Mycobacterium szulgai; malnutrition and wounds; biological indicators; sterilizing with infrared radiation - Evidence For Practice

AORN Journal,  Nov, 2002  by George Allen

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Mycobacterium szulgai keratitis caused by contaminated ice water

Clinical Infectious Diseases, April 15, 2002

After two patients who underwent laser-assisted in situ keratomileusis (LASIK) in the same facility developed keratitis caused by Mycobacterium szulgai, a retrospective control study was conducted. (1) All patients who underwent the procedure from November 2000 through March 2001 were evaluated for evidence of infection. The procedures and techniques used by the surgeons were reviewed, and environmental samples were obtained from all potential water sources.

Findings. Of the 52 patients who underwent 92 LASIK procedures during the study period, seven patients were found to have infection caused by Mycobacterium szulgai. Five culture-positive cases and two probable cases were identified among the 18 patients on whom physician A performed 30 procedures. No cases were identified among the 34 patients on whom physician B performed 62 procedures. No breeches of surgical technique were identified, and the only apparent technical difference between the physicians' technique was in the preparation of the sterile saline lavage solution. Physician A used a sterile syringe fitted with an ocular lavage tip that was chilled on the surface of a tub full of ice obtained from an ice machine. Environmental cultures from the ice machine drain revealed Mycobacterium szulgai genetically identical to the isolates recovered from the five culture-positive patients.

Clinical implications. The likely route of exposure was contamination of the lavage tip by melted ice water from the surface of the syringe or melted ice water falling onto the surgical field as the assistant passed the chilled syringe to the surgeon. At present, the risk of using chilled saline for this procedure appears to outweigh the potential benefits. Perioperative nurses should review these findings with surgeons who perform LASIK and remember them when participating in procedures in which ice is used.

Malnutrition and its effect on wound healing

Orthopedics, April 2002

This study determined the incidence of preoperative malnutrition, the correlation between abnormal nutrition and delayed wound healing, and the validity of the Rainey McDonald nutritional index in patients admitted for hip and knee replacement arthroplasty. (2) The nutritional status of 40 consecutive patients who underwent joint replacement performed by the same surgeon was assessed by serological markers 12 to 24 hours before surgery. Serum albumin of less than 3.5 g per dL, serum transferrin of 200 mg per dL, and total lymphocyte count of less than 1,500 cells per [mm.sup.3] were considered indicators of malnutrition. Likewise, a negative value on the Rainey McDonald nutritional index was considered an indicator of malnutrition.

Findings. The incidence of preoperative malnutrition was 40%. Sixteen patients had at least one abnormal serological marker, 10% serum albumin, 30% serum transferrin, and 17.5% total lymphocyte count. The Rainey McDonald nutritional index revealed a negative value in 10% of patients. All patients had healthy surgical scars after suture removal 14 to 15 days after surgery. The researchers believe that the negative effect of malnutrition on wound healing was overcome by surgeon-dependent factors, including use of antibiotic prophylaxis, surgical technique, the OR environment, and skin and wound care.

Clinical implications. Despite the high incidence of malnutrition, no delayed wound healing was noted. Perioperative nurses, however, must understand that malnutrition has been documented as a cogent risk factor for delayed wound healing and implement measures to ensure that nutritional assessment and counseling is conducted in the early preoperative period. Similarly, they must ensure that antibiotic prophylaxis is administered in a timely manner, that all staff members adhere to surgical sterility principles, and that the environment is maintained in a sanitary manner. Perioperative nurses also must facilitate thorough patient teaching and effective postoperative wound care.

Using a seven-day incubation period for biological indicators

Infection Control and Hospital Epidemiology, July 2002

This study evaluated fluorescent readout results of two different types of biological indicators in both 132[degrees]C (269.6[degrees]F) gravity displacement and 132[degrees]C (269.6[degrees]F) vacuum-assisted steam sterilization cycles using full and fractional cycles. (3) Growth data were compared to seven-day incubation cycles. This study also evaluated a new automated rapid fluorescent reader.

During the study, biological indicators were placed in a specific sterilizer using a standardized protocol for both types of indicators. A positive control was run each day. After cycle completion, the indicators were removed, cooled, and inserted into the automated reader After this reading, indicators were transferred to an aerobic incubator Growth results were recorded at 24 hours for the first type of indicator, at 48 hours for the second type of indicator, and at seven days for both. Any indicators showing negative fluorescent results but positive growth were subcultured. The new reader was not used for the seven-day incubation period.