Education and training for preventing sharps injuries and splash exposures in healthcare workers

BACKGROUND

In healthcare settings, health care workers (HCWs) are at risk of acquiring infectious diseases through sharps injuries and splash exposures to blood or bodily fluids. Education and training interventions are widely used to protect workers' health and safety and to prevent sharps injuries. In certain countries, they are part of obligatory professional development for HCWs.

OBJECTIVES

To assess the effects of education and training interventions compared to no intervention or alternative interventions for preventing sharps injuries and splash exposures in HCWs.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, NHSEED, Science Citation Index Expanded, CINAHL and OSH-update (from all time until February 2016). In addition, we searched the databases of Global Health, AustHealth and Web of Science (from all time until February 2016). The original search strategy was re-run in November 2019, and again in February 2020. In April 2020, the search strategy was updated and run in CINAHL, MEDLINE, Scopus and Web of Science (from 2016 to current).

SELECTION CRITERIA

We considered randomized controlled trials (RCTs), cluster-randomized trials (cluster-RCTs), controlled clinical trials (CCTs), interrupted time series (ITS) study designs, and controlled before-and-after studies (CBA), that evaluated the effect of education and training interventions on the incidence of sharps injuries and splash exposures compared to no-intervention.

DATA COLLECTION AND ANALYSIS

Two authors (SC, HL) independently selected studies, and extracted data for the included studies. Studies were analyzed, risk of bias assessed (HL, JL) , and pooled using random-effect meta-analysis, where applicable, according to their design types. As primary outcome we looked for sharps injuries and splash exposures and calculated them as incidence of injuries per 1000 health care workers per year. For the quality of evidence we applied GRADE for the main outcomes.

MAIN RESULTS

Seven studies met our inclusion criteria: one cluster-RCT, three CCTs, and three ITS studies. The baseline rates of sharps injuries varied from 43 to 203 injuries per 1000 HCWs per year in studies with hospital registry systems. In questionnaire-based studies, the rates of sharps injuries were higher, from 1800 to 7000 injuries per 1000 HCWs per year.  The majority of studies utilised a combination of education and training interventions, including interactive demonstrations, educational presentations, web-based information systems, and marketing tools which we found similar enough to be combined. In the only cluster-RCT (n=796) from a high-income country, the single session educational workshop decreased sharps injuries at 12 months follow-up, but this was not statistically significant either measured as registry-based reporting of injuries (RR 0.46, 95% CI 0.16 to 1.30, low-quality evidence) or as self-reported injuries (RR 0.41, 95% CI 0.14 to 1.21, very low-quality evidence) In three CCTs educational interventions decreased sharps injuries at two months follow-up (RR 0.68, 95% CI 0.48 to 0.95, 330 participants, very low-quality evidence). In the meta-analysis of two ITS studies with a similar injury rate, (N=2104), the injury rate decreased immediately post-intervention by 9.3 injuries per 1000 HCWs per year (95% CI -14.9 to -3.8). There was a small non-significant decrease in trend over time post-intervention of 2.3 injuries per 1000 HCWs per year (95% CI -12.4 to 7.8, low-quality evidence). One ITS study (n=255) had a seven-fold higher injury rate compared to the other two ITS studies and only three data points before and after the intervention. The study reported a change in injury rate of 77 injuries per 1000 HCWs (95% CI -117.2 to -37.1, very low-quality evidence) immediately after the intervention, and a decrease in trend post-intervention of 32.5 injuries per 1000 HCWs per year (95% CI -49.6 to -15.4, very low quality evidence). None of the studies allowed analyses of splash exposures separately from sharps injuries. None of the studies reported rates of blood-borne infections in patients or staff. There was very low-quality evidence of short-term positive changes in process outcomes such as knowledge in sharps injuries and behaviors related to injury prevention.  AUTHORS' CONCLUSIONS: We found low- to very low-quality evidence that education and training interventions may cause small decreases in the incidence of sharps injuries two to twelve months after the intervention. There was very low-quality evidence that educational interventions may improve knowledge and behaviors related to sharps injuries in the short term but we are uncertain of this effect. Future studies should focus on developing valid measures of sharps injuries for reliable monitoring. Developing educational interventions in high-risk settings is another priority.

Self-Inflicted Stab Wounds: A Single-Center Experience from 2010 to 2016

Despite low mortality rates, self-inflicted stab wounds (SISWs) can result in significant morbidity and often reflect underlying substance abuse and mental health disorders. This study aimed to characterize demographics, comorbidities, and outcomes seen in self-inflicted stabbings and compare these metrics to those seen in assault stabbings. A Level I trauma center registry was queried for patients with stab injuries between January 2010 and December 2015. Classification was based on whether injuries were SISWs or the result of assault stab wounds (ASWs). Demographic, injury, and outcome measures were recorded. Differences between genders, ethnicities, individuals with and without psychiatric comorbidities, and SISW and ASW patients were assessed. Within the SIWS cohort, no differences were found when comparing age, gender, or race, including need for operative intervention. However, patients with psychiatric histories were less likely to have a positive toxicology test on arrival than those without psychiatric histories (22% vs. 0%, P = 0.04). When compared with 460 ASW patients, SISW were older (41 vs. 35, P < 0.001), more likely to be white (92% vs. 64%, P < 0.001), more likely to have a psychiatric history (15% vs. 4%, P < 0.001), require operative intervention (65% vs. 50%, P = 0.008), and be discharged to a psychiatric facility (47% vs. 0.2%, P < 0.001). SISW patients have higher rates of psychiatric illness and an increased likelihood to require operative intervention as compared with ASW patients. This population demonstrates an acute need for both inpatient and outpatient psychiatric care with early involvement of multidisciplinary teams for treatment and discharge planning.

Edged weapons awareness

Edged weapons (sometimes referred to as sharp weapons or blades) are an increasing threat to military personnel, the blue light community (police, ambulance, firefighters, other first responders) and the general public worldwide. The use of edged weapons in criminal and terrorist incidents internationally means the forensic community needs an awareness of the technology of edged weapons, how they are used, the damage (clothing and wounding) that might be caused and any other forensic implications. In this paper, the magnitude of the problem is presented, prior research summarised and implications for forensic investigations discussed.

Development of a high-density nonwoven structure to improve the stab resistance of protective clothing material

The purpose of this research was to enhance the stab resistance of protective clothing material by developing a new high-density nonwoven structure. Ice picks often injure Japanese police officers due to the strict regulation of swords in the country. Consequently, this study was designed to improve stab resistance against ice picks. Most existing anti-stab protective clothing research has focused on various fabrics impregnated with resin, an approach that brings with it problems of high cost and complicated processing. Seldom has research addressed the potential for improving stab resistance by using nonwoven structures, which exhibit better stab resistance than fabric. In this research, we prepared a series of nonwoven structures with densities ranging from about 0.14 g/cm³ to 0.46 g/cm³ by varying the number of stacked layers of Kevlar/polyester nonwoven under a hot press. We then proposed two methods for producing such hot-press nonwovens: the multilayer hot-press method and the monolayer hot-press method. Stab resistance was evaluated according to NIJ Standard-0115.00. We also investigated the relationship among nonwoven density, stab resistance, and flexural rigidity, and here we discuss the respective properties of the two proposed methods. Our results show that stab resistance and flexural rigidity increase with nonwoven density, but flexural rigidity of nonwovens prepared using the monolayer hot-press method only shows a slight change as nonwoven density increases. Though the two methods exhibit little difference in maximum load, the flexural rigidity of nonwovens prepared using the monolayer hot-press method is much lower, which contributes to superior wear comfort. Finally, we investigated the mechanism behind the stabbing process. Stabbing with an ice pick is a complicated process that involves many factors. Our findings indicate that nonwovens stop penetration primarily in two ways: nonwoven deformation and fiber fractures.

A new method of ergonomic testing of gloves protecting against cuts and stabs during knife use

The paper presents a new method of ergonomic evaluation of gloves protecting against cuts and stabs during knife use, consisting of five manual dexterity tests. Two of them were selected based on the available literature and relevant safety standards, and three were developed by the authors. All of the tests were designed to simulate occupational tasks associated with meat processing as performed by the gloved hand in actual workplaces. The tests involved the three most common types of protective gloves (knitted gloves made of a coverspun yarn, metal mesh gloves, and metal mesh gloves with an ergonomic polyurethane tightener) and were conducted on a group of 20 males. The loading on the muscles of the upper limb (adductor pollicis, flexor carpi ulnaris, flexor carpi radialis, and biceps brachii) was measured using surface electromyography. For the obtained muscle activity values, correlations were found between the glove type and loading of the upper limb. ANOVA showed that the activity of all muscles differed significantly between the five tests. A relationship between glove types and electromyographic results was confirmed at a significance level of α = 0.05.

Ultrasound use for the placement of haemodialysis catheters

BACKGROUND

A significant proportion of patients starting dialysis do so with a temporary or tunnelled haemodialysis catheter. Insertion of these catheters can be achieved either by using the anatomical landmarks for the veins into which they are inserted or using ultrasound guidance. It has been suggested that the use of ultrasound guidance reduces the immediate complications of haemodialysis catheter insertions such as pneumothorax or arterial puncture.

OBJECTIVES

The aim of the review was to compare the use of real-time 2-dimensional (2-D) Doppler ultrasound venous imaging in the insertion of percutaneous central venous catheters for dialysis versus the traditional "blind" landmark method.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL). Reference lists of identified studies and relevant narrative reviews were also screened. Search date: January 2011.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs evaluating ultrasound guidance in the percutaneous insertion of central venous catheters for dialysis (both cuffed and uncuffed) against the traditional blind landmark method.

DATA COLLECTION AND ANALYSIS

Two authors assessed risk of bias and extracted data. Statistical analyses were performed using the random effects model and the results expressed as risk ratios (RR) for dichotomous outcomes or mean difference (MD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

We identified seven studies enrolling 767 patients and with 830 catheter insertions. Three of seven studies described the method of random sequence generation, none described allocation concealment, and blinding of participants and personnel was not possible. Real-time ultrasound guidance was found to significantly reduce the risk of catheter placement failure on the first attempt (5 studies, 595 catheters): RR 0.40, 95% CI 0.30 to 0.52), significantly reduce the risk of arterial puncture (6 studies, 535 catheters: RR 0.13, 95% CI 0.04 to 0.37) and haematomas (4 studies, 323 catheters: RR 0.22, 95% CI 0.06 to 0.81) when compared to the landmark method. The time taken for successful cannulation was significantly lower with the use of real-time ultrasound guidance (1 study, 73 catheters: MD -1.40 min, 95% CI -2.17 to -0.63) and there were less attempts/catheter insertion (1 study, 110 catheters: -0.35, 95% CI -0.54 to -0.16).

AUTHORS' CONCLUSIONS

Use of real-time 2-D Doppler ultrasound guidance has significant benefits with respect to the number if catheters successfully inserted on the first attempt, reduction in the risk of arterial puncture and haematomas and the time taken for successful vein puncture.

Cutting edge scheme

In a bid to reduce knife crime in Merseyside, nurse Rob Jackson does not pull his punches when talking to young offenders and schoolchildren.

[Search for optimal combinations of the hygienic and protective characteristics of body armors]

The protective composition of a body armor is generally characterized by two major parameters--the area and level of protection, i.e. resistance to bullets and fragments. These characteristics directly depend on the mass of a body armor and the sizes of the body's screening. The positive protective characteristics simultaneously have a negative impact on the most important hygienic indices of a body armor, such as convenience and easiness-to-use. The optimum combination of protective and performance characteristics of body armors makes a compromise between their mass and the level of protection.

Comparative analysis of 2 techniques of double-gloving protection during arch bar placement for intermaxillary fixation

PURPOSE

This study was conducted to comparatively evaluate, in a prospective and randomized manner, 2 techniques for providing double-gloving protection during arch bar placement for intermaxillary fixation.

MATERIALS AND METHODS

A total of 42 consecutive patients in whom application of an Erich bar was indicated for intermaxillary fixation were equally divided into 2 groups. In group 1, 2 sterile surgical gloves were used; in group 2, a nonsterile disposable inner glove was used under a sterile surgical glove. Wilcoxon, Mann-Whitney, Kruskal-Wallis, and binomial statistical tests were used to analyze the findings.

RESULTS

A total of 103 perforations were found in the outer gloves (47 in group 1 and 56 in group 2), along with 5 perforations in inner gloves in both groups (alpha = .01). No significant statistical difference was found between groups in terms of inner glove perforations (alpha = .05). The nondominant hand presented with 70.9% of the perforations, statistically significant to 1%.

CONCLUSIONS

Both double-gloving techniques were found to provide effective clinician protection. The use of a nonsterile disposable glove under the surgical glove is possible for less-invasive procedures, offering the same safety as using 2 sterile surgical gloves while decreasing operational costs. This method does not eliminate the need to change gloves when a perforation is suspected or noted during the surgery, however.

Sharps safety. Five steps for maintaining an effective program

Although most hospitals have had sharps safety programs in place for years, these programs may be out of date or may fail to address new procedures. Facilities should therefore regularly take stock of their current practices and evaluate new devices on the market. In this article, we describe a five-step process for developing, assessing, or revising a sharps safety program. Such programs are typically broad based, addressing several types of risks and the activities of multiple departments. Facilities may have well-established procedures for dealing with one of these aspects, while having few if any measures in place to address another. Consequently, the steps in the program described in this article may need to be applied in different ways to different areas within a single hospital. Yet even well-established programs require ongoing review, so these five steps are recommended regardless of how complete or effective a facility's current efforts may seem.

Sharps safety devices

Injuries from needles or other sharps are a danger to patients and clinicians alike, particularly due to the risk of bloodborne pathogen transmission. One way to reduce the likelihood of such injuries is to implement protective devices as substitutes for more dangerous conventional products. Over the years, Health Devices has evaluated several sharps safety devices. In this issue, we evaluate four new types of protective alternatives: disposable prep razors, epidural needles, ophthalmic knives, and stitch cutters. Our Evaluation discusses whether these sharps safety devices deliver the added safety that they are designed to provide and whether they are effective at performing their intended clinical purposes.

Sharpless Surgery: A Prospective Study of the Feasibility of Performing Operations using Non-sharp Techniques in an Urban, University-based Surgical Practice

CONTEXT

Percutaneous injuries occur frequently during surgical procedures and represent a significant occupational hazard to operating room personnel.

OBJECTIVES

To evaluate the feasibility of performing select general surgical procedures using a combination of non-sharp devices and techniques to replace the conventional use of scalpels and needles.

DESIGN, SETTING, AND PARTICIPANTS

Candidate procedures for which sharpless techniques could replace conventional scalpels and suture needles were identified preoperatively in an urban, university-based general surgical practice over a 1-year period (June 2003-June 2004). Non-sharp techniques included monomeric 2-octyl cyanoacrylate adhesive, electrocautery, tissue stapler, and minimally invasive instrumentation. Conventional scalpels and suture needles were readily available and used whenever necessary.

MAIN OUTCOME MEASURES

We rated the feasibility of performing specific procedures without sharps. We also documented the rate of overall reversion to sharps during operations on patients that had been identified preoperatively as candidates for sharpless surgery.

RESULTS

Of 358 procedures performed in the general surgery university practice, 91 were identified preoperatively as appropriate for sharpless surgery. Of these, 86.8% (79/91) were completed without the use of sharps, including 13/22 (59.1%) open laparotomy procedures, 20/22 (90.9%) laparoscopic procedures, and 46/47 (97.8%) soft tissue procedures. Intraoperative reversion to sharps occurred in 12 cases when deemed necessary by the surgeon.

CONCLUSIONS

Select common procedures can be performed entirely with sharpless techniques, eliminating the risk to surgical personnel associated with intraoperative percutaneous injuries.

Prevention of pressure-induced skin ischemia and impending skin penetration in a displaced clavicle fracture

This article presents a quick and effective method using adhesive tapes to prevent ischemia or penetration of the skin in clavicle fractures.

The effect of knife handle shape on stabbing performance

A quantitative knowledge of stabbing ability is a pre-requisite to establishing protection standards for stab resistant body armour. In order to determine the validity of measurements it is necessary to understand all the mechanisms that determine performance. This paper describes a series of tests that were performed in order to determine the effect of handle size and shape on the forces and impact energy that could be produced during stabbing of an armoured target. It was found that the single largest variable was that of the test participants with all other variables such as handle size and shape having only slight effects on the magnitude of impact energy. The use of a finger guard or hilt was shown to increase the mean energy delivered to the target by approximately 5J compared to a handle having no guard. It was also found that the characteristics of energy delivery were strongly influenced by the position of the grip relative to this guard. This reinforces the conclusions of previous work (Horsfall et al., 1999; Chadwick et al., 1999) on the serial nature of momentum transfer during a stabbing impact.

The safety of pumpkin carving tools

BACKGROUND

Even with optimal treatment, injuries from pumpkin carving accidents may leave people with compromised hand function. Pumpkin carving tools may reduce the incidence and/or magnitude of these injuries. However, evidence that they are safer is required before these knives can be recommended.

METHODS

Two pumpkin carving knives were compared to a serrated and a plain kitchen knife. The forces required to cut and pierce a pumpkin were determined and then applied by a servo-hydraulic machine to each knife placed against cadaver hands in a manner designed to either lacerate Zone 2 of the finger (six tests for each knife) or to puncture the hand. Inspection and dissection determined the extent of injury.

RESULTS

The pumpkin knives produced some injuries, however, they were fewer and less severe than those caused by the kitchen knives.

CONCLUSIONS

Tools designed specifically for pumpkin carving may indeed be safer. Use of these products, and increased overall awareness of the risks of pumpkin carving in general, which clinicians could help promote, might reduce the frequency and severity of pumpkin carving injuries.

Preventability of percutaneous injuries in healthcare workers: a year-long survey in Italy

The aim of the study was to examine the preventability of percutaneous injuries either through the adoption of correct behaviour or by the use of needles with safety features. We analysed the report forms of occupational needlestick or sharps injuries in a sample of healthcare workers exposed to the risk of percutaneous injuries in the period between 1 June 2000 and 31 May 2001; the forms were returned to the regional SIROH (Italian Study on Occupational Exposure to HIV) centre in which all hospitals of the Piemonte region (Italy) participate. Percutaneous injuries caused by needles (injection, phlebotomy, infusion), suture needles and scalpels were analysed; three samples were extracted according to the type of device that caused the injury. In the sample of 439 needlestick-related percutaneous injuries, 74% were caused by incorrect health worker behaviour and 26% were unpreventable, seventy-nine percent of accidents caused by incorrect behaviour and 24% of accidents could have been prevented by using needles with safety features. In the sample of 221 suture needle and 114 scalpel injuries, incorrect health worker behaviour was identified in 26.2% and 14%, respectively, and unpreventable causes in 73.8% and 50.9%, respectively. A high rate of percutaneous injuries, especially those involving needles for injection, phlebotomy, infusion, and scalpels, could be prevented by adopting safe work behaviour practices and using personal protection equipment. The introduction of devices with safety features could lead to a significant reduction in the number of injuries from needles.

Sharps injury recordkeeping activities and safety product use in California health care facilities: pilot study results from the sharps injury control program

BACKGROUND

In 1999, licensed health care facilities in California (N = 2532) were invited to participate in a survey about occupational bloodborne pathogens exposure surveillance activities, recordkeeping methods, and use of safety-enhanced sharps devices.

RESULTS

A total of 1274 facilities responded to the survey from January 1999 through August 1999 (response rate = 50%). Sharps-related injuries were recorded for multiple departments on various forms in diverse manners. Only 66% of hospitals, 37% of home health agencies, and 33% of skilled nursing facilities reported sharps injuries on a mandated sharps injury log. More than 70% of facilities stated that they used some type of safety device or needleless system, but this figure varied by type of device and facility type. Eighty-four percent of general acute care hospitals, 28% of home health agencies and skilled nursing facilities each had evaluated at least 1 safety-enhanced device. Almost 90% of all facilities expressed a need for educational materials on topics such as device selection and evaluation.

CONCLUSIONS

Standardization of surveillance and recordkeeping activities does not exist across facility types. Standards and regulations demand complex recordkeeping activities. Increased funding for distribution of educational materials and on-site training should accompany changes in mandated reporting activities when appropriate. Increased testing and evaluation of devices across facility types are necessary to ensure that safety-enhanced devices are protective of health care workers and patients.

How should the chest wall be opened at necropsy?

AIMS

To compare several different instruments used to open the chest wall during necropsy and to assess whether any one type reduced the production of sharp rib ends and thus the potential for receiving an injury.

METHODS

During the necropsy the pathologist opened the chest wall using two randomly assigned instruments from a selection of hand saw, electric saw, rib shears, and bread knife. The age, weight, sex, and height of the deceased were recorded, in addition to the textures of the resultant exposed rib ends. During the procedure, the speed, length, production of spray, and site of incision were also noted. The thoracic cavity was inspected and any details of tumours, adhesions, fluid, or organ damage were noted.

RESULTS

Twenty four necropsies were carried out on an equal number of men and women. The total number of ribs that were incised was 422, with 206 through the bony aspect (49%). Sixty seven per cent of the bony rib ends were rough, and this was found to be instrument dependent. The rib shears produced the highest number of rough bony and cartilage rib ends. The electric saw produced the smoothest contoured rib ends. Spray occurred in 29% of cases, exclusively with the use of the electric saw. Organ damage was most frequently associated with the use of the bread knife.

CONCLUSION

Rib shears, the instrument most frequently used to open the chest wall, appear to cause the highest frequency of rough, potentially dangerous rib ends. The electric saw produced the smoothest rib ends, both in cartilage and bone, and thus seems to offer the most efficacious method of reducing the potential hazard associated with ragged, spiky bone ends during the opening of the thoracic cavity. Although each of the procedures detailed in this study was shown to have its own advantages and disadvantages, personal preference and operator experience are perhaps the most important factors in ultimately determining the method used.

Ultrasound assessment of the vulnerability of the internal organs to stabbing: determining safety standards for stab-resistant body armour

Stab-resistant body armour may not always prevent the passage of a blade into the human body. The depth to which a knife may 'safely' enter the human body before it breaches the internal organs was explored by ultrasound scanning of 25 healthy volunteers. Variations in the minimum skin-to-organ distances for the organs as a function of posture are described. To determine the optimum body coverage by stab-resistant armour, the movement during the breathing cycle and the maximum exposure of the organs beneath the lower costal margin at full inspiration were measured. Although the population studied was small, trends in the vulnerability of the internal organs to the passage of a blade into the body were identified.

A telemetry-based device to determine the force-displacement behaviour of materials in high impact loading situations

Meaningful testing of stab resistant body armour requires the use of realistic body tissue simulants. A device for the determination of the force-displacement behaviour of materials in high impact loading situations has been developed for the testing of such simulants. Force measurement is achieved with the use of electrical foil strain gauges applied to a cylindrical load cell. A piezo-resistive accelerometer (+/- 500 g) is used to calculate the displacement of the device through double integration of its signal, with the impact velocity used as a boundary condition. The signals from the strain gauge circuit and the accelerometer are sampled at 2500 Hz. The data are transmitted to a receiver via telemetry using a 418 MHz FM transmitter and from the receiver to a laptop PC via the serial port. Calibration of the device is described and sample results showing forces up to 2500 N and displacements up to 0.04 m are presented.

Biomechanics of knife stab attacks

Equipment, materials and methods for the measurement of the biomechanical parameters governing knife stab attacks have been developed and data have been presented that are relevant to the improvement of standards for the testing of stab-resistant materials. A six-camera Vicon motion analysis system was used to measure velocity, and derive energy and momentum during the approach phase of the attack and a specially developed force-measuring knife was used to measure three-dimensional forces and torque during the impact phase. The body segments associated with the knife were modelled as a series of rigid segments: trunk, upper arm, forearm and hand. The velocities of these segments, together with knowledge of the mass distribution from biomechanical tables, allowed the calculation of the individual segment energy and momentum values. The instrumented knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges. Twenty volunteers were asked to stab a target with near maximal effort. Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. These styles were chosen based on reported incidents, providing more realistic data than had previously existed. The 95th percentile values for axial force and energy were 1885 N and 69 J, respectively. The ability of current test methods to reproduce the mechanical parameters measured in human stab attacks has been assessed. It was found that current test methods could reproduce the range of energy and force values measured in the human stab attacks, although the simulation was not accurate in some respects. Non-axial force and torque values were also found to be significant in the human tests, but these are not reproduced in the standard mechanical tests.

An assessment of human performance in stabbing

Stab-resistant body armour is now becoming a standard item of equipment for police officers in the United Kingdom. In the UK these are usually required to have a stab resistance as specified by the Police Scientific Development Branch KR42 standard [G. Parker, PSDB Stab Resistant Body Armour Test Procedure, Police Scientific Development Branch, Publication No 10/93, 1993]. There are several other test standards, all of which specify that body armour must resist penetration by a specific blade type delivered at a specific energy level or range of levels. However, the actual range of energy levels specified varies over almost an order of magnitude and the basis for these levels is not clearly defined. This paper describes tests to determine the energy range and characteristics of stabbing actions that might be directed against stab resistant body armour by an assailant. The energy and velocity that can be achieved in stabbing actions has been determined for a number of sample populations. Volunteers were asked to stab a target using an instrumented knife that measured the axial force and acceleration during the stabbing. The maximum energy obtained in underarm stabbing actions was 64 J whilst overarm stabbing actions could produce 115 J. The loads produced on contact with the target often approached 1000 N.

A comparison of fatal with non-fatal knife injuries in Edinburgh

Assault using a knife is a common problem in the United Kingdom. Between February 1992 and December 1996, 120 individuals died or received hospital treatment in Edinburgh after being assaulted with a knife. Twenty individuals (17%) died as a result of their injuries. Comparison of the survivors with non-survivors revealed both groups to have similar age and sex distributions, but those who died had significantly more severe injuries when scored according to the Abbreviated Injury Scale. Eight individuals died of unsurvivable chest injuries at the scene of the attack and of the remainder, only five reached hospital with signs of life. Analysis of hospital treatment using TRISS methodology revealed there to be two unexpected survivors and no unexpected deaths. The risk of death appears to depend mostly upon injuries sustained and also to a lesser extent upon other factors such as alcohol consumption and the presence of a bystander capable and willing to request emergency medical assistance. There does not appear to be much potential to save lives by improving hospital treatment for those assaulted with a knife in Edinburgh. Instead, greater focus needs to be placed upon rapid transfer to hospital and upon restricting the possession and use of knives.

Safety standards for stab-resistant body armour: a computer tomographic assessment of organ to skin distances

The protective properties of knife-resistant armour are quantified by the distance a test blade penetrates beyond a test sample into clay at a given energy. At present there are two proposed standards: penetration to 5 mm and penetration to 20 mm. Armour made to the higher standard specification (5mm) is necessarily heavier as it offers more protection. To determine the safety of these standards a retrospective review of 71 consecutive computerised tomographic (CT) scans was made. The minimum distance from the skin to the vital organs was measured. No organ would have been breached at 5 mm of knife penetration deep to body armour. 41% of pleurae, 61% of livers, 64% of femoral arteries, 25% of spleens and 6% of hearts would have been breached at a depth of 20 m of knife penetration. There was no significant difference in the minimum skin to organ distances between male and female subjects. The 20 mm standard does not offer adequate protection against knife attacks.

[Percutaneous blood exposure among Danish physicians. Mechanisms and prevention]

The study describes the mechanisms of percutaneous blood exposure (PCE) among Danish doctors and discusses rational strategies for prevention. Data were obtained as part of a nation-wide survey of occupational blood exposure. The most recent percutaneous or mucocutaneous exposure within the previous three months was described. Of 9375 doctors, 6005 (64%) participated. A total of 971 PCE were described. Inattentiveness contributed to 30.5%. Use of fingers rather than instruments was a contributing cause of 36.9% of 483 PCE on suture needles. Common concomitant causes in such cases (n = 199) were poor space in (30.2%) or view of (18.6%) the operation field. Of 689 PCE in surgical specialties, 17.4% were inflicted by colleagues. Up to 53.3% of PCE on hollow-bore needles could be attributed to unsafe routines only. In conclusion, education in safer working routines are needed in all specialties. Introduction of safer devices should have a high priority in surgical specialties, and should be considered in non-surgical specialties too.

[Poor compliance with universal precautions among Danish physicians]

In a nation-wide survey among Danish doctors, the compliance and reasons for non-compliance with universal precautions (UP) and the associated circumstances of mucocutaneous blood exposure (MCE) were studied. Of 9384 questionnaires, 6256 (67%) were returned and 6005 were eligible for analysis. Only 35% complied with the basic principles of UP. Compliance with protective barrier use in surgical versus non-surgical specialties was: Gloves 63.0% and 23.4%, masks 55.2% and 17.6% and protective eyewear 11.5% and 4.0% respectively. Common given reasons for non-compliance were: "Interferes with working skills", "forget", "wear spectacles", "not available", "too much trouble to get" or "gloves do not fit". Of 741 MCE described in detail, an estimated 84-98% were potentially preventable if appropriate barriers had been worn. More than half of MCE were preventable by two interventions only: Compulsory use of protective eyewear during operations and of gloves during insertion of peripheral i.v.-catheters. In conclusion compliance with UP is unacceptably low and the majority of MCE were potentially preventable if appropriate barriers had been worn.

Device-specific sharps injury and usage rates: an analysis by hospital department

BACKGROUND

Whether universal precautions training has reduced percutaneous sharps injuries is questioned. Prevention programs directed to specific problem areas are required to further reduce injury. Our purpose was to identify target areas.

METHODS

Device-specific sharps injury rates per 100,000 devices purchased were determined by department at Yale New Haven Hospital (1993 to 1994). Usage per full-time equivalent was calculated by department. Rates were modelled using Poisson regression.

RESULTS

Three epidemiologic patterns resulted: (1) injury rates were independent of usage (butterfly needles); (2) injury rates varied directly with usage (lancets); (3) injury rates varied inversely with usage (intravenous catheters, sutures, and scalpels). Device-specific usage and injury rates varied by department. Devices used little (9/full-time equivalent) but under difficult circumstances, such as intravenous catheters in pediatric patients, were associated with high injury rates (67.7/100,000). Devices, sometimes disassembled, such as blood collecting tubes, caused significantly more injury in departments where health care professionals work under time constraints, such as in the emergency department and nursing. Unconventional use of devices (Luer-Lok syringes and scalpels) resulted in higher rates of injury (nursing and laboratories). Building services appeared to be at risk for injury.

CONCLUSIONS

With device-specific injury and usage rates by department, injury prevention programs can now focus on specific devices and departments.

Nurses' infection-control practice: hand decontamination, the use of gloves and sharp instruments

Infection is an acknowledged hospital problem. Micro-organisms are disseminated mainly via hands but there is evidence that hand decontamination, the most important means of prevention, is performed too seldom, and not always after activities likely to result in heavy contamination. Nurses themselves are exposed to risks of infection, chiefly through contact with blood and body fluids, yet it has also been reported that gloves are not always worn during contact with patients' secretions and that the handling and disposal of sharp instruments may be performed unsafely. The study reported in this paper documents nursing behaviour in relation to hand decontamination, the use of gloves and sharps, taking into consideration a number of variables which could influence practice: availability of the expertise afforded by an infection-control nurse, clinical setting, nursing workload, knowledge and the resources available to control infection. Hands were decontaminated after 28.78% of patient contacts. Hands were decontaminated after 49.85% of activities likely to result in heavy contamination. Performance was related to nursing workload and the availability of hand decontaminating agents, especially when the nurses became busy. Use of gloves when they were available also proved good, with little evidence of wasteful use. The handling and disposal of sharps were commendable for most subjects but a few grossly unsafe incidents were nevertheless witnessed, apparently not associated with any of the variables examined.

The effectiveness of cut-proof glove liners: cut and puncture resistance, dexterity, and sensibility

Five types of commercial glove liners (within double latex gloves) were compared to single and double latex gloves for cut and puncture resistance and for relative manual dexterity and degree of sensibility. An apparatus was constructed to test glove-pseudofinger constructs in either a cutting or puncture mode. Cutting forces, cutting speed, and type of blade (serrated or scalpel blade) were varied and the time to cut-through measured by an electrical conductivity circuit. Penetration forces were similarly determined with a scalpel blade and a suture needle using a spring scale loading apparatus. Dexterity was measured with an object placement task among a group of orthopedic surgeons. Sensibility was assessed with Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry using standard techniques and rating scales. A subjective evaluation was performed at the end of testing. Time to cut-through for the liners ranged from 2 to 30 seconds for a rapid oscillating scalpel and 4 to 40 seconds for a rapid oscillating serrated knife under minimal loads. When a 1 kg load was added, times to cut-through ranged from 0.4 to 1.0 second. In most cases, the liners were superior to double latex. On average, 100% more force was required to penetrate the liners with a scalpel and 50% more force was required to penetrate the liners with a suture needle compared to double latex. Object placement task times were not significantly liners compared to double latex gloves. Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry showed no difference in sensibility among the various liners and double latex gloves. Subjects felt that the liners were minimally to moderately impairing. An acclimation period may be required for their effective use.