Chapter 13 - The Haematopoietic System

 

13.0 Introduction

In conducting an assessment, the assessor must have regard to the Principles of Assessment and the definitions contained in the Glossary.

13.1 Anaemia

Iron deficiency anaemia and megaloblastic anaemia are generally manageable with proper treatment and should not cause permanent impairment. Some haemolytic anaemias are reversible with appropriate therapy, such as steroids or splenectomy, and also should result in negligible impairment.

The impairment resulting from persistent refractory anaemia, whether haemolytic or aplastic, is assessed using Table 13.1.

Table 13.1: Anaemia

% WPI	Haemoglobin Level	Transfusion Requirements
0	100-120g/L	None
10	80-100g/L	None
20	80-100g/L	2 U every 6 weeks
40	<80g/L	2-3 U every 4 to 6 weeks
60	<80g/L	2-3 U every 2-3 weeks

13.2 Leukocyte Abnormalities or Disease

Chronic low white cell counts (for example, neutropenia) are usually associated with substantially increased risk of infection. Impairment is measured in terms of the infection.

Neoplastic disorders of leukocytes include leukaemias, lymphomas, multiple myeloma, and macroglobulinaemia. Some of these disorders (chronic lymphatic leukaemia, hairy cell leukaemia, and some lymphomas) may cause no impairment for many years.

Similarly, multiple myeloma and macroglobulinaemia may be initially asymptomatic, and cause no gastrointestinal haemorrhage, bone pain, or need for chemotherapy or radiation.

The impairment should be assessed by reference to the appropriate chapters of this Guide.

As the early stages of HIV infection are not likely to manifest in impaired organ systems, Table 13.2 alone should be used to assess any impairment. Where organ systems are impaired as the disease progresses, impairment should be assessed using those chapters of the Guide which assess impairment of the principal organ systems affected by the disease: including, but not limited to, Chapter 2 - The Respiratory System, Chapter 8 - The Digestive System, Chapter 10 - The Urinary System, and Chapter 12 - The Neurological System. If several systems are involved, the WPI ratings derived for each system are combined using the Combined Values Chart (see Appendix 1).

The combined impairment should then be compared with the WPI rating from Table 13.2 in order to ascertain the most beneficial WPI rating.

The contribution of side effects of drug treatment to overall impairment should also be considered.

The same principle applies to other conditions of the haematopoietic system where organ systems are impaired by the disease process and impairment can be assessed using other chapters of the Guide.

'Activities of Daily Living' are activities which an employee needs to perform to function in a non-specific environment (that is, to live). Performance of Activities of Daily Living is measured by reference to primary biological and psychosocial function.

For the purposes of Table 13.2: Leukocyte Abnormalities or Disease, Activities of Daily Living are those in Figure 13-A below.

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Figure 13-A: Activities of Daily Living

Activity	Examples
Self care, personal hygiene.	Bathing, grooming, dressing, eating, eliminating.
Communication.	Hearing, speaking, reading, writing, using keyboard.
Physical activity.	Standing, sitting, reclining, walking, stooping, squatting, kneeling, reaching, bending, twisting, leaning, carrying, lifting, pulling, pushing, climbing, exercising.
Sensory function.	Tactile feeling.
Hand functions.	Grasping, holding, pinching, percussive movements, sensory discrimination.
Travel.	Driving or travelling as a passenger.
Sexual function.	Participating in desired sexual activity.
Sleep.	Having a restful sleep pattern.
Social and recreational.	Participating in individual or group activities, sports activities, hobbies.

Table 13.2: Leukocyte Abnormalities or Disease

% WPI	Criteria (ALL required)
0	Signs of leukocyte abnormality but no symptoms. No or infrequent treatment needed. All the Activities of Daily Living can be performed.
10	Signs and symptoms of leukocyte abnormality. Infrequent treatment needed. Almost all the Activities of Daily Living can be performed.
20	Signs and symptoms of leukocyte abnormality. Continuous or regular treatment needed. Most of the Activities of Daily Living can be performed.
30	Signs and symptoms of leukocyte abnormality. Continuous or regular treatment needed. Interference with the performance of the Activities of Daily Living to the extent that some assistance from others is required.
50	Signs and symptoms of leukocyte abnormality. Continuous or regular treatment needed. Interference with the performance of the Activities of Daily Living to the extent that considerable assistance from others is required.
70	Signs and symptoms of leukocyte abnormality. Continuous or regular treatment needed. Interference with the performance of the Activities of Daily Living to the extent that continuous assistance from others is required.
80	Signs and symptoms of leukocyte abnormality. Continuous or regular treatment needed. Totally dependent on others for performance of all Activities of Daily Living.

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13.3 Haemorrhagic Disorders and Platelet Disorders

Thrombocytopenia does not constitute an impairment unless severe and not reversible with steroids, splenectomy, or other therapy.

A bleeding disorder that only causes problems after trauma or surgery does not constitute a permanent bleeding impairment.

Where an injury is made more severe by the presence of an underlying bleeding disorder, a combined WPI rating is allowed, incorporating values for bleeding sites or organ damage. A WPI rating obtained from tables in other Chapters may be combined with a WPI rating obtained from Table 13.3.

Other complications of bleeding disorders, including gastrointestinal, mucosal or intramuscular haemorrhage, should also be assessed according to the site of the blood loss under other Chapters of the Guide, including Chapter 8 - The Digestive System, and/or Table 13.1: Anaemia.

A WPI rating obtained from other tables in this Guide should be combined with a WPI rating obtained from Table 13.3 below.

Table 13.3: Haemorrhagic Disorders and Platelet Disorders

% WPI	Criteria
0	Splenectomy; or Easy bruising.
10	Continuous or regular medication.
25	Refractory thrombocytopenia <20,000/m L.

13.4: Thrombotic Disorders

Long-term prophylaxis means prophylaxis continuing for at least 2 years.

Employees who have permanent respiratory or cardiac limitation, secondary to massive pulmonary embolism, should be assessed as appropriate under Chapter 1 - The Cardiovascular System, and Chapter 2 - The Respiratory System.

For specific levels of impairment for post-thrombotic syndrome, use Table 1.4: Peripheral Vascular Disease of the Lower Extremities, or Table 1.6: Raynaud's Disease (Chapter 1 - The Cardiovascular System). These Tables may be used as an alternative. WPI ratings from Tables 1.4 or 1.6, and Table 13.4, must not be combined.

Tables 1.5 and 1.6 should be used as the primary guide for assessing peripheral complications of thrombosis.

Table 13.4: Thrombotic Disorders

% WPI	Criteria
0	Superficial thrombosis or thrombophlebitis.
10	Deep venous or other thrombosis requiring long-term prophylaxis with warfarin.
30	Post-phlebitic syndrome.