Sterile Information and Courses from MediaLab, Inc.

The cerebrospinal fluid sample is obtained by a physician usually via lumbar puncture in the L3-L4 region. The opening pressure is first measured (nl 90-180 mm of water in lateral position) and if it is elevated greater than 200 mm, no more than 2 ml of CSF should be withdrawn. Sterile technique is always used to reduce the risk of infection. Care must be taken to avoid injury to neural tissue.

Citron DM. Appelbaum PC.: How far should a clinical laboratory go in identifying anaerobic isolates, and who should pay? Clinical Infectious Diseases. 16 Suppl 4:S435-8, 1993Identification of anaerobic bacteria in specimens from sites of infection due to mixed organisms can be time-consuming and expensive. Laboratories should limit anaerobic workups by testing only those specimens that have been properly collected and transported to the laboratory.Use of selective and differential media for initial processing can provide rapid and relevant information to the clinician. Anaerobes isolated from normally sterile sites and sites of serious infection should always be completely identified. Group-or genus-level identifications may suffice in other instances.The Bacteroides fragilis group of organisms should always be identified because of their virulence and resistance to many antimicrobial agents.Some of the other organisms that warrant identification include Clostridium septicum (associated with gastrointestinal malignancy); Clostridium ramosum, Clostridium innocuum, and Clostridium clostridioforme (which are resistant to antibiotics); Clostridium perfringens (a cause of myonecrosis and gas gangrene,potentially serious infection); anaerobic cocci (which may be resistant to metronidazole and clindamycin); and fusobacteria (which may be virulent and resistant to clindamycin and penicillin).

Successful electrophoresis requires application of correct amount of sample with clean applicators and no air bubbles. Many gel electrophoresis for manual sample application include a sample application template to lay over the gel, a micropipet, or a thin-wire applicator. Polyacrylamide gels will have wells in the gel for the sample. Sterile pipet tips are required when applying DNA and RNA specimens.

Submerge the affected part in cold water for 10 to 45 minutes. This will relieve pain and cool tissues to prevent further damage.Give aspirin or ibuprofen to relieve pain and reduce inflammation.Cover second degree burns with a dry nonstick sterile dressing.

Give first aid. Wash needlesticks and cuts with soap and water. Flush splashes to the nose, mouth, or skin with water. Irrigate eyes with clean water, saline, or sterile irrigants. Report exposure to supervisor.

The physician ordering the bone marrow is responsible for providing information about the procedure to the patient or parent or guardian, if the patient is a child. In order to reduce the patient's anxiety about the procedure, the physician may prescribe a mild sedative to be administered about an hour before the bone marrow is scheduled. The site is aseptically prepared by shaving, if necessary, washing with soap and water, applying antiseptic and draping the area with sterile towels. A local anesthetic, such as 2% xylocaine, is injected into the bone, penetrating the covering of the bone called the periosteum. Since a number of nerve endings are located near the surface of the bone, it is important to be sure that this area is anesthetized.

Bandaging materials include: Sterile gauze pads.Band-Aids.

After collection is completed, apply pressure to the puncture site with a sterile gauze pad until bleeding has stopped.Do not apply an adhesive bandage to an infant’s foot since it may injure its delicate skin.

Blood is normally sterile. Any bacterial growth in the bloodstream is abnormal, and is an important cause of fever.Blood culture means the incubation of blood in appropriate media to allow growth and identification of bacteria or other organisms that may be present in a patient’s bloodstream. Blood cultures are performed on febrile patients to identify and treat bloodborne organisms with the most appropriate antibiotic.

These items are needed to obtain a blood culture specimen :Gloves (sterile if available)Alcohol pads and sterile gauze padsTourniquet and iodine swabsBlood culture bottlesSyringes, needles, and/or evacuated tube system.

Epithelial cells in large numbers within sputum smears means that the specimen is predominantly oral saliva, rather than true sputum from the lung. Epithelial cells in urine smears indicate that the sample has been contaminated by organisms found on the vulva or distal urethra. Bacteria found near or on epithelial cells are usually normal contaminating bacterial flora.White blood cells indicate inflammation and possible infection. The direct smear examination should focus within and around these cells.Red blood cells in a direct smear are not usually significant.Yeast may be present as normal flora in upper respiratory tract or genital tract. They may be significant if they predominate, or if budding yeast forms are seen.Hyphae are more likely to indicate the presence of fungal infection, but this determination requires correlation with clinical findings.Bacteria found in spinal fluid, blood, tissue and specimens from other sterile sites are always significant.Body fluids which are normally sterile must be examined carefully. If only one organism per oil immersion field is identified, then there are about 105 organisms per mL present in the sample! Bacteria observed in specimens from the throat, genital tract and other areas containing normal flora suggest infection only if their composition and type varies significantly from the norm.

Urine specimens should be collected in a clean, dry, disposable container. If the sample is to be cultured, the container must be sterile. The preferred method is the "clean catch" collection. The external genitalia are cleansed with a mild antiseptic solution. The first part of the urine stream is discarded while collecting only the midstream portion of the urine.