04/05/2023
هل المحاليل ليها جرعات ولا هو ملح بريت ٦٠ وخلاص؟ هل تفرق ملح من رينجر ؟ طيب ينفع اعلق محاليل لعيان بيشرب وبياكل كويس لمجرد انه عاوز محلول؟ هل علشان العيان ضغطه واطي افضل اديله محاليل ؟ هل ممكن العيان ضغطة يكون واطي ومش محتاج محاليل؟ كل دي أسئلة لازم تدور في ذهن أي حد شغال طوارئ او رعاية في البوست ده هنحاول نوضح طبقًا لأحدث الجايدلاينز والتوصيات:
أولاً: هنتكلم علي شوية فسيولوجي بُساط جدًا مهمين
Water in the adult human body makes up approximately 60% of the total body weight. The fluid is distributed in various organs, organ systems, and tissues. The sum of the water in these tissues is known as total body water.
يعني حوالي ٦٠٪ من جسمنا ميه بس يعني احنا ميه وشوية حاجات تانية 😅
طيب دول متوزعين ازاي؟
Water distributed by mean:
► Extracellular fluid (40% of TBW).
▪ Intravascular (25% of ECF).
▪ Interstitial (75% of ECF).
Intracellular fluid (60% TBW)
► As a main component of cytoplasm of cell.
يعني ال ٦٠٪ ميه دول ٦٠٪ منهم جوه الخلايا بس .
يعني المتحكم في الضغط هو ال intravascular compartment اللي هو نسبته من مية الجسم كلها ١٠٪ بس.
طيب ايه اللي يتحكم ان الميه تبقي جوه الخلية او براها يعني اللي بيأثر علي الميه جوه وبره الخلية حاجة واحدة بس ؟ وهل الميه ممكن تتحرك من بره الخلية لجواها والعكس ؟ وازااي؟
Intracellular fluid volume is largely determined by change in osmolarity.
Extracellular fluid volume is largely determined by total body sodium.
Fluids moves across compartment is classically governed by starling forces which means that balance between hydrostatic and osmotic pressure keeps normal body water distribution.
New studies provide a more acceptable model which controls fluid movement that depend on endothelial glycocalyx layer which supported by that infusion of isotonic saline solution results in similar plasma volume expansion as colloid which has a high osmoticpressure.
طيب ازاي الاسزمولارتي بتحدد كمية الميه جوه الخلية ؟
Intracellular fluid controlled by osmolarity as osmolarity greater than 284 mOsm/l associated with linear increase in ADH and stimulation of thirst center, systemic hypotension also triggers this response.
ADH will acts till 295mOsm/l than obligatory excretionof urine done to remove waste products
On other side if plasma osmolarity if below 284 water loss increase till 15-20L/day then if water intake exceeds this so water will enter cells leading to cellular swealing
طيب طالما الموضوع متنظم كده هل لو اديت ١٠٠٠ مل محلول ملح هيوصل الدورة الدموية ١٠٠٠ وهيرفع الضغط علي طول ؟
للأسف لاءه بالذات في ال crystalloid اللي هما ال saline وال Ringer .
Intravascular volume expansion by infused fluid differs from one to another as 1000ml of crystalloids expand it by 300ml, 1000 ml of D5W expand it by 100ml, 1000ml of colloid expand it by 1000ml.
After 3 hours only 15% of fluid infusion as a bolus remain intravascular.
كده خلصنا الفسيولوجي اللي كان لازم يكون عندنا خلفية عنه ودلوقتي نيجي لل clinical application او ال fluid stewardship يعني ايه أنواع المحاليل في الاستخدام وجرعاتها ونبدأها امتي ونوقفها امتي ؟
Resuscitation fluids:
► definition: It’s usage of glucose free isotonic fluid boluses to replenish the intravascular compartment to optimize tissue oxygenation and increase cardiac output by increasing the preload volume to maintain tissue perfusion.
► Approach (4 Ds: Drug=Fluid type, Dose, Duration, de-escalation)
Drug: balanced (low Cl- content) isotonic fluids e.g ringer lactate is the ideal fluid as Cl- rich fluid e.g. Nacl 0.9% associated with acidosis and decrease GFR and AKI. Saline will be the ideal fluid in case of hypochloremicmetabolic alkalosis with hypotension or hypovolemic hyponatremia or in case of economic perspective.
Dose: 3-4ml/kg given IV over 10mins (Sepsis campaignrecommend 30ml/kg/over 1 hour but in case of low hospital facilities and absence of CRRT device restrictive therapy is better to be followed) repeated as patient is fluid responsive and hemodynamic monitoring e.g., CVP“better to be used as a safety point”, COP and cardiac index, IVC, UOP ”delayed", lactate level, ScvO2, capillary refill and pulse pressure to achieve the target goal needed as UOP ≥0.5 ml/kg/hour, CVP 8-12 mmhg, MAP 65mmhg and ScvO2>65%, normal capillary refill and normal co2 gap, Cardiac Index > 2.51/m2.
~ Fluid responsiveness is generally defined as a significant increase (> 10–15 %)
in stroke volume in response to a fluid challenge (usually 500 cm3) regarded as the first step in resuscitation. Clinical studies however, demonstrate that only about 50 % of hemodynamically unstable critically ill patients (In ER, ICU or OR) are volume responsive.
~ There is a strategy was described several decades ago by Weil and Henning who proposed the 2–5 CVP Rule. According to this scheme, the CVP is measured at 10 min intervals. If the change in CVP was < 2 mmHg, the infusion was continued, if it was in the 2–5 mmHg the infusion was interrupted and re-evaluated after a 10 min wait. If the change was > 5 mmHg the infusion was stopped. However, the 2–5 CVP rule is unable to predict fluid responsiveness in patients with both high and low CVP.
~ Passive leg rising test and pulse pressure variation after therapy is acceptable indicator for assessment of fluid responsiveness.
Duration: variable till early target goal
De-escalation: when target goal done.
► Remember increase of CVP rapidly after administration of fluid therapy does not mean that patient is fluid responsive,and COP won’t further increased.
► In case of clinical non responsiveness vasopressors or inotropes are indicated to be started or presence of volume overload.
► In case of haemorrhage or anaemia Hb≤ 7g/dl pRBCs added to resuscitation fluid.
Replacement fluid:
► Definition: Fluids are also indicated in the post resuscitation phase, when the patient is no longer hypovolemia but still has ongoing abnormal fluid loss that cannot be compensated for by oral intake alonee.g., diarrhoea, vomiting and surgical drains or insensible fluid loss
► Approach: stop loss and match volume and composition (e.g., K+, HCO3-) of replacement fluid to that of the lost fluid.
~~Fluid loss mimics~~
Maintenance fluid therapy:
► Definition: fluid used to Maintain adequate hydration andorgan perfusion (organ support phase) in patient unable to maintain it orally.
► Indications of maintenance fluid: patients who cannot or are not allowed to meet their daily fluid requirements enterally.
► Types of fluid administrated:
▪ NS + D5W is better in patient with risk of starvationketosis till clinical nutrition present (daily need of glucose is 50-100 g/day).
▪ Some authors believe that normal saline is used to replace loss from GIT only not to replace sodium but to replace chloride.
▪ Fluids with normal physiologic concentration e.g., ringer lactate or plasmalyte (balanced low cl- content) is better than normal saline as in recent studies NS linked to decrease bicarbonate level and academic range PH with decrease of renal blood flow.
► In case of electrolyte deficient in replaced separately from fluid e.g. daily need 1 mmol/kg/day of K+ and Na guided by blood level.
► Patient on maintenance fluids alone for more than 3 days require specialized nutrition consultation.
► Dose of fluid therapy:
▪ 1-2ml/kg/hour (25-30ml/kg/day) based on Target UOP ≥0.5 ml/kg/hour, CVP 8-12 mmhg, MAP 65mmhg and ScvO2>65%, normal capillary refill and normal co2 gap.
▪ fluid balance must done and it better to be negativebalance ( Negative 500-1000ml).
▪ Rule of thumb may be used to dose guidance (Rate in ml/hour = (patient weight in Kg “Ideal body weight”) + 40
► TAKE CARE: Maintenance fluid varies according to patient fluid state) e.g.
▪ Oedema state e.g. CHF, cirrhosis, Nephrosis = 40-60% of maintenance fluid therapy and avoid fluid creep(Fluid administered as a drug dilution and catheter patency)
▪ CNS disease e.g TBI or Meningitis = 100% maintenance + hypertonic saline to keep plasma Na > 140mEq/L
▪ Euvolemic state with Increased ADH e.g. Pneumonia , TB , cancer and post operative setting consider that you must correct hyponatremia if present and fluid slightly less than normal
▪ Anuric patient : 25% of maintenance fluid therapy.
▪ Diuresis e.g., DKA = 1.2 X maintenance fluid
When to de-escalate all fluid therapy:
► Hemodynamically stable, with adequate tissue perfusion with capable of enteral/oral feeding and hydration.
► caloric intake of 25 kcal/kg/day from a standard enteral nutrition formula implies the co-infusion of 1600ml of water, which can be insufficient to restore a normal hydration status in case of depletion.
Remember colloids is better to avoid unless there is hypoalbuminemia ≤ 2.5g as hypo-albuminemia correlates with more adverse outcomes “Controversial” or in case of HRS,Large volume paracentesis, SPB.
Assessment of patient volume state and responsiveness will be discussed in separate post with full detalis.
طبعا مجبتش سيرة ال glucose 10% اللي بيتعلق علي الفاضي والمليان بدون داعي اللي الزجاجة ال٥٠٠ ملي منه بتعادل كوباية ميه دايب فيها ٤ معالق كبار سكر تموين عادي يعني هو مش المحلول الخارق ولا حاجة ولا جهنمي بيخفف كل حا
