Henrietta L. Logan

Adjunctive non-pharmacological analgesia for invasive medical procedures: a randomised trial

BACKGROUND Non-pharmacological behavioural adjuncts have been suggested as efficient safe means in reducing discomfort and adverse effects during medical procedures. We tested this assumption for patients undergoing percutaneous vascular and renal procedures in a prospective, randomised, single-centre study. METHODS 241 patients were randomised to receive intraoperatively standard care (n=79), structured attention (n=80), or self-hypnotic relaxation (n=82). All had access to patient-controlled intravenous analgesia with fentanyl and midazolam. Patients rated their pain and anxiety on 0-10 scales before, every 15 min during and after the procedures. FINDINGS Pain increased linearly with procedure time in the standard group (slope 0.09 in pain score/15 min, p<0.0001), and the attention group (slope 0.04/15 min; p=0.0425), but remained flat in the hypnosis group. Anxiety decreased over time in all three groups with slopes of -0.04 (standard), -0.07 (attention), and -0.11 (hypnosis). Drug use in the standard group (1.9 units) was significantly higher than in the attention and hypnosis groups (0.8 and 0.9 units, respectively). One hypnosis patient became haemodynamically unstable compared with ten attention patients (p=0.0041), and 12 standard patients (p=0.0009). Procedure times were significantly shorter in the hypnosis group (61 min) than in the standard group (78 min, p=0.0016) with procedure duration of the attention group in between (67 min). INTERPRETATION Structured attention and self-hypnotic relaxation proved beneficial during invasive medical procedures. Hypnosis had more pronounced effects on pain and anxiety reduction, and is superior, in that it also improves haemodynamic stability.

Selecting a sample size for studies with repeated measures

Many researchers favor repeated measures designs because they allow the detection of within-person change over time and typically have higher statistical power than cross-sectional designs. However, the plethora of inputs needed for repeated measures designs can make sample size selection, a critical step in designing a successful study, difficult. Using a dental pain study as a driving example, we provide guidance for selecting an appropriate sample size for testing a time by treatment interaction for studies with repeated measures. We describe how to (1) gather the required inputs for the sample size calculation, (2) choose appropriate software to perform the calculation, and (3) address practical considerations such as missing data, multiple aims, and continuous covariates.

Ethnic differences in diffuse noxious inhibitory controls.

UNLABELLED Substantial evidence indicates that the experience of both clinical and experimental pain differs among ethnic groups. Specifically, African Americans generally report higher levels of clinical pain and greater sensitivity to experimentally induced pain; however, little research has examined the origins of these differences. Differences in central pain-inhibitory mechanisms may contribute to this disparity. Diffuse noxious inhibitory controls (DNIC), or counterirritation, is a phenomenon thought to reflect descending inhibition of pain signals. The current study assessed DNIC in 57 healthy young adults from 2 different ethnic groups: African Americans and non-Hispanic whites. Repeated assessments of the nociceptive flexion reflex (NFR) as well as ratings of electrical pain were obtained before, during, and after an ischemic arm pain procedure (as well as a sham procedure). The DNIC condition (ie, ischemic arm pain) produced substantial reductions in pain ratings as well as electrophysiologic measures of the NFR for all participants when compared with the sham condition (P < .001). The DNIC condition produced significantly greater reductions in verbal pain ratings among non-Hispanic whites when compared with African Americans (P = .02), whereas ethnic groups showed comparable reductions in NFR. The findings of this study suggest differences in endogenous pain inhibition between African Americans and non-Hispanic whites and that additional research to determine the mechanisms underlying these effects is warranted. PERSPECTIVE This study adds to the growing literature examining ethnic differences in experimental pain perception. Our data suggest that these variations may be influenced by differences in descending inhibition.

Negative emotion and superficial social processing

Two studies examined whether negative emotional arousal increases the tendency to process social information less carefully. In both studies, subjects were dental patients waiting to receive a filling from a student dentist. In Study 1, 48 subjects responded to illusory correlation materials adopted from Hamilton & Rose (1980). As expected, those above the median on self-reported anxiety were more likely than low-anxious subjects to exhibit illusory correlation effects. In Study 2, fear level was manipulated. Thirty-four dental patients were instructed to evaluate critically a persuasive message after receiving either graphic descriptions of their upcoming procedure or filler information. As expected, the message evaluations made by high-fear subjects were more influenced by superficial cues (audience applause) and less influenced by central cues (message content) than the message evaluations made by subjects reporting at least moderate to high initial anxiety about dental treatment at the outset of the study. Theoretical and social implications are discussed.

Human Papillomavirus and Head and Neck Cancer

An increasing subset of patients with head and neck squamous cell carcinoma (HNSCCA) is positive for high-risk human papillomavirus (HR-HPV). Patients tend to be younger, have a minimal or absent tobacco and ethanol abuse history, increased number of lifetime sexual partners (particularly oral-genital sex), and squamous cell carcinomas (SCCAs) arising in the oropharynx. The most common HR-HPV associated with HNSCCA is HPV-16. HR-HPV positivity is associated with decreased expression of the p53 and Rb genes, overexpression of p16, decreased expression of EGFR, and a different genetic expression pattern compared with patients with HR-HPV-negative SCCAs, leading to the conclusion that this is a distinct clinical entity. Patients who have HR-HPV-positive HNSCCAs have an improved prognosis, particularly those with oropharyngeal SCCAs, leading some to speculate that the intensity of treatment might be decreased. At present, whether this can be done safely remains unclear.

Ethnic differences in the nociceptive flexion reflex (NFR)

&NA; A substantial body of literature suggests that the experience of both clinical and experimental pain differs among ethnic groups, with African Americans generally reporting greater sensitivity to chronic and experimentally induced pain when compared to non‐Hispanic whites. However, no studies to date have examined nociceptive processes that may underlie these differences. The nociceptive flexion reflex (NFR) is based on the measurement of stimulus‐induced spinal reflexes. Prior research suggests that the NFR threshold, or RIII response, is highly correlated with subjective pain thresholds. The current study evaluated responses to the nociceptive flexion reflex in healthy young adults from two different ethnic groups: African Americans (n = 29) and non‐Hispanic whites (n = 28). Perceptual responses (e.g., pain ratings) as well as physiological reflex responses (i.e., biceps femoris EMG) were assessed. Significant ethnic group differences were observed for NFR reflex threshold, with African Americans producing a reflex at lower stimulation intensities relative to non‐Hispanic whites. Interestingly, verbal pain ratings at NFR threshold were not significantly different between the groups, suggesting that the lower stimulation intensities required to elicit a reflex in African–American versus non‐Hispanic white participants were nonetheless perceived as similar. Psychological Involvement, Positive and Negative Mood, and Rumination were correlated with NFR threshold in a pattern that was consistent across both ethnic groups. These results extend previous research on ethnic differences in self‐report measures of pain by demonstrating group differences in a nociceptive muscle reflex.

Effects of relaxation and stress on the capsaicin-induced local inflammatory response.

Objective Although stress is known to modulate the inflammatory response, there has been little experimental examination of the effects of stress and stress reduction on inflammation in humans. In particular, the effects of stress and relaxation on neurogenic inflammation have been minimally studied. This study examines the effects of three experimental manipulations: mental stress, relaxation, and control on the local inflammatory response evoked by the intradermal injection of capsaicin, the active ingredient in chili peppers. Methods Fifty subjects (28 men and 22 women) were pretrained in relaxation using an imagery-based relaxation tape and then randomized to experimental condition. Subjects participated in an evening reactivity session including 20 minutes of a stress (Stroop test), relaxation (tape), or control (video) manipulation, followed by a capsaicin injection in the forearm. Digitized flare measurements were taken for 1 hour postcapsaicin, and measurements of cardiovascular variables, cortisol, adrenocorticotrophic hormone, and norepinephrine were taken at regular intervals. Results The size of the maximum capsaicin-induced flare was significantly smaller in the relaxation condition than in the stress or control conditions, which did not differ from each other. Increases in norepinephrine, heart rate, and systolic blood pressure during the experimental task, but not after capsaicin, significantly predicted size of maximum flare and total area under the curve of flare measurements. Conclusions These findings suggest that stress reduction may affect local inflammatory processes. Results are consistent with sympathetic modulation of the effects of relaxation on the flare response.

Human papillomavirus, smoking, and head and neck cancer

AIMS Smoking and human papillomavirus (HPV) are both distinct risk factors for head and neck cancer, but the nature of interaction between these 2 risk factors in the development of head and neck cancer remains unclear. The purpose of this review is to determine the potential effect of smoking in causation of HPV-related head and neck carcinoma. METHOD A literature search was carried out using the keywords human papillomavirus, head and neck cancer, smoking, tobacco, and cervical cancer. The English-language articles, references, and other relevant studies evaluating the association of smoking, HPV, and risk of head and neck cancer were collected and analyzed. CONCLUSION Overall, our review points to smoking tobacco posing an additional risk for development of head and neck cancer in the presence of HPV infection. This is consistent with available laboratory data that show evidence of biological plausibility for interaction between smoking and progression of HPV infection to carcinogenesis. It is therefore important that cessation of smoking is promoted in smokers with HPV infection.

Pain related recall predicts future pain report.

Abstract It is frequently necessary for patients to undergo multiple painful medical interventions as part of their diagnosis and care. Predictors of future pain report have yet to be established although initial pain level, affect, and memory of the procedure are often implicated. The purpose of this research was to establish a predictive model of future pain reporting using a standardized experimental pain stimulus. Forty‐three healthy subjects completed an initial forehead cold pressor task (Session 1) and an identical task nine months later (Session 2). Subjects also provided retrospective pain evaluations six months after Session 1. Hierarchical regression was used to identify predictors of Session 2 maximum pain intensity. Fifty‐six percent of the total variance (p < .01) was accounted when Session 1 maximum pain intensity, Session 1 negative affect, and remembered maximum pain intensity were loaded together in the model. Only 1% of the variance was uniquely accounted by Session 1 maximum pain intensity (p = .38) while remembered maximum pain intensity uniquely accounted for 25% of the variance (p ≤ .01) and Session 1 negative affect uniquely accounted for 17% of the variance (p ≤ .01). An additional 13% of the variance was shared between Session 1 maximum pain intensity and remembered maximum pain intensity. The level of remembered Session 1 pain was significantly exaggerated from the initial pain report (p ≤ .05) but not significantly different from the level of pain reported at Session 2. These findings provide strong evidence for a post‐pain modulation phenomenon in which cognitive processes influence both pain recall and future pain reporting.

Emotional and sensory focus as mediators of dental pain among patients differing in desired and felt dental control.

Giving patients instructions to focus on sensory (vs. emotional) stimuli during a root canal procedure significantly reduced self-reported pain, but only among patients who were classified as having strong desire for control and low felt control in dental situations. Among patients with low felt control and low desire for control, sensory-focus instructions produced greater pain reports than did emotion-focus instructions. Finally, high desire-low felt patients reported higher levels of expected pain before treatment than did other patient subgroups. These data suggested limiting conditions for H. Leventhals (1982) theory of emotion and supported the idea that desire for control might moderate the effects of perceived control.