Endoscopic thoracic sympathectomy for hyperhidrosis: Technique and results.

OUTLINE: We review the clinical features of hyperhidrosis and the range of treatments used for this condition. We describe in detail the technique of endoscopic sympathectomy. We summarize studies that have reported results of endoscopic sympathectomy. We present new data highlighting the difference in quality of life between patients with hyperhidrosis and controls.

Effect of endoscopic sympathectomy for hyperhidrosis on quality of life using the illness intrusiveness rating scale.

AIM: The objective of this study was to assess the impact of bilateral endoscopic thoracic sympathectomy (ETS) on the quality of life of patients with hyperhidrosis of the upper limbs. METHODS: This is a prospective, multicentre cohort study. Patients were studied before surgery and early (within 2 months) and late (4 months or more) after surgery. The primary outcome was the total score of the illness intrusiveness rating scale (IIRS), which on a sevenpoint Likert scale assesses the impact of their disease on each of 13 domains of quality of life. At each visit participants completed the IIRS, 10 additional questions to assess severity of disease, a global severity item, questions about employment, companionship and smoking, and a single item question reflecting the results of surgery. RESULTS: From 1994 to 2003, 22 patients underwent surgery. Early postoperative data were available in 12, and late postoperative data in 19 patients. Preoperative IIRS score was high 57 +/- 14. After surgery a statistically significant improvement was noted for the IIRS score, the severity questions, and the global severity score at both early and late postoperative time points. Preoperatively, 47% of patients were in a stable relationship, 30% were currently smoking, and 73% were employed; postoperatively, the responses were 58%, 16%, and 90%, respectively (P = NS). One patient (5%) developed a postoperative pneumothorax and one (5%) compensatory hyperhidrosis. There were no other local complications and none developed Horner's syndrome. CONCLUSIONS: Using a reliable and valid quality of life instrument we have shown that surgery is effective for the treatment of hyperhidrosis. Given the possibility of complications, we believe that surgery should be reserved for patients with the most severe form of this condition. The severity can be defined by the use of the IIRS and the 10 severity questions, which we have designed.

Emergency interventions for hyperkalaemia.

BACKGROUND: Hyperkalaemia occurs in outpatients and in between 1% and 10% of hospitalised patients. When severe, consequences include arrhythmia and death. OBJECTIVES: To review randomised evidence informing the emergency (i.e. acute, rather than chronic) management of hyperkalaemia SEARCH STRATEGY: We searched MEDLINE (1966-2003), EMBASE (1980-2003), The Cochrane Library (issue 4, 2003), and SciSearch using the text words hyperkal* or hyperpotass* (* indicates truncation). We also searched selected journals and abstracts of meetings. The reference lists of recent review articles, textbooks, and relevant papers were reviewed for additional potentially relevant titles. SELECTION CRITERIA: All selection was performed in duplicate. Articles were considered relevant if they were randomised, quasi-randomised or cross-over randomised studies of pharmacological or other interventions to treat non-neonatal humans with hyperkalaemia, reporting on clinically-important outcomes, or serum potassium levels within the first six hours of administration. DATA COLLECTION AND ANALYSIS: All data extraction was performed in duplicate. We extracted quality information, and details of the patient population, intervention, baseline and follow-up potassium values. We extracted information about arrhythmias, mortality and adverse effects. Where possible, meta-analysis was performed using random effects models. MAIN RESULTS: None of the studies of clinically-relevant hyperkalaemia reported mortality or cardiac arrhythmias. Reports focussed on serum potassium levels. Many studies were small, and not all intervention groups had sufficient data for meta-analysis to be performed. On the basis of small studies, inhaled beta-agonists, nebulised beta-agonists, and intravenous (IV) insulin-and-glucose were all effective, and the combination of nebulised beta agonists with IV insulin-and-glucose was more effective than either alone. Dialysis is effective. Results were equivocal for IV bicarbonate. K-absorbing resin was not effective by four hours, and longer follow up data on this intervention were not available from RCTs. AUTHORS' CONCLUSIONS: Nebulised or inhaled salbutamol, or IV insulin-and-glucose are the first-line therapies for the management of emergency hyperkalaemia that are best supported by the evidence. Their combination may be more effective than either alone, and should be considered when hyperkalaemia is severe. When arrhythmias are present, a wealth of anecdotal and animal data suggests that IV calcium is effective in treating arrhythmia. Further studies of the optimal use of combination treatments and of the adverse effects of treatments are needed.

Adequate early cyclosporin exposure is critical to prevent renal allograft rejection: patients monitored by absorption profiling.

This study used receiver operating characteristic analysis to investigate the properties of area under the concentration-time curve during the first 4h after cyclosporin-microemulsion dosing (AUC0-4) and cyclosporin (CyA) levels immediately before and at 2 and 3h after dosing (C0, C2 and C3) to predict the risk of biopsy-proven acute rejection (AR) at 6 months. Ninety-eight kidney transplant recipients treated with CyA-microemulsion-based triple therapy immunosuppression were studied on post-transplant days 3, 5, and 7, and at increasing intervals thereafter. The most sensitive and specific predictor of AR was AUC0-4. Of the single time-point measurements, the measurement properties of C2 were closest to those of AUC0-4, and superior to those of C3. The relationship between C0 and subsequent AR was weak and did not reach statistical significance. On day 3, CyA AUC0-4 > or = 4,400 ng.h/mL and C2 > or = 1,700 ng/mL were each associated with a 92% negative predictive value for rejection in the first 6months. Pharmacokinetic measurements on or after day 5, and measurements on day 3 in patients with delayed graft function, were not predictive of AR. Adequate exposure within the first 3days post transplantation may be critically important in preventing subsequent rejection.

Medical management versus investigate-and-operate strategy in asymptomatic carotid stenosis: a decision analysis.

OBJECTIVE: The objective of this study was to determine whether asymptomatic patients at high risk for carotid stenosis should undergo screening Duplex ultrasound (DUS), with a view to offering carotid endarterectomy (CE) to those patients with significant stenosis. METHOD: We constructed a decision analysis model to evaluate the impact of an investigate-and-operate strategy, compared with medical management alone, on the risk of stroke in patients at high risk for carotid stenosis. We studied five investigate-and-operate models addressing different thresholds for intervention (in terms of degree of stenosis) and the effects of using or not using preoperative angiography. RESULTS: For each of the strategies, under the base case conditions (30% prevalence of >50% carotid stenosis), the number needed to screen (NNS) and the number needed to treat (NNT) are high (213 to 769 and 13 to 144, respectively). The strategy of angiography for >50% stenosis and CE for >70% stenosis was harmful. Other strategies were unattractive because of unacceptably high NNT (no angiography, CE >50% stenosis), or because of unacceptably high NNS (angiography >70%, CE >70% stenosis), or both (angiography >50% stenosis, CE >50% stenosis; no angiography, CE > 70% stenosis). At 50% prevalence of >50% stenosis, two models produced more reasonable combinations of NNT and NNS: 11 and 370, respectively, for angiography >70%, CE >70% stenosis; and 27 and 286, respectively, for no angiography, CE >70% stenosis. Within the range of clinically plausible values for sensitivity and specificity of DUS, results were not greatly influenced by the measurement properties of DUS. However, angiographic or surgical rates of stroke or death were critical to the outcomes with any strategy. Only 3% to 12% of strokes in the studied population were prevented. CONCLUSIONS: Screening is acceptable only in populations at >40% to 50% risk for >50% carotid stenosis, who are surgical candidates, and who would undergo surgery if recommended. Acceptable investigate-and-operate strategies include angiography for DUS stenosis >70%, with CE if this level of stenosis is confirmed, and CE for DUS-measured stenosis >70% without angiographic confirmation. Surgery for asymptomatic carotid stenosis is unlikely to have a large impact upon the burden of stroke in society.

Prevalence and progression of internal carotid artery stenosis in patients with peripheral arterial occlusive disease.

OBJECTIVE: The purpose of this study was to determine the prevalence of significant carotid stenosis, to identify risk factors increasing this prevalence, and to determine the risk of progression of stenosis, in patients with peripheral arterial occlusive disease who are neurologically asymptomatic. STUDY DESIGN: Consecutive patients who underwent evaluation in a vascular laboratory for peripheral arterial occlusive disease, who had no recent neurologic symptoms, were investigated. RESULTS: From July 1999 to December 2000, 620 patients underwent duplex scanning on one occasion, and 417 on two occasions. The average age was 72 +/- 10 years, and 61% were men. An occluded internal carotid artery was found in 4.8% of patients. The prevalence of a carotid stenosis >50% was 33% on the initial evaluation. Age of more than 70 years (P =.007), diabetes mellitus (P =.042), history of stroke (P =.011), and ankle/brachial index of less than 0.8 (P =.0006), were independently associated with carotid stenosis >50%. The odds ratio associated with each of these risk factors was similar. The prevalence of carotid stenosis >50% was 16%, 21%, 38%, 47%, and 44% for patients with no, one, two, three, and four risk factors, respectively. The highest prevalence of carotid stenosis >50% was identified in patients with ankle/brachial indices of less than 0.4 (59%). During the follow-up period, no patient had a cerebrovascular event. In 15% of carotid arteries, progression from one class of stenosis to a more severe class was observed, and 6.5% of patients progressed from a lower degree to 50% to 99% stenosis. No differences in progression of disease were identified when the variables of age, diabetes, previous stroke, and ankle/brachial index of less than 0.8 were studied or when patients with zero to two of these putative risk factors were compared with patients with three or four. CONCLUSION: Screening for carotid stenosis in asymptomatic patients with peripheral vascular disease is justifiable, but not mandatory, when two or more risk factors are present or when the ankle/brachial index is less than 0.4. Rates of progression to clinically significant stenosis are low and do not justify reevaluation every 6 months. Further research to identify the optimal interval for reevaluation is needed.

Association between renal insufficiency and malnutrition in older adults: results from the NHANES III.

BACKGROUND: The extent to which relevant confounding variables influence the recognized association between renal insufficiency and malnutrition is not known. This study examined whether renal insufficiency was associated with malnutrition, independent of relevant demographic, social, and medical conditions in noninstitutionalized adults 60 years of age and older. METHODS: Participants (5248) in the United States Third National Health and Nutrition Examination Survey (NHANES III, 1988 to 1994), a cross-sectional study, were examined in a multivariate logistic regression model. Participants were stratified into three groups of glomerular filtration rate (GFR) by serum creatinine. Dietary and nutritional factors were estimated from 24-hour dietary recall, biochemistry measurements, anthropometry, and bioelectrical impedance. Participants were malnourished if they demonstrated at least three of the following five criteria: (1) serum albumin < or =37 g/L, (2) male weight < or =63.9 kg, female weight < or =51.8 kg, (3) serum cholesterol <4.1 mmol/L, (4) energy intake <15 kcal/kg/day, and (5) protein intake <0.5 g/kg/day. RESULTS: A GFR <30 mL/min/1.73 m(2) was present in 2.3% of men and 2.6% of women; these participants demonstrated low energy and protein intake and higher serum markers of inflammation. Thirty-one percent of individuals with malnutrition demonstrated a GFR <60 mL/min/1.73 m(2). In multivariate analysis, a GFR <30 mL/min/1.73 m(2) was independently associated with malnutrition [odds ratio 3.6 (2.0 to 6.6)] after adjustment for relevant demographic, social and medical conditions. CONCLUSIONS: It is probable that renal insufficiency is an important independent risk factor for malnutrition in older adults. Malnutrition should be considered, prevented, and treated as possible in persons with clinically important renal insufficiency. These results should be confirmed in a prospective longitudinal cohort study.

Conversion between bromcresol green- and bromcresol purple-measured albumin in renal disease.

BACKGROUND: Albumin measured by a bromcresol purple dye-binding assay (Alb(BCP)) agrees more closely with the gold standard of immunonephelometry than does bromcresol green (Alb(BCG)) measurement. Both tests are in current clinical use. A method for converting between the two would be useful. METHODS: We measured albumin by bromcresol green and bromcresol purple in 535 patients, 155 of whom had renal disease. We randomly divided data from the patients with renal disease into two equal-sized sets, and used one set to derive, and the remaining set to validate, a regression equation relating the two values. RESULTS: The relationship Alb(BCG)=5.5+Alb(BCP) performed very well in both the renal patient validation set and in the data from 380 unselected in-patients and out-patients. Intraclass correlations for agreement between measured Alb(BCG) and predicted Alb(BCG) was 0.98 in both analyses. CONCLUSIONS: The ability to convert between these measurements will be of use in clinical situations where the absolute value of the serum albumin is important, when data from laboratories using different methodologies must be combined, and in the application of the Modification of Diet in Renal Disease formula to estimate glomerular filtration rate in patients whose albumin has been measured by bromcresol purple.

Thrombolysis for restoration of patency to haemodialysis central venous catheters: a systematic review.

Urokinase, previously used to restore patency to thrombosed haemodialysis catheters, is now unavailable in North America. We performed systematic reviews of four questions related to the safety and efficacy of alternative agents for catheter thrombolysis, searching Medline and the Cochrane Controlled Clinical Trials Register. In dialysis patients, large case series have documented that urokinase is safe and effective (>70 % efficacy for catheter instillation, and >80 % for systemic lysis). Experience with streptokinase is limited and allergic complications develop with repeated use. Studies of catheter instillation with 1--2 mg of tPA per lumen reported short-term success in 83--98 % of uses. One non-peer-reviewed study described 44--59 % success using systemic tissue plasminogen activator (tPA), 2.5 mg through each of 2 lumens, over 1 h. Meta-analysis of randomized comparisons of urokinase and tPA as full-dose thrombolytic agents suggested that 1 mg tPA was likely equivalent in thrombolytic potency to 36,000 units urokinase. In nondialysis populations, four case series suggested that catheter instillation with 0.5--2 mg tPA was effective and safe in reestablishing patency, and a randomized controlled trial found 2--4 mg tPA more effective than 5,000--10,000 units urokinase. No complications have been reported in any patient treated with systemic or local tPA for catheter thrombolysis. In studies of fistula thrombolysis with 5--50 mg tPA major complications occurred in one episode in 130 patients treated. This review suggests that 1--2 mg/lumen tPA is a suitable dose for catheter instillation and likely to be more effective than 5000 units/lumen urokinase. Systemic lysis with 5--10 mg tPA is likely to be safe and effective in suitably selected patients. Further studies are needed.

Ruptured mycotic thoracoabdominal aortic aneurysms: a report of three cases and a systematic review.

We report three cases of ruptured mycotic thoracoabdominal aortic aneurysms (TAAAS) and a review of the literature. Escherichia coli and Streptococcus pneumoniae (2 patients) were the responsible organisms. Surgical management consisted of wide debridement of necrotic tissue and in situ repair with a Dacron graft. Antibiotics were administered intravenously in the hospital and continued orally after discharge for at least 6 weeks, until clinical and laboratory parameters were normalized. A review of the literature showed that Gram-negative microorganisms are found in 47% of mycotic TAAAs. A trend toward increased mortality for these organisms, compared with Gram-positive microorganisms, was observed (P =.09). Lifelong antimicrobial therapy is controversial. No difference in survival or recurrence rate was found between series advocating lifelong therapy and those suggesting prolonged (6 weeks to 12 months) therapy (median follow-up period, 18 and 19 months, respectively). In situ repair with synthetic material can be successful if prompt confirmation of infection is obtained, all possibly infected tissue is resected, and antibiotic therapy based on sensitivity data is administered for a prolonged period. A short-term survival rate as high as 82% can be expected with this strategy, but data on long-term survival rates are limited. Polytetrafluoroethylene-expanded grafts, homografts, and antibiotic-bonded grafts may offer advantages over Dacron grafts, but data are insufficient to draw conclusions. Careful long-term follow-up is an important element of the treatment of these patients. We suggest antibiotic treatment until biochemical parameters of inflammation (white cell count, erythrocyte sedimentation rate, or C-reactive protein) return to normal and a computerized tomography scan every 3 months for 1 year, then annually.

A cohort study of coagulation parameters and the use of blood products in surgery of the thoracic and thoracoabdominal aorta.

OBJECTIVES: We sought to study the hemostatic profile and the use of blood products in patients undergoing thoracic and thoracoabdominal aortic aneurysm repair. METHODS: This is a cohort study comparing three groups of patients: 7 undergoing elective acute normovolemic hemodilution (ANH); 15 undergoing elective procedures without ANH (non-ANH); and 8 undergoing repair of ruptured thoracoabdominal aneurysms. A control group of 10 patients was used for comparison of preoperative hemostasis. The parameters studied were platelet concentration, partial thromboplastin time (PTT), and international normalized ratio (before and after surgery), packed red blood cells, fresh frozen plasma, platelets, cryoprecipitates, donor exposure, and use of desmopressin and epsilon-aminocaproic acid. Analysis of variance and multiple stepwise regression analysis were used. RESULTS: Before operation the patients with aneurysms had PTTs prolonged compared with control subjects (P <.05). After operation the ANH group had higher platelet counts than the ruptured group (P =.001) and higher platelet counts (P =.05) and lower PTTs (P =.001) than the non-ANH group. The ANH group was transfused fewer platelets than the non-ANH group (P =.001) and less of every blood product than the ruptured group (P =.05); statistically significant differences were not observed for packed red blood cells, fresh frozen plasma, or platelets. The ANH group was exposed to an average of 65 donors fewer than the ruptured group (P <.001) and 34 fewer than the non-ANH group (P <.05). These differences could not be explained by baseline coagulation status or by the intraoperative use of desmopressin or epsilon-aminocaproic acid. CONCLUSIONS: The coagulation abnormality identified before surgery is that of higher PTT values, suggesting a disturbance of the extrinsic coagulation pathway. Blood losses, donor exposure, and platelet use were highest in the ruptured group and lowest in the ANH group. After surgery the ruptured group exhibited the worst coagulation parameters, and the ANH group exhibited the best with higher platelet count and lower PTT values than the other groups. The ANH technique appears to be an useful adjunct in the anesthetic management of these patients.

Kommerell's diverticulum and aneurysmal right-sided aortic arch: a case report and review of the literature.

Right-sided aortic arch is a rare variant of the thoracic vascular anatomy that may be accompanied by an aberrant origin of the left subclavian artery. We report a true aneurysm of the distal arch and descending thoracic aorta in a patient with right-sided arch and review previous descriptions of aneurysms of anomalous right-sided aortas. In our patient, the left subclavian artery originated at the junction between the distal arch and the descending thoracic aorta located in the right chest and was aneurysmal (Kommerell's diverticulum); the thoracic aorta was also aneurysmal. Extra-anatomic left subclavian-to-carotid transposition was performed before the intrathoracic procedure. Subsequently, a right thoracotomy provided adequate exposure for repairing the aortic aneurysm and oversewing the aneurysmal origin of the subclavian artery. Because the distal aortic arch was involved, deep hypothermia and circulatory arrest were used. Only five previous instances of true aneurysms of a right-sided aortic arch have been reported; four of these patients underwent operative repair (via bilateral thoracotomy, median sternotomy, or right thoracotomy). We believe that a right thoracotomy provides good exposure and avoids the morbidity associated with bilateral thoracotomy. The reconstruction of the subclavian artery has not previously been reported in this setting. Performing subclavian reconstruction as an extrathoracic procedure before the intrathoracic repair would be expected to reduce the subsequent risk of distal ischemia or subclavian steal without increasing the overall morbidity associated with the procedure.

Albumin-corrected calcium and ionized calcium in stable haemodialysis patients.

BACKGROUND: It is ionized calcium that is physiologically active and under homeostatic control; however, total calcium is more conveniently measured. Formulae for correction of calcium to account for albumin binding have not been validated in a dialysis setting. METHODS: We measured ionized calcium simultaneously with total calcium (t[Ca]), albumin, total protein and pH before dialysis in 50 stable outpatients and convalescent inpatients. RESULTS: Although 92% of patients were taking calcium supplements and 70% taking alphacalcidol, 11 patients (22%) had ionized hypocalcaemia. To facilitate comparison of calculated ionized calcium, measured total calcium (t[Ca]), and 'corrected' calcium (c[Ca]), with the criterion measure of ionized calcium, all measurements were converted to z scores, standardized on the normal range for each variable. Results are expressed as intraclass correlation coefficients (ICC: 0, all differences are due to error; 1, all differences are due to between patient variation). CONCLUSIONS: None of the published formulae greatly improved the test characteristics beyond simply using the total calcium. A correction formula in widespread use (Payne), quoted in reference texts, agreed less well with ionized calcium than did the unadjusted measured calcium. Correction formulae should be abandoned in favour of the use of uncorrected calcium. In cases of doubt, ionized calcium should be directly measured.

Is routine ureteric stenting needed in kidney transplantation? A randomized trial.

BACKGROUND: Whether routine ureteric stenting in low-urological-risk patients reduces the risk of urological complications in kidney transplantation is not established. METHODS: Eligible patients were recipients of single-organ renal transplants with normal lower urinary tracts. Patients were randomized intraoperatively to receive either routine stenting or stenting only in the event of technical difficulties with the anastomosis. All patients underwent Lich-Gregoire ureteroneocystostomy. RESULTS: Between June 1994 and December 1997, 331 kidney transplants were performed at a single center, 305 patients were eligible, and 280 patients were enrolled and randomized. Donor and recipient age, sex, donor source, whether first or subsequent grafts, ureteric length, native renal disease, and immunosuppression were similar in each group. In the no-routine-stenting group 6 of 137 patients (4.4%) received stents after randomization for intraoperative events that in the surgeon's opinion required use of a stent. In an intention-to-treat analysis there was no difference between groups in the primary outcome cluster of obstruction or leak [routine stenting 5 of 143 (3.5%) vs. no routine stenting 9 of 137 (6.6%); P=0.23], or in either of these complications analyzed separately. All urological complications were successfully managed without major morbidity. Living donor organs and shorter ureteric length (after trimming) were univariate risk factors for leaks, although increasing donor age was associated with obstruction. CONCLUSIONS: Routine ureteric stenting is unnecessary in kidney transplantation in patients at low risk for urological complications. Careful surgical technique with selective stenting of problematic anastomoses yields similar results.

Stability and sterility of recombinant tissue plasminogen activator at -30 degrees C.

We assessed whether frozen recombinant tissue plasminogen activator (rt-PA) remains stable and sterile for up to 22 weeks at -30 degrees C. Our findings confirm that rt-PA is a cost-effective alternative to urokinase for restoring patency to occluded central venous catheters.

Carotid endarterectomy for symptomatic carotid stenosis.

BACKGROUND: Severe narrowing (or stenosis) of the carotid artery is an important cause of stroke. Surgical removal of the atheromatous material from the inside of the carotid artery (endarterectomy) may reduce the risk of stroke, but carries a risk of operative complications. OBJECTIVES: This review seeks to summarize the evidence from randomized trials on the balance of risks and benefits of carotid endarterectomy in adults with symptomatic carotid stenosis. SEARCH STRATEGY: We searched the Cochrane Stroke Group's Specialized Register of trials (date last searched: March 1999), supplemented by electronic searches of several databases. SELECTION CRITERIA: Randomized controlled trials comparing 'best medical treatment plus carotid endarterectomy' with 'best medical therapy' in patients with carotid stenosis and a recent transient ischaemic attack or nondisabling ischaemic stroke in the territory of that artery. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected the studies and extracted the data. An intention to treat analysis was performed. MAIN RESULTS: Data on death or disabling stroke were available from two trials, which included 5950 patients: the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and the European Carotid Surgery Trial (ECST). The two trials used different methods to measure stenosis, but a simple formula can be used to convert between the two methods. For patients with severe stenosis (ECST > 80% = NASCET > 70%), surgery reduced the relative risk of disabling stroke or death by 48% (95% confidence interval [CI] 27 - 73%). The number of patients needed to be operated on (number needed to treat [NNT]) to prevent one disabling stroke or death over 2 to 6 years follow-up was 15 (95% CI 10 - 31). For patients with less severe stenosis (ECST 70 - 79% = NASCET 50 - 69%), surgery reduced the relative risk of disabling stroke or death by 27% (95% CI 15 - 44%). The number of patients needed to be operated on to prevent one disabling stroke or death was 21 (95% CI 11 - 125). Patients with lesser degrees of stenosis were harmed by surgery. Surgery increased the risk of disabling stroke or death by 20% (95% CI 0 - 44%). The number of patients needed to be operated on to cause one disabling stroke or death was 45 (95% CI 22 - infinity). REVIEWER'S CONCLUSIONS: Carotid endarterectomy reduced the risk of disabling stroke or death for patients with stenosis exceeding ECST-measured 70% or NASCET-measured 50%. This result is generalizable only to surgically-fit patients operated on by surgeons with low complication rates (less than 6%).

Prolonged sulfonylurea-induced hypoglycemia in diabetic patients with end-stage renal disease.

Renal impairment is a recognized risk factor for prolonged hypoglycemia, but predisposing characteristics in patients with advanced renal impairment have not been studied. We observed prolonged hypoglycemia in a number of patients with end-stage renal disease (ESRD) and conducted a case-control study at two Canadian centers to identify such risk factors. Through hospital, pharmacy, and dialysis program records, we retrospectively identified 7 case patients and 31 controls with ESRD and type 2 diabetes using oral hypoglycemic monotherapy. Control patients had no history of hospital admission for prolonged hypoglycemia. All case patients and 28 controls were receiving glyburide (glibenclamide in Europe); the remainder were treated with tolbutamide. Duration of intravenous treatment for hypoglycemia ranged from 28 to 256 hours, with 83 g to 2 kg of glucose administered per episode. Preceding treatment with glyburide varied from 2 days to 13 years. Univariate analyses showed a recent decline in oral intake (odds ratio [OR], 81; 95% confidence interval [CI], 3.6 to 1,840), previous hypoglycemic episodes (OR, 15; 95% CI, 0.77 to 297), longer duration of diabetes (22 versus 12 years; P = 0.008), and a history of cerebrovascular disease (OR, 7. 0; 95% CI, 1.0 to 47) to be associated with prolonged hypoglycemia. No association between prolonged hypoglycemia and age, sex, beta blockers, angiotensin-converting enzyme inhibitors, oral hypoglycemic dose, or duration of treatment was identified. This study describes the potentially devastating effect of sulfonylurea-based oral hypoglycemic therapy in ESRD. Patients at greatest risk appear to be those with reduced intake, previous hypoglycemic episodes, and longer duration of diabetes. We describe the mechanisms for observed hypoglycemia and suggest that alternative drugs may be considered in this patient group.

Effects of acute normovolaemic haemodilution and partial exchange transfusion on blood product utilization, haemostasis and haemodynamics in surgery of the thoracoabdominal aorta. A cohort study in consecutive patients.

BACKGROUND: This paper outlines the technique of acute normovolaemic haemodilution with partial exchange transfusion (ANHPET) in surgery of the thoracic and thoracoabdominal aorta. Perioperative coagulation parameters and patterns of blood product utilization observed with this technique are described and compared with results for historical controls treated without ANHPET. METHODS: During thoracoabdominal aneurysm repair, acute normovolaemic haemodilution with partial exchange transfusion (ANHPET) was used to withdraw of up to 3 L of blood. This was returned to the patient at the end of the reconstruction. Albumin 5% and stored packed red cells (PRC) were used for replacement. Seven patients underwent surgery with ANHPET, and fifteen without. Univariate and multivariate analysis of variance was used to examine differences between these groups. RESULTS: No differences were observed between the two groups for estimated blood loss, PRC transfused, and postoperative haemoglobin concentration. The ANHPET group received fewer platelets (8 vs 22 units, p = 0.0004), cryoprecipitate (0 vs 13 units, p = 0.02), and desmopressin or epsilon-aminocaproic acid (0 of 7 vs 4 of 15 patients, p = 0.04). FFP use was not significantly different (11 vs 17 units). Postoperatively, PTT values were less prolonged (26 vs 34 sec, p = 0.05) and platelet concentration higher (218 vs 169 x 109/L, p = 0.01) in the ANHPET group. A significant reduction in the total of blood products transfused was observed in the ANHPET group (30 vs 68 units, p = 0.003). Control of hypertension was facilitated by phlebotomy so that nitroglycerine was necessary in low doses only (0.25-1.0 microgram/kg/min). CONCLUSIONS: ANHPET reduced blood product transfusion, improved postoperative haemostatic parameters and simplified the management of cross-clamping hypertension.

Refining the indications for carotid endarterectomy in patients with symptomatic carotid stenosis: A systematic review.

OBJECTIVE: The purpose of this study was to summarize the existing literature on the efficacy of carotid endarterectomy in patients with ipsilateral symptomatic carotid stenosis. METHODS: Database searching, relevance assessment, methodologic quality assessments, and data extraction were all performed in duplicate with prespecified criteria. RESULTS: Twenty-three publications were identified from the North American Symptomatic Carotid Endarterectomy Trial, the European Carotid Surgery Trial, and the Veterans Affairs Cooperative Studies Program. Stenosis was reported as measured in the North American Symptomatic Carotid Endarterectomy Trial. In patients with >70% stenosis, carotid endarterectomy was associated with a pooled relative risk reduction of 48% (95% confidence interval [CI], 27% to 73%) and an absolute risk reduction of 6.7% (95% CI, 3.2% to 10%) for the outcome of death or major disability from stroke. This translates into a number needed to treat of 15 (95% CI, 10 to 31). For patients with 50% to 69% stenosis, the benefit of surgery was less and the confidence intervals were wider. A relative risk reduction of 27% (95% CI, 5% to 44%), an absolute risk reduction of 4.7% (95% CI, 0.8% to 8.7%), and a number needed to treat of 21 (95% CI, 11 to 125) were observed in this group. The patients with the lowest degrees of stenosis (<50%) were harmed by the intervention (number needed to harm, 45). Increasing degree of stenosis, increasing age, male sex, the presence of other medical risk factors, and the presence of hemispheric rather than retinal antecedent events were factors that increased the benefits from surgery. CONCLUSION: Carotid endarterectomy reduced death or major disability from stroke in patients with >50% symptomatic stenosis. To maximize the benefits of surgery, careful preoperative risk assessment and the maintenance of low rates of major perioperative complications are mandatory.