Assessment of blood loss

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Assessment of blood loss

Transcript of Assessment of blood loss

  • Assessment of blood loss Prof. Aboubakr elnashar Benha university hospital, Egypt Email: [email protected] Aboubakr Elnashar
  • Visual inspection is inaccurate. In some reports, the amount of blood estimated to have been lost by inspection was half the measured loss. Clinicians typically underestimate postpartum blood loss by 30%-50% Importantly, in obstetrics, part or all of the hemorrhage may be concealed. Clinicians commonly record blood loss using inaccurately low numbers. "How can we teach people to accurately and honestly record blood loss? Aboubakr Elnashar
  • On average, women lose about 500 cc in a vaginal delivery, 1,000 cc in CS, and 1,500 cc in a cesarean hysterectomy. The critical area where you want to estimate blood loss is over 2,000 cc, and we almost always underestimate that. By that point, the patient has hypotension, has significant tachycardia, and is in shock. Aboubakr Elnashar
  • A. Clinical methods Aboubakr Elnashar
  • 1. BP, HR: By the time you detect changes in BP or HR suggesting PPH, the woman already has lost 1/3 of her blood volume Orthostatic hypotension would tell you that the patient has lost 20%-25% of her blood, but if she is sitting or lying down on the delivery table, you're unlikely to detect that symptom. Hypotension reflects a loss of 30%-35% of blood volume. "Do not wait for hypotension" to treat for PPH "Do not wait to start seeing S and S. Aboubakr Elnashar
  • 2. Hematocrit: It needs 4 h for significant changes and 48 h for complete compensation In acute hemorrhage, the immediate hct may not reflect actual blood loss. After the loss of 1000 mL, the hct typically falls only 3 volume % in the first hour. When resuscitation is given with rapid infusion of IV crystalloids, there is rapid equilibration. During an episode of acute significant hemorrhage, the initial hct is always the highest. This is true whether it is measured in the delivery room, operating room, or recovery room. Aboubakr Elnashar
  • 3. Urine output One of the most important "vital signs" to follow in the bleeding patient with obstetrical hemorrhage. In the absence of diuretics, the rate of urine formation reflects the adequacy of renal perfusion and, in turn, perfusion of other vital organs, because renal blood flow is especially sensitive to changes in blood volume. Urine flow of at least 30 mL and preferably 60 mL/h should be maintained. With potentially serious hemorrhage, an indwelling catheter should be inserted to measure urine flow. Aboubakr Elnashar
  • 4. Weighing packs and correlate with blood loss: Hospital keeps scales in delivery rooms to weigh lap sponges & other materials to estimate blood loss. 1kg soaked swabs: 1000ml 5. Perhaps the easiest method of estimating is to picture a soda can, which would hold about 350 cc of blood. When you look at blood clots or blood in a canister, estimate how many cans of soda are represented, and you'll be close to blood volume lost. "The principle is to recognize volume. Aboubakr Elnashar
  • 6. Maximum capacity of Swab Small (10x10cm): 60ml Medium (30x30 cm): 140ml Large (45x45 cm): 350ml 7. Floor spill 50 cm diameter: 500ml 75 cm diameter: 1000ml 100 cm diameter: 1500ml 8. Vaginal PPH limited to bed only Unlikely to exceed 1000ml spilling from bed to floor likely to Exceed 1000ml Aboubakr Elnashar
  • B. Actual blood loss In the perioperative period clinical estimation of blood loss is inaccurate and alone should not be used to determine the need for red blood cell transfusions. Poor agreement between the Actual Blood Loss and the estimated blood loss. The 95% confidence intervals (- 719.939 ml to+1265.619 ml) suggest that clinical estimation alone may result in unacceptable under or over transfusions. In 64% of the cases the blood loss was underestimated. Clinical estimations of blood loss suffer from large interobserver variability and poor repeatability. Aboubakr Elnashar
  • The extent of blood loss and response to transfusion is reflected in the changes in the hct. This change may be used to calculate the Actual Blood Loss using suitable formulae. Aboubakr Elnashar
  • The Actual Blood Loss is a modification of the Gross formula: ABL = BV [Hct (i) - Hct (f)]/ Hct (m) Blood Volume=Body Wt in Kgs x 70 mlkg-1 Hct (i), Hct (f) and Hct (m): the initial, final and mean (of the initial and final) Hematocrits respectively. Blood volume Neonates: 85-90ml/ kg body weight Children: 80ml/ kg body weight Adults: 70ml/ kg body weight Aboubakr Elnashar
  • Calculating blood loss in theatre: 1. Weigh a dry swab. 2. Weigh blood soaked swabs as soon as they are discarded and subtract their dry weight (1ml of blood weighs approximately 1gm). 3. Subtract the weight of empty suction bottles from the filled ones. 4. Estimate blood loss into surgical drapes, together with the pooled blood beneath the patient and onto the floor. 5. Note the volume of irrigation fluids, subtract this volume from the measured blood loss to estimate the final blood loss. Aboubakr Elnashar
  • The decision to transfuse blood: 1. Percentage method. Calculate the patients blood volume. Decide on the percentage of blood volume that could be lost but safely tolerated, depending on the clinical condition of the patient, provided that normovolaemia is maintained (table) Aboubakr Elnashar
  • Patient condition Health Average Poor Percentage method Acceptable loss of blood volume before transfusion method 30% 20%