A-level Applied Science/The Role of the Pathology Service/Examples

Morriston Hospital, Swansea

The Swansea NHS Trust serves 250,000 people and manages 1800 hospital beds. It is a teaching hospital trust with all major specialities including burns, renal, cardiac surgery and neurosurgery. There are two main hospitals, Singleton (600 beds) and Morriston (850), and 7 smaller hospitals. Morriston is on the northern outskirts of the city. Singleton is west of the city centre.

Location of Swansea.

There are two main laboratories in the Swansea NHS Trust, one at Morriston and the other at Singleton. The Pathology Departments have concentrated most resources on one or other sites in order to maximise use of facilities. A comprehensive service is achieved despite this specialisation, by means of efficient IT and transport systems. The department has an annual budget of approximately £8.5 million.

The department is Clinical Pathology Accreditation (UK) Ltd (CPA) accredited. CPA is the key accreditation body for NHS pathology laboratories. Laboratories are required to apply CPA standards in all aspects of their daily operations.

CPA standards apply to the laboratory’s organisation, staffing, resources, analysis and examination methods and quality assurance.

Organisation

Pathology services in Swansea are provided by the Directorate of Pathology. The Directorate is made up of Departments of:

• Cellular Pathology (9 consultants)
• Chemical Pathology (2)
• Haematology (4-6)
• Medical Microbiology/Virology (1-3)

All pathologists are involved in the interpretation of laboratory test results and giving advice about the appropriate investigation of patients.

Workload

The department performs over 2.6 million investigations annually.

Annually, 1.7 million test requests are received, covering a huge spectrum of analysis including highly automated chemical pathology tests, the culture of an enormous range of micro-organisms, highly detailed blood and bone marrow analysis and the provision of screening programmes for breast and cervical cancer.

Staffing

There are 19 consultant medical staff in Pathology together with 5 clinical scientists and approximately 150 technical and clerical staff. Together they provide both a clinical and an analytical service.

The Directorate of Pathology is involved in several aspects of undergraduate medical teaching.

Information Management

Both medical and technical staff work together to provide the analytical service. There is a very strong emphasis on quality control and efficient timely procedures throughout. Managing such a huge volume of information is highly dependent on an effective laboratory computer system. Clinical scientists play an important role in monitoring quality control measures and undertaking research and development as well as leading teams in specific technical areas (i.e. molecular biology).

Most NHS clinical laboratories keep their documentation as paper records, but this causes problems when staff need to access documentation and problems maintaining document control. The Chemical Pathology and IT departments at Swansea NHS Trust have developed an intranet as an effective yet inexpensive method of access and storage for all its procedural documentation and record keeping.

Types of sample

Most samples received in chemical pathology and haematology are blood samples collected by phlebotomy, using the evacuated blood collection (Vacutainer^TM)system

Order of Draw of Evacuated Tubes.

1. Blood culture bottles, sterile tubes
2. Tubes without additives (red stoppers)
3. Tubes containing Gel
4. Tubes for coagulation studies (light blue - contain citrate)
5. Tubes with additives:-

• Pink/lavender stoppers (EDTA)
• Black stoppers (citrate - for ESR haematology)
• Grey stoppers (fluoride and oxalate - for glucose determination)

Serum or plasma zinc level will show misleading elevation due to the presence of zinc in the stopper. Special tubes for trace element studies (dark blue stopper - sodium salt of heparin) are available from the Chemical Pathology Department.

Health and safety

Most samples received are blood samples collected with the evacuated blood collection system. Guidelines for safely collecting blood in this way include:

• Wear gloves during venepuncture and when handling blood collection tubes to minimise exposure to hazards.
• Do not remove needle shield.
• After use, DO NOT resheath needle but dispose of both the needle and holder into an appropriate sharps disposal container

General notes about high risk samples

Under the Health and Safety at Work Act (HSWA) and the COSHH Regulations, anyone taking and/or sending potentially hazardous material for laboratory examination has a duty to conduct the work safely.

Section 3 of the HSWA requires staff to pass on knowledge of known or suspected hazards to those who need to handle the material.

Laboratories must be informed of any potential risk of infection (e.g. cases of known or suspected communicable diseases such as T.B., hepatitis B and C, HIV, CJD). Both the request and the specimen must be labelled “DANGER OF INFECTION” with a special yellow label.

Specimen containers and request forms must be transported to the laboratory in the specially-designed “double pocket” sealable pathology specimen plastic transport bag. The request form should be placed in the separate pocket.

The medical officer taking the sample must ensure that a senior member of the department is informed that the sample is to be sent. Only the most appropriate tests will be performed on hazardous samples. Prior consultation with the consultant pathologist concerned is advised.

Cellular Pathology

Cellular pathologists work closely with clinical teams, particularly in cancer care, providing key diagnostic and prognostic information and advice.

Annual Workload

Surgical Pathology (Histology): 24-25,000 including 250 frozen sections

Cytopathology: 25,000 gynaecological smears and 4,000 surgical cytology including 300 FNAs (fine needle aspiration biopsies).

Autopsies: Approximately 1000 in total. 300 at Neath, 550 autopsies requested by HM Coroners, 55 autopsies performed at the request of clinicians with relatives’ consent (“permission cases”).

Types of sample

1. Histology specimens (25,000 p.a.), including intraoperative frozen sections, endoscopic biopsies and samples from GP’s.

Gross specimens and biopsies are usually received in 10% buffered formalin , which must be about 20 times the volume of the tissue.

The bottles and buckets used to transport the specimens must have well fitting lids to prevent leakage, and be properly labelled.

Frozen Sections: The specimen must be sent dry.

Lymph Node Biopsy: Molecular diagnostic methods are increasingly important in the diagnosis of lymphoma. These methods are facilitated by the availability of snap frozen, fresh, unfixed biopsy material. Therefore these specimens should be sent as quickly as possible to the laboratory unfixed, in a dry container.

Renal Biopsy: Should be sent immediately to the laboratory.

Wales Cancer Bank: Tissues are received fresh from theatre.

2. Cytology service (30,000 specimens p.a.) including fine needle aspiration cytology and cervical screening.

Cytology: Most fluids, urines, pleural fluids, etc. should be collected in white capped universal bottles and sent to the laboratory without delay. Generally, four universal bottles are considered to be a representative sample.

Sputum Examination: Early morning deep cough specimens sent on the day of production and collected into plain universal bottles.

Fine Needle Aspiration Cytology: Specimens should be sent to the department via the portering service as soon as possible. A member of Cytology staff may assist in the collection.

Cervical Cytology: Liquid Based Cytology. (LBC)

Health and safety

The bottles and buckets used to transport the specimens must have well-fitting lids to prevent leakage, and be properly labelled. Containers of various sizes are available.

Formalin is a moderately flammable liquid when exposed to heat or naked flame. It is a known carcinogen, a strong eye, skin and mucous membrane irritant and a skin sensitiser and may be fatal if swallowed. Spillage absorption granules should be present in any department using formalin together with instructions for their correct use.

Chemical Pathology

Chemical pathologists run diabetic and lipid clinics.

The Chemical Pathology department was formed from the merger of 3 local laboratories in 1995. There is now one main laboratory (Morriston) open 24/7 and two “satellite” laboratories. In the satellite laboratories, there is no on site analyst between midnight and 8am.

Types of sample

Mostly blood samples, also urine, cerebrospinal fluid (CSF), faeces

Haematology

Haematologists have an extensive clinical practice managing patients with a wide range of blood related disorders.

Types of sample

Blood samples for full blood count (FBC) and erythrocyte sedimentation rate (ESR) tests.

Bone marrow aspirate and trephine samples.

Donor blood for cross-matching.

Microbiology

Microbiologists also advise on the management of infectious disease and monitor hospital acquired infections and community outbreaks. The Microbiology Department is part of the Public Health Laboratory Service which also deals with environmental (food, water etc.) microbiology and incorporates two national reference laboratories, for Toxoplasmosis and Cryptosporidium.

Types of sample

• Swabs
• Faeces
• Sputum
• Pus
• Urine
• Blood, clotted blood, serum
• Biopsy material, washings, aspirates, fluids (cerebrospinal, seminal, etc.), smears
• Intrauterine contraceptive devices (IUCDs)
• Vomit
• Food suspected of contamination
• Sellotape samples of threadworm eggs
• Skin, nail, hair

Health and safety

Viral Hepatitis

7ml clotted blood should be collected and labelled with a “DANGER OF INFECTION” sticker. Use warning labels for blood from patients with acute hepatitis, abnormal liver function tests, jaundice, chronic carriers, intravenous drug abuse and close contacts of cases.

HIV

If HIV test is required contact the Consultant Microbiologist. However, if the sample is collected by a GP, 7ml clotted blood should be sent , labelled "DANGER OF INFECTION".

Notifiable Diseases

The following diseases must be notified, as soon as diagnosed, to the Consultant in Communicable Disease Control.

Acute Encephalitis	Acute Meningitis	Acute Poliomyelitis	Anthrax
Cholera	Diphtheria	Dysentery (Amoebic or Bacillary)	Food Poisoning (all sources)
Infectious Jaundice	Lassa Fever	Legionnaire’s Disease	Leprosy
Leptospirosis	Malaria	Marburg Disease	Measles
Meningococcal septicaemia	Paratyphoid Fever	Plague	Rabies
Relapsing Fever	Rubella	Scarlet Fever	Smallpox
Tetanus	Tuberculosis	Typhoid Fever	Typhus
Viral Haemorrhagic Fever	Viral Hepatitis	Whooping Cough	Yellow Fever