Impact of sink design on bacterial transmission from hospital sink drains to the surrounding sink environment tested using a fluorescent marker.

In hospitals, sinks act as reservoirs for bacterial pathogens. To assess the extent of splashing, fluorescein dye was added to four hospital sinks previously involved in pathogen dispersal to the environment and/or transmission to patients, and one sink that was not. Applying dye to the p-trap or tailpiece did not result in any fluorescent droplets outside of the drain. When applied to the drain, droplets were found in all but one wash basin, and this was more common in the absence of a drain plug. Sink design considerations to install drain plugs, reduce dripping and offset the tap may help to prevent transmission from drains.

Operative notes do not reflect reality in laparoscopic cholecystectomy.

BACKGROUND: Operative notes represent an essential element in safe patient care and should therefore be clear and accurate. This comparative study examined whether operative notes accurately represented the laparoscopic cholecystectomy (LC) as performed. METHODS: Nine Dutch teaching and non-teaching hospitals were invited to record 20 successive LCs each and to collect the corresponding operative notes. The main outcome measures were overall differences and correspondence between video recordings and notes based on the Dutch guideline for LC and the occurrence of iatrogenic gallbladder perforation. A comparison was made of the cumulative results of recordings and operative notes, and individual recordings were compared with the corresponding notes. RESULTS: Seven hospitals participated in the study; 125 video recordings and operative notes were fully analysed. Recordings showed more steps of the procedure than did notes. Individual comparisons showed significant differences (P≤0·001) between the recording and the corresponding note for the steps 'Introducing trocars under vision', 'Condition of the gallbladder', 'Critical view of safety' and 'Removing first and second trocar under vision'. Iatrogenic gallbladder perforation with spilled bile occurred in 31 patients (24·8 per cent), and was both recorded and reported in 29 patients. Iatrogenic gallbladder perforation with spilled bile and spilled stones occurred in 15 patients (12·0 per cent), and was recorded and reported in 11 patients. CONCLUSION: Operative notes do not adequately represent the actual LCs performed as they describe fewer important procedural steps. It is suggested that operative notes should include video recordings.

Discrepant perceptions of communication, teamwork and situation awareness among surgical team members.

OBJECTIVE: To assess surgical team members' differences in perception of non-technical skills. DESIGN: Questionnaire design. SETTING: Operating theatres (OTs) at one university hospital, three teaching hospitals and one general hospital in the Netherlands. PARTICIPANTS: Sixty-six surgeons, 97 OT nurses, 18 anaesthetists and 40 nurse anaesthetists. METHODS: All surgical team members, of five hospitals, were asked to complete a questionnaire and state their opinion on the current state of communication, teamwork and situation awareness at the OT. RESULTS: Ratings for 'communication' were significantly different, particularly between surgeons and all other team members (P ≤ 0.001). The ratings for 'teamwork' differed significantly between all team members (P ≤ 0.005). Within 'situation awareness' significant differences were mainly observed for 'gathering information' between surgeons and other team members (P < 0.001). Finally, 72-90% of anaesthetists, OT nurses and nurse anaesthetists rated routine team briefings and debriefings as inadequate. CONCLUSIONS: This study shows discrepancies on many aspects in perception between surgeons and other surgical team members concerning communication, teamwork and situation awareness. Future research needs to ascertain whether these discrepancies are linked to greater risk of adverse events or to process as well as systems failures. Establishing this link would support implementation and use of complex team interventions that intervene at multiple levels of the healthcare system.

Vacuum grasping as a manipulation technique for minimally invasive surgery.

BACKGROUND: Laparoscopic surgery requires specially designed instruments. Bowel tissue damage is considered one of the most serious forms of lesion, specifically perforation of the bowel. METHODS: An experimental setting was used to manipulate healthy pig bowel tissue via two vacuum instruments. During the experiments, two simple manipulations were performed for both prototypes by two experienced surgeons. Each manipulation was repeated 20 times for each prototype at a vacuum level of 60 kPa and 20 times for each prototype at a vacuum level of 20 kPa. All the manipulations were macroscopically assessed by two experienced surgeons in terms of damage to the bowel. RESULTS: In 160 observations, 63 ecchymoses were observed. All 63 ecchymoses were classified as not relevant and negligible. No serosa or seromuscular damages and no perforations were observed. CONCLUSION: Vacuum instruments such as the tested prototypes have the potential to be used as grasper instruments in minimally invasive surgery.

Real-time selected ion flow tube mass spectrometry to assess short- and long-term variability in oral and nasal breath.

Breath-based non-invasive diagnostics have the potential to provide valuable information about a person's health status. However, they are not yet widely used in clinical practice due to multiple factors causing variability and the lack of standardized procedures. This study focuses on the comparison of oral and nasal breathing, and on the variability of volatile metabolites over the short and long term. Selected ion flow tube mass spectrometry (SIFT-MS) was used for online analysis of selected volatile metabolites in oral and nasal breath of 10 healthy individuals five times in one day (short-term) and six times spread over three weeks (long-term), resulting in nearly 100 breath samplings. Intra-class correlation coefficients (ICCs) were used to assess short- and long-term biological variability. Additionally, the composition of ambient air was analyzed at different samplings. The selected volatiles common in exhaled breath were propanol, 2,3-butanedione, acetaldehyde, acetone, ammonia, dimethyl sulfide, isoprene, pentane, and propanal. Additionally, environmental compounds benzene and styrene were analyzed as well. Volatile metabolite concentrations in ambient air were not correlated with those in exhaled breath and were significantly lower than in breath samples. All volatiles showed significant correlation between oral and nasal breath. Five were significantly higher in oral breath compared to nasal breath, while for acetone, propanal, dimethyl sulfide, and ammonia, concentrations were similar in both matrices. Variability depended on the volatile metabolite. Most physiologically relevant volatiles (acetone, isoprene, propanol, acetaldehyde) showed good to very good biological reproducibility (ICC > 0.61) mainly in oral breath and over a short-term period of one day. Both breathing routes showed relatively similar patterns; however, bigger differences were expected. Therefore, since sampling from the mouth is practically more easy, the latter might be preferred.

Tactile feedback exceeds visual feedback to display tissue slippage in a laparoscopic grasper.

Virtual reality can help to learn basic laparoscopic tasks. However, no haptic feedback, which alerts for tissue slippage, is provided by most simulators, although, it might be of influence for the decrease of errors. This study explored whether visual or tactile feedback can be used to alert the surgeon of tissue slippage. Twenty-four participants performed a laparoscopic grasping task and where provided with either visual or tactile feedback about tissue slippage. The reaction time with the visual feedback was compared to the reaction time with tactile feedback signal. The results showed that when tissue slippage is simulated, tactile feedback shows significant faster reaction times (269ms) than visual feedback signals (398ms).

Biomechanical model study of pelvic belt influence on muscle and ligament forces.

Many patients with low back and/or pelvic girdle pain feel relief after application of a pelvic belt. External compression might unload painful ligaments and joints, but the exact mechanical effect on pelvic structures, especially in (active) upright position, is still unknown. In the present study, a static three-dimensional (3-D) pelvic model was used to simulate compression at the level of anterior superior iliac spine and the greater trochanter. The model optimised forces in 100 muscles, 8 ligaments and 8 joints in upright trunk, pelvis and upper legs using a criterion of minimising maximum muscle stress. Initially, abdominal muscles, sacrotuberal ligaments and vertical sacroiliac joints (SIJ) shear forces mainly balanced a trunk weight of 500N in upright position. Application of 50N medial compression force at the anterior superior iliac spine (equivalent to 25N belt tension force) deactivated some dorsal hip muscles and reduced the maximum muscle stress by 37%. Increasing the compression up to 100N reduced the vertical SIJ shear force by 10% and increased SIJ compression force with 52%. Shifting the medial compression force of 100N in steps of 10N to the greater trochanter did not change the muscle activation pattern but further increased SIJ compression force by 40% compared to coxal compression. Moreover, the passive ligament forces were distributed over the sacrotuberal, the sacrospinal and the posterior ligaments. The findings support the cause-related designing of new pelvic belts to unload painful pelvic ligaments or muscles in upright posture.

Non-invasive measurement of intra-abdominal pressure: a preliminary study.

The importance of measuring intra-abdominal pressure (IAP) has increased since the negative effects of sustained increased IAP, also known as intra-abdominal hypertension (IAH), have become known. The relation between IAP and abdominal wall tension has been included in several reports. We have developed a device to measure abdominal wall tension by measuring force and distance. This device enables us to investigate the correlation between the abdominal wall tension and IAP. The abdomens of two corpses (one female, one male) were insufflated with air. IAP was increased and measured at intervals by means of a laparoscopic set-up. Abdominal tension was measured at seven points on the abdominal wall at each interval. Pearson's correlation coefficients were used to determine the relationship between IAP and tension for each point measured. ANOVA was used to assess relations between measured tensions versus applied pressure, locations and subjects. In both corpses, all points showed significant (p < 0.001) correlations between IAP and abdominal wall tension. The points along the mid transverse plane appear to be more similar compared to more cranial and caudal points. We have assessed the feasibility of a device that non-invasively can track changes in IAP. Measurements performed with the device are preliminary results, and further investigation is needed.

Haptics in minimally invasive surgery--a review.

This article gives an overview of research performed in the field of haptic information feedback during minimally invasive surgery (MIS). Literature has been consulted from 1985 to present. The studies show that currently, haptic information feedback is rare, but promising, in MIS. Surgeons benefit from additional feedback about force information. When it comes to grasping forces and perceiving slip, little is known about the advantages additional haptic information can give to prevent tissue trauma during manipulation. Improvement of haptic perception through augmented haptic information feedback in MIS might be promising.

Acquiring basic endoscopy skills by training on the GI Mentor II.

BACKGROUND: Achieving proficiency in flexible endoscopy requires a great amount of practice. Virtual reality (VR) simulators could provide an effective alternative for clinical training. This study aimed to gain insight into the proficiency curve for basic endoscope navigation skills with training on the GI Mentor II. METHODS: For this study, 30 novice endoscopists performed four preset training sessions. In each session, they performed one EndoBubble task and managed multiple VR colonoscopy cases (two in first session and three in subsequent sessions). Virtual reality colonoscopy I-3 was repeatedly performed as the last VR colonoscopy in each session. The assignment for the VR colonoscopies was to visualize the cecum as quickly as possible without causing patient discomfort. Five expert endoscopists also performed the training sessions. Additionally, the performance of the novices was compared with the performance of 20 experienced and 40 expert endoscopists. RESULTS: The novices progressed significantly, particularly in the time required to accomplish the tasks (p < 0.05, Friedman's analysis of variance [ANOVA], p < 0.05, Wilcoxon signed ranks). The experts did not improve significantly, except in the percentage of time the patient was in excessive pain. For all the runs, the performance of the novices differed significantly from that of both the experienced and the expert endoscopists (p < 0.05, Mann-Whitney U). The performance of the novices in the latter runs differed less from those of both the experienced and the expert endoscopists. CONCLUSIONS: The study findings demonstrate that training in both VR colonoscopy and EndoBubble tasks on the GI Mentor II improves the basic endoscope navigation skills of novice endoscopists significantly.

The 'AbdoMAN': an artificial abdominal wall simulator for biomechanical studies on laparotomy closure techniques.

PURPOSE: Incisional hernia remains a frequent complication after abdominal surgery associated with significant morbidity and high costs. Animal and clinical studies have exhibited some limitations. The purpose of this study was to develop an artificial human abdominal wall (AW) simulator in order to enable investigations on closure modalities. We hypothesized that a physical model of the human AW would give new insight into commonly used suture techniques representing a substantial complement or alternative to clinical and animal studies. METHODS: The 'AbdoMAN' was developed to simulate human AW biomechanics. The 'AbdoMAN' capacities include measurement and regulation of intra-abdominal pressure (IAP), generation of IAP peaks as a result of muscle contraction and measurements of AW strain patterns analyzed with 3D image stereo correlation software. Intact synthetic samples were used to test repeatability. A laparotomy closure was then performed on five samples to analyze strain patterns. RESULTS: The 'AbdoMAN' was capable of simulating physiological conditions. AbdoMAN lateral muscles contract at 660 N, leading the IAP to increase up to 74.9 mmHg (range 65.3-88.3). Two strain criteria were used to assess test repeatability. A test with laparotomy closure demonstrated closure testing repeatability. CONCLUSIONS: The 'AbdoMAN' reveals as a promising enabling tool for investigating AW surgery-related biomechanics and could become an alternative to animal and clinical studies. 3D image correlation analysis should bring new insights on laparotomy closure research. The next step will consist in evaluating different closure modalities on synthetic, porcine and human AW.

Application of ergonomic guidelines during minimally invasive surgery: a questionnaire survey of 284 surgeons.

BACKGROUND: This study aimed to obtain an answer for the question: Are ergonomic guidelines applied in the operating room and what are the consequences? METHODS: A total of 1,292 questionnaires were sent by email or handed out to surgeons and residents. The subjects worked mainly in Europe, performing laparoscopic and/or thoracoscopic procedures within the digestive, thoracic, urologic, gynecologic, and pediatric disciplines. RESULTS: In response, 22% of the questionnaires were returned. Overall, the respondents reported discomfort in the neck, shoulders, and back (almost 80%). There was not one specific cause for the physical discomfort. In addition, 89% of the 284 respondents were unaware of ergonomic guidelines, although 100% stated that they find ergonomics important. CONCLUSIONS: The lack of ergonomic guidelines awareness is a major problem that poses a tough position for ergonomics in the operating room.

Safety challenges of medical equipment in nurse anaesthetist training in Haiti.

Safety challenges related to the use of medical equipment were investigated during the training of nurse anaesthetists in Haiti, using a systems approach to Human Factors and Ergonomics (HFE). The Observable Performance Obstacles tool, based on the Systems Engineering Initiative for Patient Safety (SEIPS) model, was used in combination with exploratory observations during 13 surgical procedures, to identify performance obstacles created by the systemic interrelationships of medical equipment. The identification of performance obstacles is an effective way to study the accumulation of latent factors and risk hazards, and understand its implications in practice and behaviour of healthcare practitioners. In total, 123 performance obstacles were identified, of which the majority was related to environmental and organizational aspects. These findings show how the performance of nurse anaesthetists and their relation to medical equipment is continuously affected by more than user-related aspects. The contribution of systemic performance obstacles and coping strategies to enrich system design interventions and improve healthcare system is highlighted. In addition, methodological challenges of HFE research in low-resource settings related to professional culture and habits, and the potential of community ergonomics as a problem-managing approach are described.

Patch testing to a textile dye mix by the international contact dermatitis research group.

BACKGROUND: Disperse dyes are well-known contact sensitizers not included in the majority of commercially available baseline series. OBJECTIVE: To investigate the outcome of patch testing to a textile dye mix (TDM) consisting of 8 disperse dyes. METHODS: Two thousand four hundred ninety-three consecutive dermatitis patients in 9 dermatology clinics were patch tested with a TDM 6.6%, consisting of Disperse (D) Blue 35, D Yellow 3, D Orange 1 and 3, D Red 1 and 17, all 1.0% each, and D Blue 106 and D Blue 124, each 0.3%. 90 reacted positively to the TDM. About 92.2% of the patients allergic to the TDM were also tested with the 8 separate dyes. RESULTS: Contact allergy to TDM was found in 3.6% (1.3-18.2) Simultaneous reactivity to p-phenylenediamine was found in 61.1% of the TDM-positive patients. Contact allergy to TDM and not to other p-amino-substituted sensitizers was diagnosed in 1.2%. The most frequent dye allergen in the TDM-positive patients was D Orange 3. CONCLUSIONS: Over 30% of the TDM allergic patients had been missed if only the international baseline series was tested. Contact allergy to TDM could explain or contribute to dermatitis in over 20% of the patients. Textile dye mix should be considered for inclusion into the international baseline series.

Design criteria for the reduction of shear forces in beds and seats.

Both with respect to the aspect of pressure sores and of comfort, the inclination of backrest and seat are, amongst other factors, important design criteria. In this study the combination of seat and backrest inclination which reduces shear forces on the seat in passive seating forms the centre of attention. A biomechanical model was developed to predict these combinations and a new measurement apparatus was used for verification of the model on 10 healthy subjects (age 24.4 S.D. 2.1 yr, height 1.77 S.D. 0.08 m, mass 66.3 S.D. 11 Kg). For chairs it was found that when little shear is accepted, a fixed inclination between seat and backrest can be chosen between 90 degrees and 95 degrees. For beds a parabolic relationship was found between seat and backrest inclination with a maximum seat inclination of 20 degrees at a backrest inclination of 50 degrees. When lying with the knees bent to a position with equal inclination of thighs and shanks, the model predicts a shear force on the seat that shoves the person into the bed for every combination of seat and backrest inclination.

Mechanical effects of continuous passive motion on the lumbar spine in seating.

The aim of this study was to develop a model which describes the mechanical spinal response to small alternating pelvic stimulation induced by an active rotational movement of a normal chair. The rotary continuous passive motion (RCPM) of the seat about a vertical axis of only 0.6 degrees resulted in an increased in spinal length as opposed to the normal daily shrinkage, and back patients experienced pain relief. Passive and active exercies have been broadly applied for treating and healing spinal disorders. A rigid body package (ADAMS Android) was used to translate the stimulation of the ischial tubersoity in caudo-cranial handing-over visualisation. The parameters of the model were set so that the values of the global stiffness and geometry of the intervertebral discs could be changed. In vivo validation of the model was based on force and moment measurements using an internal AO fixator. The predicitons of the model concerning natural frequency (4.5Hz) in vertical direction and the axial torsion response on small pelvic torsion are comparable with experimental data.

Improved usability of a new handle design for laparoscopic dissection forceps.

BACKGROUND: Recent studies have shown that the shape of most instrument handles causes user discomfort and that none of the handles currently available on the market satisfies all ergonomic criteria. Therefore, we designed a handle with improved usability; i.e., it is easier to manipulate and its use entails less risk of injury for the operator. The aim of this study was to demonstrate that the intended improvements of the new design were successful. METHODS: Six handles representative of the types that are currently available were compared with the new version. Eight surgeons used the seven handles during a precision task and a rough task in a pelvi-trainer. A questionnaire and video analyses were used to assess the usability of the handles. RESULTS: Based on the responses to the questionnaire, we determined that there were significant differences between the new handle and the Aesculap handle (means of rotation and angle between handle and shaft). No significant differences were found between the new handle and the five other handles. The video analyses (documenting extreme vs neutral wrist excursions) showed significant differences between the new handle and the six other handles. CONCLUSION: Compared to the six existing handles, the new handle has significantly improved usability; in particular, its hinged design obviates the need to make extreme wrist excursions.

Improvement of foot pedals used during surgery based on new ergonomic guidelines.

BACKGROUND: This study aims to create new ergonomic guidelines for the design of foot pedals used during surgery. METHODS: Observations in the operating room, a questionnaire among 45 laparoscopic surgeons/residents, an ergonomic literature study, and clog measurements were used to assess the problems occurring during use and to compile new guidelines for foot pedals. Based on these guidelines a new foot pedal was designed and a prototype was manufactured. RESULTS: During the surgical procedure 91% of the subjects occasionally loses contact with the foot pedal, which 56% experience as very annoying. All subjects think that the current foot pedals obstruct their freedom of movement; 75% occasionally hit the wrong switch and 53% experience physical discomfort in their legs and/or feet. Therefore, 93% of the subjects would like to control the diathermy in a different way. The new prototype of a foot pedal was evaluated in a pilot test and proved to be ergonomically better than the currently used foot pedals. CONCLUSION: The new guidelines for foot pedals result in an ergonomic improvement in their design.

Evaluation of the usability of two types of image display systems, during laparoscopy.

BACKGROUND: This study was performed to assess the optimal display location of a flat-screen monitor for laparoscopy. It was also performed to assess the posture (objective), opinion, and preference (subjective) of subjects using a flat-screen monitor positioned in the optimal display location and a cathode-ray tube monitor on a tower next to the operating table (current situation). METHODS: Twelve surgeons performed cholecystectomies using the two display systems alternately. The postures of the operator and the assistant were assessed by an infrared video analysis system. RESULTS: The posture of the assistant is significantly better when using a flat-screen monitor [more neutral head flexions (p = 0.036) and neutral neck torsions (p = 0.012)]. No significant differences were found for the posture of the operator. The operators and assistants felt more comfortable when using a flat-screen monitor (p = 0.008) and they preferred this display to the use of a monitor on a tower. CONCLUSIONS: The use of flat-screen monitors is better for the physical and psychological comfort of the users, even though the technical performance is inferior in comparison with that of regular monitors.

Improvement of the laparoscopic needle holder based on new ergonomic guidelines.

BACKGROUND: The aim of this study is to create new ergonomic guidelines for the design of laparoscopic needle holders. METHODS: An ergonomic literature study, observations in the operating room, handle-shaft angle measurements, and anthropometric data were used to compile new ergonomic criteria, specified to the function of a laparoscopic needle holder. Based on these guidelines a new needle holder was designed. The prototype and three currently available needle holders were evaluated according to the new guidelines. In addition, a pelvi-trainer test was done to measure the extreme wrist excursions. RESULTS: The ergonomic evaluation of three commonly used handles and the new prototype indicate that the new handle is an ergonomic improvement in the field of laparoscopic needle holders: only the new handle satisfies all criteria. This is validated by the results of the pelvi-trainer test, which showed that the new prototype significantly (p <0.001) reduced the extreme wrist excursions. CONCLUSION: The new design guidelines for a laparoscopic needle holder result in an ergonomic improvement of the instrument.