Desmopressin for the prevention of bleeding in percutaneous kidney biopsy: efficacy and hyponatremia

International Urology and Nephrology - Desmopressin is used to reduce bleeding complications for kidney biopsies with azotemia but little is known about desmopressin-induced hyponatremia in these...     

Magnetic resonance imaging of articular cartilage: trauma, degeneration, and repair

The assessment of articular cartilage using magnetic resonance imaging has seen considerable advances in recent years. Cartilage morphologic characteristics can now be evaluated with a high degree of accuracy and reproducibility using dedicated pulse sequences, which are becoming standard at many institutions. These techniques detect clinically unsuspected traumatic cartilage lesions, allowing the physician to study their natural history with longitudinal evaluation and also to assess disease status in degenerative osteoarthritis. Magnetic resonance imaging also provides a more objective assessment of cartilage repair to augment the information obtained from more subjective clinical outcome instruments. Newly developed methods that provide detail at an ultrastructural level offer an important addition to cartilage evaluation, particularly in the detection of early alterations in the extracellular matrix. These methods have created an undeniably important role for magnetic resonance imaging in the reproducible, noninvasive, and objective evaluation and monitoring of cartilage. An overview of the advances, current techniques, and impact of magnetic resonance imaging in the setting of trauma, degenerative arthritides, and surgical treatment for cartilage injury is presented.     

The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety

Intravenous lidocaine is used widely for its effect on postoperative pain and recovery but it can be, and has been, fatal when used inappropriately and incorrectly. The risk-benefit ratio of i.v. lidocaine varies with type of surgery and with patient factors such as comorbidity (including pre-existing chronic pain). This consensus statement aims to address three questions. First, does i.v. lidocaine effectively reduce postoperative pain and facilitate recovery? Second, is i.v. lidocaine safe? Third, does the fact that i.v. lidocaine is not licensed for this indication affect its use? We suggest that i.v. lidocaine should be regarded as a ‘high-risk’ medicine. Individual anaesthetists may feel that, in selected patients, i.v. lidocaine may be beneficial as part of a multimodal peri-operative pain management strategy. This approach should be approved by hospital medication governance systems, and the individual clinical decision should be made with properly informed consent from the patient concerned. If i.v. lidocaine is used, we recommend an initial dose of no more than 1.5 mg.kg^-1, calculated using the patient’s ideal body weight and given as an infusion over 10 min. Thereafter, an infusion of no more than 1.5 mg.kg^-1.h^-1 for no longer than 24 h is recommended, subject to review and re-assessment. Intravenous lidocaine should not be used at the same time as, or within the period of action of, other local anaesthetic interventions. This includes not starting i.v. lidocaine within 4 h after any nerve block, and not performing any nerve block until 4 h after discontinuing an i.v. lidocaine infusion.     

Emergency surgery comparison of right versus left acute colonic diverticulitis: A 10-year outcome analysis

IntroductionThe difference in outcome between right (RCD) and left colonic diverticulitis (LCD) is not well established. The aim of this study was to analyse the presentation and surgical outcome of RCD versus left-sided disease following emergency surgery.MethodWe conducted a retrospective review of patients presenting with acute diverticulitis over a 10-year period from 2004 to 2014 to a tertiary unit. Patient demographics, Hinchey classification, need for emergency surgery, perioperative outcome and recurrence were evaluated.ResultsIn total 360 patients presented with acute diverticulitis, 218 (61%) were right-sided and 142 (39%) were left-sided. The mean age (57 yrs vs 68 yrs) and median length of stay (4 days vs 5 days) were significantly less in RCD (p < 0.001). The need for emergency surgery was similar between RCD and LCD (30.7% vs 23.2%, p = 0.12). Sixty-seven (31%) patients with RCD required emergency surgery, 42 (62.7%) of these were based on a presumptive diagnosis of appendicitis and underwent laparoscopic appendicectomy only. Operative morbidity (10.4% vs 51.5%, p < 0.001) and mortality were significantly higher in LCD (1.5% v 15.2%, p = 0.007). Subgroup analysis of non-appendicectomy, RCD patients, showed LCD were more likely to require surgery (11.5% vs 23.2%, p = 0.003). There was no difference in recurrence (p = 0.6).ConclusionRight colonic diverticulitis patients are younger and disease course is more benign compared to LCD. Presentation can be confused with appendicitis without proper imaging. In the rare cases where emergency surgery is required, RCD is associated with a lower operative morbidity and mortality compared to left-sided disease.     

Self‐expanding metallic stents for acute left‐sided large‐bowel obstruction: a review of 130 patients

Aim The aim of this study was to evaluate the outcomes of self‐expanding metallic stent (SEMS) placement in acute left‐sided large‐bowel obstruction. Method From 1997 to 2008, 130 patients [mean 67 (SD 14.7)] underwent SEMS insertion for acute left‐sided large‐bowel obstruction. One‐hundred and one procedures were palliative, and 29 patients underwent stent insertion as a bridge for surgery. The success rate and the outcome were analysed. Results The chief causes of obstruction were primary (67%) and recurrent (16%) colorectal carcinoma. The success rate was 88% after insertion of the first stent. In nine patients, insertion of a second stent was required. Complications occurred in 20% of the insertions, with migration (10.8%) being the most common. Perforation occurred in two patients and one developed a colovesical fistula. In patients with palliative stenting, 14 (13.9%) required subsequent surgery, with a stoma placed in all except three. Among the 29 patients who underwent SEMS insertion as a bridge to surgery, subsequent surgical resection was performed in 26 patients at a mean interval of 12 days (SD 18.0). Primary anastomosis was performed in 24 patients. The mean survival for those who underwent SEMS insertion as a bridge to surgery was 40 (95% confidence interval: 24–55) months. Conclusion SEMS placement is safe and effective in relieving acute left‐sided colonic obstruction. It allows subsequent definitive surgery on an elective setting and also serves as good palliation for advanced or disseminated disease.     

Adaptive vessel tracking: automated computation of vessel trajectories for improved efficiency in 2D coronary MR angiography

A new method was investigated for improving the efficiency of ECG-gated coronary magnetic resonance angiography (CMRA) by accurate, automated tracking of the vessel motion over the cardiac cycle. Vessel tracking was implemented on a spiral gradient-echo pulse sequence with sub-millimeter in-plane spatial resolution as well as high image signal to noise ratio. Breath hold 2D CMRA was performed in 18 healthy adult subjects (mean age 46 +/- 14 years). Imaging efficiency, defined as the percentage of the slices where more than 30 mm of the vessel is visualized, was computed in multi-slice spiral scans with and without vessel tracking. There was a significant improvement in the efficiency of the vessel tracking sequence compared to the multi-slice sequence (56% vs. 32%, P < 0.001). The imaging efficiency increased further when the true motion of the coronary arteries (determined using a cross correlation algorithm) was used for vessel tracking as opposed to a linear model for motion (71% vs. 57%, P < 0.05). The motion of the coronary arteries was generally found to be linear during the systolic phase and nonlinear during the diastolic phase. The use of subject-tailored, automated tracking of vessel positions resulted in improved efficiency of coronary artery illustration on breath held 2D CMRA.     

Induction of esophageal tumors in zinc-deficient rats by single low doses of N-nitrosomethylbenzylamine (NMBA): analysis of cell proliferation, and mutations in H-ras and p53 genes

Dietary zinc deficiency in rats induces hyperplasia in the esophagus and increases N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumor incidence. Previous work showed a direct relationship between epithelial cell proliferation and esophageal tumor incidence in rats given multiple doses of NMBA. We investigated the effects of single low doses of NMBA in zinc-deficient rats since a single dose of 5.0 mg/kg was reported to be non-carcinogenic in rats. Zinc-sufficient and deficient rats received a single i.g. dose of NMBA at 0.5 or 2.0 mg/kg. At week 14, tumor incidence was 50% with 0.8 +/- 1.0 tumors/rat, and 80% with 2.2 +/- 1.9 tumors/rat, in deficient groups, D(0.5) and D(2.0), that received the lower and higher dose, respectively. In addition, two small papillomas were found in one out of eight untreated zinc-deficient rats. None of the NMBA-treated or untreated zinc- sufficient rats had any tumors. Esophageal cell proliferation, as determined by proliferating cell nuclear antigen (PCNA) immunohistochemistry, showed that, irrespective of NMBA treatment, deficient esophagi had significant increases in the number of labeled cells, the total number of cells, and the labeling index, as compared with zinc-sufficient ones. Mutations in Ha-ras and p53 genes in esophageal tumors were detected by single strand conformation polymorphism (SSCP) analysis. DNA sequencing of variant conformers revealed a point mutation (GGA-->GAA, codon 12) in Ha-ras in 4/5 (80%) and 5/8 (63%) tumors, from D(0.5) and D(2.0) rats, respectively. Three out of eight tumors from D(2.0) rats exhibited SSCP mobility shifts within p53 exons 5 and 7: two tumors (2/8, 25%) had missense mutations and the third, a silent mutation. Of the two tumors with p53 mutations, one had a double mutation (transition at codon 164, TCA-->TTA; transversion at codon 241, AGT-->TGT), and the other tumor, a transition at codon 172 (AGA-->GGA), with amino acid changes in all cases. In parallel with PCNA expression, elevated p53 expression was associated with hyperplastic and dysplastic regions, as well as with tumors, in deficient esophagi. In short, these data indicate that dietary zinc deficiency, with its associated sustained increased cell proliferation in the esophagus, can drive an otherwise non-tumorigenic dose of NMBA into a highly tumorigenic one.      

Comparative efficacy of three 5-HT3 antagonists (granisetron, ondansetron, and tropisetron) plus dexamethasone for the prevention of cisplatin-induced acute emesis: a randomized crossover study

The purpose of this study was to compare the antiemetic efficacy of three 5-HT3 antagonists (granisetron, ondansetron, tropisetron) plus dexamethasone for the prevention of acute emesis induced by high-dose cisplatin chemotherapy. This was a randomized, open label, crossover study. Recruited into the study were 94 chemotherapy-naive patients of whom five were excluded because chemotherapy was not given, noncisplatin regimen was used instead, or presence of anticipatory vomiting. The remaining 89 evaluable patients were mostly (86.5%) male, and were all treated for head and neck cancers. The antiemetic regimens consisted of 1) granisetron 3 mg i.v. and dexamethasone 20 mg i.v. on day 1 (GRADEX); 2) tropisetron 5 mg i.v. and dexamethasone 20 mg i.v. on day 1 (TRODEX); and 3) ondansetron 8 mg i.v. and dexamethasone 20 mg i.v. to be followed by ondansetron 8 mg p.o. x 2 on day 1 (ONDEX). Patients were randomized to receive one of the three regimens in the first cycle, and treatment was crossed over to the other two regimens in subsequent cycles. Antiemetic efficacy was assessed using self-report diaries recording the number of vomiting episodes as well as duration and severity of nausea within the first 24 hours. Complete response was defined as no vomiting with or without mild nausea, and major response was defined as one vomiting episode and/or moderate to severe nausea. Major efficacy refers to either complete or major response. A total of 219 cycles was given to 89 patients: 16 received one cycle only, 16 received two cycles, and 57 received three cycles. No carryover effects were observed between cycles. Using pooled data from all cycles, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 68%, and 71%, respectively (p = 0.11); the corresponding major efficacy rates were 91%, 93%, and 86%, respectively (p = 0.36). When only the first cycle was considered, the complete response rates to GRADEX, TRODEX, and ONDEX were 81%, 75%, and 74%, respectively (p = 0.58); the corresponding major efficacy rates were 92%, 94%, and 84%, respectively (p = 0.38). Analysis of the crossover data showed that the majority of patients achieved complete response or major efficacy with the different pairs of regimens, and there were no significant differences between different regimens in terms of complete response or major efficacy. The only exception was GRADEX versus TRODEX, in which 15.5% of patient achieved complete response with GRADEX as compared with 1.7% with TRODEX (p = 0.025). The majority of patients (53%) did not report any preference, whereas 14% preferred GRADEX, 15% preferred TRODEX, and 18% preferred ONDEX. The three 5-HT3 antagonists, when used in combination with steroids, had similar major efficacy for prophylaxis against cisplatin-induced acute emesis. Although GRADEX was superior to TRODEX in terms of complete response, this may not be of clinical significance. The choice of antiemetic regimens should therefore depend on patient preference and drug cost.