SURGICAL WEBSITES BREAST DISEASE LIVER ABSCESS INGUINAL HERNIA CHOLECYSTECTOMY KIDNEY SURGERY HOW SURGICAL OPERATION IS DONE THYROID EXAMINATION MANAGEMENT OF SEVERELY INJURED PATIENT SEPSIS AND MULTIPLE ORGAN FAILURE CHEST TRAUMA BRONCHIOGENIC CARCINOMA TETANUS AND ANAEROBIC INFECTIONS POSTGRADUATE SURGERY
BLOOD TRANSFUSION
There are two main landmarks in blood transfusion which have allowed many major operations to be successfully performed.
o Firstly, the discovery of ABO isoagglutinins in 1901 by Landsteiner marked the development of safe blood transfusion.
o Secondly, the addition of acid-citrate dextrose (ACD) from 1943 provided anticoagulant activity and nutrition for the red cells which resulted in a dramatic increase in the shelf life of stored blood.
§ The main indications for transfusion of blood and its components are
· to replace acute blood loss,
· treat anaemia and to
· Correct any disorders of haemostasis.
Replacement
- Red cell transfusions are used to augment the delivery of oxygen in the hope of avoiding the deleterious effects of oxygen debt.
§ The ideal replacement fluid in rapid haemorrhage is red cells in saline-adenine-glucose-mannitol (SAG-M).
- These additives provide the nutrition and preserve the shape of the red cells.
- Large amounts of crystalloid and colloid solutions dilute blood and its clotting factors and could impair coagulation and the oxygen-carrying capacity.
- In adults, blood losses up to 1 litre can be replaced by crystalloids/colloids, but larger losses should be replaced with blood.
- Therapy for rapid blood loss should be directed primarily toward the arrest of haemorrhage.
- Neat packed cells have a high viscosity and are not indicated in the acute situation as the sole replacement fluid.
- Blood substitutes like the synthetic perfluorocarbons (PFCs) and modified haemoglobin solutions (polyhaemoglobins) did not gain popularity in clinical practice.
Anaemia
Transfusion is rarely indicated when the Hb concentration is greater than 10 g/dl and is almost always indicated when it is less than 6 g/dl, especially when anaemia is acute.
- Whether intermediate Hb concentrations (6-10 g/dl) justify or require red cell transfusion should be based on the patient's risk for complications of inadequate oxygenation.
- The use of a single Hb trigger for all patients and failure to consider all physiological and surgical factors affecting oxygenation are not recommended.
- Correction of anaemia is vital if ischaemic events like
- angina,
- claudication,
- transient ischaemic attacks and
- gut ischaemia is present or anticipated.
Haemostasis
· The major bleeding problems that accompany surgical disease occur in patients on.
§ warfarin,
§ heparin or
§ aspirin,
§ in those patients with disseminated intravascular coagulation (DIC), and
§ in patients with haemophilia,
§ liver disease,
§ thrombocytopenia and
§ Hypersplenism.
Haemostasis continued……..
· Heparin is easily reversed with protamine sulphate.
· Warfarin is reversed by intramuscular
§ Vitamin K, which takes at least 24 hours to work.
§ FFP is required for emergency reversal.
§ Regular prothrombin estimations are still required because the half-life of warfarin is much longer than that of FFP.
§ Aspirin prolongs the bleeding time by interfering with platelet function.
§ The aim of treating DIC is to correct the underlying surgical problem (usually sepsis).
§ Component therapy (platelets, clotting factors) is given on the advice of a haematologist.
Telephone: 03002467670
