The relationship between exposure to general anesthetic agents and the risk of developing an impulse control disorder.

Most studies examining the effect of extended exposure to general anesthetic agents (GAAs) have demonstrated that extended exposure induces both structural and functional changes in the central nervous system. These changes are frequently accompanied by neurobehavioral changes that include impulse control disorders that are generally characterized by deficits in behavioral inhibition and executive function. In this review, we will.

Anesthetic management of labor and delivery in patients with elevated intracranial pressure.

The anesthetic management of labor and delivery in patients with elevated intracranial pressure is complex. This review discusses the etiologies of diffuse and focal pathologies which lead to elevated intracranial pressure in pregnancy. The role of neuraxial and general anesthesia in the management of labor and delivery is also examined. Finally, a comprehensive review of strategies to minimize increases in intracranial pressure during general anesthesia for cesarean delivery is presented.

The impact of two workplace-based health risk appraisal interventions on employee lifestyle parameters, mental health and work ability: results of a randomized controlled trial.

Health risk appraisals (HRA) are a common type of workplace health promotion programme offered by American employers. In the United Kingdom, evidence of their effectiveness for promoting health behaviour change remains inconclusive. This randomized controlled trial examined the effects of two HRA interventions on lifestyle parameters, mental health and work ability in a UK context. A total of 180 employees were randomized into one of three groups: Group A (HRA augmented with health promotion and education activities), Group B (HRA only) and Group C (control, no intervention). After 12 months, changes in mean scoring in 10 lifestyle, mental health and work ability indices were compared, Groups A and B demonstrated non-significant improvements in 70% and 80%, respectively, compared with controls (40%). Odds ratios revealed that, compared with the control group, Group A was 29.2 (95% CI: 9.22-92.27) times more likely to report a perceived change in lifestyle behaviour; Group B 4.4 times (95% CI: 1.65-11.44). In conclusion, participation in the HRA was associated with a higher likelihood of perceived lifestyle behaviour change which was further increased in the augmented HRA group, thereby providing preliminary evidence that HRA and augmented HRA in particular may help UK employees make positive healthy lifestyle changes.

The saphenous nerve and its relationship to the nerve to the vastus medialis in and around the adductor canal: an anatomical study.

BACKGROUND: Recently, ultrasound-guided saphenous nerve blocks within and distal to the adductor canal have shown success. However, a potential side effect is an unintentional block of branches of the nerve to the vastus medialis resulting in undesired motor weakness. METHODS: We dissected 40 embalmed cadaver thighs to determine the course and relation of the saphenous nerve to the nerve to the vastus medialis. Measurements were taken between various landmarks, and descriptive statistics were used to present the collected data. RESULTS: In 72.5% of specimens, the most distal visible branch of the nerve to the vastus medialis pierced the muscle proximal to the site where the saphenous nerve crosses the anterior surface of the superficial femoral artery to become medial to the vessel. CONCLUSION: Knowledge of this anatomy may help establish a safe region in preventing motor blockade when performing saphenous nerve blocks.

Impact of a direct access occupational physiotherapy treatment service.

BACKGROUND: Musculoskeletal disorders (MSDs) cause significant morbidity and absence from work for both manual and sedentary occupations. AIMS: To examine the impact of a direct access physiotherapy treatment service in an occupational setting. METHODS: This was a pilot study carried out as a service audit. Physiotherapy patients were assessed pre- and post-treatment using the work function score (WFS), a visual analogue scale for pain (VASP) and adjusted clinical score (ACS). Self-report questionnaires were completed on sickness absence, attendance at work and the World Health Organization (five) Well-being Index. RESULTS: There were 231 participants. Patient improvement was reported in WFS (63%), ACS (84%) and VASP (94%). Compared with those who had one or two sessions, improvement was most likely after three to four sessions for WFS [odds ratio (OR): 4.5; 95% confidence interval: 1.4-14.3, P < 0.05], VASP (OR: 32.2; 95% confidence interval: 3.5-294.2, P < 0.01) and five to six sessions for ACS (OR: 6.9; 95% confidence interval: 1.9-25.9, P < 0.01). While the self-reported questionnaire response rate was low at 29%, respondents indicated that there was potential to reduce and prevent sickness absence and improve mental well-being. CONCLUSIONS: Brief physiotherapy treatment for MSDs may have the potential to improve not only clinical status and pain as expected but also work function, psychological well-being and sickness absence. Further research is warranted to confirm these positive impacts and to endorse physiotherapy as an effective intervention in occupational settings and a useful component in rehabilitation and 'Fit for Work' programmes.

Fatal hyperammonemia after renal transplant due to late-onset urea cycle deficiency: a case report.

We present a case of severe hyperammonemia with subsequent brain herniation in an adult man after renal transplantation. After successful surgery and an initially uneventful postoperative course, the patient developed significant mental status changes associated with seizure activity. His condition rapidly deteriorated, requiring mechanical ventilation and cardiovascular support. Laboratory studies at that time demonstrated an increased serum ammonia level without evidence of liver or kidney dysfunction. Further investigation revealed an increased orotic acid level in the urine, suggesting a urea cycle disorder (UCD). Despite aggressive therapy, the patient's condition continued to deteriorate. Magnetic resonance imaging demonstrated severe brain edema with no cerebral perfusion; after consultation with the family, care was withdrawn. The combination of hyperammonemia and elevated urine orotic acid with normal liver and kidney function suggested a UCD. It is important to note that patients with a UCD may be free of symptoms for many years. Several factors are able to trigger the disease in adulthood, leading to encephalopathy and death. In this case, the patient's seizures were initially assumed to be a side effect of immunosuppressive therapy. Further diagnostic measures were only performed late in the course of the disease, which delayed the diagnosis of UCD.

Presymptomatic prediction of sepsis in intensive care unit patients.

Postoperative or posttraumatic sepsis remains one of the leading causes of morbidity and mortality in hospital populations, especially in populations in intensive care units (ICUs). Central to the successful control of sepsis-associated infections is the ability to rapidly diagnose and treat disease. The ability to identify sepsis patients before they show any symptoms would have major benefits for the health care of ICU patients. For this study, 92 ICU patients who had undergone procedures that increased the risk of developing sepsis were recruited upon admission. Blood samples were taken daily until either a clinical diagnosis of sepsis was made or until the patient was discharged from the ICU. In addition to standard clinical and laboratory parameter testing, the levels of expression of interleukin-1beta (IL-1beta), IL-6, IL-8, and IL-10, tumor necrosis factor-alpha, FasL, and CCL2 mRNA were also measured by real-time reverse transcriptase PCR. The results of the analysis of the data using a nonlinear technique (neural network analysis) demonstrated discernible differences prior to the onset of overt sepsis. Neural networks using cytokine and chemokine data were able to correctly predict patient outcomes in an average of 83.09% of patient cases between 4 and 1 days before clinical diagnosis with high sensitivity and selectivity (91.43% and 80.20%, respectively). The neural network also had a predictive accuracy of 94.55% when data from 22 healthy volunteers was analyzed in conjunction with the ICU patient data. Our observations from this pilot study indicate that it may be possible to predict the onset of sepsis in a mixed patient population by using a panel of just seven biomarkers.

Hearing Surveillance Chart--a tool for tracking serial audiometry results and predicting future hearing impairment.

High frequency hearing loss is related to noise-induced deafness. We decided to develop a method of recording serial audiogram results that would provide an accessible overview of trends for an individual. Health & Safety Executive (HSE) warning and referral levels for high frequency hearing losses were plotted against age. A third line was added to indicate a level of 'significant' handicap. This graph is inserted in each individual's hearing surveillance record. High frequency hearing loss results are plotted for each ear over time. Someone with known hearing loss but minimal deterioration will exceed the HSE warning level at every review, whereas someone with perfect hearing suffering a significant deterioration may not exceed the warning level initially. The latter should be of more concern to their current employer.

Educational psychology in medical learning: a randomised controlled trial of two aide memoires for the recall of causes of electromechanical dissociation.

OBJECTIVES: Although mnemonics are commonly used in medical education there are few data on their effectiveness. A RCT was undertaken to test the hypothesis that a new aide memoire, "EMD-aide", would be superior to the conventional "4Hs+4Ts" mnemonic in facilitating recall of causes of electromechanical dissociation (EMD) among house officers. METHOD: "EMD-aide", organises causes of EMD by frequency of occurrence and ease of reversibility: four groups organised by shape, colour, position, numbering, clockwise sequence, and use of arrows. Eight hospitals were randomised in a controlled trial and 149 house officers were then recruited by telephone. Baseline ability to recall causes of EMD was recorded at one minute and overall. House officers were then sent a copy of either "4Hs+4Ts" or "EMD-aide" according to randomisation group. Recall ability was retested at one month. RESULTS: 68 of 80 and 51 of 69 house officers completed the study in the "4Hs+4Ts" and "EMD-aide" groups respectively (NS) with similar baseline recall. After intervention median number of recalled causes was greater in the "EMD-aide" group, eight compared with seven at one minute (p = 0.034) and eight compared with seven overall, p = 0.067. Recall of all eight causes was more common in "EMD-aide" group, 54% compared with 35%, p = 0.054, and these house officers spent longer examining their aide memoire, p<0.001. CONCLUSIONS: "EMD-aide" may be superior to "4Hs+4Ts" in facilitating the recall of the causes of electromechanical dissociation. Educational psychology of medical learning and the use of aide memoires in general are worthy of further study.

Survey of abuse and violence by patients and relatives towards intensive care staff.

A postal survey of senior nurses in intensive care units in England and Wales was conducted. The aim was to ascertain the frequency of abusive and violent behaviour by patients and relatives towards intensive care staff, discover the perceived causes, effects and documentation of such behaviour and define the current and proposed security arrangements for intensive care units. Response rate was 94%. During the study period, verbal abuse of nurses by patients and by relatives occurred in 87% and 74% of intensive care units, respectively. The relevant figures for doctors were 65% and 59%, respectively. Nurses experienced physical abuse by patients and by relatives in at least 77% and 17% of intensive care units, respectively (doctors 38% and 8%). Illness was the main perceived cause of offences by patients whereas 'distress' (45%), alcohol (24%), sociopathic behaviour (27%) were the main putative causes amongst relatives. Whilst 43% of intensive care units have no security system at the door, staff awareness, training and communication skills may be the principle tools in reducing the frequency and consequences of violent and abusive behaviour. This survey probably underestimates the problem.

Presentation of diaphragmatic herniae during pregnancy and labour.

We report two cases of pregnancy-related diaphragmatic hernia. Case one was a 36-year-old woman who presented in her ninth pregnancy, after eight vaginal deliveries. Eight months after a stab wound to the chest, she developed persistent vomiting. The diagnosis was made by chest X-ray after a contralateral central line had been inserted for parenteral nutrition. A 6 x 4 cm stab-induce defect in the diaphragm was repaired. Close by was a second healed diaphragmatic stab wound. Case two involved a 32-year-old woman with a history of repaired childhood diaphragmatic hernia. She developed atypical shoulder and precordial chest pain during labour. Delivery was achieved by the vaginal route, ventouse-assisted. Persistent pain and vomiting led to insertion of a nasogastric tube and the diagnosis was made on the subsequent chest X-ray. The omentum was very adherent to the lung and could only be mobilised via a thoracotomy, at which significant air leaks occurred but settled rapidly. The difficulties of diagnosis are discussed along with the embryology, mechanisms and management of this condition.

Creating healthy workplaces in Northern Ireland: evaluation of a lifestyle and physical activity assessment programme.

An observational study was carried out on 2595 Northern Ireland civil servants who attended a workplace lifestyle and physical activity assessment programme involving self-reported lifestyle history, measurement of physiological parameters and a 6 month follow-up postal questionnaire survey. Almost two-thirds of participants did not engage in regular moderate physical activity, with females twice as likely not to than men. Approximately one in six participants were smokers and three-quarters were found to have body fat estimations above the acceptable level, with females much more likely to be obese than men. Aerobic capacity was below average in 17% of participants and was associated with increasing age, smoking in the under 35s and poor physical activity levels. Excessive alcohol intake was found in 8% of all participants, and was more likely in men and smokers. In the follow-up survey, 83% needed to make one or more changes to their lifestyle. Smoking was the most difficult to change, with only 14% remaining abstinent after 6 months. Almost two-thirds were maintaining improved dietary habits and exercise activity, with around one-half moderating alcohol intake and achieving weight reduction. Overall, the average level of non-attempted behaviour change was one in five (19.6%), tried but failed accounted for almost one in three (31.2%) and successful maintenance of positive lifestyle change occurred in one-half (49.2%). Brief lifestyle and physical activity assessment programmes are effective interventions in getting employees to modify their lifestyles. The impact this has on wider organizational issues such as absenteeism and productivity needs further evaluation.

Nasopharyngeal oxygen therapy produces positive end-expiratory pressure in infants.

UNLABELLED: The World Health Organisation recommends nasopharyngeal catheters as a safe and efficient method of oxygen administration in infants. However, little is known about the mechanisms of the improvement in oxygenation. The aim of the present study was to determine whether nasopharyngeal oxygen therapy produces positive end-expiratory pressure (PEEP). Nine spontaneously breathing infants (median age 13 months, range 10 days to 20 months) after heart surgery were investigated. All patients had normal pulmonary blood flow at the time of the study (Qp:Qs=1:1). Oxygen (oxygen fraction 1.0) was delivered by an 8 F catheter inserted into the nasopharynx (tip just visible below the soft palate). The pulmonary mechanics were analysed using a single compartment model of the respiratory system. Oesophageal pressure (Pes) at end-expiration, dynamic lung compliance (C(L)) and resistance (R(L)), minute ventilation, PaCO2 and PaO2 were measured at baseline without a nasopharyngeal catheter or oxygen, and at oxygen flows of 0.5 l/min, 1.0 l/min and 2.0 l/min. All the flows generated significant increases in PEEP. Mean difference in PEEP (SD, paired t-test versus baseline): 1.6 cm H2O (1.4, P=0.008) with 0.5 l/min of oxygen; 2.8 cm H2O (2.7, P=0.014) with 1.0 l/min of oxygen; and 4.0 cm H2O (2.9, P = 0.004) with 2.0 l/min of oxygen. There was a significant correlation between all the nasopharyngeal flows (in ml/kg per min) and the generated PEEP (P<0.001) and between the C(L) values and the generated PEEP (P < 0.05). There was no significant difference in PaCO2 and R(L). Minute ventilation was significantly less with nasopharyngeal oxygen than at baseline. As expected, PaO2 increased significantly with increasing oxygen flows. CONCLUSION: Administration of oxygen through an 8 F nasopharyngeal catheter at flow rates recommended by the World Health Organisation (0.5 l/min in newborns, 1.0 l/min in infants) produces moderate amounts of positive end-expiratory pressure. The levels achieved may contribute to an improvement in oxygenation by altering the visco-elastic properties of the lung.

Effects of forearm bier block with bretylium on the hemodynamic and metabolic responses to handgrip.

We tested the hypothesis that a reduction in sympathetic tone to exercising forearm muscle would increase blood flow, reduce muscle acidosis, and attenuate reflex responses. Subjects performed a progressive, four-stage rhythmic handgrip protocol before and after forearm bier block with bretylium as forearm blood flow (Doppler) and metabolic (venous effluent metabolite concentration and (31)P-NMR indexes) and autonomic reflex responses (heart rate, blood pressure, and sympathetic nerve traffic) were measured. Bretylium inhibits the release of norepinephrine at the neurovascular junction. Bier block increased blood flow as well as oxygen consumption in the exercising forearm (P < 0.03 and P < 0.02, respectively). However, despite this increase in flow, venous K(+) release and H(+) release were both increased during exercise (P < 0.002 for both indexes). Additionally, minimal muscle pH measured during the first minute of recovery with NMR was lower after bier block (6.41 +/- 0.08 vs. 6.20 +/- 0.06; P < 0.036, simple effects). Meanwhile, reflex effects were unaffected by the bretylium bier block. The results support the conclusion that sympathetic stimulation to muscle during exercise not only limits muscle blood flow but also appears to limit anaerobiosis and H(+) release, presumably through a preferential recruitment of oxidative fibers.

Upright posture reduces forearm blood flow early in exercise.

The hypothesis that upright posture could modulate forearm blood flow (FBF) early in exercise was tested in six subjects. Both single (2-s duration) and repeated (1-s work/2-s rest cadence for 12 contractions) handgrip contractions (12 kg) were performed in the supine and 70 degrees head-up tilt (HUT) positions. The arm was maintained at heart level to diminish myogenic effects. Baseline brachial artery diameters were assessed at rest in each position. Brachial artery mean blood velocity (MBV; Doppler) and mean arterial pressure (MAP) (Finapres) were measured continuously to calculate FBF and vascular conductance. MAP was not changed with posture. Antecubital venous pressure (Pv) was reduced in HUT (4.55 +/- 1.3 mmHg) compared with supine (11.3 +/- 1.9 mmHg) (P < 0.01). For the repeated contractions, total excess FBF (TEF) was reduced in the HUT position compared with supine (P < 0.02). With the single contractions, peak FBF, peak vascular conductance, and TEF during 30 s after release of the contraction were reduced in the HUT position compared with supine (P < 0.01). Sympathetic blockade augmented the FBF response to a single contraction in HUT (P < 0.05) and tended to increase this response while supine (P = 0.08). However, sympathetic blockade did not attenuate the effect of HUT on peak FBF and TEF after the single contractions. Raising the arm above heart level while supine, to diminish Pv, resulted in FBF dynamics that were similar to those observed during HUT. Alternatively, lowering the arm while in HUT to restore Pv to supine levels restored the peak FBF and vascular conductance responses, but not TEF response, after a single contraction. It was concluded that upright posture diminishes the hyperemic response early in exercise. The data demonstrate that sympathetic constriction restrains the hyperemic response to a single contraction but does not modulate the postural reduction in postcontraction hyperemia. Therefore, the attenuated blood flow response in the HUT posture was largely related to factors associated with diminished venous pressures and not sympathetic vasoconstriction.

Laboratory simulation of splashes and spills of organophosphate insecticides on chemically protective gloves used in agriculture.

Agricultural workers rely on chemically protective gloves for protection from dermal exposure to insecticides. In Australia the most widely used gloves are manufactured from polyvinyl chloride or nitrile butadiene rubber. During insecticide application splashes and spills frequently occur on the external surfaces of gloves which may compromise the integrity of the membrane. Interaction of two organophosphate insecticides, chlorpyrifos (Lorsban 500 EC(R)) and diazinon (Jetdip(R)), with glove surfaces was investigated in laboratory conditions. The external surface of gloves was treated with concentrated insecticides for one minute and diluted and concentrated insecticides for 24, 36 and 48 hours and later examined by environmental scanning electron microscopy. Two classes of defects, cavities and convexities, were evident in the polyvinyl chloride gloves following all treatments, whereas cracking was significant in the nitrile butadiene rubber gloves after 24 hours. In addition, X-ray energy-dispersive microanalysis was used to evaluate chemical changes on the glove surfaces. Phosphorus and sulfur were useful indicators for organophosphate retention over specific time frames. Results corroborated the need for more robust chemically protective gloves to be developed for routine agricultural use.