ACS caused by coronary artery spasm?

Coronary Artery Spasm as a Cause of Acute Coronary Syndrome

About one in two ACS patients without artery occlusion exhibited vasospasm.

Coronary artery spasm is a potential cause of ischemia, but what is the incidence of spasm in patients who present to emergency departments with suspected acute coronary syndrome (ACS)? In this European study, investigators studied 488 consecutive patients with suspected ACS (defined as acute chest pain associated with ischemic changes on electrocardiogram or cardiac biomarker elevations) who underwent angiography.

In 138 patients (28%), epicardial coronary angiography did not reveal clear culprit lesions: 22 patients received alternative diagnoses (e.g., myocarditis) without spasm testing; 30 did not undergo spasm testing for various reasons; and 86 underwent provocative testing with intracoronary acetylcholine to see whether spasm (defined as a 75% constriction), associated with reproduction of symptoms, could be provoked. Spasm was confirmed in 42 patients. Among the 86 tested patients, cardiac enzyme levels generally were normal and were similar in patients with and without coronary spasm.

Comment: In this largely white cohort, angiography detected no culprit lesions in roughly one in four patients with suspected ACS. Of those who underwent acetylcholine challenges, almost half exhibited inducible vasospasms. As an editorialist notes, this study lacks outcome data to tell us whether vasospasm is associated with adverse outcomes in these patients and whether routine testing and treatment for spasm would be helpful in improving outcomes. However, clinicians should remember to consider vasospasm as an alternative diagnosis in patients with suspected ACS, especially when angiography reveals no clear culprit lesions.

— Kirsten E. Fleischmann, MD, MPH

Published in Journal Watch General Medicine September 30, 2008

Citation(s): Ong P et al. Coronary artery spasm as a frequent cause of acute coronary syndrome: The CASPAR (Coronary Artery Spasm in Patients With Acute Coronary Syndrome) study. J Am Coll Cardiol 2008 Aug 12; 52:523

TIA syndromes

KEY CONCEPTS

• Most transient ischemic attacks last less than 1 hour.
• Almost half of transient ischemic attacks result in cerebral infarction on diffusion-weighted imaging; the chance of infarction increases with increasing duration of symptoms.
• According to new proposed criteria in 2002, the presence of a new infarction on CT or MRI in association with a referable symptom, regardless of symptom duration, is defined as a stroke.
• Isolated dizziness (including vertigo) and syncope are rarely transient ischemic attacks.
• Weakness in the face on the side opposite to weakness in the arm and leg suggests brainstem ischemia.
• Gaze deviation toward the side of weakness suggests brainstem ischemia, whereas gaze deviation away from the weakness suggests hemispheric ischemia.

Ann Emerg Med. 2008;52:S7-S16.

TIA management

Figure. One approach to management of patients with transient ischemic attack. ER, Extended-release; ICA, internal carotid artery; INR, international normalized ratio; IV, intravenous; LMWH, low-molecular-weight heparin; UFH, unfractionated heparin.

KEY CONCEPTS

• Clinical features that predict increased short-term risk of stroke after transient ischemic attack include older age,hypertension, diabetes, symptoms of weakness or speechimpairment, and symptom duration greater than 10minutes.
• Magnetic resonance imaging with diffusion-weighted imaging and vascular imaging may play an important role in risk-stratifying patients with transient ischemic attack.
• Flat head positioning, isotonic fluid administration, and permissive hypertension are basic measures to improve cerebral blood flow and mitigate cerebral ischemia.
• For most patients with transient ischemic attack, aspirin should be started as soon as neuroimaging has ruled out the possibility of hemorrhage.
• The specific cause of the transient ischemic attack in individual patients must be determined to select the most appropriate long-term preventive therapy.
• Patients who experience stroke after transient ischemic attack
  should be considered for thrombolysis.

Ann Emerg Med. 2008;52:S27-S39.

TIA work-up in ED

A transient ischemic attack portends significant risk of a stroke. Consequently, the diagnostic evaluation in the emergency department is focused on identifying high-risk causes so that preventive strategies can be implemented. The evaluation consists of a facilitated evaluation of the patient’s metabolic, cardiac, and neurovascular systems. At a minimum, the following tests are recommended: fingerstick glucose level, electrolyte levels, CBC count, urinalysis, and coagulation studies; noncontrast computed tomography (CT) of the head; electrocardiography; and continuous telemetry monitoring. Vascular imaging studies, such as carotid ultrasonography, CT angiography, or magnetic resonance angiography, should be performed on an urgent basis and prioritized according to the patient’s risk stratification for disease. Consideration should be given for echocardiography if no large vessel abnormality is identified.

KEY CONCEPTS

• The risk of stroke is greatest immediately after a transient ischemic attack; thus, a rapid evaluation to determine the cause of the event and potentially preventable risk factors is imperative.
• At a minimum, the ED evaluation of a transient ischemic attack should include noncontrast CT of the head, fingerstick glucose level, serum chemistry studies, CBC count, a coagulation profile, urinalysis, electrocardiography, and a pregnancy test when appropriate.
• The subsequent evaluation of a patient who has had a transient ischemic attack should focus on identifying highrisk causes and thus involve cardiac monitoring; vascular imaging such as carotid ultrasonography, computed tomographic angiography, or magnetic resonance angiography; and echocardiography if the previous evaluation result is negative or if there is a potential high-risk cardiac source.
• Carotid duplex ultrasonography is excellent for identifying internal carotid artery stenosis as a cause of a transient ischemic attack; however, it visualizes only a short segment of the carotid artery and is relatively insensitive for dissection.
• If cervicocephalic arterial dissection is suspected, MRI with axial fat-saturated T1 images or computed tomographic angiography should be ordered.

Ann Emerg Med. 2008;52:S17-S26.

Dermabond for eye-area use

如何避免Dermabond流入眼睛

Lung Cancer

Lung cancer is the leading cause of cancer deaths in the United States and worldwide. The two major forms of lung cancer are non–small-cell lung cancer (about 85% of all lung cancers) and small-cell lung cancer (about 15%). Non–small-cell lung cancer is divisible into three histologic subtypes: squamous-cell carcinoma, adenocarcinoma, and large-cell lung cancer.

Despite advances in early detection and standard treatment, non–small-cell lung cancer is often diagnosed at an advanced stage and has a poor prognosis.

What type of lung cancer is most common among nonsmokers?
A: Adenocarcinoma is the most common type of lung cancer in patients who have never smoked.

What type of lung cancer is most common among smokers?
A: Smoking causes all types of lung cancer but is most strongly linked with small-cell lung cancer and squamous-cell carcinoma.

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New England Journal of Medicine - Vol. 359, No. 13, September 25, 2008

Ipratropium 沒有想像中安全

Ipratropium Associated with Higher Mortality Risk in Recently Diagnosed COPD
Ipratropium carries a higher cardiovascular mortality risk than other drugs used to treat chronic obstructive pulmonary disease (COPD), according to an Annals of Internal Medicine report.

Using a nested case-control design, researchers examined mortality risks in a 145,000-member cohort of U.S. veterans recently diagnosed with COPD. Analysis of Veterans Affairs databases revealed a higher risk for cardiovascular death among those with ipratropium exposure in the 6 months preceding their death than among matched controls who had not received ipratropium in the same 6-month period (odds ratio, 1.34). Inhaled corticosteroids were associated with a decrease in cardiovascular deaths.

The authors, noting that their data suggest "a substantial number of premature deaths" due to ipratropium use, conclude that "caution is warranted" in using the drug alone in patients with a recent diagnosis of COPD.

http://firstwatch.jwatch.org/cgi/content/full/2008/916/2
Published in Physician's First Watch September 16, 2008

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Inhaled Anticholinergics Linked to Increased Cardiovascular Risk in COPD
Patients using inhaled anticholinergics (ipratropium or tiotropium bromide) to treat chronic obstructive pulmonary disease face increased risk for cardiovascular events, according to a meta-analysis in JAMA.

The analysis included 17 trials that randomized nearly 15,000 patients with COPD to an inhaled anticholinergic or control therapy. Follow-up ranged from 6 weeks to 5 years.

Risk for the primary endpoint — a composite of cardiovascular death, myocardial infarction, and stroke — was significantly higher among patients on anticholinergics than among controls (1.8% vs. 1.2%). Increased incidence of MI and cardiovascular death appeared to account for the elevated risk.

When long- and short-term studies were analyzed separately, risk for the composite endpoint remained significantly elevated in long-term trials, while the increased risk in short-term studies was not statistically significant.

The authors conclude that COPD patients on long-term anticholinergics must be closely monitored for cardiovascular events.

JAMA article
http://jama.ama-assn.org/cgi/content/short/300/12/1439

Interval for Screening Colonoscopy

What Is the Optimal Interval for Screening Colonoscopy?
At 5-year repeat colonoscopy, only 1% of 1250 participants had advanced neoplasms.

U.S. guidelines generally recommend a 10-year interval after a normal initial screening colonoscopy, but the optimal interval is uncertain. In this study, researchers examined the prevalence of abnormalities among employees of a company that offered routine colonoscopic screening at 5-year intervals.

A total of 2436 asymptomatic people (age, 50) had no adenomas on first-time screening colonoscopy; 1256 of them returned for rescreening at 5 years. One or more neoplastic polyps were found in 201 (16%) of these rescreened people, but only 16 (1.3%) had advanced neoplasms (tubular adenomas 1 cm, polyps with a villous component, or polyps with high-grade dysplasia).

Comment: In this study, people for whom initial screening colonoscopy results were normal had a very low prevalence of advanced neoplasia on 5-year follow-up colonoscopy. These findings suggest that the rescreening interval should be at least 5 years. For policy makers, a more relevant study would be a randomized trial in which 5-year and 10-year intervals are compared, but the requirement for long-term enrollment would make such a trial difficult to complete successfully. For now, we have no reason to change screening guidelines in the U.S.

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Allan S. Brett, MDPublished in Journal Watch General Medicine September 23, 2008Citation(s):Imperiale TF et al. Five-year risk of colorectal neoplasia after negative screening colonoscopy. N Engl J Med 2008 Sep 18; 359:1218.

Chesty babies - bronchiolitis

A useful update into current management of bronchiolitis - the commonest lower respiratory tract infection to affect infants.

• No evidence of benefit from antibiotics or oral steroids
• Inhaled salbutamol, theophyllines, and adrenaline do not have strong evidence for their use
• Limited evidence for antiviral ribavirin - currently used for immunosuppressed children only
• Admit to hospital if child is hypoxic, dehydrated, or high risk, eg immunosupressed (oxygen and nasogastric feeding are still the mainstays of hospital treatment)
• After bronchiolitis, a child remains likely to get respiratory symptoms like wheeze, which can last until early adolescence
• Immunisation against RSV is an option - RSV is the commonest but not only cause of bronchiolitis

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Source: Archives of Disease in Childhood 2008;93:793-798

Aspirin doesn't help memory loss

Does aspirin help to prevent memory loss if you're over 50?

We know that age related cognitive decline may be due to atherosclerosis, which aspirin helps to combat. But unfortunately, this well designed study didn't show any cognitive benefit in men and women over 50 who took daily low dose aspirin.

An editorial says that drugs that lower blood pressure are probably the best way of slowing vascular cognitive decline. Daily aspirin should be advised only for people at high risk of strokes or heart attacks and low risk of bleeding.

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Source: BMJ 2008;337:a1198

Any alternatives to warfarin?

We know that atrial fibrillation increases the risk of stroke fivefold and is the cause of a sixth of all strokes. But being on warfarin is a nuisance for our patients, and they often ask about other options. This editorial summarized the current position:

• Anticoagulation with warfarin remains the first line treatment
• Aspirin and combined antiplatelet therapy are not nearly as effective as warfarin
• Agents are being tested to replace warfarin (eg Ximelagratan, a direct thrombin inhibitor) but there is risk of liver toxicity
• Surgical techniques (ligation atrial appendage or catheter ablation) are not alternatives to warfarin
• Left atrial appendage occlusion by the catheter technique may prove to be a safe alternative for those who can't or won't take warfarin (the PROTECT atrial fibrillation study is ongoing)

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Source: Heart 2008;94:1113-1116

Pill or op for reflux?

If you had long standing acid reflux, would you take a pill or consider surgery?

This three year study compared the effectiveness and safety of a daily tablet (esomeprazole 20-40mg) versus laparoscopic antireflux surgery (LARS) for chronic gastro-oesophageal reflux disease (GORD). Both groups did well; 93% on medical treatment remained symptom free after three years, compared to 90% after surgery. There were no major postoperative complications after surgery.

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Source: Gut 2008;57:1207-1213

Preventing postop gout

After an operation, no one wants to get an attack of gout. Typically, gout starts four days after surgery, affects the big toe, and often affects several joints at once. Risk factors for getting gout after surgery are

• History of gout
• High uric acid levels (>9 g/dl)
• Surgery for cancer

To reduce the risk of gout after surgery, lower the patient's uric acid levels (preferably to below 7 mg/dl) or give colchicine to those whose levels remain high.

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Source: Annals of the Rheumatic Diseases 2008;67:1271-1275

TPA? 也許可以延到4.5小時

Good Outcomes for Thrombolysis at 3.0 to 4.5 Hours After Stroke
In a large registry study, rates of mortality, symptomatic intracerebral hemorrhage, and independence at 3 months were similar between patients treated with alteplase within 3.0 hours and patients treated at 3.0 to 4.5 hours after ischemic stroke onset.

Based on results from several studies, recombinant tissue plasminogen activator (rTPA) is approved for use in ischemic stroke only within 3 hours after symptom onset. However, other studies have suggested benefits even after a delay to treatment of more than 3 hours (JW Neurol May 20 2004). In an observational industry-sponsored study, investigators used data from an international registry of thrombolysis (involving more than 700 centers in 35 countries) to compare outcomes in 664 patients who received alteplase (0.9 mg/kg) at 3.0 to 4.5 hours after symptom onset and 11,865 patients who received it within 3 hours after onset.

Functional status at 3 months was similar in the two groups; independence (modified Rankin score 2) was achieved by 58% of patients in the group treated at 3.0 to 4.5 hours and by 56% in the group treated within 3 hours (a nonsignificant difference). Rates of symptomatic intracerebral hemorrhage within 24 hours (2.2% vs. 1.6%, respectively) and mortality at 3 months (12.7% vs. 12.2%, respectively) also did not differ significantly between groups.

Comment: Although this was not a controlled trial, the study provides evidence that thrombolysis for acute ischemic stroke can be as beneficial at 3.0 to 4.5 hours after symptom onset as within 3 hours. One caveat: The higher rates of mortality and intracerebral hemorrhage in the later-treatment group nearly reached statistical significance (at the P<0.05 level). That finding reinforces what we already know: Overall benefit from thrombolysis is clearly time dependent. Centers that are capable of performing thrombolysis within 3 hours after stroke onset should now consider doing so up to 4.5 hours after onset in patients who are appropriate candidates, particularly young patients with severe deficits. Clearly, nothing is absolute about the 3-hour time window, and thrombolysis should not be withheld for the sole reason that this amount of time has elapsed, particularly if this occurs while preparations for thrombolysis are being finalized. In light of these new findings, acute stroke services and emergency departments should revisit protocols to optimize therapeutic options for patients with this devastating condition.

— Daniel J. Pallin, MD, MPH

Citation(s): Wahlgren N et al. Thrombolysis with alteplase 3–4·5 h after acute ischaemic stroke (SITS-ISTR): An observational study. Lancet 2008 Sep 15; [e-pub ahead of print]. (http://dx.doi.org/10.1016/S0140-6736(08)61339-2)

Refeeding syndrome

Q: What is refeeding syndrome?

Refeeding syndrome describes what can occur when a patient with anorexia or extreme malnutrition begins to ingest more food. During refeeding, there is a shift from fat to carbohydrate metabolism. Increased amounts of insulin are released, facilitating cellular glucose uptake and protein anabolism. This results in an increased cellular uptake of phosphate, magnesium, and potassium, leading to decreased serum phosphorous levels.

Consequences can include rhabdomyolysis, decreased cardiac muscle function, cardiomyopathy, respiratory and cardiac failure, hemolysis, acute tubular necrosis, seizures, and delirium.

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New England Journal of Medicine - Vol. 359, No. 12, September 18, 2008

Wound management

Q: What organism or infection can be associated with a puncture wound in the foot of a patient wearing tennis shoes?
A: Puncture wounds in patients who were wearing tennis shoes that were saturated with sweat at the time of injury may become associated with pseudomonas tissue infection or osteomyelitis.

Q: What information should always be obtained concerning the patient's history when managing acute skin wounds?
A: When treating an acute skin wound, the patient's tetanus-immunization status should always be ascertained, and standard recommendations followed to ensure that the patient is protected against tetanus.

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New England Journal of Medicine - Vol. 359, No. 10, September 4, 2008

Mammalian Bites

The risk of infection after dog and cat bites ranges from 3 to 18% for dog bites to 28 to 80% for cat bites. Whereas most cat bites are deep puncture wounds, many dog bites cause open lacerations.

Large observational studies and limited clinical trials suggest that after high-pressure irrigation of the wound, it is safe to close most bite wounds (even on the extremities) up to 12 hours after injury (healing by primary intention).

However, human bites that are sustained over the metacarpophalangeal joints (“clenched-fist bites”) are especially prone to infection and require aggressive irrigation and treatment with antibiotics and should not be closed with sutures.

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New England Journal of Medicine - Vol. 359, No. 10, September 4, 2008

Chemical Burns

Chemical burns cause tissue injury through the interaction of the chemical agent with the tissue. Initial treatment consists of copious water lavage and removal of any particles. The important exception to the treatment of a chemical burn with water lavage involves injury from the elemental metals (i.e., lithium, sodium, magnesium, and potassium), because the metal residue will spontaneously ignite on contact with water.

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New England Journal of Medicine - Vol. 359, No. 10, September 4, 2008