Seasonal variations of renal colics and urolithiasis: is this the time for a shared benchmark to study the phenomenon?

Are there seasonal variations in renal colic in uric acid stone formers in Germany?

PURPOSE

Seasonal variations in renal colic have been described by many authors for different countries worldwide. In most studies, there was no differentiation with regard to stone composition. Recently, we demonstrated that there was no seasonal variation in renal colic and urine chemistry for calcium oxalate stone formers in Germany. As we have many uric acid stone formers (UASFs) in our region, we were interested in learning the situation of this type of stone.

METHODS

We studied 286 consecutive UASFs with symptoms of renal colic. We divided them into four groups according to the quarters of the year. For stone analysis, X-ray diffraction/polarizing microscopy was used. Additionally, the following general parameters were examined in all patients: age, BMI, blood pressure, stone frequency, diabetes mellitus; blood: creatinine, glucose, uric acid, calcium, sodium and potassium; urine: pH, volume, calcium, uric acid, citrate, ammonia, and urea. Using the statistical program Prism 5 (GraphPad Software, San Diego, USA), significant differences between the four groups were calculated by the Kruskal-Wallis test.

RESULTS

We observed significantly more UASFs with renal colic in the third and fourth quarters of the year. This is in contrast to our findings in calcium oxalate patients. However, there was no variation in metabolic parameters.

CONCLUSION

The reasons are unclear; different temperatures are not a sufficient explanation, as one quarter is in the warm season and the other one is in the cold season. Unfortunately, no data have been reported in the literature thus far. Further studies are required to better understand these findings.

Time of admission, gender and age: challenging factors in emergency renal colic - a preliminary study

BACKGROUND

Nephrolithiasis is a relatively common problem and a frequent Emergency Department (ED) diagnosis in patients who present with acute flank/abdominal pain. The pain management in these patients is often challenging.

OBJECTIVES

To investigate the most effective dose of morphine with the least side effects in emergency renal colic patients.

MATERIALS AND METHODS

150 renal colic patients who experienced a pain level of 4 or greater, based on visual analog scale (VAS) at admission time were included. Pain was scored on a 100 mm VAS (0 = no pain, 100 = the worst pain imagined). When patients arrived at ED, a physician would examine the patients and assessed initial pain score, then filled a questionnaire according to the patient information. Patients were assigned to receive 2.5 mg morphine sulfate intravenously. We monitored patients' visual analog scale (VAS), and adverse events at different time points (every 15 minutes) for 90 minutes. Additional doses of intravenous morphine (2.5 mg) were administered if the patient still had pain. (Max dose: 10 mg). The cumulative dose of morphine, defined as the total amount of morphine prescribed to each patient during the 90 minutes of the study, was recorded. Patients were not permitted to use any nonsteroidal anti-inflammatory drugs as coadjuvant analgesics during the study period. Subjects with inadequate pain relief at 90 minutes received rescue morphine and were excluded from the study. The primary end point in this study was pain relief at 90 minutes, defined as either VAS<40 or decrease of 50% or more as compared to the initial VAS. The secondary objective was to detect the occurrence of adverse effects at any time points in ED.

RESULTS

The studied patients consisted of 104 men and 46 women with the mean age of 43 ±14 years (range, 18 to 75 years). There was no statistically significant difference between the mean age and gender differences in pain response. Rescue analgesia at 30 minutes were given in 54.5% receiving morphine. The average time to painless was 35 minutes. But there were no statistically significant differences between the mean age and gender differences in pain response (P > 0.05). Older patients responded sooner to morphine than the young. Most of the patients had a pain score of 90 -100 (77.3 %) at the beginning that was reduced to 29.4% during the 30 minutes follow up. During the first hour, we found that 94.7% of the patients had no pain or significant pain reduction and only 2.1% of the patients still had pain.

CONCLUSIONS

We conclude that there were no significant differences among the gender, time of admission and side - effects in renal colic patients in response to morphine.