216

15

15.1 DESCRIPTION

15.1.1 Introduction

Clinical laboratories provide all of the routine clinical testing required for patient care. Inpatient and outpa-tient specimens are collected; tests are conducted; and residual specimens and completed test materials of a chemical, biological, and radiological nature are dis-posed of in a safe manner; and reports are generated. As the numbers of tests and types available for diagnos-tic purposes have increased, clinical laboratories are gaining more importance. Many of the decisions made on patient admission, discharge, medication, and treat-ment are based upon clinical laboratory patient test results. Figure 15-1 shows the cycle from specimen col-lection to the clinical laboratory testing.

Unlike a research laboratory, clinical laboratories are more process oriented and designed to provide desired test results quickly and effi ciently. Many of the concepts in process engineering are adopted in the design of clini-cal laboratories.

15.1.2 Work Activities

Clinical laboratory activities include common proce-dures associated with hematology, bacteriology, virology, and pharmacology. They involve making aliquots, mixing, blending, centrifuging, heating, cooling, distilling, evapo-rating, diluting, plating-out pathogens, examining speci-

mens under the microscope, and making radiochemical measurements, plus many similar operations. The use of automated, computer-controlled instruments to perform routine tests in busy hospital laboratories has become prevalent, thereby reducing the need for handling chemicals.

Per Battisto (2004), the clinical laboratory in general has three classifi cations:(1) Clinical pathology (dis-cussed in this chapter); (2) anatomical pathology, which involves the analysis of tissues and cells and the process-ing of surgical and gynecological specimens including histology and cytology (Chapter 17 ), gross anatomy (Chapter 18 ), and autopsy laboratories (Chapter 19 ), and morgue facilities (Chapter 20 ); and (3) blood bank, which is discussed in this chapter, Section 15.2.5.4 , Blood Transfusion Laboratory. Clinical laboratories can also be classifi ed by the work done in the facility:

• Clinical Chemistry Laboratory • Acute Care Laboratory (STAT Lab or Rapid

Response Lab) • Microbiology Laboratory • Blood Transfusion Laboratory • Tissue Typing Laboratory • Clinical Immunology Laboratory • Thyroid / Endocrine Laboratory • Neurochemistry /Amino Acid Laboratory • Point of Care Testing (PoCT)

CLINICAL LABORATORIES

Guidelines for Laboratory Design: Health, Safety, and Environmental Considerations, Fourth Edition. Louis J. DiBerardinis, Janet S. Baum, Melvin W. First, Gari T. Gatwood, and Anand K. Seth.© 2013 John Wiley & Sons, Inc. Published 2013 by John Wiley & Sons, Inc.

DESCRIPTION 217

system connects the patient area to the clinical labora-tory. A fan or a pump provides a vacuum in the tube. A specially designed carrier inserted from a dispatch station can quickly arrive at the laboratory receiving station. Figure 15-2 shows a sample of a carrier.

Accessioning , which is the logging-in and distribution of the specimens in the required testing sequence, is a critical function in clinical laboratories. The objective is to achieve rapid turnaround and accurate results that will be transmitted to physicians as part of the patient ’ s medical records. Turnaround time (TAT) and accuracy of results are critical metrics for clinical laboratories.

15.1.3 Materials and Equipment Used

The amount and variety of materials and equipment present in clinical laboratories depend upon the type of facility it serves: a large general teaching hospital, a satellite medical center, a clinic, or a doctor ’ s offi ce. Typical equipment includes microscopes; hot plates; mixers; autoclaves; balances; centrifuges; and such special instruments as blood cell counters; atomic absorption spectrometers; gas and liquid chromato-graphs; and mechanized, automatic specimen-analyzing blood chemistry devices. Because many manual opera-tions are still performed in microbiology laboratories, handling of presumptively infectious specimens and examination of bacterial, viral, and fungal cultures derived from infectious specimens should be conducted in biological safety cabinets and with appropriate per-sonal protective equipment. See Chapter 14 , Biosafety Laboratory, Section 14.1.3 and Chapter 32 , Laboratory Hoods and Other Exhaust Air Contaminant-Capture Facilities and Equipment, for information on biological safety cabinets. A large variety in small quantities of

• Infectious Disease Molecular Diagnostics Laboratory

• Gastrointestinal Laboratory • Pharmacogenetics Laboratory • Hematology Laboratory(see Section 15.2.5.1 Clini-

cal Chemistry Laboratory) • Special Clotting Laboratory(see Section 15.2.5.1

Clinical Chemistry Laboratory)

Details of these clinical laboratories are described below in Section 15.2.5 .

Clinical laboratories are not usually located in medical schools; they are associated with hospitals, clinics, or independent contract testing companies. They either specialize in certain specifi c types of tests or attempt to perform them all. An example of the former type is a hematology laboratory (where only human blood tests are processed) or a comprehensive analyti-cal laboratory (where blood, urine, stool, and other bodily fl uids are analyzed). In clinical laboratories, the trend continues toward computerization, miniaturiza-tion, and automation. In the past, even when automatic systems were used, some samples required preparation and processing on a manual basis.

Today ’ s most advanced equipment, however, can perform almost every routine test on a single sample by programming the testing system. A large number of tests can be completed very rapidly by automation. Refer to Section 15.2.3 below for more details.

In hospitals, rapid delivery of specimens to clinical laboratories is often necessary, and pneumatic tube systems are sometimes used for this service. A tube

FIGURE 15-1. Clinical test cycle. (Adapted from and cour-tesy of Jack Zakowaski and Diane Powel, IVD Technology.)

Sample Drawn

Physician

Orders Test

Physician

Receives

Results

Label Tube

Transport to Lab

Lab Verifies Receipt

Sort, Send to

Worksta on

Centrifuge

Serum Indices

Aliquot / Relabel

In Clinical

Laboratory

Store Sample

System Operates

Program System

Calibrate System

Prepare Reagents

Reload Reagents

Determine

Cri cal Ranges

Check Quality

Control

Verify Results

Repeat Results

FIGURE 15-2. Pneumatic tube.

218 CLINICAL LABORATORIES

rapid TAT and accuracy, bar code labels are routinely used. Space for bar code readers and printers is required where specimens are accessioned and received.

15.2.3 Future Trends: Automation

There is a marked trend to completely automate clinical laboratory functions by installing robotic instruments. Automation in clinical laboratories has evolved from automating specimen and liquid handling manipulation to an information-based system driven by technology solutions. Robotics is not a total panacea for crowded staff conditions; it presents real challenges to the labora-tory designer in terms of space layout.

Automation in clinical laboratories is in two forms.

1. Automation of individual equipment or process—reducing manual effort and time duration. Some examples of automated equipment (Steitberg et el., 2009) are a. Automated Centrifuge: This equipment signifi -

cantly reduces manual labor and promotes effi -ciency. For example in a manual operation, if a centrifuge is not opened when samples are ready, there is a delay. Conversely, premature unloading of centrifuges has inherent ineffi ciency.

b. Intelligent Aliquot System: This consists of a serum-level detector, secondary tube labeler, and aliquot unit. It also has improved effi ciency. Before such units were available, most clinical laboratories prepared aliquots when necessary. Ongoing availability allows immediate testing and has inherent effi ciency. See Figure 15-3 for an example.

2. Automation that connects different processes and tests in series is even more automated and time effi cient. Several layouts ranging from equipment in linear, I-, U-, or L-shaped arrangements have been developed to provide further planning effi -ciency. Figure 15-4 shows layouts as examples only; no attempt has been made to identify any specifi c equipment. Dimensions provided are also only examples and should not limit actual required dimensions.

Other ways to classify automation in clinical labora-tories are

1. Islands of automation: Several analyzers are ganged together.

2. Total lab automation (TLA): Here preanalytical functions are combined with analyzers.

3. Continuous processing vs. batch processing

organic solvents, acids, and bases, as well as radioactive materials may also be used in clinical laboratories.

All clinical laboratories are BSL-2 (or higher) as they use human blood specimens. Review the Universal Precautions and the Bloodborne Pathogen Standard (29CFR 1910.1030; OSHA, 2012) for additional details.

15.1.4 Exclusions

Clinical laboratories seldom engage in research for its own sake or conduct unusual test procedures, although some types of medical research use routine clinical test results as essential elements of data. No animals are used in clinical laboratories. There are some access restrictions for specifi c clinical laboratory functions (see Section 15.2.5 ).

15.2 LABORATORY LAYOUT

15.2.1 Introduction

The layout of a clinical laboratory will be determined by its size and by the nature and number of clinical tests that will be performed, as well as by the number of staff, shifts, and automated instruments. It usually resembles a combination of analytical chemistry and biosafety laboratories. Large clinical laboratories resemble team laboratories in that many diverse activities take place in the same space. Chapters 5 and 21 provide more infor-mation. Good practice standards for laboratory layouts, as outlined in Chapters 1 and 2 , Section 2, should be followed. The Joint Commission, also known as JCAHO (2009), may impose special requirements. In addition, special process workstations, laboratory benches, and seating should be carefully designed to promote the ergonomic safety of workers because clinical laboratory activities are highly repetitive and many have the poten-tial to cause repetitive stress injuries. Clinical laborato-ries also include offi ce space, lockers, and other personnel support spaces, and signifi cant area for storage facilities. These may be within or outside the secure zone of the laboratory.

15.2.2 Specimen Handling

The facility must include an effi cient system to get speci-mens from patients to the laboratory. This may require manual transport or an automated system. Pneumatic tubes are an example of an automatic system. Space must be provided in the laboratory layout for a receiving station(s) and accessioning counters or tables to record receipt and transfer of specimens. It is critical that each patient sample is accurately identifi ed. Bar code systems are routinely used in clinical laboratories; to maintain

LABORATORY LAYOUT 219

FIGURE 15-3. Example of automation.

FIGURE 15-4. Automation in clinical laboratories.

Before selecting a level of automation, laboratory managers and designers should conduct studies and estimates of laboratory test volumes, both for the present and the future. In many older laboratories, the addition of automation arrays have sometimes created more crowded and potentially unsafe conditions

15.2.4 Ergonomic Considerations

Where possible, to accommodate different sizes of equipment and personnel height vertically adjustable work surfaces should be provided. In addition with the increases in computerization in the laboratory, ergo-nomically proper data entry workstation arrangements should be made. See Chapter 2 , Section 2.2.4 .

15.2.5 Common Elements

Clinical laboratories may provide a wide range of stan-dard tests on patient specimens in an open laboratory layout. Layouts follow guidelines given in Chapter 21 , Open or Team Research Laboratory, and Section 2 of Chapters 1 and 2 . Layouts must be based upon effi cient process analyses. All laboratory surfaces and furniture should be cleanable and nonporous. However, the fol-lowing clinical laboratory functions should be located in separate spaces for the purpose of contamination

220 CLINICAL LABORATORIES

lation Service is available. This may require a separate offi ce in which patients are seen.

Microbiology section deals with infectious materials that require containment in Biosafety cabinets. A fume hood may also be needed (see Section 15.2.5.3 for more information). Additionally, radioactive isotopes may be used, requiring a special chemical hood. These special venting provisions are required to ensure the safety of the staff. Chapter 32 , Laboratory Hoods and Other Exhaust Air Contaminant-Capture Facilities and Equip-ment, should be consulted for additional details.

In the Nuclear Medicine section, radioactive isotopes (e.g., radioactive xenon) are used in diagnostic proce-dures in this area. Chapter 13 should be reviewed for additional details.

15.2.5.2 Acute Care Laboratory (STAT Lab or Rapid Response Lab). Acute care laboratories in health care facilities are operated 24 hours a day, 7 days a week. The laboratory serves all acutely and critically ill patients, individuals in intensive (ICU) or intermediate care units, patients requiring oxygen therapy or artifi cial ven-tilation, and all patients with threatened cardiovascular collapse. Many of the tests performed in this laboratory are also performed elsewhere, but the critical timeliness of these tests requires them to be conducted promptly in this laboratory and the results transmitted immedi-ately. The tests provided by the laboratory usually include blood gases (PO 2 , PCO 2 ), pH, blood oxygen content, electrolytes (sodium, potassium, and ionized calcium), total protein, osmolality, blood glucose, and hematocrit. Due to the criticality of these tests to patients’ survival, equipment in this laboratory must be supplied with emergency or back-up power. In some cases, they may be connected to uninterruptible power supply (UPS) electric power and provide all piped utili-ties with back-up supply and control systems so they are always available and do not fail.

Layouts of acute care laboratories follow the guide-lines of a general or analytical chemistry laboratory (Chapter 5 ). Acute care laboratories may be located close to ICUs, operating rooms (ORs), or other hospital areas where care is provided to the most ill patients. These laboratories may be separate and removed from the main clinical chemistry laboratory. Because acute care laboratories house fewer functions and have lower specimen volumes, the laboratory area required is less. Large hospitals may provide more than one acute care laboratory, each convenient to critical patient service areas.

15.2.5.3 Microbiology Laboratory. Microbiology lab-oratories provide test menus in bacteriology, virology,

control or for maintaining clean, tightly controlled envi-ronmental conditions. These laboratories are described here. Cleanliness and protection of specimens from con-tamination is a primary goal in these separate spaces.

15.2.5.1 Clinical Chemistry Laboratory. The clinical chemistry laboratory may be organized into several major sections for specifi c testing equipment and proto-cols: biochemistry, hematology, and coagulation. In addition, receipt of specimens, accessioning, primary sample preparation, solutions aliquot, and distribution are major functions of main clinical laboratories. Open laboratory layouts allow for zoning different, but com-patible functions. Flexibility is an important functional requirement for the design of main clinical chemistry laboratories due to frequent upgrades and replacement of major instruments.

Many clinical chemistry laboratory instruments and equipment are individually automated and computer operated. In addition, instruments can be connected to other instruments and automated processes in long linear arrays, similar to industrial assembly lines. Linear arrays can be modifi ed into L- and U-shapes to improve area effi ciency and to fi t into existing spaces.

Chemistry sections of main clinical laboratories gen-erally handle the highest specimen and testing volumes. The chemistry section menu of tests includes general chemistries, blood gas analysis, therapeutic drug testing, endocrine testing, comprehensive emergency toxicol-ogy, and psychotropic drug testing services. Certain pro-cesses and reagent preparation and handling may require use of chemical fume hoods. Chemical hoods should be located within chemistry sections of clinical laboratories according to guidelines shown in Chapter 32 , Laboratory Hoods and Other Exhaust Air Contaminant-Capture Facilities and Equipment, and in Chapter 5 , General or Analytical Chemistry Laboratory. Hematology sections test for cell counts of blood and other body fl uids and measures prothrombin time (PT), partial thromboplastin time (PTT), fi brinogen, D-dimer, and erythrocyte sedimentation rate. For chemotherapy patients, an automated estimate of absolute neutrophil count may be needed quickly. Specialized fl ow cytomet-ric techniques provide the ability to analyze T-cell subsets in human immunodefi ciency virus (HIV) infec-tion and to analyze reticulocytes. Wright-Giemsa, iron, and enzyme cytochemical stains are used in the workup of acute leukemia and hairy cell leukemia.

Special clotting sections of clinical laboratories provide tests for evaluation of coagulopathy that include polymerase chain reaction (PCR) testing of activated protein C resistance. An active and comprehensive con-sultation service conducted by physicians on the Coagu-

LABORATORY LAYOUT 221

7 days, samples should be frozen immediately at –70°F (–20°C) is not suffi cient). The U.S. FDA heavily regu-lates the recordkeeping of blood products; this activity requires data entry, bar coding, and label printing. Offi ce facilities are required within these laboratories.

The layout of blood transfusion laboratories includes arrangement of one or more large blood-bank refrigera-tors, freezers, centrifuges, and lyophilizers. Laboratory benches are required for some processes and equip-ment, such as fi lling, assembling, and labeling product containers. In addition, clear fl oor area is required for boxes of fi nished products and supplies, as well as for transfer of these boxes in and out of these laboratories. Due to the size and number of large fl oor-mounted equipment and transport activities, a fl exible laboratory design is highly desirable, including use of mobile benches and storage shelf units. Hand-washing and lab-oratory cleanup stations with large sinks must be dis-tributed to offer easy access for personnel.

15.2.5.5 Tissue Typing Laboratory. Tissue typing laboratories perform all of the testing required for bone marrow and solid organ transplantation services. Tests usually include both serologic and DNA-based tissue typing, determination of HLA antibody frequency (PRA) and specifi city, lymphocytotoxicity cross match-ing, mixed lymphocyte culture assays, and monitoring for chimerism and bone marrow engraftment.

To reduce risk of contaminated air and particles from entering, this laboratory should be located in a separate and secure space and may or may not be adjacent to the main hospital clinical laboratory. Layouts of tissue typing laboratories follow the guidelines for a Biosafety Level 2 (BSL-2) laboratory as described in Chapter 14 , Bio-safety Laboratory. Biological safety cabinets are used to prevent cross contamination of human specimens.

15.2.5.6 Clinical Immunology Laboratory. Clinical immunology laboratories use agarose gel electrophore-sis, immunoelectrophoresis, and immunofi xation to detect monoclonal proteins in serum, urine, and CSF. Other procedures may include immunofl uorescence, immunodiffusion, and radioimmunoassay for detection of antinuclear antibodies, antinative DNA antibodies, cytoproteins, cancer antigens, and antibodies to hyper-sensitivity pneumonitis antigens, as well as enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies.

To maintain cleanliness in these laboratories and reduce risk of contamination of specimens, a separate space is required for this function. The layout of these laboratories follows guidelines given in Chapter 5 , General or Analytical Chemistry Laboratory. The

parasitology, mycobacteriology, mycology, and serology of infectious diseases.

Because infectious agents, at times of unknown severity or origin, are present in microbiology laborato-ries, these laboratories are designed and operated as Biosafety Level 2 facilities and guidelines for layouts are shown in Figures 14-6, and 14-7 in Chapter 14 .

In addition to conventional methods, the laboratory offers several rapid diagnostic tests and detection of diffi cult-to-culture pathogens using nucleic acid probe technology. The molecular diagnostics section of the laboratory may offer:

• Nucleic acid amplifi cation testing for the detection of herpes simplex virus from cerebrospinal fl uid (CSF) specimens

• HIV-1 RNA quantitation (viral load) from plasma specimens

• Mycoplasma pneumoniae from respiratory specimens

• Mycobacteria tuberculosis from AFB smear-positive sputum specimens

The gastrointestinal testing section within virology usually performs diagnostic hepatitis virology tests other than those used for routine screening of blood donors. Biological safety cabinets as well as an auto-clave should also be available.

15.2.5.4 Blood Transfusion Laboratory. Blood trans-fusion laboratories are usually responsible for the storage and dispensing of all blood components, all patient samples’ testing, and the preparation of frozen red blood cells, plasma, platelets, and other specialized blood components. In addition, these laboratories may support the transfusion needs of a number of specialty services including cardiac and vascular surgery, bone marrow and solid organ transplantation, burn service, mass casualty treatment facility, and the neonatal inten-sive care unit. It may also operate as an AABB (Ameri-can Association of Blood Banks) accredited reference laboratory for the resolution of diffi cult serological problems.

Blood storage areas (blood banks) require locked doors and access control to keep out unauthorized persons. Blood products for transfusion must be kept uncontaminated and stored at tightly controlled, con-tinuously monitored temperatures. Samples need refrig-eration to 39.2°F (4°C) immediately after collection. They can also be shipped in refrigerated packaging at 39.2°F (4°C). At that temperature they are stable for 7 days. If it is anticipated that analysis cannot occur within

222 CLINICAL LABORATORIES

15.2.5.10 Infectious Disease Molecular Diagnostics Laboratory. This is a growing fi eld with great promise. There is limited standardization of technique and pro-cesses. This laboratory may require a BSC and layout similar to a microbiology laboratory described in Section 15.2.5.3 . Today, a signifi cant amount of testing is done manually, but automation is imminent. As the quantity of laboratory equipment will probably increase, some expansion space is recommended.

15.2.5.11 Pharmacogenetics Laboratory. Another growing fi eld is pharmacogenetics. This laboratory determines how a particular patient will respond to a specifi c medication. These laboratories may become more popular as demand for “personalized” medicine grows. It should be designed as a microbiology labora-tory described in Section 15.2.5.3 .

15.3 HEATING, VENTILATING, AND AIR-CONDITIONING

The HVAC system for clinical laboratories must main-tain reasonable temperature control to ensure the correct operation of electronic and other testing devices that will normally be present. Clinical laboratories should be at negative pressure with respect to the rest of the hospital. There may be a desire to have different pressure or directional air fl ow between the laborato-ries. This requirement is diffi cult to maintain without anterooms or air locks (Chapter 2 , Section 2.2.2.3 ), and good seals of gaps in laboratory enclosures and open-ings in enclosures for pipes, ducts, and conduit. The rec-ommendations contained in Chapters 1 and 2 , Section 3 are generally applicable to clinical laboratories and should be considered for implementation with the fol-lowing additions and comments.

15.3.1 Chemical Hoods

Chemical hoods, when they are used, should conform to the recommendations contained in Chapter 2 , Section 2.3.4.4 and in Chapter 32 . Perchloric acid hoods are required in this type of laboratory only when perchloric acid digestions of samples are conducted routinely. When perchloric acid hoods are needed, the recommen-dations contained in Chapter 2 , Section 2.3.4.4.3 and Chapter 32.4 should be followed.

15.3.2 Local Exhaust Air Hoods

When there are discrete systems or processes in clinical laboratories that emit dangerous or obnoxious fumes

majority of analytical equipment here is bench-top mounted. However, benches that are height adjustable are very desirable to reduce lab workers’ fatigue and improve ergonomic safety.

15.2.5.7 Thyroid / Endocrine Laboratory. Thyroid/endocrine laboratories provide a full range of diagnostic testing, test interpretation, and management consultation for patients with endocrine and metabolic disorders, plus state-of-the-art metabolic assays for the diagnosis of endocrine disorders including thyroid, pituitary, adrenal, and bone disease. Processes and instruments specifi c to endocrine testing should be separated from the main hospital clinical laboratory. Layout of these laboratories follows guidelines given in Chapter 5 , General or Analytical Chemistry Laboratory.

15.2.5.8 Neurochemistry/Amino Acid Laboratory. Neurochemistry/amino acid laboratories provide diag-nosis and treatment of disorders associated with the abnormal metabolism of amino acids, organic acids, car-nitine, and their derivatives. This laboratory offers diag-nostic testing for patients suspected of having an inborn error of metabolism and subsequent treatment for patients with various disorders including homocystin-uria, maple syrup urine disease, urea cycle disorders, hyperammonemic syndromes, methylmalonic acidemia, and other associated organic acid disorders.

This laboratory may also offer special tests and pro-cedures including testing for biochemical genetic meta-bolic disorders, quantitative amino acid analysis, organic acid analysis by gas chromatography-mass spectrome-try, free and total carnitine determination, biotinidase activity, orotic acid, total homocysteine, argininosucci-nate lyase activity, screening for succinyl purines, and DNA diagnostic tests.

Processes and instruments specifi c to neurochemistry and amino acid testing should be separated from the clinical chemistry laboratory. Because chemical and DNA testing is performed, layout of these laboratories follows guidelines given in Chapter 5 , General or Ana-lytical Chemistry Laboratory, but layout will also include locating biological safety cabinets to protect specimens during DNA extraction.

15.2.5.9 Point of Care Testing (PoCT). PoCt is pro-vided at the patient ’ s bedside in patient rooms, in the OR, ICU, or neonatal ICU (NICU) where a quick tests and results are needed to aid in patient treatment. These test devices are either handheld or are smaller versions of larger instruments. These tests usually support, but do not replace many traditional clinical laboratory tests. The menu for these tests is small though increasing.

LOSS PREVENTION, INDUSTRIAL HYGIENE, AND PERSONAL SAFETY 223

(e.g., some hematology procedures) or large amounts of heat (e.g., autoclaves), providing local exhaust air facilities for each device reduces the total ventilation air requirements for the laboratory. Local exhaust facilities may consist of an enclosure housing the entire process equipment system, a canopy hood directly over the process or equipment, an engineered slot-type capture hood especially designed and built for the application, or a simple, open-ended fl exible exhaust hose to handle a small emission source such as an atomic absorption instrument. See Chapter 32 for more information on selecting and designing appropriate local exhaust hoods.

15.3.3 Biological Safety Cabinets

Biological safety cabinets are needed in many clinical laboratories to handle specimens from infectious patients. Universal precautions assume that all body fl uid specimens may be infectious. Biosafety cabinets should be ventilated in accordance with the require-ments outlined in Chapter 14 , Section 14.1.3 . Most Class II biological safety cabinets used in hospital clinical laboratories will be a Type A model that permits recir-culation of air inside the laboratory rather than requir-ing a direct exhaust connection to the roof. When volatile chemotherapy drugs will be associated with clinical specimens, consider using a Type B cabinet that is totally exhausted to the outdoors.

15.3.4 System Components

A central building HVAC system generally serves hos-pital-based clinical laboratories. Accepted practices of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE, 2009, 2010, 2011, 2012) and the Sheet Metal and Air Conditioning Con-tractors’ National Association (SMACNA, 2005) are satisfactory.

15.3.4.1 Supply Air Systems. Clinical laboratories acquire large, bulky, automatic electronic analytical equipment on an ongoing basis. Consequently, the dis-tribution of supply air becomes more diffi cult, not only to maintain a uniform temperature in the laboratory, but also to prevent drafts and unsatisfactory air distribu-tion patterns. For best results, supply air should be pro-vided by a ducted distribution system located above the ceiling. Discharges to the laboratory should be through multiple outlets designed to avoid drafts. The Facility Guidelines Institute (FGI, 2010) and the ASHRAE standard 170, Ventilation of Health Care Facility (ASHRAE, 2008), provide guidelines on supply air fi ltration.

15.3.5 Temperature Control

A uniform temperature ( ± 75°F, − 24°C) is needed for the reliable operation of some analytical devices. Some equipment may require lower space temperature. Actual temperature requirement of equipment should be confi rmed. Heating and air-conditioning control systems must be provided to achieve thermal consis-tency. When tight humidity control is required, although it is seldom necessary, the simultaneous operation of heating and cooling systems may be needed. Many kinds of HVAC systems, including local cooling units and central systems, have been successfully used for servic-ing hospital clinical laboratories. An important consider-ation is that all elements of temperature control systems should be interlocked so that a uniform temperature can be maintained throughout the year. In a facility retrofi t, it may be cost effective to install a separate air cooling and heating system for a clinical laboratory rather than connecting the laboratory to the building system because laboratories have different HVAC requirements than those in hospitals. When not separated, a large hospital central system must be operated at an inappropriate, and hence uneconomical, level to maintain desired con-ditions for a small laboratory suite.

15.3.6 Heat Gain Calculations

To calculate the cooling needs of a clinical laboratory, information is needed on the heat emission rates of commonly used equipment and instruments. Table 15-1 (reprinted here from Alereza, 1984) gives the heat load from commonly used items. Other references are in ASHRAE Laboratory Design Guide (McIntosh, Dorgan, & Dorgan, 2004). Information on many of the new instruments and other devices used today is not readily available, and manufacturers must be contacted to get the information.

HVAC engineers must also consider diversity. All of the equipment in clinical laboratories may not operate continuously at full load. A reasonable diversity esti-mate would eliminate overdesign of the HVAC system. At the same time, clinical laboratories tend to add new systems continuously. A safety margin should be included in the heat gain calculations; 20% is a reason-able safety factor.

15.4 LOSS PREVENTION, INDUSTRIAL HYGIENE, AND PERSONAL SAFETY

15.4.1 Introduction

The recommendations contained in Chapters 1 and 2 , Section 4 are generally applicable to clinical laboratories

224 CLINICAL LABORATORIES

TABLE 15-1. Heat Release Rate of Hospital Clinical Laboratory Equipment

Equipment Type Size MaximumInput Rating

(BTU/h)

Recommended Rate of Heat Gain (BTU/h) a

Ave Small Unit Ave Low Ave Low

Autoclave (bench) 0.7 (0.02) ft 3 (m 3 ) 4,270 480Bath: hot or cold circulating,

small1.0 (3.8) 9.7 (36.7) gallon (liters) 6,140 2,560 1,0602,010 (sensible) 440

(latent) 850Blood analyzer 120 samples/hour 2,510 2,510Blood analyzer with CRT screen 115 samples/hour 5,120 5,120Centrifuge (large) 8 24 places 3,750 3,580Centrifuge (small) 12 4 places 510 480Chromatograph 6,820 6,820Cytometer (cell sorter) 1,000 cells/sec 73,230 73,230Electrophoresis power supply 1,360 850Freezer b , blood plasma, medium, − 40°F ( − 22°C)

13 (1.2) ft 3 (m 3 ) 340 136

Hotplate, concentric ring, 212°F (100°C)

4 holes 3,750 2,970

Incubator, CO 2 , 130°F (54.4°C) 10 (0.28) 5 (0.14) ft 3 (m 3 ) 9,660 4,810Incubator, forced draft, 140°F

(60°C)80 (2.26) 10 (0.28) ft 3 (m 3 ) 2,460 1,230

Incubator, general apps, 160°F (71°C)

11 (0.31) 1.4 (0.04) ft 3 (m 3 ) 220 160 110 80

Magnetic stirrer 2,050 2,050Microcomputer c 256 16 Kbytes 2,047 341 1,800 300Minicomputer c 15,000 7,500 15,000 7,500Oven, general purpose, small,

460°F (238°C)2.8 (0.08) 1.4 (0.04) ft 3 (m 3 ) 2,120 290

Refrigeratord , laboratory, 39°F (3.9°C)

106 (3.0) 22 (0.62) ft 3 (m 3 ) 80 34

Refrigeratord , blood, small, 39°F (3.9°C)

20 (0.57) 7 (0.2) ft 3 (m 3 ) 260 102

Spectrophotometer 1,710 1,710Sterilizer, free-standing, 270°F

(132°C)212 (6.0) 3.9 (0.11) ft 3 (m 3 ) 71,400 8,100

Ultrasonic cleaner, small 1.4 (0.04) ft3 (m 3 ) 410 410Washer, glassware 7.7 (0.22) ft 3 (m 3 ) 15,220 10,000Water still e 15 (56.8) 5 (18.9) gallon (liters) 14,500 320

Source : Alereza (1984). Adapted with permission from ASHRAE. a For hospital equipment installed under a hood, the heat gain is assumed to be zero. b Heat gain per cubic foot of interior space. c Input is not proportional to memory size. d Heat gain per 10 cubic feet of interior space. e Heat gain per gallon of capacity.

and should be considered for implementation with the following additions and comments. Large clinical labo-ratories may operate like a production laboratory and will resemble an open or team laboratory; Chapter 21 , Open or Team Research Laboratory, should be con-sulted to understand unique requirements.

15.4.2 Egress

Because clinical laboratory activities range from simple to very complex and diverse, good zoning, and even segregation of activities, should be considered in large facilities. Otherwise, maintenance of adequate exit

LOSS PREVENTION, INDUSTRIAL HYGIENE, AND PERSONAL SAFETY 225

%5Ftest= 1 ) There are several quality standards employed in clinical laboratories. An example is ISO 15189 (2012), Accreditation for Clinical Laboratories.

15.4.6 Medical Waste

The waste from clinical laboratories may have come in contact with the body fl uids of patients and is presumed to be infectious. Until recently, steam autoclaving of such waste before municipal waste disposal was consid-ered adequate. With concern about HIV infection, all medical waste is considered to be infectious whether autoclaved or not. The EPA and other regulators pre-scribe strict guidelines on how these wastes must be handled and disposed of. A typical system begins with the collection of medical waste in double red bags. Red bags may be packed in cardboard boxes then shipped from the laboratory to a central location. At central collection facilities, boxes are treated in an approved fashion. EPA regulations have resulted in eliminating most medical waste incinerators in the United States. Many other medical waste treatment systems are avail-able in the marketplace. A strictly enforced documenta-tion is required to track the waste from source to ultimate destruction. See Chapter 27 , Hazardous Chem-ical, Radioactive, and Biological Waste Handling Rooms, for more information on waste handling.

15.4.7 Emergency and Clean Electrical Power

Many new automated testing systems require “clean” electric power, that is, power free from electrical “noise.” Chapter 1 , Section 1.5.5 should be consulted for addi-tional information on clean power. Local power condi-tioning devices are manufactured to isolate specifi c clinical and analytical instruments. This is a cost-effective approach for clinical laboratories that contain such systems.

Continuous operation of many of the automated testing devices is vital for patient care. Therefore, it is necessary that some equipment be on generator emer-gency power. Many may need to be placed on UPS.

Information technologies used in these clinical labo-ratories create their own issues and UPS is needed to provide reliability. If a UPS system is battery-based, they should be placed in appropriately designed loca-tions. See Chapters 1 and 2 .It is important that ability to continuously test power systems. To achieve this results all clinical testing equipment is connected to emergency power, and if needed, to UPS systems. If not all clinical laboratory test equipment is connected, at least one of each type should be connected to emergency power, to ensure that during loss of normal power conditions, all

routes and routes to fi re extinguishers, deluge showers, and other emergency equipment may become diffi cult. Follow the guidelines in Chapters 1 and 2 .

15.4.2.1 Access Control. It may be necessary to con-sider security access for such laboratories, or sections of main clinical laboratories such as blood bank, tissue typing, and microbiology laboratories.

15.4.3 Chemical Storage

Chemical storage facilities should be carefully located with consideration of exit access, fi refi ghting, spill control, and laboratory operation exposures in mind. Storage within the laboratory should be provided only for small amounts of chemicals. This restriction should be maintained by careful laboratory management.

15.4.4 Fire Suppression

In general, the requirements of Chapter 1 , Section 1.4.4.2.2 pertain to clinical laboratories. For the place-ment of hand-portable fi re extinguishers in clinical labo-ratories, the following criterion should be considered. It may be more critical to get to a fi re extinguisher than to be able to make a rapid exit. For this reason, 2A-40 BC dry chemical extinguishers, with their increased extinguishing capacity, compared to CO 2 -type units, are considered the most appropriate for use in clinical labo-ratories. They should be placed in the back of the labo-ratory as well as at each exit door to enable personnel remote from the exit to get to a unit quickly and safely.

15.4.4.1 Sprinklers. Water-sprinkling systems provide excellent fi re suppression for clinical laboratories. In general, semirecessed heads in ceiling tiles provide reasonable protection against accidental breakage of sprinkler heads and resulting water damage. Further protection against accidental release can be obtained by the use of reaction systems whereby two detector heads in parallel must trigger to open a solenoid valve that allows water to pass. For example, in a clinical labora-tory with a preaction-type sprinkler system that must be activated by smoke as well as fi re.

15.4.5 Codes and Standards

NFPA 99, Health Care Facility Code (NFPA, 2012), which covers laboratories in health-related institutions, should be consulted for additional regulatory require-ments. (This standard is available at http://www.nfpa.org/aboutthecodes/list_of_codes_and_standards.asp?cookie

226 CLINICAL LABORATORIES

15.4.9 Other Utilities

Provide laboratory grade compressed air, vacuum, pure-water (RODI grade), CO 2 , and other compressed gases as necessary.

As clinical tests become more computerized, exten-sive IT systems requirements also grow. Space must be allocated for these systems, such as server rooms. Expanded use of wireless technology should also be considered where data security is not a signifi cant issue.

routine clinical tests can still be conducted and patient care is not compromised.

15.4.8 Wastewater

Wastewater from clinical laboratories may contain trace amounts of metals (lead, mercury, zinc, etc.), volatile organic compounds (formaldehyde, etc.), and other chemicals prohibited by the local wastewater authority. Chapter 1 , Section 1.5.3.2 explains some issues that must be considered.