Impact of case-relevant and case-irrelevant communication within the surgical team on surgical-site infection.

BACKGROUND: Surgical-site infections (SSIs) are the most common complications after surgery. An influence from talking and distractions during surgery on patient outcomes has been suggested, but there is limited evidence. The aim of this prospective observational study was to assess the relationship between intraoperative communication within the surgical team and SSI, and between intraoperative distractions and SSI. METHODS: This prospective observational study included patients undergoing elective, open abdominal procedures. For each procedure, intraoperative case-relevant and case-irrelevant communication, and intraoperative distractions were observed continuously on site. The influence of communication and distractions on SSI after surgery was assessed using logistic regressions, adjusting for risk factors. RESULTS: A total of 167 observed procedures were analysed; their mean(s.d.) duration was 4·6(2·1) h. A total of 24 SSIs (14·4 per cent) were diagnosed. Case-relevant communication during the procedure was independently associated with a reduced incidence of organ/space SSI (propensity score-adjusted odds ratio 0·86, 95 per cent c.i. 0·77 to 0·97; P = 0·014). Case-irrelevant communication during the closing phase of the procedure was independently associated with increased incidence of incisional SSI (propensity score-adjusted odds ratio 1·29, 1·08 to 1·55; P = 0·006). Distractions had no association with SSI. CONCLUSION: More case-relevant communication was associated with fewer organ/space SSIs, and more case-irrelevant communication during wound closure was associated with incisional SSI.

Adverse effect of noise in the operating theatre on surgical-site infection.

BACKGROUND: The aim of this pilot study was to evaluate the noise level in an operating theatre as a possible surrogate marker for intraoperative behaviour, and to detect any correlation between sound level and subsequent surgical-site infection (SSI). METHODS: The sound level was measured during 35 elective open abdominal procedures. The noise intensity was registered digitally in decibels (dB) every second. A standard questionnaire was used to evaluate the behaviour of the surgical team during the operation. The primary outcome parameter was the SSI rate within 30 days of surgery. RESULTS: The overall rate of SSI was six of 35 (17 per cent). Demographic parameters and duration of operation were not significantly different between patients with, or without SSI. The median sound level (43·5 (range 26·0-60·0) versus 25·0 (25·0-60·0) dB; P = 0·040) and median level above baseline (10·7 (0·6-33·3) versus 0·6 (0·5-10·8); P = 0·001) were significantly higher for patients who developed a SSI. The sound level was at least 4 dB above the median in 22·5 per cent of the peaks in patients with SSI compared with 10·7 per cent in those without (P = 0·029). Talking about non-surgery-related topics was associated with a significantly higher sound level (P = 0·024). CONCLUSION: Intraoperative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a surrogate parameter by which to assess the behaviour of a surgical team.

CTSim: Changing teaching practice in radiography with simulation.

INTRODUCTION: Simulation offers radiography students the possibility to experiment with Computed Tomography (CT) in a way not possible in clinical practice. The aim of this work was to test a newly developed simulator 'CTSim' for effectiveness in teaching and learning. METHODS: The simulator was tested in two phases. The first phase used a test-retest methodology with two groups, a group that experienced a Simulation based learning intervention and one which did not. The second phase subsequently tested for changes when the same intervention was introduced as part of an existing CT training module. RESULTS: Phase 1 demonstrated statistically significant improvement of mean scores from 58% to 68% (P < .05) for students who experienced the intervention against no change in scores for the control group. Phase 2 saw mean scores improve statistically significantly in a teaching module from 66% to 73% (P < .05) following the application of the intervention as an active learning component. CONCLUSION: The use of the CTSim simulator had a demonstrable effect on student learning when used as an active learning component in CT teaching. IMPLICATIONS FOR PRACTICE: Simulation tools have a place in enhancing teaching and learning in terms of effectiveness and also introduce variety in the medium by which this is done.

Human factors in resuscitation: Lessons learned from simulator studies.

Medical algorithms, technical skills, and repeated training are the classical cornerstones for successful cardiopulmonary resuscitation (CPR). Increasing evidence suggests that human factors, including team interaction, communication, and leadership, also influence the performance of CPR. Guidelines, however, do not yet include these human factors, partly because of the difficulties of their measurement in real-life cardiac arrest. Recently, clinical studies of cardiac arrest scenarios with high-fidelity video-assisted simulations have provided opportunities to better delineate the influence of human factors on resuscitation team performance. This review focuses on evidence from simulator studies that focus on human factors and their influence on the performance of resuscitation teams. Similar to studies in real patients, simulated cardiac arrest scenarios revealed many unnecessary interruptions of CPR as well as significant delays in defibrillation. These studies also showed that human factors play a major role in these shortcomings and that the medical performance depends on the quality of leadership and team-structuring. Moreover, simulated video-taped medical emergencies revealed that a substantial part of information transfer during communication is erroneous. Understanding the impact of human factors on the performance of a complex medical intervention like resuscitation requires detailed, second-by-second, analysis of factors involving the patient, resuscitative equipment such as the defibrillator, and all team members. Thus, high-fidelity simulator studies provide an important research method in this challenging field.

Unnecessary interruptions of cardiac massage during simulated cardiac arrests.

BACKGROUND AND OBJECTIVE: Cardiopulmonary resuscitation should not be interrupted until the return of spontaneous circulation or the decision to withhold further treatment. There are no data on how consistent in-hospital cardiopulmonary resuscitation is performed. Accordingly, the aim of the present study was to identify length and type of unnecessary interruptions in simulated cardiac arrests. METHODS: The study was carried out in a patient simulator. A scenario of cardiac arrest due to ventricular fibrillation was used. Resuscitation teams consisted of three nurses, a resident and a staff physician. Using videotapes recorded during simulations, the activities of the teams were coded in 5-s intervals. Unnecessary interruptions were defined as any interruptions in cardiac massage of 10 s or more that were not caused by defibrillation or endotracheal intubation. RESULTS: Twelve teams were studied. The total time of possible cardiac massage was 414 +/- 125 s. In each team at least one unnecessary interruption occurred (range 1-5). Interruptions mounted up to 65 +/- 40 s (range 20-155) or 16 +/- 10% (range 5-41) of the total time of possible cardiac massage. Failure to swiftly resume cardiac massage after an unsuccessful defibrillation accounted for 14 of 39 episodes and for 44 +/- 40% of the time of unnecessary interruptions. The debriefings revealed that participants had generally not noticed the unnecessary interruptions during the simulation. CONCLUSIONS: The present study identified a significant amount of unnecessary interruptions in cardiac massage. These interruptions were not noticed by the health-care workers involved.

[Health status of methadone recipients before entering a methadone program]. / Der Gesundheitszustand der Methadonbezüger und -bezügerinnen vor dem Eintritt ins Methadonprogramm.

Data were analyzed from 905 opiate addicts who participated for the first time in a methadone maintenance program in the Canton of Bern, Switzerland, between 1979 and 1989. Data of their physical and psychological state at the time of application for the methadone maintenance program were related to data of the addiction history and program progress. Only one fifth of the participants in the methadone maintenance program report to be in good health. Poorer health corresponds to reported psychological disorders. No correlation between demographical data and health status could be found, except that less qualified patients were in poorer health. Poorer health status is associated with the consumption of a higher amount of heroin per kg body weight and often with consumption of benzodiazepines before entrance into the methadone maintenance program. Methadone maintenance patients with a lower health status are given higher methadone doses. Compared to patients in better shape, more do not work before and during the methadone program. The physicians express less optimism with regard to the success of the program in patients in poorer health, and these are more often expelled from the program by their physicians or the health department. The results indicate that patients generally profit from the methadone maintenance treatment. However, better integrated patients and persons in better health may derive greater benefit from the methadone maintenance treatment.

New kinetic parameters for rat liver arginase measured at near-physiological steady-state concentrations of arginine and Mn2+.

A cytosolic cell-free system from rat liver containing the last three enzymes of the urea cycle, a number of cofactors and the substrates aspartate and citrulline was shown to synthesize urea at near-physiological rates ranging between 0.40 and 1.25 mumol/min per g of liver. This system was used to determine the kinetic parameters for arginase. With saturating amounts of Mn2+ (30 microM), arginine remained at a steady-state concentration of 5-35 microM depending on the aspartate and citrulline supply. Vmax. at micromolar arginine concentrations was between 1.10 and 1.25 mumol/min per g of liver, the K0.5 (arginine) between 6.0 and 6.5 microM and positive co-operativity was observed (Hill coefficient 2). Omission of Mn2+ caused a significant accumulation of arginine during the incubation, suggesting a regulatory effect of arginase. Under these conditions, Vmax. was 1.10-1.65 mumol/min per g of liver and the Km (arginine) increased up to 14.4-21.1 microM. The apparent Ka for Mn2+ in the presence of physiological concentrations of ATP, Mg2+ and arginine was calculated to be maximally 8 microM. Initial-velocity experiments with millimolar arginine concentrations as the direct substrate gave the following results, which are in good agreement with literature data. In the absence of Mn2+, Vmax. was 71.3 mumol/min per g of liver and the Km (arginine) 1.58 mM. With 30 microM-Mn2+, Vmax. was 69.4 mumol/min per g of liver and the Km (arginine) decreased to 0.94 mM. On the basis of our results, we propose the presence of high-affinity and low-affinity sites for arginine on rat liver arginase and postulate that alterations in arginase activity arising from changes in the concentration of arginine and of the cofactor Mn2+ may contribute to the regulation of ureagenesis in vivo.

A physiological role of Mn2+ in the regulation of cytosolic phosphoenolpyruvate carboxykinase from rat liver is unlikely.

A cytosolic cell-free system prepared from rat liver was used to study the effect of bivalent cations on the activity of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK). Steady-state concentrations of oxaloacetate in the range 5-50 microM were generated from increasing concentrations of malate+fumarate (10:1); 2 mM ITP and 3 mM Mg2+ were added as cofactors. Micromolar concentrations of Mn2+, Fe2+ and, to a lesser extent, of Zn2+ and Co2+ were shown to stimulate PEPCK activity. Vmax. (mumol/min per g of liver) increased from 0.67 to 1.68 on addition of 5 microM Fe2+ and to 2.34 with 2 microM Mn2+, whereas no significant effect on the Km for oxaloacetate was observed. The apparent K(a) values (total) were 0.62 microM for Mn2+, 1.48 microM for Zn2+, 1.92 microM for Co2+ and 3.37 microM for Fe2+, being 2-8-fold lower than the corresponding published values. Variations of the free Mn2+ concentration were obtained (a) by increasing the Mn2+ concentration (i.e. activation curve) and (b) by simultaneous addition of Mn2+ and increasing concentrations of the chelating agent EGTA (i.e. inactivation curve). Different results were obtained for the activation and inactivation curves. The inactivation curve showed that PEPCK activity was almost unaffected by variations of the free Mn2+ concentration over the range 0.05-0.15 microM. Under comparable experimental conditions, rat liver arginase (another Mn(2+)-dependent enzyme) was completely inactivated. From kinetic evidence, the existence of two distinct molecular forms of cytosolic rat liver PEPCK with different Mn2+ affinities is postulated. Considering the high affinity of PEPCK for Mn2+ and its relative insensitivity to changes in the free Mn2+ concentration, it seems rather unlikely that changes in the free cation concentration play a major role in regulating PEPCK activity in vivo.