2008年6月28日 星期六

只做 CT 無法排除 SAH

Is Multidetector CT Sufficient for ED Diagnosis of Subarachnoid Hemorrhage?

Newer multidetector helical CT is not sensitive enough to be used as the sole diagnostic test.
The standard emergency department work-up for subarachnoid hemorrhage (SAH) includes noncontrast head computed tomography (CT) followed by lumbar puncture (LP), if CT is negative. LP is thought to be required after a negative CT result because the reported sensitivity of CT for detecting SAH (90% to 95%) is insufficient for CT to serve as a stand-alone diagnostic modality. Recent reports that newer-generation multidetector helical CT scanners are 98% to 100% sensitive for detecting SAH have prompted some clinicians to advocate for use of these newer CT scanners alone to rule out SAH in ED patients.

Researchers retrospectively assessed the sensitivity of multidetector CT (4-slice, 4-detector) in a review of all patients who had an ED diagnosis of SAH at one academic medical center during a 3-year period. Among the 149 patients, SAH was diagnosed by a positive multidetector CT result alone in 139 patients (sensitivity, 93%) and by a positive LP result after a normal CT result in 10 patients (7%). In the subgroup of 117 patients with a diagnosis of aneurysm or arteriovenous malformation, SAH was diagnosed by a positive CT result alone in 110 (sensitivity, 94%). In the subgroup of 67 patients who had a diagnosis of aneurysm or arteriovenous malformation and who presented with headache and normal mental status, the sensitivity of CT alone was 91%.

Comment: This study shows that CT with newer-generation scanners is inadequate as a stand-alone diagnostic tool to rule out SAH in ED patients. The current practice of performing LP in patients with normal CT scans whose differential diagnosis includes SAH should not change.

— Richard D. Zane, MD, FAAEM
Published in Journal Watch Emergency Medicine June 27, 2008
Citation(s): Byyny RL et al. Sensitivity of noncontrast cranial computed tomography for the emergency department diagnosis of subarachnoid hemorrhage. Ann Emerg Med 2008 Jun; 51:697.

2008年6月26日 星期四

Red Urine

The most common cause of red urine is hematuria. Hematuria can be associated with cystitis or malignancy along with other causes. Other causes of red urine include other sources of heme including myoglobin. Various foods and drugs can also cause red urine. The most common cause of red urine due to food intake is the ingestion of beets. Porphyrins may cause pink or red urine, and the presence of red urine without dysuria, accompanied by abdominal and pelvic pain, raises the question of porphyria.

New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

Acute Porphyria

In patients with severe abdominal pain, dark or reddish urine, systemic arterial hypertension, tachycardia, and constipation, the possibility of acute porphyria should be considered. Unfortunately, all of these symptoms occur in other more common conditions, and the diagnosis of porphyria is often overlooked. The diagnostic study of choice is the measurement of 5-aminolevulinic acid (ALA) and porphobilinogen in urine or serum. There are four types of porphyria, and all are due to deficiencies of one or more of the enzymes required for normal heme synthesis. Most types of porphyria are inherited, although the most common type, porphyria cutanea tarda, is usually an acquired disorder associated with liver disease and iron overload.

Q: What is the differential diagnosis of rapidly progressive weakness?
A: The differential diagnosis of rapidly progressive weakness is broad and includes myelopathy, myasthenia gravis, Guillain–Barré syndrome, vasculitic polyneuropathy, neoplastic polyradiculoneuropathy (Eaton–Lambert syndrome), acute porphyria, lead poisoning, arsenic or shellfish ingestion, thallium, hypokalemia, hypomagnesemia, and hypophosphatemia.

Q: Why are the acute porphyrias more common in women than in men?
A: Female sex hormones, particularly progesterone, are porphyrogenic; thus, the acute porphyries are more often clinically manifested in women than in men, and it is rare for symptoms to develop before puberty.

New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

Biliary colic 應避免使用 morphine

Q: What is the potential problem with giving intravenous morphine to a patient with biliary colic?

A: Morphine, while potentially providing pain relief, can cause problems in patients with biliary colic of acute cholecystitis as it can induce spasm of the sphincter of Oddi. The nonsteroidal antiinflammatory diclofenac has been shown to reduce pain in patients with biliary colic, but trials are lacking to assess its effects in patients with acute cholecystitis.

New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

Acute cholecystitis 為何用抗生素?

Q: When is it necessary to give antibiotics for acute cholecystitis?

A: The rationale for the use of antibiotics and the choice of which antibiotic to use is based on the results of bile cultures from patients with acute cholecystitis. The guidelines of the Infectious Diseases Society of America recommend that antimicrobial therapy be instituted if infection is suspected on the basis of laboratory and clinical findings :
  1. more than 12,500 white cells per cubic millimeter
  2. body temperature of more than 38.5°C and
  3. radiographic findings (e.g., air in the gallbladder or gallbladder wall)
New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

Acute Cholecystitis 早點手術為宜

Early laparoscopic cholecystectomy is considered the treatment of choice for most patients with acute cholecystitis. In randomized and prospective trials comparing early laparoscopic cholecystectomy (generally defined as at the time of the initial attack but can be defined as late as 7 days after the onset of symptoms) with a delayed procedure (2 to 3 months after the initial attack), as well as in meta-analyses, early treatment has consistently been associated with shorter overall hospitalization.

In the small minority of patients with severe acute cholecystitis, initial conservative management with antibiotics is recommended, preferably in a high-acuity setting, with the use of percutaneous cholecystostomy as needed; surgery is reserved for patients in whom non-surgical treatment fails.

New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

Jaundice in Acute Cholecystitis

Frank jaundice in a patient with signs and symptoms of acute cholecystitis is uncommon. When present, it should raise suspicion of :
  1. concomitant choledocholithiasis,
  2. Mirizzi's syndrome (obstruction of the bile duct as a result of external compression of a stone in the gallbladder or cystic duct), or
  3. another complication, such as gallbladder perforation.
New England Journal of Medicine - Vol. 358, No. 26, June 26, 2008

2008年6月23日 星期一

2008年6月19日 星期四

Broselow tape 有那麼好用嗎?

Comparison of Two Methods of Pediatric Resuscitation and Critical Care Management

Study objective
We compare time to drug delivery and the incidence of dosage error between 2 different systems of medication administration: The Broselow Pediatric Emergency Tape and a standardized volume/weight-based dose reformulation of resuscitation and critical care medications (reformulated to 0.1 mL/kg).

This was a randomized crossover trial, in which volunteers (n=16) from emergency department (ED) pediatric resuscitation teams from the ED of a large, urban, teaching hospital in Australia were assigned to manage simulated (Advanced Pediatric Life Support scenario) patients. The volunteers were each presented with 3 case scenarios (brady-asystolic arrest, status epilepticus, and rapid sequence intubation requiring administration of 4, 5, and 4 medications, respectively). The order of presentation was randomized for the 2 methods. The volunteers were then asked to manage 3 case scenarios using one and then the other method (resulting in a total of 6 cases managed per participant). The dosage of each medication ordered, as well as the time to the simulated administration of that medication, was recorded for all scenarios. The expected dosages were compared with the actual dosages delivered to determine which system provided greater accuracy in medication administration. Statistical analysis was undertaken using the Wilcoxon signed rank test and McNemars test for paired proportions.

Compared with the Broselow tape, the standardized volume/weight-based dose reformulation significantly reduced median time to medication delivery for all clinical scenarios (147 versus 72 seconds; 197 versus 87 seconds; 146 versus 64 seconds; P<.001). The proportion of dosing errors with Broselow tape across the 3 scenarios was greater than with volume/weight-based dosing (0.08 versus 0, 0 versus 0, and 0.08 versus 0.02, respectively).

Use of a standardized volume/weight-based dose reformulation method is a simple, fast, and accurate method of medication delivery for the pediatric patient that eliminates the need for memorization and/or calculation. The standardized volume/weight-based dose reformulation method performs better than the Broselow tape in speed of delivery of medications used for pediatric resuscitation and critical care without any reduction in dosing accuracy.

Annals of Emergency Medicine Volume 52, Issue 1, July 2008, Pages 35-40.e13

2008年6月17日 星期二

知道什麼是 TNA 嗎?

Incidence and Prognosisof Transient Neurological Attacks

也不知道這個診斷什麼時候會有ICD code
但如小侯所言,在chart上寫個TNA似乎比dizziness, cause pending
或numbness, cause pending還來的炫一點

2008年6月16日 星期一


Early complications of high-dose methylprednisolone in acute spinal cord injury patients

Injury, Int. J. Care Injured (2008) 39, 748—752

2008年6月11日 星期三

Appropriate target for HbA1c

ACCORD Trial: Intensive Glucose Control and Mortality
In the ACCORD trial, the intensive-therapy group (targeting glycated hemoglobin to less than 6.0%) as compared to the standard-therapy group, had a relative increase in mortality of 22% and an absolute increase of 1.0% during the follow-up period, with similar differences in death from cardiovascular causes. This increase in mortality is equivalent to one extra death for every 95 patients who were treated for 3.5 years. The cause for the rise in the rate of these unexpected, excess deaths in the ACCORD trial is not certain.

Q: What is the most appropriate target for glycated hemoglobin level in a diabetic?
A: The most appropriate target for glycated hemoglobin level is 7%. Both editorials published in this latest issue of the Journal, include discussion suggesting that the benefits of achieving glycemic targets below 7% in patients with type 2 diabetes remain uncertain.

2008年6月9日 星期一

Tight Glycemic Control

Does Tight Glycemic Control Prevent Cardiovascular Events in Type 2 Diabetic Patients?
In two trials, tight glycemic control had no significant effect on macrovascular events.

Contrary to popular belief, evidence that intensive glucose-lowering therapy improves macrovascular outcomes in patients with type 2 diabetes is limited. In two new randomized trials, researchers address this issue.

The NIH-sponsored ACCORD study involved 10,251 type 2 diabetic patients (mean age, 62; median glycosylated hemoglobin [HbA1c], 8.1%) with known cardiovascular disease or at least two additional risk factors. Patients received either intensive therapy (target HbA1c, 6%, with antidiabetic regimens individualized by clinicians) or standard therapy (target HbA1c, 7%–7.9%). Although glycemic control was significantly better with intensive treatment than with standard treatment throughout the trial (median HbA1c, 6.4% vs. 7.5%), the trial was stopped after an average follow-up of 3.5 years, because mortality was higher in the intensive-treatment group than in the standard-treatment group (5% vs. 4%; P=0.04). Moreover, the groups did not differ significantly in the primary composite outcome of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke (6.9% vs. 7.2%). Severe hypoglycemia and weight gain were more common in the intensive treatment group, but the factors mediating the higher mortality with intensive treatment were unclear.

The second study — the ADVANCE trial — involved 11,140 patients (mean age, 66; median HbA1c, 7.2%). The intensively treated group received the sulfonylurea gliclazide as initial therapy (with other drugs added as required to reach target HbA1c of 6.5%), and the standard-treatment group received any drugs except gliclazide (with no specified target HbA1c). Although HbA1c averaged 6.5% with intensive treatment and 7.3% with standard treatment during 5 years of follow-up, no significant difference was noted between groups for the primary endpoint of cardiovascular death, nonfatal MI, or nonfatal stroke (10.0% vs. 10.6%) or for all-cause mortality. The microvascular outcome of new or worsening nephropathy occurred significantly less often in the intensive-treatment group (4.1% vs. 5.2%), but severe hypoglycemia was more common with intensive treatment. This study was supported by the maker of gliclazide.

Yet again, presumably favorable modification of a surrogate endpoint — in this case, HbA1c — did not necessarily improve clinical outcomes in high-risk populations. Although why intensive treatment was associated with increased mortality in ACCORD but not in ADVANCE is unclear, the trials are consistent in showing no significant effect of tight glycemic control on macrovascular events. Clinicians should aim for reasonable glycemic control in older diabetic patients, but aggressive attempts to normalize HbA1c are not routinely warranted in this patient population.

Allan S. Brett, MD
Published in Journal Watch General Medicine June 6, 2008

  1. Patel A et al. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med 2008 Jun 6; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa0802987)
  2. Gerstein HC et al. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 2008 Jun 6; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa0802743)


The ACCORD and ADVANCE Trials: Implications for Patients with Type 2 Diabetes
Interventions that produced improvements in microvascular measures did not produce improvements in patient-important outcomes.

In patients with diabetes, high glycated hemoglobin (HbA1c) levels are associated with elevated risks for cardiovascular events and death. Some, but not all, studies have shown that lowering HbA1c levels reduces cardiovascular risk, and these data have been used to support current guidelines that recommend a target HbA1c level of 7.0%. To further investigate the effect of tight glucose control on cardiovascular outcomes in high-risk patients with type 2 diabetes, two studies were conducted: the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial.

In the ACCORD trial, 10,251 type 2 diabetic patients (mean age, 62; 38% women) were randomized to receive intensive glucose-lowering therapy (target HbA1c, <6.0%) or standard therapy (target HbA1c, 7.0%–7.9%). The primary outcome was a composite of nonfatal MI, nonfatal stroke, and cardiovascular-related death. The glucose-control arm of the 2x2 factorial design study was discontinued after 3.5 years of follow-up because of a greater number of deaths among patients receiving intensive therapy than among those receiving standard therapy (257 vs. 203; hazard ratio [HR], 1.22; P=0.04) (JW Cardiol Feb 13 2008).

Within 4 months after randomization, median HbA1c levels decreased more in the intensive-therapy group (from 8.1% to 6.7%) than in the standard-therapy group (from 8.1% to 7.5%); at 1 year, median HbA1c levels had stabilized (at 6.4% and 7.5%, respectively). Thiazolidinediones were used by 92% of patients in the intensive-therapy group versus 58% of those in the standard-therapy group; the use of other glucose-lowering treatments was also more common in the intensive-therapy group. The primary outcome occurred in 6.9% of patients in the intensive-therapy group and in 7.2% of those in the standard-therapy group (HR, 0.90; P=0.16), but hypoglycemia was more common among intensive-therapy patients (10.5% vs. 3.5%; P<0.001). The higher mortality rate associated with intensive therapy could not be explained by severe hypoglycemia, differences in drug use, or weight change. Microvascular events were not reported.

In the ADVANCE trial, 11,140 type 2 diabetic patients (mean age, 66; 43% women) were randomized to intensive therapy (target HbA1c, <6.5%) or standard therapy (target HbA1c defined by local guidelines). The primary outcomes, redefined during the study, were a composite of major macrovascular events (nonfatal MI, nonfatal stroke, or cardiovascular-related death) as well as separate and joint assessments of major microvascular events (nephropathy and retinopathy).

Mean HbA1c levels at study’s end (median follow-up, 5.0 years) decreased more in the intensive-therapy group (7.5% to 6.5%) than in the standard-therapy group (7.5% to 7.3%). Again, both thiazolidinediones and other treatments were used by a higher proportion of intensive-therapy patients than standard-therapy patients (17% vs. 11%). Macrovascular events occurred at a lower rate in patients receiving intensive therapy (10.0% vs. 10.6%; HR, 0.94; P=0.3), as did microvascular events (9.4% vs. 10.9%; HR, 0.86; P=0.01). Mortality was slightly lower in the intensive-therapy group (8.9% vs. 9.6%; HR, 0.93; P=0.3). Severe hypoglycemia was more common among intensive-therapy patients (2.7% vs. 1.5%; HR, 1.86; P<0.001).

These two studies, involving different strategies with different patterns of medication use, fail to support the hypothesis that tight glucose control in patients with type 2 diabetes will reduce their risk for macrovascular complications. Moreover, the strategies were associated with an increased risk for hypoglycemia in both studies and with higher mortality in ACCORD. The lower risk for microvascular complications in ADVANCE (this outcome was not reported in ACCORD) was the only favorable finding. The bottom line is that these studies will cause a reexamination of guidelines and performance measures and are further evidence that knowing the effect of a strategy on a surrogate outcome, such as a risk factor, does not always tell you the effect on patients.

Harlan M. Krumholz, MD, SM
Published in Journal Watch Cardiology June 6, 2008

  1. Patel A et al. for the ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med 2008 Jun 6; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa0802987).
  2. Gerstein HC et al. for the Action to Control Cardiovascular Risk in Diabetes Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 2008 Jun 6; [e-pub ahead of print]. (http://dx.doi.org/10.1056/NEJMoa0802743).

Tight glucose control?

Intensive Glucose Control Does Not Prevent Major Cardiovascular Events in Type 2 Diabetes
Physician's First Watch for June 9, 2008

Intensive glucose control among adults with type 2 diabetes does not reduce macrovascular events, according to two studies released online by the New England Journal of Medicine.

In the ACCORD study, some 10,000 patients (mean age, 62) with type 2 diabetes and elevated cardiovascular risk were randomized to intensive glucose lowering (target hemoglobin A1c, <6.0%) or standard therapy (target, 7.0-7.9%). Intensive treatment was stopped early, after 3.5 years, because recipients showed significantly higher all-cause mortality than those on standard therapy (5% vs. 4%). The primary endpoint — a composite of myocardial infarction, stroke, and cardiovascular death — did not differ between the groups.

In ADVANCE, researchers compared intensive gliclazide-based glucose control (target hemoglobin, ≤6.5%) with standard therapy among roughly 11,000 older patients. After 5 years, intensive therapy showed no effect on macrovascular events or all-cause mortality, although it did reduce nephropathy.

These studies will cause a reexamination of guidelines and performance measures. Aggressive attempts to normalize HbA1c are not routinely warranted in older diabetic patients.


2008年6月6日 星期五

One-lung intubation



Acute myocardial infarction after administration oflow-dose intravenous epinephrine for anaphylaxis

This case describes a 29-year-old woman who presented with an acute severe anaphylactic reactionto penicillin. In addition to other medications administered in the emergency department,she received 0.1 mg intravenously of 1:10 000 epinephrine, after which she immediately developedsevere chest pain. Her ECG showed ST elevations consistent with an anterior myocardial infarction,and her serum troponin level was elevated. A CT angiogram showed no signs of coronaryartery disease or abnormal anatomy. This case is an example of vasospasm-induced myocardial injuryand illustrates a potential danger of intravenous epinephrine use. The authors were able toidentify only 2 other case reports where therapeutic doses of epinephrine have been reported tocause this phenomenon.

Can J Emerg Med 2006;8(4):289-94


[1] 要 obtain 知情同意
[2] 要留觀一段時間

Hypothermia for Head Trauma in Children

Hypothermia for Head Trauma in Children
Hypothermia therapy did not improve neurologic outcomes in children with traumatic brain injury and might have contributed to increased mortality.

Both animal studies and studies involving limited numbers of children suggest that hypothermia might improve neurologic outcomes after head trauma. In an international trial, researchers randomized 225 children (age range, 1–17 years) with traumatic brain injury (Glasgow Coma Scale score 8) to receive either hypothermia therapy (esophageal temperature, 32.5°C for 24 hours) initiated within 8 hours after injury or routine care (normothermia).

At 6 months after discharge, an unfavorable outcome (severe disability, persistent vegetative state, or death) was more likely in the hypothermia group than in the normothermia group (31% vs. 22%; P=0.14). Mortality was greater in the hypothermia group than in the control group (21% vs. 12%; P=0.06).

Hypothermia, as used in this study, did not improve neurologic outcomes — and possibly increased mortality — in children with traumatic brain injury. Whether earlier or more-sustained hypothermia would be more effective is unclear. Note that hypothermia was also ineffective in a study conducted in adults with traumatic brain injury (JW Emerg Med Apr 18 2001).

Howard Bauchner, MD
Published in Journal Watch Pediatrics and Adolescent Medicine June 4, 2008

Citation(s): Hutchison JS et al. Hypothermia therapy after traumatic brain injury in children. N Engl J Med 2008 Jun 5; 358:2447.

2008年6月5日 星期四

Hydrochlorothiazide and gout

Q: Hydrochlorothiazide can increase the risk for what problem in the joints?

A: Hydrochlorothiazide may cause hyperuricemia and, thus, over time, can increase the risk of gouty arthritis in susceptible patients.

Teaching topics from the New England Journal of Medicine - Vol. 358, No. 23, June 5, 2008

Parvovirus B19 polyarthritis

Q: What virus can cause arthritis in an adult?

A: Parvovirus B19 infection can cause polyarthritis and a pure red-cell aplasia. The arthritis is generally polyarticular, with a predilection for involvement of the small joints.

Teaching topics from the New England Journal of Medicine - Vol. 358, No. 23, June 5, 2008