Kidney Stones ============= þ Which stones will pass? - About 90% of ureteric stones smaller than 5 mm pass spontaneously, compared with about 50% of stones between 5 mm and 10 mm, so conservative management is preferred for ureteric stones - up to 98% of stones less than 0.5 cm. in diameter, especially in the distal ureter, will pass spontaneously. Shock wave lithotripsy is recommended as first line treatment for most patients with stones 1 cm. or less in the proximal ureter. Shock wave lithotripsy and ureteroscopy are acceptable treatment choices for stones 1 cm. or less in the distal ureter. [Segura JW, Preminger GM, Assimos DG, et al. Ureteral Stones Clinical Guidelines Panel summary report on the management of ureteral calculi. The American Urological Association. The Journal of urology 1997;158:1915-21.] þ How long does it take to pass? Size % that pass time to pass avg time to pass <2 mm 95% by 8 d 95% by 31 d 8.2 d 2-4 mm 83% by 12 d 95% by 40 d 12.2 d 4-6 mm 50% by 22 d 95% by 39 days 22.1 d * (based on asymptomatic on 1 week visit, may be a lot faster than this) [Miller, O. F. and C. J. Kane (1999). "Time to stone passage for observed ureteral calculi: a guide for patient education." The Journal of urology 162(3 Pt 1): 688-690; discussion 690-681.] PURPOSE: We analyze the natural history of stone passage in patients with ureterolithiasis, and define factors predictive of spontaneous passage. MATERIALS AND METHODS: A total of 75 patients with ureteral calculi were prospectively followed for stone passage. Clinical data included patient gender and age, stone size and location, pain medication requirements and interval to stone passage. Of the 75 patients 13 (17%) required intervention and 62 (83%) were followed until spontaneous stone passage. Stones requiring intervention were not included in the time to passage analysis. RESULTS: Of the 75 patients 41 (55%) had ureteral stones 2 mm. or smaller with an average time to stone passage of 8.2 days and only 2 (4.8%) required intervention, 18 (24%) had stones between 2 and 4 mm. with an average time to stone passage of 12.2 days and 3 (17%) required intervention, and 16 had stones 4 mm. or greater with an average time to stone passage of 22.1 days and 8 required intervention. For 95% of stones to pass it took 31 days for those 2 mm, or less, 40 days for those 2 to 4 mm. and 39 days for those 4 to 6 mm. Multivariate analysis revealed that size, location and side were statistically related to stone passage interval (p = 0.012). Stones that were smaller, more distal and on the right side were more likely to pass spontaneously and required fewer interventions. CONCLUSIONS: Interval to stone passage is highly variable and dependent on stone size, location and side. Degree of pain, and patient gender and age had no bearing on the time to stone passage. Of ureteral stones 95% 2 to 4 mm. pass spontaneously but passage may take as long as 40 days. Intervention may be required in 50% of ureteral calculi greater than 5 mm. þ Hematuria - 90% have hematuria acutely, drops to 65% by day 3 þ Infected Kidney Stone? - expect ^ temp, ^ WBC, ? slight ^ Cr - bacteria in urine, WBC in urine þ Hydronephrosis - seen 2/3 of time on CT - probably about 50% for ultrasound (less sensitive) þ X-Rays and CT for Kidney Stones þ Drugs for Kidney Stones? (give a 1-week prescription with 3 refills; urology recommends Rx for a month) Hollingsworth, J. M., M. A. Rogers, et al. (2006). "Medical therapy to facilitate urinary stone passage: a meta-analysis." Lancet 368(9542): 1171-9. BACKGROUND: Medical therapies to ease urinary-stone passage have been reported, but are not generally used. If effective, such therapies would increase the options for treatment of urinary stones. To assess efficacy, we sought to identify and summarise all randomised controlled trials in which calcium-channel blockers or alpha blockers were used to treat urinary stone disease. METHODS: We searched MEDLINE, Pre-MEDLINE, CINAHL, and EMBASE, as well as scientific meeting abstracts, up to July, 2005. All randomised controlled trials in which calcium-channel blockers or alpha blockers were used to treat ureteral stones were eligible for inclusion in our analysis. Data from nine trials (number of patients=693) were pooled. The main outcome estimate of effect associated with medical therapy use using random-effects and fixed-effects models. FINDINGS: Patients given calcium- channel blockers or alpha blockers had a 65% (absolute risk reduction=0.31 95% CI 0.25-0.38) greater likelihood of stone passage than those not given such treatment (pooled risk ratio 1.65; 95% CI 1.45-1.88). The pooled risk ratio for alpha blockers was 1.54 (1.29-1.85) and for calcium-channel blockers with steroids was 1.90 (1.51-2.40). The proportion of heterogeneity not explained by chance alone was 28%. The number needed to treat was 4. INTERPRETATION: Although a high-quality randomised trial is necessary to confirm its efficacy, our findings suggest that medical therapy is an option for facilitation of urinary-stone passage for patients amenable to conservative management, potentially obviating the need for surgery. þ Differential Diagnosis of Flank Pain/Hematuria - AAA rupture (especially if L flank pain or LLQ pain) - endocarditis þ Fluid administration will neither (1) make kidney stones come out more quickly, nor (2) make the pain better or worse. [Edna TH. Acute renal colic and fluid intake. Scand J Urol Nephrol 1985;17:175.] þ Degree of hematuria is not significantly related to degree of ureteral obstruction. [Stewart DP, et al. Microscopic hematuria and calculus-related ureteral obstruction. J Emerg Med 1990;8:693.] þ Recurrence of Kidney Stones - After their first stone, 37% of patients will have a recurrence within 1 year, and greater than 50% will have a recurrence within their lifetime. Reference: Rosen CD-ROM line 30810 þ Types of Kidney Stones - Most kidney stones (~75%) are composed of calcium (either calcium oxalate or a mix of calcium oxalate and calcium phosphate). - 15% of stones are composed of magnesium-ammonium-phosphate (struvite), and - 10% are composed of uric acid. - Cystine stones are rare. Reference: Rosen CD-ROM line 30811 - From the 1997 edition of Manual of Clinical Problems in Adult Ambulatory Care (pp 276-7), comes this recommendation: "The composition of stones should be determined, whenever possible... Treatment is largely influenced by the type of stones." The authors then make the following recommendations: + For most stones, which are calcium-containing, initial drug treatment is HCTZ along with a low-calcium low-oxalate diet. Allopurinol may be used for patients who do not respond and who also have hyperuricosuria along with their calcium stones. + For uric acid or cystine stones, potassium citrate with or without acetazolamide can be used to alkalinize the urine and dissolve these stones. For cystinuria with cystine stones refractory to other treatment, d-penicillamine, which forms soluble complexes with cystine, can be used. --James Li, M.D. þ Renal Obstruction - There may be a measurable loss of renal function when total renal obstruction has persisted for 5 days. After this, the chance of irreversible loss of function increases. At 2 weeks, irreversible loss of function is certain. Reference: Rosen CD-ROM line 30835 þ Which Stones will Pass? - A stone in the lower ureter which is less than 5mm in diameter will pass spontaneously 90% of the time. This percentage drops to 5% if the diameter is greater than 8mm. The actual stone size is about 80% of the apparent size on x-ray. Reference: Rosen CD-ROM line 30838 ------------------------------------------------------------------------------ > I would like to know when >IVP's should be ordered on patients that look like a stone, smell like a >stone and taste like a stone (not literally of course) who have dramatically >improved symptomatically with minimal treatment in the ED. Here is a recent study in the Annals that looked at this issue. They conclude that everyone should have an IVP, as the incidence of unexpected findings is significant, with a change in management of 60% of patient studied. --Greg Johnston, M.D. Wrenn K Emergency intravenous pyelography in the setting of possible renal colic: is it indicated? Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA. Ann Emerg Med 1995 Sep;26(3):304-7 Article Number: UI95390511 ABSTRACT: STUDY OBJECTIVE: To determine whether emergency IV pyelography (IVP) adds significant information to clinical judgment in the setting of possible renal colic. DESIGN: A prospective voluntary survey of a convenience sample of physicians at the time of patient encounter. SETTING: The emergency department of a university hospital, annual census 50,000 visits. PARTICIPANTS: Emergency medicine faculty physicians. INTERVENTION: Physicians were surveyed before and after IVP was performed on patients with possible renal colic. RESULTS: Over the course of 12 months, 62 patients with possible kidney stones were evaluated by 14 different faculty ED physicians, who filled out surveys. Before IVP results were obtained, 63% of patients were thought to have a high (more than 75%) probability of ureteral obstruction. In 59% of these patients, the IVP results showed ureteral obstruction. The IVP revealed unexpected findings in 42% of all patients, including normal results in 19%, ureteral stones in 5%, higher than expected grade of obstruction in 6%, and lower than expected grade of obstruction in 6%, and lower than expected grade of obstruction in 5%. Management was reported to have been changed in 60% of all patients for a wide variety of reasons, but consideration of alternative diagnosis was the most common reason, occurring in 23%. Management changes included unexpected hospital admission in five patients (9%) and emergency urologic consultation in five patients (9%). CONCLUSION: Emergency IVPs are useful in the evaluation of patients with suspected renal colic, primarily when they rule out ureteral obstruction and allow consideration of alternative diagnoses. Not uncommonly, emergency urologic consultation or hospitalization occurs on the basis of IVP findings. ------------------------------------------------------------------------ Certainly, distension of the collecting system appears to be responsible for the pain of ureteral colic. In part, the 'unreasonable effectiveness' of prostaglandin inhibitors seems related to their ability to acutely reduce renal blood flow and mitigate this distension (1). Reduction of intraluminal pressure by NSAIDS also appears to account for their effectiveness in alleviating biliary colic (2). Nevertheless, as the above comments indicate, I have seen several patients who lack hematuria OR have severe pain show minimal, if any, hydronehprosis on IVP. I suspect that early on, intraluminal pressure rises rapidly with obstruction before the collecting system adapts by dilating--similar to the observation that pericrdial effusion, when acute in onset, causes a rapid rise in intrapericardial pressure and may cause tamponade with only a small amount of fluid which does not alter the cardiac sillouette. By contrast massive pericardial effusion may have no hemodynamic consequences when chronic and the pericardium has had a chance to gradually accomodate to the increased volume. Thus, I do not accept the proposition that patients who lack hematuria or have severe pain invariably have hydronephrosis. H. Louzon MD (1) Perlmutter A, Miller L, Trimble LA, Marion DN, Vaughan ED Jr, Felsen D Toradol, an NSAID used for renal colic, decreases renal perfusion and ureteral pressure in a canine model of unilateral ureteral obstruction. J Urol 1993 Apr;149(4):926-30 Toradol is a new parenteral, nonsteroidal anti-inflammatory drug which is efficacious in treating renal coli. In the present experiments, Toradol was administered to both control dogs and dogs with unilateral ureteral obstruction. In control dogs, Toradol had no effect on RBF or GFR, despite inhibition of renal prostaglandin synthesis (measured as urinary prostaglandin release). In contrast, RBF fell acutely by 35% (p < 0.001) within 15 minutes of Toradol administration in the setting of ureteral obstruction; contralateral RBF was unaffected. Ipsilateral ureteral pressure also fell. Changes in RBF and ureteral pressure, together with the known effects of NSAIDs on pain pathways, may contribute to the pain relief observed clinically with Toradol. However, the abrupt changes in renal hemodynamics brought on by Toradol to the obstructed kidney may compromise renal reserve, and Toradol should be used cautiously in treating renal colic. (2) Anez MS, Martinez D, Pacheco JL, Gonzalez H, Rivera J, Pelaschier E, Uzcategui L, Romero MD, Molina Z, Roditti de Montilla M, et al [Indomethacin in the treatment of acute cholecystitis and biliary colic] G E N 1991 Jan-Mar;45(1):32-7 Prostaglandins GE2 produces on the gallbladder a rise in intraluminal pressure, an increase in in intraluminal secretion, improves gallbladder contraction and decreases its absorption capacity. In this study, patients who received indomethacin twice a day by rectum, showed a significant reduction in volume and area of gallbladder after 24 and 48 hours (P < 0.05). The gallbladder volume after 24 hours had SEM 9.13 cm3, 95% CI 55.28 + 73.49 (P < 0.05). Score pain reduction after 24 hours was also significant (P < 0.001). The patients who underwent the classical Baralcina treatment of one IV vial BID showed a reduction in diameter and area of gallbladder but this was not statistically significant (P < 0.10). Reduction of volume at 24 hours was SEM 5.34 cm3 95% CI - 64.72 + 76.60 P 0.10 NS; and at 48 hours SEM 3.5 cm3, 95% CI 59.52% + 66.52 P 0.40. Score pain reduction was only significant at 48 hours P 0.001. The number of patients without pain at 24 hours was significantly higher in the indomethacin group ESP 0.21; 95% CI 0.46 + 0.88 P 0.001. In conclusion indomethacin is a useful medication in the treatment of acute cholecystitis and biliary colic due to its anti-prostaglandin effect on the gallbladder.