Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A comparison of the different interpair intervals in the conditioning-testing P50 paradigms

The conditioning-testing P50 paradigm is used to demonstrate sensory gating of responsiveness to auditory stimuli. Sensory gating is measured in terms of a suppression of the second (test) P50 component in that paradigm. The time course of sensory gating can be determined by examining subjects' gating of responsiveness to stimuli repeated at various interpair intervals. In the present study auditory evoked potentials were recorded using a paired click, conditioning-testing P50 paradigm in 11 normal subjects with no family history of any psychotic disorder. Recordings were made at conditioning-testing intervals of 250 ms, 500 ms, 750 ms and 1000 ms. Whereas the grand averages of the P50 conditioning-testing response for the 250- and 500-ms intervals were 3.07% and 37.2%, respectively, indicating almost complete suppression, the grand averages of the ratios for the 750- and 1000-ms intervals were 114.35% and 92.92%, respectively, indicating little or no suppression. There was significant correlation in the C-T ratios with the increasing intervals. Our results suggest that the mechanism(s) responsible for sensory gating is activated mostly during the 500 ms after stimulus presentation. Other gating mechanism(s) functioning at longer intervals appear to be uncertain. (C) 2001 Elsevier Science B.V. All rights reserved

The effect of immobilization stress on sensory gating in mice

Central sensory filtering processes can be demonstrated using a paired stimulus paradigm. Normal humans show a diminished, vertex-recorded midlatency (50 ms) of auditory evoked potential to the second of paired clicks (0.5 s apart), a phenomenon termed as auditory gating. A loss of 50 ms in auditory gating is strongly related to psychosis. The N40 auditory evoked potential (EP) in rats has been used to develop an animal model for the study of sensory gating mechanisms. Previous animal studies of auditory gating have used psychotomimetic drug administration to induce sensory gating. However, a nonpharmacologic model of deficient gating would be advantageous

Blood pressure relationship to nitric oxide, lipid peroxidation, renal function, and renal blood flow in rats exposed to low lead levels

The results of experiments designed to show that inhibition of nitric oxide production in rats exposed to low lead levels increases vascular resistance, decreases renal blood flow and glomerular function, and enhances oxidative stress. Forty-five adult male Sprague-Dawley rats were divided into four groups. Group A was used as controls and consisted of rats that received no treatment; group B acted as NO-inhibited controls by receiving L-NAME (N-G-nitro-L-arginine methyl ester) as the NO inhibitor; group C was injected intraperitoneally with 8 mg/kg lead acetate for 2 wk; and group D receiving lead acetate Plus L-NAME

An assessment of working memory using P300 wave in healthy subjects

Working memory (WM) has three cognitive components, i.e. encoding and retaining of information, and the retrieval of stored expressions. It is accepted that the left frontal slow wave negativity is an indicator of the functions of working memory. This study aims to investigate the encoded functions of working memory through the variations in the amplitude and latency of P300 wave recorded from three separate locations (Fz, Cz and Pz). The study was performed on five healthy subjects with ages varying between 25 and 30 in the Institute of Cognitive Sciences of Bremen University. The task given to the subjects was to define the stimuli by pressing the buttons in their right and left hands. Event-related potentials (ERPs) were elicited from increasing working memory load in three conditions of an n-back task. It was observed that the amplitude of P300 was low in Fz when compared with those in Cz and Pz. Meaningfully significant differences of P300 amplitude were found among locations only in two-back task (Fz: 5.32 +/- 4.93, Cz: 6.55 +/- 5.31, Pz: 9.97 +/- 6.19; p < 0.05). There were no differences for P300 latency in Fz, Pz and Cz locations. It was concluded that P300 amplitude increased in parallel with the increase in load of working memory. (c) 2004 Elsevier B.V All rights reserved

Electrodermal activity in hypothyroid patients and healthy subjects

The involvement of the central nervous system either in hypothyroidism or in hyperthyroidim has previously been shown on the basis of visual, auditory, somatosensory, and central motor evoked potential studies by some investigators. In to our previous study, we found that abnormal electrodermal activity in nonmedicated hyperthyroid patients was not associated with psychiatric symptoms. In this study, our purpose was to investigate whether hypothyroidism results in electrodermal abnormalities in the absence of measurable pyschiatric symptoms. Electrodermal activity was recorded with a skin conductance unit connected to a personal computer. Basal levels of electrodermal activity and responsiveness to repeated acoustic stimulation were studied in 14 nonmedicated hypothyroid patients and 14 healthy controls. Psychiatric rating scores indicated that patients and healthy controls had normal levels of anxiety and depression. Hypothyroid patients had lower skin conductance levels, lower fluctation rates and prolonged onset latencies compared with controls. None of the hypothyroid patients had amplitude changes. In conclusion, hypothyroid patients may have abnormal electrodermal activity that is related to the change of hypothalamic-pituitary-thyroid axis function, without associated psychiatric symptoms

Effects of cigarette smoking on cognitive processing

Several previous studies have reported that cigarette smoking enhances performance of cognitive processing. These enhancements are generally attributed to the pharmacological effects of nicotine, while there is some debate whether the effects of smoking/nicotine are a result of recovery from abstinence. Evoked potentials (EPs) and event related potentials (ERPs) of the brain have been applied as an index of information processing in a wide variety of normal and cognitive impaired subjects. This study, was carried out on 20 health students (23 +/- 2.3 years old) from the medical faculty of 007 University. Study population. comprised ten chronic cigarette smokers consuming an average of 14 +/- 4.2 cigarettes per day, with a history of smoking for more than one year. Ten non-smokers served as control. Standard oddball paradigm was presented, and EEG activity was recorded at the F-z, C-z, P-z electrode sites. Twenty responses to target stimuli were averaged at each location. N1, P2, N2, and P300 components were evaluated in these recordings. Amplitudes were measured relative to prestimulus baseline, and peak latencies were defined as the time point of maximum amplitude. It was found that there were no significant differences between either N1, P2, N2, P300 amplitudes or peak latency values of cigarette smokers and non smokers. As a result, chronic cigarette smoking generally does not improve cognitive processing

Zinc-induced alterations in contractile properties of rat diaphragm muscle in vitro

The effect of zinc ions on the isometric contraction of rat diaphragm muscles in the presence and in the absence of external calcium was studied. Using a transducer, the isometric force was measured as a function of supramaximal electrical stimulation, either directly or indirectly applied to the muscle. The following parameters were measured: peak twitch tension, PT, twitch contraction time, CT, relaxation half-time, RT-1/2, and peak rates of tension increase and decrease, +dP/dt and -dP/dt. The following zinc-induced alterations were observed: an increase of the PT; a decrease of the RT-1/2; an increase in the +dP/dt and -dP/dt. The CT was not changed significantly. Our results suggest that zinc ions have a positive inotropic effect on isolated diaphragm muscle. The increase in PT may be explained by a zinc-activated Ca2+ uptake by sarcoplasmic reticulum. This was followed by an increase in the rate of rise of tension development, which was secondary to increased -dP/dt. The mechanism(s) by which extracellular Ca2+ contributes to this action of zinc is not known

Effect of hyperglycemia on electrodermal activity in diabetic rats

This study investigated the relationship between hyperglycemia and electrodermal activity ( EDA) parameters in streptozotocin ( STZ) induced diabetic rats. The article evaluates the course of development of neurophysiological alterations in the peripheral nervous system in diabetic rats through EDA. Rats were made diabetic using a moderate dose of STZ ( DI) and high dose ( DII). The placebo group ( P) was injected with physiological saline. EDA was recorded 1 h before the injection ( beginning, 0, day), 1st day ( one day after the injection) and 10th day. Skin conductance level ( SCL) was lower in DII than P on the 1st and the 10th days. The SCL and SC fluctuation rate ( SCFr) of DI were significantly lower on the 10th day compared to their first record. SC response rate ( SCRr) was lower on the 10th day compared to the 1st day, in the DI. In the DI, SCL, SC fluctuation rate ( SCFr) and SC response rate ( SCRr) were lower on the 10th day compared to the 1st day. The DII was statistically higher in electrodermal non-responsiveness compared to other groups on the 1st day. The results obtained show that hyperglycemia affects the peripheral nervous system, and EDA parameters are affected by blood glucose level. It is suggested that EDA is a simple and non-invasive electrophysiological method in early diagnosis of diabetic neuropathy