Blood contamination of anesthesia equipment and monitoring equipment

Mechanically Robust and Flame-Retardant Superhydrophobic Textiles with Anti-Biofouling Performance

The attachment of bio-fluids to surfaces promotes the transmission of diseases. Superhydrophobic textiles may offer significant advantages for reducing the adhesion of bio-fluids. However, they have not yet found widespread use because dried remnants adhere strongly and have poor mechanical or chemical robustness. In addition, with the massive use of polymer textiles, features such as fire and heat resistance can reduce the injuries and losses suffered by people in a fire accident. We developed a superhydrophobic textile covered with a hybrid coating of titanium dioxide and polydimethylsiloxane (TiO₂/PDMS). Such a textile exhibits low adhesion to not only bio-fluids but also dry blood. Compared to a hydrophilic textile, the peeling force of the coated textile on dried blood is 20 times lower. The textile's superhydrophobicity survives severe treatment by sandpaper (400 mesh) at high pressure (8 kPa) even if some of its microstructures break. Furthermore, the textile shows excellent heat resistance (350 °C) and flame-retardant properties as compared to those of the untreated textile. These benefits can greatly inhibit the flame spread and reduce severe burns caused by polymer textiles adhering to the skin when melted at high temperatures.

Elastic Superhydrophobic and Photocatalytic Active Films Used as Blood Repellent Dressing

Durable and biocompatible superhydrophobic surfaces are of significant potential use in biomedical applications. Here, a nonfluorinated, elastic, superhydrophobic film that can be used for medical wound dressings to enhance their hemostasis function is introduced. The film is formed by titanium dioxide nanoparticles, which are chemically crosslinked in a poly(dimethylsiloxane) (PDMS) matrix. The PDMS crosslinks result in large strain elasticity of the film, so that it conforms to deformations of the substrate. The photocatalytic activity of the titanium dioxide provides surfaces with both self-cleaning and antibacterial properties. Facile coating of conventional wound dressings is demonstrated with this composite film and then resulting improvement for hemostasis. High gas permeability and water repellency of the film will provide additional benefit for medical applications.

Evaluation of emergency department ultrasound machines for the presence of occult blood

OBJECTIVES

Bedside ultrasound in the emergency department is a common diagnostic tool, especially when evaluating trauma patients. Many trauma patients have blood on their chest and abdomen that may contact the probe during examination. The primary aim of this study was to investigate whether occult blood contamination was present on the emergency department ultrasound machine, both after daily use and after use in trauma.

METHODS

For a period of 31 days, the ultrasound machine at the trauma centre emergency department in Saskatoon, Saskatchewan, was tested once daily and following all Level 1 traumas. The ultrasound machine probes and keyboard were swabbed, and contamination was detected using a commercially available phenolphthalein blood testing kit. Any visible blood contamination was also noted. The machine was then cleaned following each positive test and re-tested to ensure the absence of contamination.

RESULTS

Over the study period, the ultrasound machine tested positive for occult blood contamination on 10% of daily tests and on 43% of assessments after its use in trauma. The curvilinear probe was most frequently contaminated (daily, 6%; trauma, 26%), followed by the keyboard (daily, 3%; trauma, 26%), but both lacked visible contamination.

CONCLUSIONS

In this single centre study, there was evidence of occult blood on the emergency department ultrasound machine after both routine use and major trauma cases, highlighting the need for a standardized cleaning and disinfection protocol.

Bacterial Contamination and Disinfection Status of Laryngoscopes Stored in Emergency Crash Carts

Objectives

To identify bacterial contamination rates of laryngoscope blades and handles stored in emergency crash carts by hospital and area according to the frequency of intubation attempts.

Methods

One hundred forty-eight handles and 71 blades deemed ready for patient use from two tertiary hospitals were sampled with sterile swabs using a standardized rolling technique. Samples were considered negative (not contaminated) if no colonies were present on the blood agar plate after an 18-hour incubation period. Samples were stratified by hospital and according to the frequency of intubation attempts (10 attempts per year) using the χ²-test and Fisher exact test.

Results

One or more species of bacteria were isolated from 4 (5.6%) handle tops, 20 (28.2%) handles with knurled surfaces, and 27 (18.2%) blades. No significant differences were found in microbial contamination levels on the handle tops and blades between the two hospitals and two areas according to the frequency of intubation attempts. However, significant differences were found between the two hospitals and two areas in the level of microbial contamination on the handles with knurled surfaces (p<0.05).

Conclusions

Protocols and policies must be reviewed to standardize procedures to clean and disinfect laryngoscope blades and handles; handles should be re-designed to eliminate points of contact with the blade; and single-use, one-piece laryngoscopes should be introduced.

Hand hygiene compliance monitoring in anaesthetics: Feasibility and validity

Background:

Hand hygiene compliance scores in the anaesthetic department of an acute NHS hospital were persistently low.

Aims:

To determine the feasibility and validity of regular accurate measurement of HHC in anaesthetics and understand the context of care delivery, barriers and opportunities to improve compliance.

Methods:

The hand hygiene compliance of one anaesthetist was observed and noted by a senior infection control practitioner (ICP). This was compared to the World Health Organization five moments of hand hygiene and the organisation hand hygiene tool.

Findings:

In one sequence of 55 min, there were approximately 58 hand hygiene opportunities. The hand hygiene compliance rate was 16%. The frequency and speed of actions in certain periods of care delivery made compliance measurement difficult and potentially unreliable. During several activities, taking time to apply alcohol gel or wash hands would have put the patients at significant risk.

Discussion:

We concluded that hand hygiene compliance monitoring by direct observation was invalid and unreliable in this specialty. It is important that hand hygiene compliance is optimal in anaesthetics particularly before patient contact. Interventions which reduce environmental and patient contamination, such as cleaning the patient and environment, could ensure anaesthetists encounter fewer micro-organisms in this specialty.

Disinfection of laryngoscopes: A survey of practice

Background and Aims:

The laryngoscope is a common piece of equipment used by anaesthesiologists. It has been identified as a potential source of cross infection. Although guidelines exist regarding appropriate disinfection practices, recent reviews suggest ineffectiveness of current methods of disinfection and poor compliance with the established protocols. We conducted a questionnaire-based survey to study the current disinfection practices being followed by a cross section of anaesthesiologists.

Methods:

A simple questionnaire containing 13 questions was distributed amongst anaesthesiologists in an anaesthesia conference. Data were analysed with percentage analysis.

Results:

Out of 250 delegates who attended the conference, 150 submitted the completed questionnaires. Residents constituted 41% and 46% were consultants. Eighteen (12%) used only tap water for cleaning and 132 (88%) used a chemical agent after rinsing with water. Out of 132, 76 (51%) used detergent/soap solution, 29 (19%) would wash and then soak in disinfectant or germicidal agents (glutaraldehyde, povidone iodine and chlorhexidine) and 18 (12%) would wipe the blade with an alcohol swab. With respect to disinfection of laryngoscope handles, 70% respondents said they used an alcohol swab, 18% did not use any method, 9% were not aware of the method being used, while 3% did not respond.

Conclusion:

Our results indicate wide variation in methods of decontamination of laryngoscopes. Awareness regarding laryngoscope as a potential source of infection was high. We need to standardise and implement guidelines on a national level and make available resources which will help to improve patient safety.

Double gloves: a randomized trial to evaluate a simple strategy to reduce contamination in the operating room

BACKGROUND

Oral flora, blood-borne pathogens, and bacterial contamination pose a direct risk of infection to patients and health care workers. We conducted a study in a simulated operating room using a newly validated technology to determine whether the use of 2 sets of gloves, with the outer set removed immediately after endotracheal intubation, may reduce this risk.

METHODS

Forty-one anesthesiology residents (PGY 2-4) were enrolled in a study consisting of individual or group simulation sessions. On entry to the simulated operating room, the residents were asked to perform an anesthetic induction and tracheal intubation timed to approximately 6 minutes; they were unaware of the study design. Of the 22 simulation sessions, 11 were conducted with the intubating resident wearing single gloves, and 11 with the intubating resident using double gloves with the outer pair removed after verified intubation. Before the start of the scenario, we coated the lips and inside of the mouth of the mannequin with a fluorescent marking gel as a surrogate pathogen. After the simulation, an observer examined 40 different sites using a handheld ultraviolet light in the operating room to determine the transfer of surrogate pathogens to the patient and the patient's environment. Residents who wore double gloves were instructed by a confederate nurse to remove the outer set immediately after completion of the intubation. Forty sites of potential intraoperative pathogen spread were identified and assigned a score.

RESULTS

The difference in the rate of contamination between anesthesiology residents who wore single gloves versus those with double gloves was clinically and statistically significant. The number of sites that were contaminated in the operating room when the intubating resident wore single gloves was 20.3 ± 1.4 (mean ± SE); the number of contaminated sites when residents wore double gloves was 5.0 ± 0.7 (P < 0.001).

CONCLUSIONS

The results of this study suggest that when an anesthesiologist wears 2 sets of gloves during laryngoscopy and intubation and then removes the outer set immediately after intubation, the contamination of the intraoperative environment is dramatically reduced.

Cleaning assessment of disinfectant cleaning wipes on an external surface of a medical device contaminated with artificial blood or Streptococcus pneumoniae

BACKGROUND

Improperly cleaned, disinfected, or sterilized reusable medical devices are a critical cause of health care-associated infections. More effective studies are required to address the improvement of cleaning and disinfection instructions, as well as selection of cleaning and disinfecting agents, for surfaces of reusable devices and equipment.

METHODS

Six commercially available disinfectant cleaning wipes were evaluated for their effectiveness to remove a coagulated blood test soil or Streptococcus pneumoniae bacteria from the surface of a reusable medical device. Liquid aliquots of the coagulated blood or bacteria were dried onto the surface of the device and removed with the wipes. Effectiveness of the wipes was assessed by 3 methods: residual protein debris by o-phthaldialdehyde analysis, bacterial survival by adenosine triphosphate measurement, and force required to remove the dried debris by force measurement.

RESULTS

A sodium hypochlorite wipe was most effective in removing protein debris from the device surface. All tested wipes were equivalent in disinfecting bacterial contamination from the device surface.

CONCLUSION

The active ingredient, wipe design, and wipe wetness are important factors to consider when selecting a disinfectant cleaning wipe. Additionally, achieving conditions that effectively clean, disinfect, and/or inactivate surface bacterial contamination is critical to preventing the spread of health care-associated infections.

Modification of anesthesia practice reduces catheter-associated bloodstream infections: a quality improvement initiative

BACKGROUND

A major strategic hospital goal is the prevention of catheter associated bloodstream infections (CABSI). In 2009, at our institution, the CABSI rate for patients who traveled out of the ICU to the operating room and other procedural areas under the care of an anesthesiologist was increased compared to patients who remained on the unit.

AIMS

Our objective was to develop countermeasures to improve intraoperative cleanliness by anesthesia providers, minimize contamination of intravenous access points, and ultimately reduce CABSIs.

MATERIALS & METHODS

A multidisciplinary team identified barriers to following best practices for reducing contamination of intravenous line entry-ports. Using Continuous Performance Improvement (CPI) or Lean techniques, staff directly impacted by the changes developed countermeasures to improve anesthesia practice. Compliance with the new "best practices" improved with coaching and feedback.

RESULTS

Postimplementation, CABSI rates for patients traveling off the ICU with anesthesiology providers decreased from 14.1 per thousand trips off the ICU preintervention in 2009 to 9.7 per 1000 trips in 2010 and to 0 per 1000 trips in 2011 postintervention. Hospital-wide CABSI rates decreased from 3.5 per 1000 central line days preintervention to 2.2 per 1000 central line days after.

CONCLUSION

Practice modification by anesthesiology providers in the operating room can decrease workspace contamination and is associated with decreased CABSI rates.

Lack of correlation between age and/or gender with the force utilized in cleaning an anesthesia machine

Several human factors influence the cleaning of reusable medical devices and equipment. This study evaluated whether a correlation exists between age and/or gender of a person cleaning, with the force applied to remove artificial blood soil on the surface of an anesthesia machine. The findings from this study may be used to increase our understanding of human factors in the cleaning of reusable medical equipment and suggest improvements in equipment design to address issues of concern.

Difficult intubation provokes bacteremia

PURPOSE

To evaluate the prevalence of bacteremia after mask ventilation, laryngoscopy, and endotracheal intubation before induction of general anesthesia and to discover any correlation between traumatic manipulations and bacteremia. The specific bacteria responsible, knowledge of which may guide the prophylactic use of antibiotics, also were investigated.

METHODS

Fifty patients were enrolled. Three 10-mL blood samples were collected from a peripheral vein 10 min before induction of anesthesia, 10 min after mask ventilation, and 10 min after intubation. All samples were placed in aerobic and anaerobic bottles for culture and bacterial identification.

RESULTS

Cultures received 10 min after intubation were positive in 12% of patients. The following strains were isolated: Escherichia coli in two cases, Staphylococcus aureus in three cases, and Peptostreptococcus anaerobius in one case. A strong positive correlation was found between difficult intubation and bacteremia. No correlation between bacteremia and easy intubation or between bacteremia and face mask ventilation was identified.

CONCLUSION

Traumatic manipulations during difficult laryngoscopy and endotracheal intubation could cause bacteremia. This finding may justify and guide prophylactic use of antibiotics.

Use of condoms as blade covers during laryngoscopy, a method to reduce possible cross infection among patients

OBJECTIVES

Laryngoscope blades are in close contact with mucous membranes and can possibly contaminated with virulent or readily transmissible organisms. As laryngoscopy is often required during endotracheal intubation, proper cleaning and sterilization of the laryngoscope blade is crucial to prevent cross-contamination among patients.

METHODS

We tested the effectiveness of latex condom using as a laryngoscope blade cover during endotracheal intubation. Both control (no condom) and study group blades were rinsed with sterile saline after intubation. The rinse was sent for bacteria culture, and appearance of bacterial colonization was counted as positive. A water leak test (WLT) was performed on used condoms to verify their integrity.

RESULTS

There were total 162 laryngoscopes studied with 83 (51.2%) scopes in the study group and 79 (48.8%) in the control group. Rate of positive bacterial culture were 13.3% and 88.6% in the study and control group, respectively. Although WLT (+) rate of 41% was found in the study group, a high negative culture rate (71.6%) was also noted among the WLT (+) group.

CONCLUSIONS

Condom when using as a blade cover during laryngoscopy is a simple, inexpansive and effective way in reducing cross contamination among patients.

[Airway equipment and its maintenance for a non difficult adult airway management (endotracheal intubation and its alternative: face mask, laryngeal mask airway, laryngeal tube)]

The airway equipment for a non difficult adult airway management are described: endotracheal tubes with a specific discussion on how to inflate the balloon, laryngoscopes and blades, stylets and intubation guides, oral airways, face masks, laryngeal mask airways and laryngeal tubes. Cleaning and disinfections with the maintenance are also discussed for each type of airway management.

What anaesthetists need to know about viral hepatitis

BACKGROUND

Viral hepatitis is a major world-wide public health issue. An increasing number of virus hepatitis carriers with acute or chronic hepatitis at all stages of the disease will be referred to anaesthetists. An update of what anaesthetists should know about viral hepatitis was believed to be warranted.

METHODS

The present review focuses on (a) diagnosis criteria and main biological and clinical patterns of acute and chronic hepatitis, and (b) extrahepatic manifestations, and adverse effects resulting from specific drug therapy likely to influence anaesthetic care.

RESULTS

Elective surgery should be postponed and any medications that could be harmful to the liver should be disregarded in patients suspected of having acute viral hepatitis. A prothrombin time decrease to less than 50% (INR > 1.75) is the first sign of acute severe liver failure. Extrahepatic manifestations resulting mainly from small- and medium-sized vessel alteration, and adverse effects caused by specific drug therapy are associated with chronic viral hepatitis and are likely to alter anaesthetic care. A titrated anaesthesia should be provided and agents not eliminated by the liver should be favoured. Vasopressor therapy should be administered early to control a systemic intraoperative blood pressure decrease associated with a high cardiac output. Prophylactic antibiotics should take into consideration the risk of translocation of gut bacteria to the systemic circulation. Prophylactic guidelines of hepatitis nosocomial transmission should be respected.

CONCLUSIONS

Anaesthetists are likely to play a key role in immediate acute hepatitis and chronic hepatitis perioperative assessment and care.

Eliminating protein from reusable laryngeal mask airways. A study comparing routinely cleaned masks with three alternative cleaning methods

Laryngeal mask airways (LMAs) have the potential to act as a vector for the transmission of prion diseases. This study was undertaken to define the problem of protein contamination and to investigate three alternative cleaning methods. Forty-eight LMAs were allocated to one of four groups, stained with erythrosin and given a total stain score and a grid stain score in order to determine the degree of protein contamination. Eighteen randomly selected LMAs that had been routinely cleaned and sterilised (group 1) were compared with 12 LMAs that had been washed and scrubbed with the benefit of prior staining (group 2), 13 that had been washed and scrubbed without any visual guide (group 3) and 13 that had been cleaned using a Biosonic ultrasonic cleaning system (group 4). The results show that none of the cleaning methods achieved optimal results, as all methods left proteinaceous material on some masks. The study showed that: (i) staining as a guide to cleaning does not lead to more effective removal of proteinaceous material; (ii) systematic cleaning and scrubbing does lead to more effective removal of proteinaceous material from surfaces other than the grid area; and (iii) ultrasonic cleaning was more effective than other methods of cleaning for the removal of proteinaceous material from those areas of the mask most inaccessible, such as the grid.

The effect of a disposable probe cover on pulse oximetry

The re-use of pulse oximeter probes presents the possibility of between-patient contamination. Use of a disposable polyethylene cover may reduce this risk. In a controlled, prospective study we examined the effect of such a cover on the accuracy of pulse oximetry. Each of ten volunteer subjects was monitored simultaneously by two identical Nellcor pulse oximeters, one with a plastic cover and the other, without a cover, used as a control. The pulse oximetry (SpO2) reading for each probe was recorded while subjects breathed 21% O2 and again while they breathed 10% O2. The probe cover was then swapped onto the other probe and the recordings were repeated. Ninety-five per cent limits of agreement in SpO2 (mean difference in SpO2 (1.95 x standard deviation of difference) between covered and non-covered probes were -0.6% to 0.6% while breathing 21% oxygen and -2.0% to 2.9% while breathing 10% oxygen. We conclude that a protective plastic sheath may induce a small error in pulse oximetry reading that is most marked during hypoxaemia. This error is unlikely to be of clinical significance.

Decontamination of laryngoscopes in The Netherlands

In this study the decontamination procedures of laryngoscopes in Dutch hospitals are described, based on a structured telephone questionnaire. There were substantial differences between decontamination procedures in Dutch hospitals and the standards of the APIC (Association of Professionals in Infection Control and Epidemiology), CDC (Centers of Disease Control) and ASA (American Society of Anesthesiology) were met in full in 19.4% of the hospitals. The standards of manual decontamination, used in 78% of the 139 hospitals, were particularly disappointing; manual cleaning was considered inadequate in 22.9% of these hospitals and manual disinfection did not meet the standards of the APIC, CDC or ASA in any of these hospitals. Decontamination by instrument cleaning machines as a standard procedure was used in 30 (22%) hospitals. In three of these hospitals the blades were subsequently sterilized. We suggest adherence to the infection control guidelines of the CDC, APIC and ASA, until the safety of less conservative infection control practices are demonstrated.

Visible and occult blood contamination of laryngeal mask airways and tracheal tubes used in adult anaesthesia

The purpose of this study was to compare visible and occult blood contamination of 50 laryngeal mask airways and 50 tracheal tubes following routine anaesthesia for procedures not involving the oropharyngeal or nasal cavities. All airway devices were examined visually for the presence of blood before washing in 100 ml of water. A semiquantitative dipstick was used to test for the presence of blood in the washings. Laryngeal mask airways were examined visually by both authors to test agreement. The results show that occult blood contamination occurred in 78% of tracheal tubes and 76% of laryngeal mask airways, while visible blood contamination was 16% and 12%, respectively. Other studies reporting visible blood contamination of airway devices probably underestimate the true incidence of blood contamination. Oral secretions following the use of these devices should be considered as high risk for transmission of blood-born viruses. Anaesthetic and recovery staff should be protected against the risks of occupational exposure to oral secretions following the use of airway devices.

The routine wearing of gloves: impact on the frequency of needlestick and percutaneous injury and on surface contamination in the operating room

The impact of wearing gloves on surface contamination and on the incidence of percutaneous injury were prospectively compared for two 4-mo periods in a single anesthesia department. Period I was immediately prior to the institution of mandatory glove wearing, and Period II followed a 1-mo adjustment period of mandatory glove use. Recording of all needlestick and other percutaneous injuries was performed on an ongoing basis, and incident reporting was actively and regularly solicited. During the final week of each period, 12 specific sites at each of nine anesthetizing locations were tested for occult blood. The incidence of needlestick injury was 0.28% for Period I versus 0.10% for Period II (P = 0.10) and the incidence for all percutaneous injuries was 0.60% for Period I and 0.27% for Period II (P = 0.06). If the one needlestick that occurred during noncompliance with gloving during Period II is eliminated, then there was a significant reduction in both needlestick and overall percutaneous injury (P < 0.05). Of 109 operating room sites, 42.2% were contaminated after Period I versus 31.2% after Period II (P = 0.07). The implementation of a mandatory glove use policy was associated with nonsignificant trends toward reduction in the incidence of needlestick and other percutaneous injury and in the level of surface contamination in the anesthesia workplace. Compliance with glove use resulted in a significant reduction in needlestick injury and overall percutaneous injuries.

Preventing perioperative transmission of infection: a survey of anesthesiology practice

Given the societal and economic impact of perioperative infection, it is essential that anesthesiologists and other operating room personnel use appropriate precautions to reduce the potential for transmission of infectious agents to the patients under their care. This study, therefore, was designed to evaluate the degree to which anesthesiologists utilize appropriate hygienic techniques for the prevention of infection in the perioperative period. A total of 1149 questionnaires were mailed to anesthesiologists randomly selected from the membership of the American Society of Anesthesiologists (ASA). Of these, 493 (44%) were completed and returned. Forty-nine percent and 75.3% of respondents always used gloves and masks, respectively, in their everyday practice. Only 58% of respondents stated that they always washed their hands after every patient contact and 85% reported that they always used aseptic technique for placing indwelling catheters. Knowledge of universal precautions for prevention of occupational transmission of infection was associated with good hygienic practice. Twenty percent of the respondents reported frequently or always reusing syringes for more than one patient and 34.4% reported never or rarely disinfecting the septum of multidose vials prior to use. The practice of reusing syringes was significantly greater among private than university practitioners (P < 0.01). On a scale of 0-10 (10 = high) anesthesiologists rated their potential for transmitting or contributing to patient potential for transmitting or contributing to patient infection as 4.7 +/- 0.12 (mean +/- SE). Results of this study suggest that, whereas most responding anesthesiologists exhibit appropriate infection control behaviors, there are several potentially hazardous practices that continue.