Secondary Logo

Journal Logo

A New Approach to Pathogen Containment in the Operating Room

Sheathing the Laryngoscope After Intubation

Birnbach, David J. MD, MPH*; Rosen, Lisa F. MA*; Fitzpatrick, Maureen MSN, ARNP-BC*; Carling, Philip MD; Arheart, Kristopher L. EdD; Munoz-Price, L. Silvia MD, PhD§

doi: 10.1213/ANE.0000000000000854
Patient Safety: Research Report
Free

BACKGROUND: Anesthesiologists may contribute to postoperative infections by means of the transmission of blood and pathogens to the patient and the environment in the operating room (OR). Our primary aims were to determine whether contamination of the IV hub, the anesthesia work area, and the patient could be reduced after induction of anesthesia by removing the risk associated with contaminants on the laryngoscope handle and blade. Therefore, we conducted a study in a simulated OR where some of the participants sheathed the laryngoscope handle and blade in a glove immediately after it was used to perform an endotracheal intubation.

METHODS: Forty-five anesthesiology residents (postgraduate year 2–4) were enrolled in a study consisting of identical simulation sessions. On entry to the simulated OR, the residents were asked to perform an anesthetic, including induction and endotracheal intubation timed to approximately 6 minutes. Of the 45 simulation sessions, 15 were with a control group conducted with the intubating resident wearing single gloves, 15 with the intubating resident using double gloves with the outer pair removed and discarded after verified intubation, and 15 wearing double gloves and sheathing the laryngoscope in one of the outer gloves after intubation. Before the start of the scenario, the lips and inside of the mouth of the mannequin were coated with a fluorescent marking gel. After each of the 45 simulations, an observer examined the OR using an ultraviolet light to determine the presence of fluorescence on 25 sites: 7 on the patient and 18 in the anesthesia environment.

RESULTS: Of the 7 sites on the patient, ultraviolet light detected contamination on an average of 5.7 (95% confidence interval, 4.4–7.2) sites under the single-glove condition, 2.1 (1.5–3.1) sites with double gloves, and 0.4 (0.2–1.0) sites with double gloves with sheathing. All 3 conditions were significantly different from one another at P < 0.001. Of the 18 environmental sites, ultraviolet light detected fluorescence on an average of 13.2 (95% confidence interval, 11.3–15.6) sites under the single-glove condition, 3.5 (2.6–4.7) with double gloves, and 0.5 (0.2–1.0) with double gloves with sheathing. Again, all 3 conditions were significantly different from one another at P < 0.001.

CONCLUSIONS: The results of this study suggest that when an anesthesiologist in a simulated OR sheaths the laryngoscope immediately after endotracheal intubation, contamination of the IV hub, patient, and intraoperative environment is significantly reduced.

Published ahead of print July 23, 2015

From the *Department of Anesthesiology, University of Miami – Jackson Memorial Hospital Center for Patient Safety, University of Miami Miller School of Medicine, Miami, Florida; Department of Medicine Infectious Diseases, Boston Medical Center, Boston, Massachusetts; Department of Public Health Science, University of Miami Miller School of Medicine, Miami, Florida; and §Institute for Health and Society, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin.

Accepted for publication May 5, 2015.

Published ahead of print July 23, 2015

Funding: Departmental.

The authors declare no conflicts of interest.

Reprints will not be available from the authors.

Address correspondence to David J. Birnbach, MD, MPH, University of Miami – Jackson Memorial Hospital Center for Patient Safety, University of Miami Miller School of Medicine Institute, 4th Floor 1611 NW 12 Ave., Miami, FL 33136. Address e-mail to dbirnbach@med.miami.edu.

Anesthesiologists’ inadequate hand hygiene (HH) has been shown to play a role in the transmission of infection.1,2 However, the task-dense period associated with anesthetic administration may preclude optimal HH practices and compliance.3 With an average of 34 to 41 HH opportunities and 149 to 155 contacts with potentially contaminated surfaces during a single hour of an anesthetic,4 it becomes difficult for an anesthesiologist to comply with World Health Organization HH recommendations during the administration of an anesthetic.5 The period of greatest risk of contamination is during induction, which is also the time when it is most challenging for the anesthesia provider to comply with optimal HH practices.5

Since anesthesia providers may contribute to the ongoing problem of health care–associated infection,1,6 a more efficient approach to operating room (OR) pathogen containment, especially during induction of anesthesia, is warranted. Although suboptimal HH practices among anesthesia providers should be addressed,7,8 other approaches to decrease contamination of the patient and environment are also necessary.9–11 It has been shown in a simulated OR environment that the use of gloves during induction of anesthesia reduces the contamination of the anesthesia provider’s hands and the transmission of a surrogate of oral cavity pathogens and blood to the patient and environment, including the IV hub.12 Risk reduction is improved if gloves are removed and replaced after each contact, but that may be difficult during administration of anesthesia because of time constraints and logistical issues. Gloves are not a substitute for HH because gloved hands act as a carrier in the same way as nongloved hands.10,11 If anesthesiologists use gloves in lieu of HH, they may be playing a key role in pathogen transmission.10,13,14 A proposed solution may be to perform HH routinely every 5 to 10 minutes (e.g., after an automatic prompt) rather than after specific contacts,4 yet this may also be impractical given the task density of anesthesia care.3

Patients, anesthesia provider hands, and the anesthesia work environment have all been identified as specific sources of infectious risk and 2 time epochs, induction and emergence, have the highest potential for pathogen spread and subsequent contamination.3,15 Once pathogens are present on the OR surfaces, they become a vector for recontamination16 and further spread, even if the anesthesia provider performs frequent HH. If a contaminated laryngoscope blade is placed in the anesthesia work environment after induction, a perpetual cycle of recontamination may occur.

There are alternative solutions to prevent contamination of the work area by the contaminated laryngoscope and blade, such as depositing them in a contained compartment or bag or removal from the area immediately after use by a nurse or a technician. The cleaning of the OR between cases that is provided by personnel in environmental services may also be inadequate,17 resulting in pathogen transmission to other patients in that room through the cumulative high frequency of hands touching surfaces and patients successively.18 This infection risk can carry over to subsequent patients having procedures performed in the same OR.

Previous studies have established the spread of blood and pathogens (or surrogate markers for them) from the patient throughout the OR after anesthesia induction.19,20 Both the laryngoscope handle and blade have been documented as at risk for being contaminated with blood, body fluids, and potentially pathogenic microorganisms during clinical use,21,22 yet there is no standardized approach of what to do with the laryngoscope handle and blade after use. A study of anesthesiologists in a simulated environment demonstrated that wearing a single pair of gloves and not changing them after intubation leads to significant OR contamination.9 The risk is considerably reduced by wearing 2 sets of gloves and removing the outer pair immediately after intubation,9 but there are few data to guide practice relating to the removal of gloves and disposal of the used laryngoscope.

Hand contamination of anesthesia providers is an important risk factor for intraoperative bacterial transmission1,19; however, there has been insufficient investigation regarding hand contamination of anesthesia providers by the laryngoscope after its use. This contamination could be direct (e.g., placing the laryngoscope on a clean surface or allowing it to touch the patient or medication syringes that would be used later) or indirect (the anesthesia provider touching an area that had been contaminated by the laryngoscope).

We hypothesized that the soiled laryngoscope can contaminate the IV hub, anesthesiologists, and their immediate environment, and if the laryngoscope were sheathed in the removed outer glove, OR contamination would be reduced.

The primary aim of this study was to determine whether contamination of the external surface of the IV hub would be reduced when an anesthesia provider wore 2 sets of gloves for induction and sheathed the used laryngoscope and blade in one of the outer gloves immediately after use. This site of potential contamination was chosen because of the risk of potential bloodstream infection and associated morbidity and mortality.23,24 In addition, many anesthesia providers do not routinely disinfect the IV hub properly, which may exacerbate the risk of IV transmission of bacteria.9,25,26 Because both the blade and handle may be contaminated after laryngoscopy,12 in this study, they were sheathed as a unit.

A secondary aim of this study was to evaluate pathogen spread to the patient and to the overall anesthesia workplace. Seven sites on the patient and 18 sites in the anesthesiologist’s environment were compared for potential contamination by using 3 groups: a control group wearing single gloves; double gloves with removal of the outer set after intubation; and double gloves with removal and sheathing of the laryngoscope handle and blade.

Back to Top | Article Outline

METHODS

Forty-five anesthesiology residents (postgraduate year [PGY] 2–4) were enrolled in a simulation-based educational program conducted at the University of Miami-Jackson Memorial Hospital Center for Patient Safety. This study was conducted for approximately 1 year between December 2013 and December 2014 and was designed as a randomized, controlled trial. Participating residents were randomly assigned, by random number generation, to single gloves, double gloves, or double gloves with sheathing on a 1:1:1 ratio. Because the task of sheathing the laryngoscope was new to most residents, the participants in that group received instruction and were given time to practice before the simulation. There was no instruction in any scenario as to where to place the used laryngoscope, although plastic kidney basins were clearly evident on both the anesthesia machine and the cart. Data collection for this study was completed before the publication of 2 previous studies evaluating pathogen spread in the OR using fluorescence.12,20 The study was granted an exemption by the University of Miami Miller School of Medicine Institutional Review Board.

Residents were asked to perform a standardized anesthetic induction on a human patient simulator (HPS; CAE, Quebec, Canada) in an OR scenario that was timed to last for approximately 6 minutes and included endotracheal intubation. Induction included the use of IV propofol and succinylcholine followed by laryngoscopy and intubation. This duration of simulation was chosen because it has been used in previous studies,12 and it has been shown that OR contamination occurs in as little as 4 minutes.27 As previously reported,20 before the start of the scenario, the lips and inside of the mouth of the adult HPS were coated with 0.5 mL DAZO fluorescent marking gel (Ecolab, St. Paul, MN) as a surrogate for oral cavity pathogens or blood. Twenty-five sites of potential intraoperative pathogen spread were identified a priori (7 on the patient and 18 in the intraoperative environment). These sites were based on a previously reported study.20

After the simulation session was completed, an observer examined each of the 25 identified sites using a handheld ultraviolet light to determine the transfer of fluorescence to the HPS and the surrounding environment. The observer was different from the investigator who created the randomly allocated sequence.

As reported previously, the OR was cleaned between simulations with both alcohol-based hand rub and soap and water to remove all previously placed fluorescent marker.12,20 To verify that the OR was adequately cleaned before each simulation, an observer examined the OR and HPS using an ultraviolet light to determine the presence of any residue of fluorescent marker. If residual marker was found, it was removed with additional alcohol-based hand rub before initiation of the next simulation. Disposable materials that could not be easily cleaned (reservoir bag, IV tubing, and syringes) were replaced between simulations. The residents did not know that DAZO had been applied to the mannequin; thus, they were blinded to the intervention.

The number of participants was chosen based on the primary end point of identifying a difference in IV hub contamination using a power analysis determined by results of a previously published study.12 The proportion of objects positive for fluorescent markers based on the single versus double glove versus sheathing was calculated using conservative estimates of 10% contamination in the double-gloves scenario and 70% contamination with single gloves. A 90% power at the 0.05 2-sided α level required a sample size of 15 per group.

The proportion of contamination detected on each of the 25 sites is reported as percents with 95% Clopper-Pearson confidence intervals. Exact χ2 tests for differences in proportions were conducted to compare the proportion of contamination of the IV hub between the gloving conditions. After determining that there was an overall significant difference among the groups, 3 separate 2 × 2 analyses were conducted to compare pairs of groups. A Bonferroni adjustment was applied to the resulting P values. Generalized linear models were used to compare the counts of contaminated items on the patient (n = 7) and in the anesthesia environment (n = 18). There was no overdispersion evident in the data; therefore, a Poisson regression was used. Multiple comparisons of the back-transformed mean contamination counts of the 3 gloving method groups were made using the Bonferroni adjustment of the P values. Covariates for level of participant training and sex were included in the regression model to remove their possibly confounding effects.

Back to Top | Article Outline

RESULTS

All 45 participants completed the study. The distribution of level of training and sex of the participants in the simulation are shown in Table 1. The participants were predominantly PGY2 or PGY3 and male. The percentage and 95% confidence intervals of the 25 sites that were tested for contamination are presented in Table 2. The proportion of contaminated items was highest for single gloves, followed by double gloves with no sheathing, and lowest for double gloves with sheathing.

Table 1

Table 1

Table 2

Table 2

The rate of contamination with 95% Clopper-Pearson confidence intervals for each of the 25 sites is shown in Table 2. The difference in the rate of contamination of the IV hub between anesthesiology residents in the 3 groups (single gloves, 93% [95% Clopper-Pearson confidence interval, 68–100]; double gloves with no sheathing, 80% [52–96]; double gloves with sheathing, 0 [0–22]) was clinically and statistically significant (P < 0.001). Contamination was not significantly different with single gloves compared with double gloves without sheathing (P = 1.000); however, double gloves with sheathing resulted in significantly smaller proportions of contamination when compared with the amount of contamination when either double with no sheathing or single gloves were used (P < 0.001 for both comparisons).

The results of the Poisson regression comparing the 3 gloving methods adjusted for level of training and sex are provided in Table 3. The average number of contaminated sites of the 7 patient sites was 5.6 (95% confidence interval, 4.4–7.1) for single gloves, which was significantly higher than the contamination with double gloves with no sheathing (2.5 [1.8–3.5; P < 0.001]) and with double gloves with sheathing (0.3 [0.1–0.8]; P < 0.001). Double gloves with no sheathing had significantly more contaminated sites than double gloves with sheathing (P = 0.002).

Table 3

Table 3

The average number of contaminated sites of the 18 anesthesia environment sites was 13.3 (95% confidence interval, 11.3–15.7) for single gloves, which was significantly higher than the contamination with double gloves with no sheathing (3.2 [2.3–4.3]; P < 0.001) and with double gloves with sheathing (0.6 [0.3–1.2]; P < 0.001). Double gloves with no sheathing had significantly more contaminated sites than double gloves with sheathing (P < 0.001).

Back to Top | Article Outline

DISCUSSION

Since anesthesia providers have been shown to contaminate their work environment16,28 and do not routinely disinfect the IV hub site, it has been suggested that new approaches to protecting patients in the OR are indicated.9,23,27

One previously reported strategy would use double gloves with removal of the exterior pair after induction to reduce IV hub and overall OR contamination.12 No study has evaluated the impact of using the exterior glove to sheathe the laryngoscope handle and blade after use. In this study, there was a dramatic reduction in the number of contaminated sites between individuals in groups who wore either a single or a double set of gloves (discarding the outer glove after intubation) and participants who sheathed the laryngoscope in the removed outer glove after endotracheal intubation. In particular, numerous sites frequently contaminated with a single set of gloves (IV hub, anesthesia machine surface, syringes, reservoir bag, head of bed, and face) were reduced to 0% when sheathing of the laryngoscope was performed.

This study has several limitations. First, this study was performed in a simulated OR setting and should guide future research in actual clinical settings. Second, if sheathing is to be used in clinical practice, another laryngoscope and blade would be required to be available in the event another laryngoscopy needed to be performed. Third, it is unclear exactly when in the double-glove group that the outside gloves should be optimally removed in actual practice (e.g., before or after connection of the breathing circuit to the endotracheal tube). In this study, it was performed before connection of the endotracheal tube to the breathing circuit. Further research is necessary to evaluate if the 3- to 5-second delay in ventilation while removing the outer set of gloves is clinically relevant. Allowing anesthesiologists to touch other materials (reservoir bag, anesthesia machine, tape, and other supplies on the clean cart) before removing the outer gloves may reduce the benefit of double gloving. Fourth, it may be that a kidney basin (or some other type of container) in which the dirty laryngoscope could be placed after use would be as effective as sheathing in reducing contamination. However, it should be noted that none of the participants in this study used the kidney basins to deposit the laryngoscope after use. If this option were to be used in practice, it might require extensive educational initiatives. An alternative to this might be to have the circulating nurse assist in removal of the laryngoscope after use. Finally, the participants in the sheathing group may have been aware that infection prevention was being assessed and thus changed their practice because they were educated about this particular technique before the simulation.

Anesthesiologists face the daunting challenge of meeting HH requirements in the OR during every case. In the absence of specific strategies for pathogen containment of laryngoscopes after use, practitioners follow numerous, variable approaches.29 Sheathing the laryngoscope offers a simple way to significantly reduce contamination of the IV hub, the anesthesia work area, and the patient’s environment.

Back to Top | Article Outline

DISCLOSURES

Name: David J. Birnbach, MD, MPH.

Contribution: This author helped design the study, conduct the study, analyze and collect the data, and write the manuscript.

Attestation: David J. Birnbach has seen the original study data, reviewed the analysis of the data, approved the final manuscript, and is the author responsible for archiving the study files.

Name: Lisa F. Rosen, MA.

Contribution: This author helped design the study, conduct the study, analyze and collect the data, and write the manuscript.

Attestation: Lisa F. Rosen has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Maureen Fitzpatrick, MSN, ARNP-BC.

Contribution: This author helped design the study, conduct the study, collect the data, and write the manuscript.

Attestation: Maureen Fitzpatrick has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Philip Carling, MD.

Contribution: This author helped design and conduct the study.

Attestation: Philip Carling has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Kristopher L. Arheart, EdD.

Contribution: This author helped analyze the data and write the manuscript.

Attestation: Kristopher L. Arheart has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: L. Silvia Munoz-Price, MD, PhD.

Contribution: This author helped design the study, conduct the study, analyze and collect the data, and write the manuscript.

Attestation: L. Silvia Munoz-Price has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

This manuscript was handled by: Sorin J. Brull, MD.

Back to Top | Article Outline

ACKNOWLEDGMENTS

The authors thank Sorin J. Brull, MD, for his guidance and help with the design of this study.

Back to Top | Article Outline

REFERENCES

1. Loftus RW, Koff MD, Brown JR, Patel HM, Jensen JT, Reddy S, Ruoff KL, Heard SO, Yeager MP, Dodds TM. The dynamics of Enterococcus transmission from bacterial reservoirs commonly encountered by anesthesia providers. Anesth Analg. 2015;120:827–36
2. Loftus RW, Koff MD, Brown JR, Patel HM, Jensen JT, Reddy S, Ruoff KL, Heard SO, Yeager MP, Dodds TM. The epidemiology of Staphylococcus aureus transmission in the anesthesia work area. Anesth Analg. 2015;120:807–18
3. Biddle C, Shah J. Quantification of anesthesia providers’ hand hygiene in a busy metropolitan operating room: what would Semmelweis think? Am J Infect Control. 2012;40:756–9
4. Munoz-Price LS, Riley B, Banks S, Eber S, Arheart K, Lubarsky DA, Birnbach DJ. Frequency of interactions and hand disinfections among anesthesiologists while providing anesthesia care in the operating room: induction versus maintenance. Infect Control Hosp Epidemiol. 2014;35:1056–9
5. Rowlands J, Yeager MP, Beach M, Patel HM, Huysman BC, Loftus RW. Video observation to map hand contact and bacterial transmission in operating rooms. Am J Infect Control. 2014;42:698–701
6. Loftus RW, Koff MD, Birnbach DJ. The dynamics and implications of bacterial transmission events arising from the anesthesia work area. Anesth Analg. 2015;120:853–60
7. Fernandez PG, Loftus RW, Dodds TM, Koff MD, Reddy S, Heard SO, Beach ML, Yeager MP, Brown JR. Hand hygiene knowledge and perceptions among anesthesia providers. Anesth Analg. 2015;120:837–43
8. Shafer SL. Making a difference in perioperative infection. Anesth Analg. 2015;120:697–9
9. Munoz-Price LS, Lubarsky DA, Arheart KL, Prado G, Cleary T, Fajardo-Aquino Y, Depascale D, Eber S, Carling P, Birnbach DJ. Interactions between anesthesiologists and the environment while providing anesthesia care in the operating room. Am J Infect Control. 2013;41:922–4
10. Scheithauer S, Lemmen SW. How can compliance with hand hygiene be improved in specialized areas of a university hospital? J Hosp Infect. 2013;83(suppl 1):S17–22
11. Prielipp RC, Brull SJ. If one is good, are two always better? Anesth Analg. 2015;120:706–8
12. Birnbach DJ, Rosen LF, Fitzpatrick M, Carling P, Arheart KL, Munoz-Price LS. Double gloves: a randomized trial to evaluate a simple strategy to reduce contamination in the operating room. Anesth Analg. 2015;120:848–52
13. Zingg W, Pittet D. Stopcock contamination: the source does not explain it all. Anesth Analg. 2012;114:1151–2
14. Fuller C, Savage J, Besser S, Hayward A, Cookson B, Cooper B, Stone S. “The dirty hand in the latex glove”: a study of hand hygiene compliance when gloves are worn. Infect Control Hosp Epidemiol. 2011;32:1194–9
15. Munoz-Price LS, Patel Z, Banks S, Arheart K, Eber S, Lubarsky DA, Birnbach DJ. Randomized crossover study evaluating the effect of a hand sanitizer dispenser on the frequency of hand hygiene among anesthesiology staff in the operating room. Infect Control Hosp Epidemiol. 2014;35:717–20
16. Munoz-Price LS, Weinstein RA. Fecal patina in the anesthesia work area. Anesth Analg. 2015;120:703–5
17. Munoz-Price LS, Birnbach DJ, Lubarsky DA, Arheart KL, Fajardo-Aquino Y, Rosalsky M, Cleary T, Depascale D, Coro G, Namias N, Carling P. Decreasing operating room environmental pathogen contamination through improved cleaning practice. Infect Control Hosp Epidemiol. 2012;33:897–904
18. Clack L, Schmutz J, Manser T, Sax H. Infectious risk moments: a novel, human factors-informed approach to infection prevention. Infect Control Hosp Epidemiol. 2014;35:1051–5
19. Loftus RW, Brown JR, Koff MD, Reddy S, Heard SO, Patel HM, Fernandez PG, Beach ML, Corwin HL, Jensen JT, Kispert D, Huysman B, Dodds TM, Ruoff KL, Yeager MP. Multiple reservoirs contribute to intraoperative bacterial transmission. Anesth Analg. 2012;114:1236–48
20. Birnbach DJ, Rosen LF, Fitzpatrick M, Carling P, Munoz-Price LS. The use of a novel technology to study dynamics of pathogen transmission in the operating room. Anesth Analg. 2015;120:844–7
21. Muscarella LF. Reassessment of the risk of healthcare-acquired infection during rigid laryngoscopy. J Hosp Infect. 2008;68:101–7
22. Williams D, Dingley J, Jones C, Berry N. Contamination of laryngoscope handles. J Hosp Infect. 2010;74:123–8
23. Loftus RW, Muffly MK, Brown JR, Beach ML, Koff MD, Corwin HL, Surgenor SD, Kirkland KB, Yeager MP. Hand contamination of anesthesia providers is an important risk factor for intraoperative bacterial transmission. Anesth Analg. 2011;112:98–105
24. Loftus RW, Brindeiro BS, Kispert DP, Patel HM, Koff MD, Jensen JT, Dodds TM, Yeager MP, Ruoff KL, Gallagher JD, Beach ML, Brown JR. Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a passive catheter care system. Anesth Analg. 2012;115:1315–23
25. Mermel LA, Bert A, Chapin KC, LeBlanc L. Intraoperative stopcock and manifold colonization of newly inserted peripheral intravenous catheters. Infect Control Hosp Epidemiol. 2014;35:1187–9
26. Lockman JL, Heitmiller ES, Ascenzi JA, Berkowitz I. Scrub the hub! Catheter needleless port decontamination. Anesthesiology. 2011;114:958
27. Loftus RW, Koff MD, Burchman CC, Schwartzman JD, Thorum V, Read ME, Wood TA, Beach ML. Transmission of pathogenic bacterial organisms in the anesthesia work area. Anesthesiology. 2008;109:399–407
28. Loftus RW, Brown JR, Patel HM, Koff MD, Jensen JT, Reddy S, Ruoff KL, Heard SO, Dodds TM, Beach ML, Yeager MP. Transmission dynamics of gram-negative bacterial pathogens in the anesthesia work area. Anesth Analg. 2015;120:819–26
29. Hopf HW. Bacterial reservoirs in the operating room. Anesth Analg. 2015;120:700–2
© 2015 International Anesthesia Research Society