Patients' Bath Basins as Potential Sources of Infection: A Multicenter Sampling Study

Debra Johnson, RN, BSN, OCN, CIC; Lauri Lineweaver, RN, BSN, CCRN; Lenora M. Maze, RN, MSN, CNRN

Disclosures

Am J Crit Care. 2009;18(1):31-38, 41. 

In This Article

Discussion and Recommendations

Clark and John[13] reviewed the literature on tap water contamination in health care facilities and suggested the need to keep contaminated water away from patients who are immunosuppressed, have fresh surgical wounds, or are at high risk for infection. Shannon et al[17] found that bath water specimens collected after a routine patient's bath contained bacterial counts of more than 105 colony-forming units/mL, a colony count similar to the number of bacteria found in urine samples from patients with urinary tract infections. In addition, they noted that most nurses disposed of used bath water in hand washing sinks, a practice that could contaminate the sink and surrounding areas[17] .

Biofilm Formation

In recently published correspondence, Cerviaet al[18] noted the concurrent reemergence of gram-negative HAI and recent reports of gram-negative bacteria, including Pseudomonas and Enterobacter organisms, in hospital water supplies. Cervia et al also mentioned the problem of the formation of biofilms, which may occur despite efforts to prevent contamination of water supplies. In addition, they sampled the water of 9 metropolitan area hospitals and found as many as 14 bacterial species in samples from a single source. Disturbingly, about one third of the bacterial species found were known to be responsible for HAIs. The authors[18] concluded that further investigation was warranted to determine whether or not water should be considered a potential source of HAI.

Cross-contamination

It is a universally accepted practice for caregivers to wash their hands to reduce bacterial transmission between patients and themselves and objects in the environment. Cross-contamination can occur when a caregiver touches a patient who is colonized with a bacterial species and then touches an object in the environment. If MRSA or VRE resides on an object in the environment and the caregiver touches that object, he or she can transmit the organisms to the next object or person he or she touches. Additionally, bath basins are often left out in the patient's room and are often used as storage basins. Basins are often used to hold personal items and may be used to hold soiled cloths from incontinence cleanups or may even be used as emesis basins.[19]

Disinfection and Sterilization

A rational approach to disinfection and sterilization of objects in the patient environment to reduce bacterial spread was developed by Spaulding,[20] who divided the objects into 3 categories: critical items, semicritical items, and noncritical items. Critical items are those that enter sterile tissue or the vascular system and that can thus introduce infection; these items should be sterilized before use. Examples include surgical instruments and catheters.

Semicritical items are those that come into contact with mucous membranes or nonintact skin. The mucous membranes and nonintact skin are not sterile tissue but are susceptible to the introduction of certain pathogens. Respiratory therapy equipment and laryngoscopes are examples of these types of items. Bathing with contaminated supplies can potentially expose a patient's mucous membranes or nonintact skin to bacteria. Thus, it is reasonable to consider that although a bath basin is classified as a noncritical item, at times it is a semicritical item. The Spaulding classification suggests that these semicritical items should be free of all microorganisms.

At-risk Patients

Exner et al[1] noted that control of waterborne pathogens must include reducing the number of harmful microbes and specifically protecting patients at high risk for infection. Attentiveness to identifying which patients are at high risk is a prerequisite for protecting them from potential pathogens. Patients at high risk are numerous and include both children and adults who are immunocompromised, have indwelling catheters or drains, undergo invasive procedures such as surgery, or have wounds or underlying disease. In addition, the elderly are at increased risk.[21,22,23,24] Environmental factors such as widespread microbial antibiotic resistance and a lack of infection control measures and environmental hygiene also play a role in determining risk for hospitalized patients.[21,24]

Hospitalized patients themselves can harbor potentially dangerous microorganisms. Increasing rates of colonization by antibiotic-resistant organisms, such as MRSA, VRE, and Acinetobacter organisms, may present significant problems in patients who have indwelling catheters or in those who are immunocompromised.[17,25,26] Methicillin-resistant Staphylococcus epidermidis has also received attention recently for its role in purulent infection in soft tissues and skin.[27]

During bathing, mechanical friction releases skin flora into bathwater.[28] Via inhalation, ingestion, or direct contact with excoriated skin, contaminated water in bath basins can become a source of cross-contamination of organisms from one body system to another and can be potential reservoirs for the transmission of HAI.[12,16] The bath basin itself often becomes contaminated with gram-negative bacteria from the environment and can be a source of bacterial exposure during future baths.[29,30]

Our results confirm that potentially harmful microorganisms are present in bath basins even after the bath water is removed; 98% of all cultures grew some form of bacteria, either on plating or after enrichment. All at-risk patients admitted to intensive care units and surgical and medical care units in 1 of the 3 hospitals in the study were screened for MRSA(nares) on admission and VRE, and all the patients so tested during the course of the study were negative for MRSA. Therefore, VRE and MRSA were present in the hospital environment and were cultured from patients who had not been previously identified as carriers of VRE or MRSA.

In 1 patient whose basin sample was positive for MRSA, a sternal wound infection developed from which MRSA was cultured. The patient did not have colonization with MRSA at the time of admission, but did have MRSA in the nares at the time of discharge(on day 7 of admission). In another patient, a VRE infection developed after VRE was detected in the patient's wash basin. This patient initially had negative cultures for VRE/MRSA, but samples obtained when he was readmitted from a nursing home 10 days later were positive. In this patient, the first cultures possibly were false-negatives (ie, the patient was colonized during his stay in the nursing home) or the VRE exposure in the hospital led to the wound infection and to the colonization that was noted upon readmission. These temporal associations are not sufficient to establish a cause-and-effect relationship, but they raise the question of whether the infections were due to exposure to the contaminated wash basin. It is not surprising that bacteria were cultured from samples from patients' bath basins, because previously documented evidence has indicated that water in health care settings may harbor microorganisms. Our results suggest that the bath basins themselves may be an additional way that harmful bacteria are spread.

Of note, 100% of the basins sampled were positioned upright instead of upside down. Storing basins upright allows any remaining droplets of water to pool at the bottom, and the pooling allows biofilms to form. Additionally, multiple basins were stacked on top of each other, and items used for incontinence cleanup were stored inside (see Figure),a situation that creates another opportunity for contamination.

Typical storage of bath basin. Note upright storage, sink,and used incontinence tubes.

The finding of MRSA and VRE in the basins is not surprising, given the difficulty in eradicating microorganisms from the hospital environment, yet this finding underscores the need to identify and eliminate reservoirs where possible. Doing so is particularly important for bath basins because of the direct exposure to the bacteria that can occur if a contaminated basin is used for bathing. It is reasonable to anticipate that patients who are immunocompromised or who have open wounds would beat risk for infection after direct exposure to contaminated bathing materials. Any activity that potentially spreads antibiotic-resistant bacteria from a contaminated surface to the skin works directly against efforts to eradicate such bacteria from the hospital or health care environment.

We recommend interventions or protocols that address bath basins as a potential source of bacterial exposure for patients. Sterilizing bath basins is not common practice and may not be cost-effective or provide the most efficient use of time for staff members. Alternative methods of bathing that are effective and cost- and time-efficient have been reviewed in the literature and deserve further evaluation and consideration.[29,30,31]

Alternative Bathing Methods and Research

Larson[29] and Vernon et al[31] found that microbial counts on patients' skin were lower after a prepackaged bath than after a bath given with a patient bath basin, although these differences were not significant. Larson concluded that the disposable bath is a desirable form of bathing, and possibly preferable to traditional basin baths, for patients in both critical care and long-term care settings who cannot bathe themselves.

Furthermore, McGuckin et al[32] investigated the rate of urinary tract infections after a hospital eliminated a prepackaged bath product and replaced it with standard basins, tap water, and paper towels. The study findings showed a significant increase in the rate of urinary tract infections after the elimination of the prepackaged bath product and an increase in cost of $107 741, which represented an increase in cost in a 14-bed intensive care unit during a 9-month period.

Although contaminated water within the health care environment and the development of biofilms on bath basins are important concerns, Lazzari et al[33] point out that HAIs are preventable. Multiple opportunities for intervention exist in the health care setting, many of which are related to the removal of potential etiologic factors.

Use of cleansing cloths can reduce microbial counts and avoids exposing patients to potentially contaminated bath basins[29,30] and potentially contaminated tap water and water conduits.[1] The use of a prepackaged bath product has other benefits as well. With a properly used bath pack, the same washcloth is not used to bathe the entire body, thus possibly reducing the potential for spread of bacteria from one area of the body to another.[29,30] The use of bath packs would also allow bathing methods to be standardized, thus reducing variability in technique between nurses. Such baths require less time to administer than do bed baths and appear to avoid the skin-drying effects associated with the use of soap, water, and towel drying.[29,30] More important, use of a product that contains a skin conditioner apparently is less damaging to the skin than are plain soap and water and towel drying.[29,30]

Of note, our study had a few weaknesses. Clean bath basins were not cultured because of cost restraints; however, a null hypothesis of 5% was used throughout data analysis to account for presumed contamination. Incontinence materials were found within basins, and these materials were not tested inside or outside of the basin. Basins were not sampled on the same day of use, and some may have been used more than others were. The presence of urinary catheters, drains, and/or wounds was not accounted for. A close examination of these variables in future studies may elicit additional valuable data.

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