Young, vulnerable and uncertain: Young workers' perceptions of work health and safety.

BACKGROUND: Young workers are at an increased risk of work place injury, and are less likely to report hazards or injuries, or apply for workers' compensation even though they are over-represented in workers' compensation statistics in comparison with their older peers. OBJECTIVE: To identify young workers' perceptions of work health and safety (WHS), why and how they report (or do not report) hazards and injuries, and examine where they source WHS information. This paper reports on the first stage of a larger, mixed methods study on WHS and young workers in South Australia. METHODS: A total of 226 young South Australian workers aged between 12 and 25 years completed an online survey. Data were analyzed using chi-squared analysis for categorical variables and t-tests where the dependent variable was continuous. RESULTS: Three quarters of young workers identified stress at work, not being trained to do the job, fatigue from work and lifting heavy things at work as WHS issues, although not necessarily as issues that they have personally experienced. Most young workers obtained information about WHS through their employer although a sizable proportion sourced this information from friends and social media. Young workers identified that they lacked confidence to report WHS issues. When they did report issues, many young workers reported these issues to their parents, despite identifying that their parents were often unable to help. CONCLUSIONS: Our findings contribute to our understanding of young workers' perceptions of work health and safety. Although young workers could identify their concerns about particular health and safety related issues at work, they lacked the confidence to report their concerns and had limited information about where to go for help. The research suggests that there is a need to empower young people to report WHS concerns to their employer and provide structures and processes that encourage reporting.

Changes in structural aspects of mood during 39-66 h of sleep loss using matched controls.

A number of studies have described mood change during sleep loss in the laboratory, however, an understanding of fluctuations in structural aspects of mood under such conditions is lacking. Sixty-two healthy young adults completed one of three possible conditions: one (n = 20) or two (n = 23) nights of sleep loss or the control condition which consisted of one (n = 9) or two (n = 10) nights of 9 h time in bed. The Mood Scale II was completed every two waking hours and data were analysed in terms of the frequency and intensity of mood reports. Overall, sleep loss conditions were associated with significantly less frequent happiness and activation and more frequent fatigue reports (p < 0.001). Intensity was also significantly reduced for activation and happiness, and increased for depression, anger and fatigue (p < 0.05). Interestingly, there were no significant differences in anger following two nights in the laboratory with or without sleep. Further, two nights in the lab with normal sleep was associated with significant increases in depression intensity (p < 0.05). Findings support the hypothesis of a mood regulatory function of sleep and highlight the relative independence of frequency and intensity and of positive and negative mood dimensions. Findings also suggest that the laboratory environment, in the absence of sleep loss, may have a significant negative impact on mood.

Extending the storage life of chilled beef: microwave processing.

This study investigates whether it is possible to use microwave technology to reduce the bacterial load of meat to such an extent that shelf-life is extended while the product retains the appearance of fresh meat. It investigates the use of microwaves in raising the surface temperature of vacuum-packed beef steak, recording the total aerobic and anaerobic bacterial count, the appearance of the meat and the amount of purging of meat juices within the package.

The effects of cortisol supplementation on the metabolic and hormonal response to surgery.

The role of cortisol in determining the metabolic and hormonal changes associated with a standardized surgical operation was investigated. Twelve patients undergoing pelvic surgery were studied. Six received steroid supplementation with an infusion of hydrocortisone sodium succinate at a rate of 8 mg/h for 24 h, together with 1.5 g hydrocortisone acetate intraperitoneally at the completion of surgery, while the remainder acted as a control group. Steroid supplementation resulted in plasma cortisol values in the range 1913-2265 nmol/l from 4 to 24 h after the start of surgery. However, this marked hypercortisolaemia had no significant effects on circulating metabolites other than glucose, and did not alter plasma ACTH, GH and insulin values. The usual glycaemic response to surgery was significantly augmented by 1.0-1.5 mmol/l in the cortisol group. We conclude that changes in substrate mobilization observed after cortisol administration in normal volunteers may not accurately predict the effects found after surgery, when catabolic hormones and other modulators such as interleukin-1 may influence metabolism.

Monoclonal and polyclonal antibodies compared for radioimmunoassay of somatomedin-C in patients with acromegaly or hypopituitarism.

We used a synthetic recombinant analog of somatomedin-C (Sm-C) to directly compare the performance of polyclonal and monoclonal antibodies for measuring Sm-C in serum of normal persons and in acromegalic or hypopituitary patients. Mean concentrations of Sm-C in healthy adults were 181 (SD 42) micrograms/L as measured with the monoclonal antibody, 194 (SD 61) micrograms/L with the polyclonal antibody. Both antisera gave excellent discrimination between acromegalics and normals. However, the assay with the polyclonal antibody was more sensitive than that with the monoclonal antibody (lower detection limits: 5 vs 100 micrograms/L) and thus better suited for quantifying Sm-C in samples from hypopituitary patients.

Fentanyl and the beta-endorphin, ACTH and glucoregulatory hormonal response to surgery.

The effect of the supplementation of nitrous oxide-oxygen anaesthesia with either fentanyl 15 micrograms kg-1 or 0.5% halothane on the beta-endorphin, ACTH, glucoregulatory hormonal and metabolic response to pelvic surgery was investigated. Fentanyl inhibited the increases in circulating beta-endorphin, ACTH, growth hormone, cortisol and glucose concentrations found in the patients receiving halothane. Changes in circulating beta-endorphin concentrations during surgery probably reflect alterations in pituitary secretion and appear to have no major metabolic effects. The suppression of pituitary secretion persisted for at least 4 h after the start of surgery.

Hormonal and metabolic responses to cardiac surgery with sufentanil-oxygen anaesthesia.

The effects of sufentanil, 10 and 20 micrograms kg-1 on the hormonal and metabolic responses to coronary artery surgery were compared in 20 patients. The most important finding was that the changes in circulating beta-endorphin, ACTH, cortisol, GH, glucose, lactate and glycerol concentrations during and after cardiac surgery were similar with both doses of sufentanil. Although sufentanil prevented a significant increase in plasma beta-endorphin, ACTH and cortisol values until 6 h after cardiopulmonary bypass (CPB), a significant increase in GH secretion occurred with the onset of CPB. Plasma insulin concentrations declined significantly after 30 min CPB, but recovered after 60 min CPB with the restoration of normothermia. Blood glucose values did not change during surgery before CPB, but started to rise with the onset of CPB and continued to increase significantly in the postoperative period. Changes in blood lactate and plasma glycerol concentrations primarily reflected the load of CPB and the effects of heparin, respectively. The results show that increasing the dose of sufentanil up to 20 micrograms kg-1 does not result in better suppression of the endocrine and metabolic changes associated with cardiac surgery.

Effects of enflurane and halothane on carbohydrate metabolism in isolated perfused rabbit lungs.

Isolated, perfused rabbit lungs were used to investigate the effects of enflurane and halothane on pulmonary carbohydrate metabolism. The development of oedema in the preparation was assessed by continuous measurement of pulmonary artery pressure, airway pressure and lung weight. Ventilation of the lungs with 2% enflurane for 3 h had no effect on the rates of glucose utilization and lactate production and there were only small changes in the indices of oedema. Likewise, ventilation with 1% halothane for 1 h had no effect on the rates of glucose utilization and lactate production, and did not change significantly the concentrations of glycogen, glucose, glycolytic intermediates and high-energy phosphate compounds in lung tissue. Enflurane and halothane, at clinically relevant concentrations, probably do not influence carbohydrate metabolism in the lung.

Effects of two differing halothane concentrations on the metabolic and endocrine responses to surgery.

The effects of two differing concentrations of halothane, 2.1 MAC or 1.2 MAC, on the metabolic and endocrine responses to abdominal hysterectomy were investigated. The changes in blood glucose and lactate values, and plasma glycerol, cortisol, insulin and catecholamine concentrations were similar in both groups. We conclude that high concentrations of halothane do not suppress the responses to pelvic surgery, and that accurate quantification of the dose of halothane, within the concentration range of 1.2 to 2.1 MAC, is not essential in studies of metabolic changes associated with surgery.

Effects of cortisol suppression by etomidate on changes in circulating metabolites associated with pelvic surgery.

The effects of cortisol suppression by etomidate on the changes in circulating metabolites associated with pelvic surgery were investigated in healthy female patients. The use of etomidate resulted in the inhibition of cortisol secretion for 24 h compared with a control group of patients. However, the inhibition of steroidogenesis was not associated with a significant effect on blood glucose, blood lactate and plasma nonesterified fatty acid values, although the glycaemic response to surgery was consistently less in those patients who received etomidate. Heart rate and arterial pressure were significantly decreased during surgery in the etomidate group compared with the control group, but were similar in the postoperative period when the difference in plasma cortisol between the groups was greatest. The results suggest that cortisol has only a minor role in determining changes in circulating metabolites associated with surgery.

Epidural diamorphine and the metabolic response to upper abdominal surgery.

The effect of the administration of diamorphine 10 mg epidurally on the metabolic response to cholecystectomy was investigated and compared with a control group of patients given intravenous papaveretum. There were no significant differences in blood glucose, lactate and pyruvate, and plasma nonesterified fatty acid values between the epidural diamorphine group and the control group. Plasma cortisol concentrations were significantly lower in the epidural diamorphine group postoperatively and this was associated with a marked improvement in pain relief. We conclude that epidural opiates do not directly influence the metabolic response to surgery, but decrease the cortisol response postoperatively secondary to improved analgesia.

Effects of ketamine anaesthesia on the metabolic response to pelvic surgery.

The effects of ketamine anaesthesia on the metabolic and endocrine response to pelvic surgery were investigated, and compared with results obtained in a control group of patients anaesthetized with thiopentone and halothane. Ketamine anaesthesia before the onset of surgery was associated with a significant increase in blood glucose and plasma cortisol concentrations, and in heart rate. However, when surgery was established there were no metabolic, endocrine or haemodynamic differences between ketamine and halothane anaesthesia. We conclude that ketamine does not exacerbate the metabolic response to surgery.

Effects of high-dose fentanyl anaesthesia on the established metabolic and endocrine response to surgery.

The effect of the administration of fentanyl 50 micrograms/kg body weight on the established metabolic response to pelvic surgery was investigated. In comparison with a control group of patients in whom anaesthesia was supplemented with halothane, fentanyl was associated with a significant decrease in only blood lactate concentrations and heart rate. There were no significant differences in blood glucose, plasma non-esterified fatty acids, and plasma cortisol values between the two anaesthetic techniques. It is concluded that the administration of high-dose fentanyl has little effect on the established metabolic response to surgery, compared with the marked changes observed when the same dose is given before the onset of surgical stimulation.

Low-dose insulin infusion and substrate mobilization during surgery.

The effects of the i.v. infusion of insulin, 70 mu. kg-1h-1 for the first 60 min and 35 mu. kg-1h-1 subsequently, on the metabolic and endocrine responses to gynaecological surgery were investigated. In comparison with a control group of patients, the insulin infusion caused a marked decrease in circulating glucose, non-esterified fatty acids and beta-hydroxybutyrate concentrations, and an increase in blood lactate values. The plasma cortisol response to surgery was unaffected by the decrease in blood glucose, but the growth hormone response was increased. Heart rates and arterial pressures during surgery were not altered by the metabolic changes associated with insulin infusion, but there was a greater decrease in aural temperature. The results demonstrate the importance of insulin suppression during surgery in mediating changes in circulating metabolites.

Effect of different intraoperative fluid regimens on circulating metabolites and insulin during abdominal surgery.

The effects of infusion i.v. of 0.9% sodium chloride solution, Hartmann's and 5% dextrose solution on the concentrations of circulating metabolites and insulin were compared in patients undergoing cholecystectomy. Hartmann's solution had a similar effect on the metabolic response to 0.9% sodium chloride solution, but the use of 5% dextrose was associated with an exacerbation of the hyperglycaemic response to surgery. Plasma insulin concentrations increased significantly in the group receiving 5% dextrose showing that the usual suppression of insulin during abdominal surgery can be overcome by a strong glycaemic stimulus.

Changes in liver glycogen and glycolytic intermediates during abdominal surgery in man.

1. Changes in liver glycogen and glycolytic intermediates were determined in ten patients undergoing abdominal surgery for carcinoma of the colon. 2. One hour of surgery resulted in a 19% decrease in liver glycogen, together with an increase in hepatic glucose 6-phosphate and glucose concentrations. 3. Blood glucose increased from 5.01 to 6.67 mmol/l during the hour between liver biopsies. 4. We conclude that the hyperglycaemia of surgery is associated with stimulation of hepatic glycogenolysis.

Effect of phentolamine on the metabolic response to gynaecological surgery.

The effect of the infusion of phentolamine 0.5 mg min-1 on the metabolic response to gynaecological surgery was investigated. In comparison with the control group of patients, phentolamine was associated with a significant increase in plasma insulin concentration after 30 and 60 min of surgery. The glycaemic response to surgery was decreased by alpha-adrenergic blockade, but this was only significant after 120 min of surgery. The hypotension produced by the administration of phentolamine was well tolerated.

Changes in colloid osmotic pressure with plasma albumin concentration associated with extracorporeal circulation.

Colloid pressure (COP), plasma albumin concentration, haematocrit, and blood-gas tensions were measured in 16 patients undergoing open-heart surgery with cardiopulmonary bypass. The use of crystalloid priming and cardioplegia solutions resulted in a 60% decrease in COP, a 48% decrease in plasma albumin concentration and a 35% decrease in haematocrit. These measurements had returned to pre-perfusion values 6 h after the end of surgery. The alveolar-arterial PO2 difference increased significantly after by-pass and returned to pre-perfusion values within the same time scale. Right-to-left shunt increased from 7.9 to 10.3% 30 min after the end of by-pass. It is concluded that, in the absence of an increase in left atrial pressure, marked decreases in COP can be tolerated without the occurrence of pulmonary oedema.