of other semisynthetic
Balanced salt solutions
are pragmatic initial resuscitation fluids, although there is little direct evidence regarding their comparative safety and efficacy.The use of
normal saline
has been associated with the development of metabolic acidosis and acute kidney injury.The safety of
hypertonic solutions
has not been established.All resuscitation fluids can contribute to the formation of interstitial edema, particularly under inflammatory conditions in which resuscitation fluids are used excessively.
Critical care physicians
should consider the use of resuscitation
Although the use of resuscitation fluids is one of the most
common interventions in medicine ,
no currently available
resuscitation fluid can be considered to be ideal.
Selection, timing, and doses of intravenous fluids should be evaluated as carefully as they are in the case of any other intravenous drug, with the aim of maximizing efficacy and minimizing iatrogenic toxicity.
Chloride is implicated in impaired renal function with
hyperchloraemia resulting in less natiuresis than might be expected after saline infusion.
Chloride may influence the renal vasculature.
There is also some evidence that renin secretion is mediated by chloride.
Hyperchloraemia may also influence coagulation.
Thromboelastography indicates more effects on coagulation and platelet function with saline when compared with a balanced salt solution
In summary:
- hyperchloraemic acidosis is seen with the use of large volumes of saline and is
almost certainly due to the chloride load; - there appear to be some side-effects
associated with saline use, but to date these have not translated into clinically important outcomes, though this may be through lack of data.
Is usually the result of sodium bicarbonate
infusion for metabolic acidosis,or aggressive
use of hyprtonic saline to treat intracranial
pressure.
When
renal sodium excretion is impaired
it
may be necessary to increase it with a
diuretic
.
Because the urinary sodium concentration
during furosemide (~ 80 mEq/l) is
less
than
plasma sodium concentration, diuresis can
aggravate the hypernatremia.
Lactate clearance = LactateED Presentation - LactateHour 6 × 100 LactateED Presentation
Associations between increased cumulative positive fluid
balance and long-term adverse outcomes have been
reported in patients with sepsis.
In trials of liberal versus goal-directed or restrictive fluid
strategies in patients with the acute respiratory distress
syndrome (particularly in perioperative patients),
restrictive fluid strategies were associated with reduced
morbidity.
However, since there is no consensus on the definition of
these strategies, high-quality trials in specific patient
Recently advocated approaches include waiting until the rate of drainage is less than 100 mL , less than 150 mL less than 2 mL/kg body weight, less than 200mL, less than 300 mL , or less than 400mL per 24 hours, or
essentially ignoring the rate of drainage .
Since properly functioning, non occluded chest tubes typically produce some fluid, it is unusual to wait until there is no drainage to remove tubes, although this approach has also been described
Pleural fluid/kg body weight : 0.13 ± 0.06 mL
5 to 35 µm
Production and reabsorption : 0.01 to 0.02 mL / kg / h
Microvascular filtrate . Protein content : approx. 1 g/dL
Ann Thorac Surg 2013;96:2262–7
Pleural fluid layer
Pleural surface area of both hemithoraces : 4,000 cm
2Visceral and parietal pleural layers 30 to 40 µm
Because of this increased rate of absorption, a
increase in the rate of fluid production results in only a
10- fold
15% to 20% increase in steady-state pleural fluid volume.
In addition to increased pleural fluid volume/pressure,
stimulation of α
2-adrenergic and β
2-adrenergic receptors
appears to increase lymphatic drainage from the pleural
space in rabbits. A
70-kg adult normally
should
be able to
reabsorb 470 mL of pleural fluid per day from each
hemithorax.
Two studies of patients with clinically
apparent pleural effusions estimated the
rate of
reabsorption as 0.11 and 0.36 mL/ kg /h
In summary, judging from the variety of approaches described in the literature and available data bearing on the safety of these approaches, there appears to be no consensus as to the rate of drainage that should be used as a threshold for tube removal and no
evidence to suggest that it is unsafe to remove tubes that still have a relatively high rate of fluid drainage. To help resolve this question, a non inferiority
randomized trial is currently examining
patient-centered outcomes to assess the safety of removal of chest tubes independent of the rate of drainage
relative to a 2 mL/kg body weight per day threshold.
