Bipolar Visual Analog Scale Research Articles

Usability of Visual Analogue Scales in Assessing Human Perception of Sound with University Students Using a Web-Based Tablet Interface

Response scales in auditory perception assessment are critical for capturing the true responses of listeners. Despite its impact on data, response scales have received the least attention in auditory perception assessment. In this study, the usability of visual analogue scales for auditory perception assessment was investigated. Five response scales (a unipolar visual analogue scale–negated to regular, a unipolar visual analogue scale—regular to negated, a bipolar visual analogue scale–positive to negative, a bipolar visual analogue scale—negative to positive, and a unipolar 11-point scale (ISO/TS 15666:2021)) for auditory perception assessment are presented. Music and traffic noise were presented to 60 university students at two different levels, i.e., 45 and 65 dBA, respectively. A web-based experimental design was implemented, and tablet pads were provided to the respondents to record their responses. The unipolar 11-point scale required the longest response time, followed by the two unipolar visual analogue scales and two bipolar visual analogue scales with statistical significance. All response scales used in this study achieved statistical reliability and sensitivity for the auditory perception assessment. Among the five response scales, the bipolar visual analogue scale (negative to positive) ranked first in reliability over repeated measures, exhibited sensitivity in differentiating sound sources, and was preferred by the respondents under the conditions of the present study. None of the respondents preferred the unipolar 11-point scale. The visual analogue scale was favoured over the traditional unipolar 11-point scale by young educated adults in a mobile-based testing environment. Moreover, the bipolar visual analogue scale demonstrated the highest reliability and sensitivity, and it was preferred the most by the respondents. The semantic labelling direction from negated to regular, or from negative to positive, is preferred over its opposite counterpart. Further research is necessary to investigate the use of response scales for the general public including children and the elderly, as well as that of semantic adjectives and their counterparts for auditory perception assessment.

Identification of Optimal Measures of Human Abuse Potential: A Post Hoc Assessment of 19 Studies.

Human abuse potential studies include multiple measures to assess the subjective effects of central nervous system-active drugs. In this retrospective analysis, measurement properties of commonly used measures were assessed, and factor analysis was conducted to identify a core battery of measures. Measures of positive, negative and other effects, for example, bipolar "at-the-moment" Drug Liking visual analog scale (VAS), were derived for active controls and placebo from 19 studies in recreational drug users (N = 570). Distribution, placebo response, variability, convergent/discriminant validity, parameter effect sizes (eg, maximum effect [Emax], time-averaged area under the effect curve), and predictive validity were evaluated. A factor analysis was conducted with 9 studies. Most parameters were not normally distributed. Bipolar VAS exhibited the lowest variability. Drug Liking VAS Emax was very sensitive, showed large effect sizes (>1.0), and was moderately to strongly correlated with Emax of other positive effects measures (r > 0.5), but weaker with less specific scales (eg, high, Any Effects VAS); time-averaged area under the effect curve showed higher variability and lower effect sizes. Maximum effect at any dose (EmaxD) was significantly correlated with Emax across all selected measures and showed higher effect sizes. In the overall factor analysis, factors could be categorized into positive effects/euphoria (77% of variance), negative effects (17.9%), and pharmacologic effects (5%). For predictive validity, effect sizes for Drug Liking VAS Emax/EmaxD were moderately correlated with postmarket adverse events related to abuse (R = 0.52). A core battery of 7 subjective measures was proposed, with additional measures added based on pharmacologic effects.

Comparison of Response Scales as Measures of Indoor Environmental Perception in Combined Thermal and Acoustic Conditions

Response scales are widely used to assess the personal experience of sensation and perception in built environments, and have a great impact on the quality of the responses. The purpose of this study was to investigate the effects of response scales on human sensation and perception in moderate indoor environments. Four different response scales were compared under three room temperatures (19.0 °C, 24.5 °C, and 30.0 °C) and five acoustic stimuli (ambient noise, 42 and 61 dBA × water sounds and traffic noise): a bipolar seven-point scale according to ISO 10551:1995, a unipolar 11-point scale according to ISO/TS 15666:2003, these two scales combined for each sensory comfort assessment, and a bipolar visual analogue scale. The degree of relative differentiation based on indoor physical factors made no significant difference across the four response scales. Therefore, the effects of physical factors on human response could be assessed by using any of the four scales tested in this study, with a statistical significance at p < 0.05 in moderate environments. The choice of response scale would depend not only on the type of physical stimulus but also on the question of sensation or perception. The reliability of each response scale was different according to the subjective attributes. The bipolar visual analogue scale was subjectively preferred by the respondents.

Pharmacokinetics and Abuse Potential of Benzhydrocodone, a Novel Prodrug of Hydrocodone, After Intranasal Administration in Recreational Drug Users.

ObjectiveDeveloping an acetaminophen-free, immediate-release hydrocodone product remains an unmet medical need; however, new opioid analgesics should not introduce new abuse risks. Benzhydrocodone is a prodrug of hydrocodone that must be metabolized into hydrocodone by enzymes in the intestinal tract to optimally deliver its pharmacologic effects. This study evaluated the intranasal pharmacokinetics and abuse potential of benzhydrocodone active pharmaceutical ingredient (API) compared with hydrocodone bitartrate (HB) API.DesignSingle-center, randomized, double-blind, crossover study.SettingClinical research site.SubjectsHealthy adult, nondependent, recreational opioid users.MethodsSubjects (N = 51 Completers) were randomized to receive 13.34 mg of intranasal benzhydrocodone API and 15.0 mg of intranasal HB API (molar-equivalent doses of hydrocodone). Blood samples were taken, and Drug Liking scores (assessed on a bipolar visual analog scale) were obtained throughout each dosing interval. Nasal irritation and safety were assessed.ResultsPeak hydrocodone plasma concentration (Cmax) was 36.0% lower, and total hydrocodone exposures (AUClast and AUCinf) were 20.3% and 19.5% lower, respectively, for benzhydrocodone API compared with HB API (P < 0.0001). All partial AUC values were lower for benzhydrocodone API, with a ≥ 75% reduction in hydrocodone exposure at all time intervals up to one hour postdose (P < 0.0001). Median Tmax of hydrocodone following benzhydrocodone API was delayed by more than one hour compared with HB. Drug Liking score, as assessed by maximal liking (Emax), was significantly lower for benzhydrocodone API vs HB API (P = 0.004), with 45% of subjects showing a ≥ 30% reduction in Drug Liking Emax.ConclusionReductions in hydrocodone exposure and associated decreases in Drug Liking relative to HB suggest that the prodrug benzhydrocodone may deter intranasal abuse.

(421) CR845, a novel peripherally-acting kappa opioid receptor agonist, has low abuse potential compared with pentazocine

CR845, a potent, peripherally-acting, selective kappa opioid receptor agonist, is being developed for the treatment of acute and chronic pain. This study examined the relative abuse potential of CR845 compared to placebo or pentazocine, a schedule IV opioid analgesic. Recreational polydrug users with experience with opioids and hallucinogenic agents were enrolled in this single-center, randomized, double-blind, active- and placebo-controlled study. Thirty-nine subjects received a single bolus IV dose of the following 4 treatments in random order: CR845 5 mcg/kg (therapeutic dose), CR845 15 mcg/kg (supra-therapeutic dose), placebo, and pentazocine 0.5 mg/kg. Treatments were separated by 48-hour washout period. Drug liking bipolar Visual Analog Scale (VAS) was the primary measurement, and was assessed periodically between 5 minutes and 8 hours after dosing. This trial met the primary endpoint with drug liking scores for pentazocine significantly greater than that of placebo and either doses of CR845 (P<0.0001 for each comparison to pentazocine). The least squares (LS) mean for the maximum drug liking VAS (Emax) scores (±standard error of LS mean) were 87.6±1.9 for pentazocine, 65.3±1.9 for CR845 5 mcg/kg, 66.9±1.9 for CR845 15 mcg/kg, and 52.4±1.9 for placebo, indicating that both doses of CR845 had significantly lower drug liking response compared to pentazocine. Additional bipolar VAS measurements were lower for CR845 compared with pentazocine for “overall drug liking” (P<0.0001 for both doses of CR845) and “take drug again” (P<0.0003 for CR845 5 mcg/kg and P<0.0001 for CR845 15 mcg/kg). These VAS scores for CR845 were equivalent for both doses and were similar to those of placebo. These results suggest that the novel and selective peripherally acting kappa agonist CR845 may present a low risk for abuse liability in humans. Sponsored by Cara Therapeutics. CR845, a potent, peripherally-acting, selective kappa opioid receptor agonist, is being developed for the treatment of acute and chronic pain. This study examined the relative abuse potential of CR845 compared to placebo or pentazocine, a schedule IV opioid analgesic. Recreational polydrug users with experience with opioids and hallucinogenic agents were enrolled in this single-center, randomized, double-blind, active- and placebo-controlled study. Thirty-nine subjects received a single bolus IV dose of the following 4 treatments in random order: CR845 5 mcg/kg (therapeutic dose), CR845 15 mcg/kg (supra-therapeutic dose), placebo, and pentazocine 0.5 mg/kg. Treatments were separated by 48-hour washout period. Drug liking bipolar Visual Analog Scale (VAS) was the primary measurement, and was assessed periodically between 5 minutes and 8 hours after dosing. This trial met the primary endpoint with drug liking scores for pentazocine significantly greater than that of placebo and either doses of CR845 (P<0.0001 for each comparison to pentazocine). The least squares (LS) mean for the maximum drug liking VAS (Emax) scores (±standard error of LS mean) were 87.6±1.9 for pentazocine, 65.3±1.9 for CR845 5 mcg/kg, 66.9±1.9 for CR845 15 mcg/kg, and 52.4±1.9 for placebo, indicating that both doses of CR845 had significantly lower drug liking response compared to pentazocine. Additional bipolar VAS measurements were lower for CR845 compared with pentazocine for “overall drug liking” (P<0.0001 for both doses of CR845) and “take drug again” (P<0.0003 for CR845 5 mcg/kg and P<0.0001 for CR845 15 mcg/kg). These VAS scores for CR845 were equivalent for both doses and were similar to those of placebo. These results suggest that the novel and selective peripherally acting kappa agonist CR845 may present a low risk for abuse liability in humans. Sponsored by Cara Therapeutics.

(425) Evaluation of the relative intranasal abuse potential of a hydrocodone extended-release tablet formulated with abuse-deterrence technology in nondependent, recreational opioid users

Misuse and abuse of opioids pose serious public health and safety risks. A hydrocodone bitartrate extended-release (ER) tablet, formulated with CIMA® Abuse-Deterrence Technology, provides resistance against rapid release of hydrocodone when tablets are manipulated or taken with alcohol, potentially reducing abuse liability when misused or abused. This study examined the relative abuse potential of manipulated intranasal hydrocodone ER in healthy nondependent adults with a history of recreational and intranasal opioid use. Subjects able to tolerate a 45-mg intranasal dose of hydrocodone active pharmaceutical ingredient (API) powder and discriminate effects of hydrocodone from placebo were randomized into a double-blind, 5-period crossover, treatment phase to assess abuse potential. Subjects received each of the following: intranasal manipulated hydrocodone ER 45 mg, intranasal hydrocodone API 45 mg, intact oral hydrocodone ER 45 mg, intranasal manipulated Zohydro 45 mg (commercially available hydrocodone ER capsule), and placebo. Forty-five subjects were enrolled; 34 were evaluable for pharmacodynamic assessments performed through 48 hours after administration of study drug. Maximum effect (Emax) of “at this moment” drug liking based on a bipolar Visual Analog Scale (VAS; primary endpoint) was significantly (P=0.004) lower for hydrocodone ER vs. hydrocodone API and Zohydro (72.8 vs. 80.2 and 83.2, respectively) and significantly (P<0.001) higher vs. oral hydrocodone ER (57.3) and placebo (58.6). Emax of end-of-day/next-day Overall Drug Liking VAS (co-primary endpoint) was also significantly (P=0.004) lower for hydrocodone ER vs. hydrocodone API and Zohydro (68.5 vs. 77.1 and 79.8, respectively) and significantly (P≤0.001) higher vs. oral hydrocodone ER (57.8) and placebo (57.7). No new safety signals were observed. Abuse potential via the intranasal route, one of the two most common routes of abuse, was significantly lower with hydrocodone ER compared with non–abuse-deterrent opioid products, including Zohydro. When administered as intended (intact orally), liking scores for hydrocodone ER were similar to placebo. Misuse and abuse of opioids pose serious public health and safety risks. A hydrocodone bitartrate extended-release (ER) tablet, formulated with CIMA® Abuse-Deterrence Technology, provides resistance against rapid release of hydrocodone when tablets are manipulated or taken with alcohol, potentially reducing abuse liability when misused or abused. This study examined the relative abuse potential of manipulated intranasal hydrocodone ER in healthy nondependent adults with a history of recreational and intranasal opioid use. Subjects able to tolerate a 45-mg intranasal dose of hydrocodone active pharmaceutical ingredient (API) powder and discriminate effects of hydrocodone from placebo were randomized into a double-blind, 5-period crossover, treatment phase to assess abuse potential. Subjects received each of the following: intranasal manipulated hydrocodone ER 45 mg, intranasal hydrocodone API 45 mg, intact oral hydrocodone ER 45 mg, intranasal manipulated Zohydro 45 mg (commercially available hydrocodone ER capsule), and placebo. Forty-five subjects were enrolled; 34 were evaluable for pharmacodynamic assessments performed through 48 hours after administration of study drug. Maximum effect (Emax) of “at this moment” drug liking based on a bipolar Visual Analog Scale (VAS; primary endpoint) was significantly (P=0.004) lower for hydrocodone ER vs. hydrocodone API and Zohydro (72.8 vs. 80.2 and 83.2, respectively) and significantly (P<0.001) higher vs. oral hydrocodone ER (57.3) and placebo (58.6). Emax of end-of-day/next-day Overall Drug Liking VAS (co-primary endpoint) was also significantly (P=0.004) lower for hydrocodone ER vs. hydrocodone API and Zohydro (68.5 vs. 77.1 and 79.8, respectively) and significantly (P≤0.001) higher vs. oral hydrocodone ER (57.8) and placebo (57.7). No new safety signals were observed. Abuse potential via the intranasal route, one of the two most common routes of abuse, was significantly lower with hydrocodone ER compared with non–abuse-deterrent opioid products, including Zohydro. When administered as intended (intact orally), liking scores for hydrocodone ER were similar to placebo.

Vital capacity and inspiratory capacity as additional parameters to evaluate bronchodilator response in asthmatic patients: a cross sectional study

BackgroundBronchodilator response in patients with asthma is evaluated based on post-bronchodilator increase in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). However, the need for additional parameters, mainly among patients with severe asthma, has already been demonstrated.MethodsThe aim of this study was to evaluate the usefulness of vital capacity (VC) and inspiratory capacity (IC) to evaluate bronchodilator response in asthma patients with persistent airflow obstruction. The 43 asthma patients enrolled in the study were stratified into moderate or severe airflow obstruction groups based on baseline FEV1. All patients performed a 6-minute walk test before and after the bronchodilator (BD). A bipolar visual analogue scale post-BD was performed to assess clinical effect. The correlation between VC and IC and clinical response, determined by visual analogue scale (VAS) and 6-minute walk test (6MWT), was investigated.ResultsPatients in the severe group presented: 1) greater bronchodilator response in VC (48% vs 15%, p = 0.02), 2) a significant correlation between VC variation and the reduction in air trapping (Rs = 0.70; p < 0.01), 3) a significant agreement between VC and VAS score (kappa = 0.57; p < 0.01). There was no correlation between IC and the reduction in air trapping or clinical data.ConclusionsVC may be a useful additional parameter to evaluate bronchodilator response in asthma patients with severe airflow obstruction.

Does an IV Bolus of Methylprednisolone Relieve Dyspnea in Asthma Exacerbations?

To assess whether IV methylprednisolone exerts a specific early effect on dyspnea in patients with an exacerbation of asthma. Randomized, placebo-controlled, double-blind crossover trial. Medium-sized university general hospital. Twenty-five asthma patients attending the chest clinic with spontaneous complaints of increases in dyspnea and with a Borg scale dyspnea rating >/= 1 at rest. At 0 min, IV methylprednisolone (125 mg) vs saline solution; at 60 min, 5 x 500 microg terbutaline inhaled from an inhaler device. Change in dyspnea was assessed with bipolar visual analog scale (VAS) (much more short of breath, -100%; much less short of breath, + 100%), FEV(1), and visual memory (using the Benton visual retention test). Eighteen subjects (mean age, 61 years) completed the study. At 5 min and 60 min, shortness of breath improved with no statistically significant difference between saline solution and methylprednisolone. The mean (SD) VAS rating at 60 min was 29% (39%) on the day that saline solution was administered and 36% (25%) on the day the steroid was administered. FEV(1) and Benton score did not significantly change from baseline on either study day. Shortness of breath and FEV(1) improved following terbutaline administration, with no significant difference between the days on which saline solution and the steroid were administered. In the seven subjects who were randomized to receive methylprednisolone on the first day, baseline dyspnea rated on the Borg scale was significantly lower on the second day (first day: median, 3; range, 3 to 4; second day: median, 2; range, 0.5 to 3; p = 0.040). We conclude that in patients with an exacerbation of asthma, an IV bolus of methylprednisolone does not reduce dyspnea more than saline solution after 5 min and 60 min.

Do counselling supervisors want or need to have their supervision supervised? An exploratory study

In response to a survey of counselling supervisors, 70 practitioners provided information about their practice as supervisors of counsellors and supervisors of supervisors. Questions were asked about the practice of supervision for supervision and attitudes towards the BAC Code of Ethics and Practice for Supervisors requirement that supervisors have access to supervision for their supervisory work. All but six of the respondents claimed to have supervision for supervision. In response to questions about the helpfulness, general importance, ethical importance and desirability of supervision for supervision, for which a bipolar visual analogue scale was provided, mean scores were all above 70%, indicating that there was considerable satisfaction with supervision for supervision requirements. Factor analysis revealed only one factor including all four questions. Questions were asked about contracts with supervision supervisors. A total of 55.7% used the same supervisor for their clinical work and supervision. In response to a question about issues raised in supervision, four categories accounted for the majority of comments: boundaries, competence of supervisees, training and ethics.

Disabling dyspnoea in patients with advanced disease: lack of effect of nebulized morphine

The purpose of this placebo-controlled, double-blind, randomized study was to assess the effect of nebulized morphine on dyspnoea perceived at rest by patients with advanced disease. Seventeen hospital in-patients with disabling dyspnoea received isotonic saline or morphine via nebulization for 10 min through a mouthpiece, combined with oxygen via nasal prongs. On four consecutive days, they were given one of the four following treatments in random order: saline with 2 L x min(-1) oxygen; 10 mg morphine with 2 L x min(-1) oxygen; 20 mg morphine with 2 L x min(-1) oxygen; and 10 mg morphine without oxygen (prongs fixed, no flow). Dyspnoea was assessed on a bipolar visual analogue scale (VAS) (-100% much more short of breath, +100% much less short of breath), and arterial oxygen saturation (Sa,O2) and respiratory frequency (fR) were recorded at the end of nebulization and 10 min later. In 14 subjects who completed the study, mean VAS ratings 10 min after the end of nebulization ranged +30 to +43%, with no significant difference between the four study days (VAS 20 mg morphine minus VAS saline, 95% confidence interval (95% CI) -6 to +8%). Sa,O2 significantly increased on the 3 days with supplemental oxygen, and remained stable on the zero flow day. Respiratory frequency significantly decreased on the 4 days, with a trend to correlation between VAS rating and parallel change in respiratory frequency (Spearman's rank correlation coefficient (r(s))=0.46; p=0.09). We conclude that the subjects benefited from saline or morphine via a placebo effect and/or a nonspecific effect, and that nebulized morphine had no specific effect on dyspnoea.

Perception of dyspnoea during acute changes in lung function in patients with either asthma or COPD

The aim of the study was to evaluate the relationship between several lung function indices and perceived dyspnoea during bronchoconstriction. Acute changes in lung function were induced by inhaled histamine followed by terbutaline, in 12 asthmatics and 12 subjects with chronic obstructive pulmonary disease (COPD). A bipolar visual analogue scale (VAS), allowing subjects to report either improvement or worsening when moving off from a ‘nochange’ midpoint, was used to rate shortness of breath. Large swings in ratings were seen in all asthmatics and in seven out of 12 COPD subjects (high perceivers). Using linear regression of VAS rating against parallel change in lung function, on a within-subject basis, the highest degree of correlation between dyspnoea and objective response was found to involve the change in specific inspiratory resistance (sRin) in the asthmatics. In the five low perceivers, the ability to discriminate an increase in airway obstruction, estimated as the VAS/change in lung function slope, was very poor. Using a stepwise multiple regression analysis, the sensation of dyspnoea was found to be significantly related to the FEV 1 and the sRin in the asthmatics, to the inspiratory vital capacity and the maximal inspiratory flow at 50% FVC (MIF 50) in the COPD subjects with high perception, and to the MIF 50 in the COPD subjects with low perception.

How do patients with either asthma or COPD perceive acute bronchodilation?

The purpose of this study was to assess the perception of bronchodilation, as a change in shortness of breath on a bipolar visual analogue scale (VAS), in 16 asthmatics and 20 subjects with COPD. Bronchodilation was gradually induced by five consecutive terbutaline inhalations (cumulated dose 800 micrograms). The subjects were categorized into high and low perceivers, on the basis of a cut-off of 25% VAS line length (after the fifth inhalation). The quality of perception was studied on a within-subject basis by linear regression analysis of VAS ratings against changes in lung function, and was characterized in terms of strength of correlation (squared correlation coefficient, r2), slope, and VAS axis intercept. Fourteen out of 16 asthmatics, and 13 out of 20 COPD subjects, were high perceivers. In the COPD group, the high perceivers had a larger objective response--particularly in inspiratory vital capacity--than the low perceivers. The strongest correlation between subjective and objective response was obtained in asthmatics when the improvement in shortness of breath was evaluated against the decrease in specific inspiratory resistance (median r2 = 0.831). In COPD low perceivers, subjective and objective response were unrelated, while COPD high perceivers differed from the asthmatics by larger intercepts. The perceptual characteristics were unrelated to the degree of baseline obstruction, whilst a modest relationship (r = 0.51) was found between the increase in forced expiratory volume in one second (FEV1) and r2 of the VAS/delta FEV1 analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Human studies on abecarnil a new beta‐carboline anxiolytic: safety, tolerability and preliminary pharmacological profile.

1. Abecarnil (isopropyl-6-benzyloxy-4-methoxymethyl-beta-carboline-3-carboxylate), a beta-carboline with high affinity for benzodiazepine receptors, was tested in healthy male subjects; single doses of abecarnil were given in five dosage levels (1 mg, 5 mg, 10 mg, 20 mg, 40 mg) and in a multiple dose study in four dosage levels (15 mg, 30 mg, 60 mg, 90 mg day-1) for 7 days. On two days following multiple dose treatment, placebo was given in single-blind conditions (follow-up). In each dosage level, in both studies drug was given to 10 subjects (7: verum, 3: placebo). 2. Safety and tolerability were evaluated by changes in vital signs, incidence and severity of adverse reactions and biochemical and haematological screening. Drug effects were estimated utilizing a bipolar visual analogue scale (poles: 'sleepy'-'alert') and a psychomotor task, the digit symbol substitution task. The pharmacokinetics of single and multiple doses were also determined in the multiple dose study. 3. Abecarnil was generally well tolerated. In the single dose study the most frequently reported side effects associated with abecarnil at high doses (20 and 40 mg) were dizziness, unsteady gait, and lack of concentration. A decrement in performance on the digit symbol substitution task was also observed in the two high dosage groups 20 mg and 40 mg. Evaluation of visual analogue scale ratings did not reveal a sedative effect even at higher doses. 4. In the multiple dose study the most frequently reported side effects during the treatment period were dizziness, unsteady gait, and lack of concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Perceived effect on shortness of breath of an acute inhalation of saline or terbutaline: variability and sensitivity of a visual analogue scale in patients with asthma or COPD

The purpose of the study was to validate a bipolar visual analogue scale (VAS) to assess the perceived effect on shortness of breath of an acute inhalation and to search for differences in perception between asthmatics and subjects with chronic obstructive pulmonary disease (COPD). Thirty two subjects with airway obstruction and a diagnosis of either asthma (n = 16) or COPD (n = 16) received three consecutive inhalations of isotonic saline, followed by two inhalations of 400 micrograms terbutaline. Saline was perceived by asthmatics as a slight improvement: VAS (median, 95% confidence interval) 9%, 0-18% of line length. COPD subjects could be separated into two subgroups: "high perceivers" (n = 8, VAS 43%, 33-53%) and "low perceivers" (n = 8, VAS 5%, 3-7%). The median intrasubject coefficient of variation of the three post-saline VAS ratings was 19.4% (asthma), 12.5% (COPD high perceivers), and 14.5% (COPD low perceivers). After terbutaline, asthmatics had, by selection, a larger increase in forced expiratory volume in one second (FEV1) than COPD subjects. However, for other indices (expiratory specific resistance, inspiratory vital capacity and maximal inspiratory flow at 50% forced vital capacity) the changes were smaller in COPD low perceivers than in both asthmatics and COPD high perceivers. The parallel improvement in VAS was 24%, 20-39% (asthma), 15%, 6-25% (COPD high perceivers) and 1%, -1-8% (COPD low perceivers). The most sensitive index was FEV1 in asthmatics, vital capacity in COPD subjects, VAS being among the most sensitive indices in the former, but among the least sensitive in the latter. We conclude that the sensitivity of this VAS to bronchodilation is better in asthmatics than in COPD subjects. The latter can however be separated into subgroups with high and low level of perception.

Quantitative measurement of anxiety in patients undergoing surgery for renal calculus disease

The anxiety experienced by patients undergoing surgical procedures is well documented and may affect the outcome of any operation. This has not been considered in modern urological surgery which is moving away from highly-invasive techniques towards minimal and even non-invasive procedures. Little work has been carried out to examine the patient's reaction to this new technology. This work has two aims: to assess patient anxiety before and after different procedures for renal calculus removal and to identify, where possible, factors that contribute to pre- and post-operative anxiety. The main method of quantifying stress was the measurement of palmar sweat by means of an evaporimeter. Other measurements used were a bi-polar visual analogue scale and the Spielberger State Anxiety Questionnaire. The results of the study demonstrated a highly significant reduction in the palmar sweat production (P less than 0.0001) and score obtained for the analogue scale (P less than 0.05) following open surgery, but no changes before and after treatment in any of the variables in patients undergoing percutaneous nephrolithotomy or lithotripsy. Analysis of the data in relation to the surgery demonstrated a significantly higher preoperative analogue score in patients undergoing open surgery compared with lithotripsy (P less than 0.05). Post-operatively, patients undergoing lithotripsy had a significantly higher palmar sweat response compared with patients undergoing open surgery (P less than 0.01). Pre-operatively, fear of a general anaesthetic was identified as a factor contributing to anxiety and post-operatively, pain was the most commonly identified stressor. The implications of these results to the patient and to both nursing and medical staff in terms of practice are discussed. This must include a careful pre-operative explanation.