Effectiveness of safety-engineered devices in reducing sharp object injuries.

BACKGROUND: Sharps injuries remain a common factor in occupational exposure of healthcare workers to blood-borne viruses. The extent to which the introduction of safety-engineered devices has been effective in reducing such injuries among healthcare workers is unclear. AIMS: To investigate the incidence of sharp object injury among healthcare workers in the Capital Health Region of Alberta, Canada and to determine the effectiveness of the introduction of safety- engineered devices in preventing these. METHODS: All reports of sharp object injuries to Capital Region Workplace Health and Safety offices from healthcare workers 2003-10 were analysed. Rates of sharp object injury were compared before (2006), during (2007-08) and after (2009-10) the introduction of safety-engineered devices, adjusting for other potential risk factors using Poisson regression and log-linear models. RESULTS: Between 2003 and 2010, a total of 4707 sharp object injuries were reported from 15 healthcare facilities. The sharp object injury rate per 1000 full-time equivalent employees per year declined from 35 before the introduction period to 30 during the introduction period (rate ratio [RR]: 0.88, 95% confidence interval [CI]: 0.78, 0.99) among most healthcare workers, but then rebounded again slightly after the intervention. Physician risks showed little change during the period of introduction (odds ratio [OR]: 0.99, 95% CI: 0.85, 1.14) but decreased significantly after the intervention (OR: 0.83, 95% CI: 0.71, 0.97). CONCLUSIONS: The introduction of safety-engineered devices was associated with a modest reduction in reported sharp object injuries but this appeared to be relatively short-lived for most workers.

The air-Q(®) intubating laryngeal airway vs the LMA-ProSeal(TM) : a prospective, randomised trial of airway seal pressure.

We performed a prospective, open-label, randomised controlled trial comparing the air-Q(®) against the LMA-ProSeal™ in adults undergoing general anaesthesia. One hundred subjects (American Society of Anesthesiologists physical status 1-3) presenting for elective, outpatient surgery were randomly assigned to 52 air-Q(®) and 48 ProSeal devices. The primary study endpoint was airway seal pressure. Oropharyngolaryngeal morbidity was assessed secondarily. Mean (SD) airway seal pressures for the air-Q(®) and ProSeal were 30 (7) cmH (2) O and 30 (6) cmH(2) O, respectively (p = 0.47). Postoperative sore throat was more common with the air-Q(®) (46% vs 38%, p = 0.03) as was pain on swallowing (30% vs 5%, p = 0.01). In conclusion, the air-Q(®) performs well as a primary airway during the maintenance of general anaesthesia with an airway seal pressure similar to that of the ProSeal, but with a higher incidence of postoperative oropharyngolaryngeal complaints.

BOugie or stylet in patients UnderGoing Intubation Emergently (BOUGIE): protocol and statistical analysis plan for a randomised clinical trial.

INTRODUCTION: Intubation-related complications are less frequent when intubation is successful on the first attempt. The rate of first attempt success in the emergency department (ED) and intensive care unit (ICU) is typically less than 90%. The bougie, a semirigid introducer that can be placed into the trachea to facilitate a Seldinger-like technique of tracheal intubation and is typically reserved for difficult or failed intubations, might improve first attempt success. Evidence supporting its use, however, is from a single academic ED with frequent bougie use. Validation of these findings is needed before widespread implementation. METHODS AND ANALYSIS: The BOugie or stylet in patients Undergoing Intubation Emergently trial is a prospective, multicentre, non-blinded randomised trial being conducted in six EDs and six ICUs in the USA. The trial plans to enrol 1106 critically ill adults undergoing orotracheal intubation. Eligible patients are randomised 1:1 for the use of a bougie or use of an endotracheal tube with stylet for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is severe hypoxaemia, defined as an oxygen saturation less than 80% between induction until 2 min after completion of intubation. Enrolment began on 29 April 2019 and is expected to be completed in 2021. ETHICS AND DISSEMINATION: The trial protocol was approved with waiver of informed consent by the Central Institutional Review Board at Vanderbilt University Medical Center or the local institutional review board at an enrolling site. The results will be submitted for publication in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03928925).

Protocol and statistical analysis plan for the PREventing cardiovascular collaPse with Administration of fluid REsuscitation during Induction and Intubation (PREPARE II) randomised clinical trial.

INTRODUCTION: Cardiovascular collapse is a common complication during tracheal intubation of critically ill adults. Whether administration of an intravenous fluid bolus prevents cardiovascular collapse during tracheal intubation remains uncertain. A prior randomised trial found fluid bolus administration to be ineffective overall but suggested potential benefit for patients receiving positive pressure ventilation during tracheal intubation. METHODS AND ANALYSIS: The PREventing cardiovascular collaPse with Administration of fluid REsuscitation during Induction and Intubation (PREPARE II) trial is a prospective, multi-centre, non-blinded randomised trial being conducted in 13 academic intensive care units in the USA. The trial will randomise 1065 critically ill adults undergoing tracheal intubation with planned use of positive pressure ventilation (non-invasive ventilation or bag-mask ventilation) between induction and laryngoscopy to receive 500 mL of intravenous crystalloid or no intravenous fluid bolus. The primary outcome is cardiovascular collapse, defined as any of: systolic blood pressure <65 mm Hg, new or increased vasopressor administration between induction and 2 min after intubation, or cardiac arrest or death between induction and 1 hour after intubation. The primary analysis will be an unadjusted, intention-to-treat comparison of the primary outcome between patients randomised to fluid bolus administration and patients randomised to no fluid bolus administration using a χ2 test. The sole secondary outcome is 28-day in-hospital mortality. Enrolment began on 1 February 2019 and is expected to conclude in June 2020. ETHICS AND DISSEMINATION: The trial was approved by either the central institutional review board at Vanderbilt University Medical Center or the local institutional review board at each trial site. Results will be submitted for publication in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER: NCT03787732.

Preventing transmission of bloodborne viruses from infected healthcare workers to patients: Summary of a new Canadian Guideline.

BACKGROUND: Although it is well documented that bloodborne viruses (BBVs), including human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) have been transmitted from patients to healthcare workers (HCWs), there has also been reported transmission from HCWs to patients during the provision of health care. With remarkable progress in infection prevention, diagnosis tools, treatment regimens and major improvements in guideline development methodology, there was a need to develop an evidence-based guideline to replace the 1998 Canadian consensus document for managing HCWs infected with BBVs. PURPOSE: This article summarizes the Canadian Guideline on the Prevention of Transmission of Bloodborne Viruses from Infected Healthcare Workers in Healthcare Settings. METHODS: A Guideline Development Task Group was established and key questions developed to inform the guideline content. Systematic reviews were conducted to evaluate the risk of HCW-to-patient transmission of HIV, HCV and HBV. Environmental scans were used to provide information on Expert Review Panels, disclosure of a HCW's serologic status and lookback investigations. Federal, provincial and territorial partners and key stakeholder organizations were consulted on the Guideline. RESULTS: The risk of HCW-to-patient BBV transmission was found to be negligible, except during exposure-prone procedures, where there is a risk that injury to the HCW may result in exposure of a patient's open tissues to the HCW's blood. Risk of ensuing transmission and the rate of transmission varied by BBV, and were lowest with HIV and highest with HBV. The Guideline provides key content, including recommendations regarding criteria to determine if a procedure is an exposure-prone procedure, management of HCWs infected with a BBV, including considerations for the HCW's fitness for practice, Expert Review Panels, HCW disclosure obligations and right to privacy and lookback investigations. CONCLUSION: This new Guideline provides a pan-Canadian approach for managing HCWs infected with a BBV, with recommendations related to preventing HCW-to-patient transmission of BBVs during the provision of care.

Mycobacterium chimaera Infection After Aortic Valve Replacement Presenting With Aortic Dissection and Pseudoaneurysm.

We present a case of Mycobacterium chimaera infection presenting with aortic dissection and pseudoaneuysm in a 22-year-old man with a past history of aortic valve replacement. Clinicians should consider M. chimaera infection in those presenting with aortic dissection as a late complication of cardiovascular surgery.

Epidemiological studies of nosocomial infections with Pseudomonas aeruginosa using a DNA probe.

A DNA probe encoding the Pseudomonas aeruginosa pilin gene has been developed in the authors' laboratory and has been shown to be a useful epidemiological tool. In the present study this technology, together with other typing methods, has been used to define relatedness and possible transmission routes of P aeruginosa strains isolated in several hospital wards. Clusters of P aeruginosa infections, suspected to be the result of nosocomial transmission, developed in a general intensive care unit (ICU) and a neurosurgical ward/ICU, as well as in a burn unit, were studied using antibiograms, lipopolysaccharide-serotyping, and gene probe analysis. Results of these studies demonstrated that each of the general and neurosurgical ICU isolates were different, making nosocomial transmission very unlikely. However, within the burn unit, patient isolates had identical profiles, suggesting that spread between patients was occurring or that a common source of infection was present. Changes in infection control measures within the unit were introduced and may have contributed to eradication of the outbreak. DNA probe studies were valuable in clarifying epidemiological relatedness of isolates that was not evident with the other typing strategies and identified a possible burn-associated strain.

The self-pressurising air-Q® Intubating Laryngeal Airway for airway maintenance during anaesthesia in adults: a report of the first 100 uses.

The self-pressurising air-Q® Intubating Laryngeal Airway is a new, commercially available, supraglottic airway device that incorporates a self-regulating periglottic cuff. In this retrospective review, we describe our initial clinical experience using the device in 100 patients. The ease and number of insertion attempts, airway seal pressure, device positioning, intubation success and oropharyngeal morbidity were recorded. The air-Q Intubating Laryngeal Airway was successfully inserted in all 100 patients and functioned adequately as a primary airway in 70 of the 72 patients in which it was used for this purpose. The median (interquartile range [range]) airway seal pressure was 22 (19-29, [10-40]) cmH2O. Intubation via the air-Q Intubating Laryngeal Airway was successful in 28 of 29 (97%) patients. Eleven percent of patients complained of sore throat postoperatively before discharge. In our series, the air-Q Intubating Laryngeal Airway performed adequately as a primary airway during anaesthesia with respect to ease of insertion, adequacy of airway maintenance and as a conduit for intubation in both anticipated and unanticipated difficult airways. Although our initial experience is positive, further investigation with larger numbers of observations are needed as the upper limits of the 95% confidence intervals for device failure (the worst failure rate the clinician could expect) are still high.

The second-generation air-Q intubating laryngeal mask for airway maintenance during anaesthesia in adults: a report of the first 70 uses.

The second-generation air-Q intubating laryngeal airway is a newer commercially available supraglottic airway device. In this retrospective review, we describe our initial clinical experience of 70 insertions. The ease and number of insertion attempts, airway leak pressure, device positioning, duration of use, success of fibreoptic-aided intubation and oropharyngeal morbidity were recorded. The intubating laryngeal airway was successfully inserted in all 770 patients and functioned adequately as a primary airway in all 57 patients in which it was used. The median airway leak pressure was 25 and 30 cmH2O for the single-use and reusable devices (P = 0.001), respectively. Fibreoptic-aided intubation using the intubating laryngeal airway as a conduit was successful in 12/13 (92%) cases. One in four (26%) patients complained of mild sore throat postoperatively before discharge. In our series, the intubating laryngeal airway performed adequately as a primary airway during anaesthesia with respect to ease of insertion, adequacy of airway maintenance, and as a conduit for intubation in both anticipated and unanticipated difficult airways. Further investigation is warranted regarding the role of the intubating laryngeal airway as a conduit for both blind and fibreoptic-aided intubation. In addition, the incidence of postoperative throat complaints deserves further scrutiny.

Intubation through the LMA-Supreme: a pilot study of two techniques in a manikin.

The LMA-Supreme is a single-use disposable laryngeal mask that combines features of several laryngeal mask airways in one device. The primary aim of our study was to compare ease of use and operator preference for fibreoptic-aided intubation through the LMA-Supreme using an Aintree Intubating Catheter or Arndt Airway Exchange Catheter Set. Twenty participants experienced in fibreoptic-aided intubation performed a total of 40 intubations on an AirSim airway manikin through a #4 LMA-Supreme. Intubation using the Arndt Airway Exchange Catheter Set was easier than with the Aintree Intubating Catheter. Half of the participants preferred Aintree Intubating Catheter-assisted intubation, citing fewer steps and faster performance as the reasons. All 20 (100%) Arndt Airway Exchange Catheter Set-assisted intubations and 18/20 (90%) of Aintree Intubating Catheter-assisted intubations were successful. Aintree Intubating Catheter and Arndt Airway Exchange Catheter Set-assisted intubations can be performed quickly, successfully and with minimal difficulty through the LMA-Supreme by experienced operators. While the Arndt Airway Exchange Catheter may be easier the Aintree Intubating Catheter is faster.

Respirator-fit testing: does it ensure the protection of healthcare workers against respirable particles carrying pathogens?

OBJECTIVE: Respiratory protection programs, including fit testing of respirators, have been inconsistently implemented; evidence of their long-term efficacy is lacking. We undertook a study to determine the short- and long-term efficacy of training for fit testing of N95 respirators in both untrained and trained healthcare workers (HCWs). DESIGN: Prospective observational cohort study. METHODS: A group of at-risk, consenting HCWs not previously fit-tested for a respirator were provided with a standard fit-test protocol. Participants were evaluated after each of 3 phases, and 3 and 14 months afterward. A second group of previously fit-tested nurses was studied to assess the impact of regular respirator use on performance. RESULTS: Of 43 untrained fit-tested HCWs followed for 14 months, 19 (44.2%) passed the initial fit test without having any specific instruction on respirator donning technique. After the initial test, subsequent instruction led to a pass for another 13 (30.2%) of the 43 HCWs, using their original respirators. The remainder required trying other types of respirators to achieve a proper fit. At 3 and 14 months' follow-up, failure rates of 53.5% (23 of 43 HCWs) and 34.9% (15 of 43 HCWs), respectively, were observed. Pass rates of 87.5%-100.0% were observed among regular users. CONCLUSIONS: Without any instruction, nearly 50% of the HCWs achieved an adequate facial seal with the most commonly used N95 respirator. Formal fit testing does not predict future adequacy of fit, unless frequent, routine use is made of the respirator. The utility of fit testing among infrequent users of N95 respirators is questionable.

Anticoagulant therapy for prevention of spontaneous abortion in a patient with a lupus anticoagulant.

Lupus anticoagulants are associated with venous and arterial thrombosis and with recurrent spontaneous abortion resulting from placental infarction. Treatment with high-dose prednisone and aspirin has been reported to reduce the otherwise very high frequency of spontaneous abortion in affected women. We report the case of a young woman with an idiopathic lupus anticoagulant who had a history of arterial and venous thrombosis and of previous spontaneous abortion; anticoagulation throughout pregnancy was associated with normal fetal growth and with an absence of placental infarction. We conclude that anticoagulation without concurrent prednisone or aspirin may provide an alternative approach to prevention of habitual abortion in some women with lupus anticoagulants.

Use of a pilin gene probe to study molecular epidemiology of Pseudomonas aeruginosa.

Strains of Pseudomonas aeruginosa from patients with cystic fibrosis (CF) are unusual. The majority have a rough lipopolysaccharide (LPS) which renders them nontypeable by conventional typing systems based on a serological reaction with the O polysaccharide of smooth LPS. We developed a new typing scheme using a pilin gene probe as a marker for hybridization with endonuclease-digested genomic DNA from P. aeruginosa. Twenty-one different restriction fragment length polymorphism (RFLP) types were found among 249 isolates. RFLP type 7 was recovered only from patients with thermal burns (9 of 14 isolates) in both Vancouver, British Columbia, and Edmonton, Alberta, Canada. None of the other RFLP types showed a clear predilection for disease state or environmental niche. Multiple morphologically different isolates from individual patients with CF were studied; each isolate in 33 of 40 sputum samples had an identical RFLP type, despite considerable LPS serotype heterogeneity. Sequential isolates from 23 patients were studied; in 10 isolates there was a clear change in both the RFLP and the LPS serotype. We conclude that patients with CF usually harbor a single P. aeruginosa RFLP type in their sputa, but that one strain can replace another as the predominant colonizing type.

Serial isolates of Pseudomonas aeruginosa from a cystic fibrosis patient have identical pilin sequences.

Five isolates of Pseudomonas aeruginosa (CD2, CD3, CD4, CD5, and CD10) from a patient with cystic fibrosis were examined with regard to several genotypic and phenotypic characteristics to determine whether the patient was colonized with one or several distinct strains. Isolates CD2, CD3, and CD4 were obtained from a single sputum sample, and CD5 and CD10 were obtained 1 and 2 years later, respectively. On the basis of colonial morphology, serotyping, and antibiograms, the five isolates appeared to be different strains. However, Southern blot analysis with a 1.2-kilobase DNA probe containing the P. aeruginosa PAK pilin gene indicated that all five strains were identical at that genetic locus. The pilin genes of the five isolates were cloned and sequenced at the nucleotide level and found to be identical. Southern blot analysis with a probe from a separate region of the P. aeruginosa chromosome, a 741-base-pair PstI-NruI DNA fragment adjacent to the exotoxin A gene, also revealed genetic identity among these five clinical isolates. On this basis, it was concluded that this patient was colonized with a single strain of P. aeruginosa and that the strain had remained genetically stable over a period of 2 years. The predicted pilin sequence of the CD isolates was almost identical to that of strain PA103 (97% homology) and serologically related to PAO pilin, with which it shared 80% homology. No immunological cross-reactivity was detected between the CD and PAK pilins, which shared the least homology (62%) among the four pilins considered in this study. Although all five CD isolates contained identical pilin genes, three had acquired mutations which prevented normal expression of the pilus system. CD3 was a putative regulatory mutant which was unable to produce normal amounts of pilin, and CD4 and CD10 were putative assembly mutants which produced normal amounts of pilin but were unable to assemble the pilin subunit into intact pili.

Epidemiology of infections with Pseudomonas aeruginosa in burn patients: the role of hydrotherapy.

Pseudomonas aeruginosa remains a cause of serious wound infection and mortality in burn patients. By means of restriction fragment length polymorphism analysis and a DNA probe for the pilin gene of Pseudomonas, a lethal strain of nosocomial P. aeruginosa was identified as the cause of an outbreak of wound infections among burn patients. Environmental surveys suggested an association of the outbreak with hydrotherapy provided to many patients in a common facility. In a trial of burn wound care without hydrotherapy, overall mortality was reduced significantly, mortality associated with pseudomonas sepsis was eliminated, and the strain of P. aeruginosa associated with earlier mortality was eradicated. Moreover, fewer nosocomial pseudomonas infections, lower levels of pseudomonas resistance to aminoglycoside antibiotics, significantly fewer pseudomonas infections of skin graft donor sites, and later appearance of Pseodomonas species in burn patients were found during the period when hydrotherapy was not used.

Identification of tandem genes involved in lipooligosaccharide expression by Haemophilus ducreyi.

A transposon insertion mutant of Haemophilus ducreyi 35000 possessing a truncated lipooligosaccharide (LOS) failed to bind the LOS-specific monoclonal antibody 3E6 (M. K. Stevens, L. D. Cope, J. D. Radolf, and E. J. Hansen, Infect. Immun. 63:2976-2982, 1995). This transposon was found to have inserted into the first of two tandem genes and also caused a deletion of chromosomal DNA upstream of this gene. These two genes, designated lbgA and lbgB, encoded predicted proteins with molecular masses of 25,788 and 40,236 Da which showed homology with proteins which function in lipopolysaccharide biosynthetic in other gram-negative bacteria. The tandem arrangement of the lbgA and lbgB genes was found to be conserved among H. ducreyi strains. Isogenic LOS mutants, constructed by the insertion of a cat cartridge into either the lbgA or the lbgB gene, expressed an LOS phenotype indistinguishable from that of the original transposon-derived LOS mutant. The wild-type LOS phenotype could be restored by complementation with the appropriate wild-type allele. These two LOS mutants proved to be as virulent as the wild-type parent strain in an animal model. A double mutant with a deletion of the lbgA and lbgB genes yielded equivocal results when its virulence was tested in an animal model.

The role of polar pili in the adherence of Pseudomonas aeruginosa to injured canine tracheal cells: a semiquantitative morphologic study.

Pseudomonas aeruginosa adheres to respiratory epithelial cells in a highly specific fashion. In order to study the role of P. aeruginosa polar pili in the adherence process we conducted a quantitative morphological electron microscopic examination of P. aeruginosa adherence to SO2 injured canine tracheal cells in vitro. A pilin lacking background strain of P. aeruginosa PAK (BLP2) was constructed using a gene replacement and it in turn was engineered to express either the pilin gene of P. aeruginosa PAO, PAK, or no pilin gene. After 30 minutes incubation of these bacterial strains with injured canine tracheal rings the P. aeruginosa strains expressing pili adhered quantitatively more to the injured tracheal cells than did the pili lacking strains. PAO bearing strains adhered in greater numbers than PAK bearing strains. Healthy tracheal cells did not have any bacteria bound to their surfaces. The bacteria bound to the cilia and lateral edge of the exfoliating tracheal cells. Invasion of tracheal cells by piliated P. aeruginosa bacteria and penetration into the submucosa was also demonstrated. These data confirm the role of pili as important adhesins to injured tracheal cells. The difference in the adherence characteristics of pilin types PAK versus PAO may relate to the differences in the primary structure of these two pilin molecules.