Heart rate variability parameters do not correlate with pain intensity in healthy volunteers.

OBJECTIVE: When patients cannot indicate pain, physiological parameters may be useful. We tested whether heart rate variability (HRV) parameters, as reflection of sympathetic and vagal tone, can be used to quantify pain intensity. DESIGN: Prospective study. SUBJECTS AND SETTING: A standardized heat stimulus was applied to the forearm in 75 healthy volunteers during three study periods of 2 minutes. METHODS: Before and after each application, pain intensity was measured by a visual analog scale (VAS) and inter beat interval (IBI) was recorded. Standard deviation of normal to normal beat intervals (SDNN) of the IBI, the power of the low (LF, 0.07-0.14 Hz) and high frequency (HF, 0.15-0.50 Hz) band, and LF/HF ratio were calculated. Log transformation resulted in normal distribution. Correlation between HRV parameters and pain intensity was assessed by Pearson's correlation coefficient. RESULTS: Data from 73 volunteers (44 women) could be analyzed. The mean age was 30 ± 11 years. Compared with baseline, during all heat periods, pain intensity measured by VAS increased from 2 ± 3 mm, 3 ± 5 mm, and 2 ± 4 mm, to 40 ± 20 mm, 42 ± 21 mm, and 44 ± 22 mm, respectively. Log transformed SDNN (lnSDNN) and LF (lnLF) decreased; lnSDNN from 4.0 ± 0.4 to 3.9 ± 0.5, P = 0.002; 4.0 ± 0.4 to 3.9 ± 0.5, P = 0.016; and 4.1 ± 0.4 to 3.9 ± 0.4, P = 0.004, respectively; lnLF from 6.3 ± 1.0 to 6.1 ± 1.2, P = 0.001; 6.4 ± 1.0 to 6.2 ± 1.1, P = 0.019; and 6.5 ± 1.0 to 6.2 ± 1.1, P = 0.020, respectively. No correlation of any HRV parameter with VAS score was found. CONCLUSION: HRV parameters may detect responses to heat pain, but are not suitable to assess pain intensity.

Prostate specific antigen testing policy worldwide varies greatly and seems not to be in accordance with guidelines: a systematic review.

BACKGROUND: Prostate specific antigen (PSA) testing is widely used, but guidelines on follow-up are unclear. METHODS: We performed a systematic review of the literature to determine follow-up policy after PSA testing by general practitioners (GPs) and non-urologic hospitalists, the use of a cut-off value for this policy, the reasons for repeating a PSA test after an initial normal result, the existence of a general cut-off value below which a PSA result is considered normal, and the time frame for repeating a test. Data sources. MEDLINE, Embase, PsychInfo and the Cochrane library from January 1950 until May 2011. Study eligibility criteria. Studies describing follow-up policy by GPs or non-urologic hospitalists after a primary PSA test, excluding urologists and patients with prostate cancer. Studies written in Dutch, English, French, German, Italian or Spanish were included. Excluded were studies describing follow-up policy by urologists and follow-up of patients with prostate cancer. The quality of each study was structurally assessed. RESULTS: Fifteen articles met the inclusion criteria. Three studies were of high quality. Follow-up differed greatly both after a normal and an abnormal PSA test result. Only one study described the reasons for not performing follow-up after an abnormal PSA result. CONCLUSIONS: Based on the available literature, we cannot adequately assess physicians' follow-up policy after a primary PSA test. Follow-up after a normal or raised PSA test by GPs and non-urologic hospitalists seems to a large extent not in accordance with the guidelines.