Perioperative Management of Jehovahs Witnesses

Jehovah's Witnesses refuse to consent to transfusions of whole blood, red cells, plasma, platelets, white cells, and predonated autologous blood due to their religious beliefs. It is a matter of individual conscience whether Jehovah's Witnesses allow fractions derived from any primary component of blood (e.g., anti-D), medical procedures involving the use of autologous blood that do not involve storage (e.g., intraoperative cell salvage),

Table 3.12. Standard intravenous dosages of antiemetics (pediatric dosage should not exceed adult dosage), modified from (1)

Substance

Point of action

Adult prophylaxis

Adult therapy

Pediatric prophylaxis

Ondansetron

5-HT3

4mg

1 mgb,c to 4 mga-b

50 |ig/kgb,c to 100 |ig/kg

Tropisetron

5-HT3

2 mg

1 mgcto 2 mga

100-200 |g/kgb'c

Dolasetron

5-HT3

12.5 mga-c to 50 mgb'c

12.5 mg

350 |g/kgc

Granisetron

5-HT3

0.35-1 mgb-c,3mga

0.1-0.3 mgc, 3 mga

10-20 |g/kgc, 40 |g/kg (>2years)a

Dexamethasone

Unsettled

4-5 mg earlyb,c,

Not recommendedc

150 |g/kga-c to 500 |g/kg(>2 years)a

8-20 mgpreopa

8-20 mga

500 |g/kgb'c to 1.25 mg/kga

Dimenhydrinate

H1

ó2a-c to 124 mga

32 mgc, 62-124 mga

Droperidol

D2

0.625-1.25 mgb-c

0.625 mgb'c

50-75 |g/kgb'c

Metoclopramide

Not recommended due to insufficient antiemetic effect

Modified from Apfel and Roewer (2004)

5-HT3 antagonist at 5-hydroxytryptamine (serotonin)-3 receptor, H1 antagonist at histamin-1-receptor, D2 antagonist at dopa-min-2 receptor a Scientific information b Proved by studies c Expert opinion

Modified from Apfel and Roewer (2004)

5-HT3 antagonist at 5-hydroxytryptamine (serotonin)-3 receptor, H1 antagonist at histamin-1-receptor, D2 antagonist at dopa-min-2 receptor a Scientific information b Proved by studies c Expert opinion or organ transplant. Nevertheless, Jehovah's Witnesses request all other kinds of medical treatment to save their lives.

Legal Issues

Patient management depends on the laws of the country; e.g., in the United States, it is the right of a competent adult to refuse transfusion even though the result of such a refusal may be death of the individual.

The perioperative strategy seems to be quite easy if the patient can express his or her wish not to receive any blood or blood products in an elective setting. The key conditions for a legal informed consent are "competency" and "adulthood". There should be a high grade of suspicion concerning competency if the patient has abnormal or unstable vital signs, altered mental status, evidence of impaired judgment as from a central nervous system injury or illness, or any sign of alcohol or drug intoxication. In regard to the definition of a minor, individuals are generally considered too young to make a decision for themselves if they are under the age of 18; however, exceptions can be made for self-sufficient minors and emancipated minors. A self-sufficient minor is one who is age 15 or older and lives separately and apart from his or her parents or legal guardian. An emancipated minor is any person under the age of 18 who has entered into a valid marriage.

Concerning minors, the courts have ordered transfusions for children in life-threatening situations despite the objections or their parents or legal guardians. The same applies to incompetent adult patients, where courts have predominantly ruled that a physician has a legally recognized right to proceed with emergency procedures such as transfusion therapy even over the objections of the relatives (Rashad Net University 2006).

Physiology of Anemia

To understand the physiology and compensatory measures of a reduced hemoglobin concentration and deduct possible strategies to maintain oxygen supply of the body, the following parameters should be discussed.

The oxygen delivery of the organism (DO2) is the product of the cardiac output (CO) and the arterial oxygen content of the blood (caO2).

DO2 Oxygen supply, normal range 900 -1,200 ml/min CO Cardiac output, normal range: 4-8 l/min caO2 Oxygen content of the arterial blood, normal range: 19± 1 ml/dl

The content of oxygen of the arterial blood consists of the major part of 98.5% that is stored in the hemoglobin (SaO2*Hb*1.39) and the minor part of 1.5 % that is physically stored (paO2*0.003).

SaO2 Oxygen saturation of the arterial blood, normal range 96%-100% Hb Hemoglobin concentration, normal range 12-16 g/dl in women, 14-18 g/dl in men paO2 Partial pressure of oxygen in arterial blood, normal range 70-100 mmHg (Fresenius and Heck 2001)

Physiologic compensation of anemia (decrease in hemoglobin concentration) to maintain adequate oxygen delivery is achieved by increased cardiac output (tachycardia, increased contractility). Therapeutic measures include lowering oxygen consumption and administering high inspiratory oxygen concentrations (increase in SaO2 and paO2) by sedation and mechanical ventilation. Oxygen consumption can also be lowered (7% per °C) by hypothermia. When the hemoglobin concentration is very low, the oxygen content of the blood decreases dramatically, because the physically stored oxygen (paO2 * 0.003) is only a minor part of oxygen transport in the blood. The physically stored oxygen can only be increased significantly in hyperbaric conditions.

Other mechanisms to improve tissue oxygenation include lowering of the hematocrit with consecutive decrease in viscosity and improvement of blood flow. The peripheral vascular resistance is lowered to additionally increase blood flow. The oxygen saturation curve, which describes the dependency of saturation on the partial pressure, shifts to the right due to acido-sis, anemia, and an increase in 2,3-diphosphoglycerate and consecutively improves donation of oxygen to the tissues (Rashad Net University 2006).

Strategies to Avoid Blood Transfusions

Perioperative care of Jehovah's Witnesses should ideally start weeks before the surgical procedure. After a positive benefit-risk analysis by the surgeon that includes the determination of the possible blood loss, the patient should also be assessed by the anesthesiologist to determine the patient's preferences and preclusions. After all parties agree on how to proceed with medical management, the patient must sign a consent form memorializing his or her request not to transfuse under any circumstances. At this early stage of planning, an oral iron medication should be considered.

Donation and deposition of autologous blood is commonly not accepted by the patients, but the preop-erative acute normovolemic hemodilution can be an option to reduce intraoperative blood loss if the collect-

ing system "maintains in the circulatory system". Additionally a cell-saving device can be used intraoperative-ly, if no contraindications exist and the patient accepts its use.

Deliberate hypotension with the reduction of the systolic blood pressure to 80-90 mmHg decreases intraoperative blood loss. Contraindications are cardioTable 3.13. Perioperative management to avoid blood transfusions vascular disease, particularly coronary artery disease and congestive heart failure, poorly controlled hypertension, raised intracranial pressure, and coexistent central nervous system pathologies. Additional side effects of deliberate hypotension are increased alveolar dead space and decreased renal blood flow, so monitoring arterial blood gases and urinary output is advis-

Strategy

Measures

Effect

Fluids

Ringer's lactate

Maintain blood volume

Hydroxyethyl starch

Dextran

Gelatin solutions

Oxygen transporting solutions

Transport of oxygen

Drugs

Erythropoietin

Stimulation of red blood cells

Interleukin-11

Stimulation of platelets

GM-CSF, G-CSF

Stimulation of white blood cells

Aprotinin, Tranexamic acid

Antifibrinolytics

Desmopressin

Release of vWF

Vitamin K

Vitamin K-dependent coagulation factors

Recombinant Factor Vila, VIII

Activation of extrinsic pathway

Biological

Collagen pad

Direct sealing of wounds

hemostats

Cellulose woven pad

Fibrin glue

Blood

Cell-saving machines

Recovery of red blood cells

salvage

Surgical

Thorough operative planning

Minimizing blood loss during procedure

techniques

Prompt action to stop bleeding

Dividing large surgeries into

smaller ones

Minimally invasive procedures

Endoscopic procedures

Arterial embolization

Applied direct pressure

Ice packs

Positioning of body

Tourniquet

Surgical

Electrocautery or electrosurgery

Closing vessels

tools

Laser surgery

Argon beam coagulator

Gamma knife radiosurgery

Microwave coagulating scalpel

Shaw hemostatic scalpel

Ultrasonic scalpel

Cryosurgery

Anesthe-

Controlled hypotension

Reduced blood pressure

siologic

Regional anesthesia

techniques

Maintaining normothermia

Maintain coagulation

Acute normovolemic hemodilu-

Reduced blood loss

tion

Pediatric microsampling equip-

Reduced sample volumes

ment

Multiple tests per sample

Management

Stop the bleeding

Basis of all efforts

of anemia

Oxygen support

Increased SaO2

Maintain intravascular volume

Iron

Erythropoiesis

Folic acid

Vitamin B12 injection

Hyperbaric oxygen chamber

Increased paO2

Mechanical ventilation

Reduced oxygen consumption

able. Hypotension can be achieved by inhalational anesthetics, sodium nitroprusside, nitroglycerin, and tri-methaphan. Neuroaxial blocks such as spinal or epidu-ral anesthesia also lower the blood pressure, but controlling the amount of hypotension is more difficult.

Positioning the patient so that the surgical field is at a high point may result in less blood loss.

Mild hypothermia is another possible measure to reduce oxygen demand in anemic patients, as mentioned before. A target core temperature of 30-32°C is typically chosen to balance the reduction of oxygen consumption with the side effects of cardiac arrhythmias and the hypocoagulatory state. Desmopressin, a synthetic analog of the antidiuretic hormone, can elevate the coagulation factor VIII and von-Willebrand factor. Aminocaproic acid and other antifibrinolytics can reduce blood loss by inhibiting the physiologic or increased lysis of already formed clots. Recombinant human erythropoietin stimulates the synthesis of eryth-rocytes but takes a while to produce an effect and is quite expensive. The artificial substances such as per-fluorocarbon that transport oxygen are not as effective as hemoglobin and still need further development.

Table 3.13 lists the possible strategies, measures, and effects to avoid blood transfusions. From this summary, the treating physician should extract the measures applicable to a specific patient.

Conclusion

If a hospital anticipates they might administer emergency care to Jehovah's Witnesses, it should establish a protocol for such treatment to help avoid any medical, ethical, or legal dilemmas that may arise.

All the blood-saving techniques discussed above also apply to the regular patient in order to minimize blood loss and the need for transfusions.

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