2009年3月26日 星期四

Splenic artery embolization (SAE)

The impact of splenic artery embolization (SAE) on the management of splenic trauma: an 8-year review

The increased use of SAE as an adjunct to nonoperative management (NOM) ofsplenic injuries is associated with a statistically significantreduction in the number of laparotomies for splenic trauma.No overall changes were observed in the failure rate ofNOM except in patients with grade II injuries, where anincreased salvage rate was noted in the 4-year period inwhich SAE was frequently performed. SAE should be considered as a standard valuable adjunctin the management of splenic trauma.

The American Journal of Surgery (2009) 197, 337–341

LR 比 NS 好?

動物實驗:外傷做volume resuscitation時,LR確實比NS好!

Resuscitation of hemorrhagic shock with normal saline vs. lactated Ringer's: effects on oxygenation, extravascular lung water, and hemodynamics

Critical Care 2009, 13:R30doi:10.1186/cc7736

Pulmonary edema and impairment of oxygenation are reported as common consequences of hemorrhagic shock and resuscitation (HSR). Surprisingly, there is little in the literature examining differences in crystalloid type during the early phase of HSR regarding the development of pulmonary edema, the impact on oxygenation and the hemodynamic response. These experiments were designed to determine if differences exist due to crystalloid fluid type in the development of edema, the impact on oxygenation and the hemodynamic response to fluid administration in early HSR.

20 anesthetized swine underwent a grade V liver injury and bled without resuscitation for 30 minutes. The animals were randomized to receive, in a blinded fashion, either normal saline (NS) (n=10) or lactated Ringer's (LR) (n=10). They were then resuscitated with study fluid to, and maintained at, the preinjury mean arterial pressure (MAP) for 90 minutes.

Extravascular lung water index (EVLWI) began to increase immediately with resuscitation with both fluid types, increasing earlier and to a greater degree with NS. A 1ml/kg increase in EVLWI from baseline occurred after (mean +/- SEM) 68.6 ml/kg +/- 5.2 ml/kg of normal saline and 81.3 ml/kg +/- 8.7 ml/kg of LR (p=0.027). After 150 ml/kg of fluid EVLWI increased from 9.5 +/- 0.3 to 11.4 +/- 0.3 ml/kg NS and from 9.3 +/- 0.2 to 10.8 +/- 0.3 ml/kg (p = 0.035) LR. Despite this, oxygenation was not significantly impacted (DeltaPaO2/FiO2 [greater than or equal to]100) until approximately 250 ml/kg of either fluid had been administered. Animals resuscitated with NS were more acidemic (with lower lactates), pH 7.17 +/- 0.03 NS vs. 7.41 +/- 0.02 LR, p< 0.001.

This study suggests that early resuscitation of hemorrhagic shock with NS or LR has little impact on oxygenation when resuscitation volume is less than 250 ml/kg. LR has more favorable effects than NS on EVLWI, pH, and blood pressure but not on oxygenation.


2009年3月24日 星期二

不要再濫用 KUB...

Abdominal x rays - rarely useful
Is there ever a reason to request an abdominal x ray (AXR)?

Hardly ever, according to this review of evidence for their use in emergency departments. An AXR gives a radiation dose equivalent to that from 35 chest x rays and no longer has a place in the routine investigation of abdominal pain.

Evidence based reasons for requesting an urgent AXR include
  • Acute abdominal pain, if bowel obstruction is suspected
  • Esophageal foreign body is suspected
  • Sharp or poisonous foreign body is suspected.
Source: Emergency Medicine Journal 2009;26:160-163

Angina is as bad as AMI

We tend to think of angina as less serious than an acute myocardial infarction (AMI). But this study suggests that both conditions have a similar prognosis. Similar numbers of people will have a further AMI or need intervention such as a coronary artery bypass graft. And over a 4.5 year follow-up, people with angina have more physical impairment than those who have had an AMI. The implication is that we should be focused in our efforts to minimise risk factors in people with angina, not wait for them to have a heart attack.

Source: Heart 2009;95:461-467

2009年3月19日 星期四


Symptoms of Carbon Monoxide Poisoning
The symptoms of carbon monoxide poisoning are nonspecific. Mild exposures result in headache, myalgias, dizziness, or neuropsychological impairment. Severe exposures to carbon monoxide result in confusion, loss of consciousness, or death. Patients with subclinical exposures may recognize poisoning only after an acute event or on coincidental discovery of a carbon monoxide leak.

Carboxyhemoglobin Levels
A carboxyhemoglobin level greater than 3% in nonsmokers or greater than 10% in smokers confirms exposure to carbon monoxide, but the level does not correlate with the presence or absence of initial symptoms or with later outcomes. Health care providers in the emergency department should consider hyperbaric oxygen for treating poisoned patients. Clinicians should consider that the level of carboxyhemoglobin on presentation may underestimate earlier levels because of carboxyhemoglobin elimination over time, which is hastened by the application of supplemental oxygen by emergency medical personnel before the patient arrives at the emergency department. Carbon monoxide causes hypoxia by forming carboxyhemoglobin and shifting the oxyhemoglobin dissociation curve to the left.

What is hyperbaric-oxygen therapy?
A: Hyperbaric-oxygen therapy is defined as the breathing of 100% oxygen by patients within hyperbaric chambers compressed to greater than 1.4 atmospheres of absolute pressure.

NEJM Vol. 360, No. 12, March 19, 2009

2009年3月17日 星期二


Impact of Transfusion of Fresh-frozen Plasma and Packed Red Blood Cells in a 1:1 Ratio on Survival of Emergency Department Patients with Severe Trauma
ACADEMIC EMERGENCY MEDICINE 2009; 16:1–8 © 2009 by the Society for Academic Emergency Medicine

Objectives: Coagulopathy is common after severe trauma and occurs very early after the initial insult. Some investigators have suggested early and aggressive treatment of the trauma-induced coagulopathy by transfusion of fresh-frozen plasma (FFP) and packed red blood cells (PRBC) in a 1:1 ratio. This evidence-based emergency medicine (EBM) review evaluates the evidence regarding the impact of 1:1 ratio of FFP:PRBC transfusion on survival of emergency department (ED) patients with severe trauma.

Methods: The MEDLINE, EMBASE, Cochrane Library, and other databases were searched. Studies were selected for inclusion if they included trauma patients who required blood transfusion. The outcome measures of interest included mortality and adverse effects of high FFP:PRBC ratios. For comparison, the patients were classified into high ratio (1:1, defined as a ratio of 1:≤1.5) and low ratio (1:>1.5) groups.

Results: The authors did not identify any randomized controlled trials (RCT), but included four observational studies (three retrospective registry and one prospective cohort studies), which enrolled 1,511 patients cumulatively. One study found a statistically significant difference in mortality rate, favoring high FFP:PRBC ratio (relative risk = 0.72, 95% confidence interval [CI] = 0.59 to 0.89), while three studies showed no benefits. One study reported higher rates of sepsis and single/multiorgan failure (MOF), and another study revealed a higher risk of nosocomial infections and acute respiratory distress syndrome (ARDS) in the high FFP:PRBC ratio group.

Conclusion: Three retrospective registry reviews with suboptimal methodologies and one prospective cohort study provide inadequate evidence to support or refute the use of a high FFP:PRBC ratio in patients with severe trauma.

2009年3月13日 星期五

頭號癌殺手 大腸癌打敗肝癌


衛生署國民健康局昨日公布「九十五年癌症登記報告」,全台癌患共新增七萬三千兩百九十三名,平均每七分十秒就有一人罹癌。男、女癌症發生率排名第二的結直腸癌(統稱為大腸癌),新增病人數首度超越肝癌,總人數也躍居為國人頭號癌症殺手。 口腔癌雖居男性癌症的第四名,但新增病人數為男性癌症之首,也引起注意。 國健局副局長趙坤郁表示,國人罹癌多集中在大腸、肝、肺、乳房及口腔。男性所有癌症增幅百分之三點九、女性百分之四點七,不過男性的罹癌風險是女性的一點四倍,主要與食道癌與口腔癌發生率增加,皆為女性十倍以上。
就發生率看,肝癌與乳癌仍蟬連男、女性癌症排行榜首位,女性乳癌發生率為所有癌症之冠,且是女性新增人數最多癌症,一年約增加六千八百餘人。 發生率居次的大腸癌,新增病人數首度超越肝癌,男女病人數合計一萬兩百四十八人,它和肝癌的病人數都已突破萬人大關,值得民眾提高警覺。 大腸癌「後來居上」,趙坤郁說,主要與國人飲食西化,攝取過多脂肪、紅肉及燒烤食物,加上缺乏攝取蔬菜水果,以及少運動有關。
此外,嚼食檳榔的人口增加,使得口腔癌、食道癌的發生率、死亡率呈直線攀升。國人檳榔消耗量近年雖有趨緩,但口腔癌的增加率百分之十二點八,是男性各種癌症之首,確診年齡平均五十二歲,比其他癌症的六十五歲要早。 趙坤郁說,嚼檳榔的族群多為藍領階級,又都是家庭支柱,一旦罹癌後影響家庭經濟甚鉅。 衛生署並表示,國內婦癌有年輕化的現象,包括乳癌、子宮頸癌、子宮癌和卵巢癌,病患確診的年齡多數不到六十歲,婦女應早做防範。

2009年3月10日 星期二

臨床執業指引(CPG) 的陷阱

Critique of Clinical Practice Guidelines
Guidelines have strayed from their original purpose and value — perhaps it is time for new approaches.

Clinical practice guidelines (CPGs), once somewhat spare and elegant in their creation, dissemination, and application, have become commonplace, tedious, and of questionable clinical relevance.

In a review of all American College of Cardiology and American Heart Association (ACC/AHA) CPGs that were issued from 1984 to 2008 (53 CPGs with 7196 recommendations on 22 topics), 16 current guidelines provided evidence levels for supporting data. Only 314 of 2711 recommendations that provided evidence levels were supported by level A evidence (multiple randomized trials or meta-analyses). Nearly half these recommendations (1246) were supported by only level C evidence (expert opinion, case studies, or standards of care). Only 245 of 1305 level I recommendations (evidence or general agreement that a given procedure or treatment is useful and effective) had level A evidence. Thirty of 350 level III recommendations (evidence or general agreement that a given procedure or treatment is not useful or effective and might be harmful) were based on level A evidence. Among guidelines that had been revised at least once, the number of recommendations was 48% higher in revisions than in first versions.

The National Guideline Clearinghouse currently contains 2373 CPGs from 285 organizations. The guideline development process originally was designed to produce evidence-based "rules of thumb" that focus attention on a few core concerns for diagnosing and treating complex conditions. But, for some conditions, guidelines have become plethoric (e.g., at least 10 CPGs are available for management of pharyngitis in adults) and obsolete (relative to the rapidly changing world of biomedical research); they often are used to establish medical (and sometimes legal) standards of care and are influenced unduly by "expert" dogma. When recommendations are supported largely by opinion instead of evidence, we have the very problem CPGs were supposed to solve! The large number of guidelines, and the many guideline revisions, lead to the most important recommendations being lost in the blizzard of minor self-evident ones.

One example that is relevant to primary care is the 2002 and 2007 ACC/AHA CPGs on perioperative evaluation of patients who are scheduled for elective noncardiac surgery. An analysis of these guidelines showed substantial inconsistencies between the cited evidence and associated recommendations. For example, the guideline writers note mixed support for stress testing and beta-blocker therapy, yet their algorithm suggests these interventions for many patients. What results is a body of unclear recommendations, unsupported by evidence, which might lead clinicians to initiate interventions "just to be safe."

In another recent essay, writers call for several reforms of the CPG process, including substantial changes in leadership and membership from one version of a CPG to the next, posting of guideline drafts for both broad public review and structured scientific review, detailed reporting of conflicts of interest for both panel members and sponsoring professional associations, and centralization of the CPG development process under a government agency (such as the Agency for Healthcare Research and Quality). All in all, the process of creating and using CPGs needs a major overhaul.

Thomas L. Schwenk, MD
Published in Journal Watch General Medicine March 10, 2009

  1. Tricoci P et al. Scientific evidence underlying the ACC/AHA clinical practice guidelines. JAMA 2009 Feb 25; 301:831.
  2. Shaneyfelt TM and Centor RM. Reassessment of clinical practice guidelines: Go gently into that good night. JAMA 2009 Feb 25; 301:868.

2009年3月7日 星期六


Vitamin K for Warfarin-Induced Hypocoagulation
Low-dose vitamin K conferred no more clinical benefit than placebo, despite lowering INRs more rapidly.

Patients who over-respond to warfarin are often treated with vitamin K, which quickly lowers INR. Investigators at 14 anticoagulation clinics in Canada, the U.S., and Italy conducted a randomized, placebo-controlled trial to find out whether low-dose oral vitamin K (1.25 mg) would reduce bleeding events in patients with INRs between 4.5 and 10.0 on warfarin. Patient characteristics did not differ significantly between the two groups, and all patients were treated with vitamin K (n=355) or placebo (n=369), as allocated.

Ninety days after enrollment, 56 (15.8%) of the vitamin K recipients and 60 (16.3%) of the placebo recipients had had a bleeding event; such events occurred within 7 days in 28 (7.9%) and 34 (9.2%) patients in the vitamin K and placebo groups, respectively. Major bleeding occurred in nine vitamin K recipients and four placebo recipients. An analysis stratified by center did not affect the results. Thromboembolism occurred in four vitamin K recipients (1.1%) and three placebo recipients (0.8%). INR decreased more rapidly in vitamin K recipients than in placebo recipients. The average reduction in INR was 1.4 units in the placebo group and 2.8 units in the vitamin K group, a statistically significant difference. In patients aged 70 or older (200 vitamin K recipients and 188 placebo recipients), the rates of bleeding events, thromboembolism, and death did not differ significantly between the two treatment arms.

In this multicenter, randomized trial, vitamin K did, indeed, lower INR more and faster than placebo did, but those effects did not lead to fewer major bleeding events. These results suggest that simply stopping warfarin may suffice to treat patients with elevated INRs.

Joel M. Gore, MD
Published in Journal Watch Cardiology March 4, 2009

Citation(s): Crowther MA et al. Oral vitamin K versus placebo to correct excessive anticoagulation in patients receiving warfarin: A randomized trial. Ann Intern Med 2009 Mar 3; 150:293.

2009年3月5日 星期四

The SYNTAX Trial

CABG vs. Stenting for Severe Coronary Disease
Specific benefits and harms differ somewhat for the two interventions.

Although coronary-artery bypass grafting (CABG) has been the standard of care for patients with left-main or three-vessel coronary disease who require revascularization, percutaneous coronary intervention (PCI) with stenting is also an option in such cases. These two interventions were compared in the SYNTAX trial, which was sponsored by the manufacturer of the Taxus drug-eluting stent.

Eighteen hundred patients with previously untreated left-main or three-vessel disease were randomized to CABG or PCI; in each case, either intervention was deemed feasible by a cardiologist and a surgeon. At 1 year, incidence of the primary composite endpoint (death, stroke, myocardial infarction, or repeat revascularization) was significantly lower with CABG than with PCI (12.4% vs. 17.8%). The Table shows differences in outcomes for individual components of the composite endpoint.

In this study, CABG was superior to PCI for a predefined composite endpoint; the difference was driven largely by less need for repeat revascularization in the CABG group. However, CABG patients had a small but significantly higher rate of stroke, which was defined as a neurologic deficit lasting more than 72 hours and resulting in "irreversible brain damage or body impairment." The short follow-up (1 year) is an important limitation.

These results should inform discussions with patients who require revascularization for severe coronary disease. Choosing CABG (over PCI) implies a roughly 8-per-100 lower probability of needing another procedure during the ensuing year, at the expense of a roughly 2-per-100 higher risk for stroke. Other issues include longer recuperation time after CABG than after stenting and need for prolonged dual antiplatelet therapy with drug-eluting stents. Patients are likely to differ in how they weigh these tradeoffs.

Allan S. Brett, MD
Published in Journal Watch General Medicine March 5, 2009


PPI 可能導致 Plavix 無效

美國食品藥物管制局目前正在調查為何有5-15%的病人對clopidogrel無效,這被稱為clopidogrel阻抗。美國食品藥物管制局懷疑這和基因或藥物之間的交互作用有關。加拿大Sunnybrook Health Sciences Center的David Juurlink則發現這與質子幫浦阻斷劑有關。

在長達六年的急性心臟病人的研究中,發現使用clopidegrel的病人如果同時使用三種質子幫浦阻斷劑之一則再次發生心肌梗塞的機會比沒有的病人增加27%。這是因為clopidogrel需要肝臟中的細胞色素P450酵素來活化它,特別是細胞色素P450 2C19酵素。而這是很普遍且完全可以避免的藥物交互作用。

這三個藥物分別是omeprazole (Losec, Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex)。而pantoprazole (Protonix) 則沒有發現這個問題。

質子幫浦阻斷劑是一種強力的制酸劑,可以有效的減少消化性潰瘍及治療胃食道逆流,因clopidogrel有如阿司匹靈般預防血栓形成的效果且不傷胃,用於預防心肌梗塞的再次發生、心導管支架放置後預防支架的急慢性栓塞、非Q波的急性心肌梗塞、以及心導管手術前使用以減少手術併發症有不錯的效果。但因有不少病人是因服用阿司匹靈產生腸胃不適甚至潰瘍才用,目前健保規定也是必需有阿司匹靈過敏或有胃鏡證實有因阿司匹靈引起的消化性潰瘍才能處方,此時醫師為了治療潰瘍常開質子幫浦阻斷劑,這時病人已停用阿司匹靈,而如果處方時用了這三種質子幫浦阻斷劑則會使clopidogrel無效,病人等於完全沒有抗血小板的藥物保護,再次心肌梗塞的機會因此大幅增加。該研究中未提及的esomeprazole (Nexium) 因其代謝也主要由2C19酵素進行,因此很可能也會導致clopidogrel無效。

Clopidogrel and Proton-Pump Inhibitors
Risk for adverse cardiac events was elevated in patients taking both medications.
Prior biochemical studies have suggested that proton-pump inhibitors (PPIs) reduce the inhibitory effect of clopidogrel on platelet aggregation. A recent FDA review raised concerns about this issue, but data were insufficient to make a specific recommendation.
In this study, a Veterans Affairs database was used to retrospectively assess this interaction clinically in 8205 patients discharged with acute coronary syndromes (ACS); 5244 (64%) were taking both clopidogrel and a PPI, and the rest were taking clopidogrel alone. Medication use was assessed by pharmacy prescription data.At a mean follow-up of roughly 18 months, death or rehospitalization for ACS had occurred in 1561 patients (30%) taking both medications and 615 (21%) of patients taking only clopidogrel. In analyses adjusted for about 25 demographic and clinical variables, risk for death or rehospitalization was roughly 25% higher in patients taking both medications (86% higher for recurrent ACS, 49% higher for revascularization procedures, but no difference for death alone).
As with any retrospective analysis, there are confounders for which statistical adjustment might not be fully adequate, so prospective clinical trials are needed to confirm this result. However, based on plausible biological mechanisms (e.g., inhibition by PPIs of the cytochrome P450 enzyme system responsible for the active metabolite of clopidogrel), clinicians should be more parsimonious in their use of PPIs for specific indications, rather than using them for routine prophylaxis, as is often done.
Thomas L. Schwenk, MDPublished in Journal Watch General Medicine March 12, 2009
Citation(s): Ho PM et al. Risk of adverse outcomes associated with concomitant use of clopidogrel and proton pump inhibitors following acute coronary syndrome. JAMA 2009 Mar 4; 301:937.