2011年7月1日 星期五

細菌性腸炎

Invasive Bacterial Enteropathies

How do patients with invasive enteropathies present?
Patients with acute invasive enteropathies typically present with fever and frequent bowel movements that contain mucus or blood or both; the mucus or blood often contains leukocytes.

What are the causes of invasive bacterial enteropathies?
Causes of invasive bacterial enteropathies in adults include campylobacteriosis, salmonellosis, shigellosis, enteroinvasive Escherichia coli, and yersiniosis, among others. Vibrio parahaemolyticus, which is most commonly reported in Asia, can cause either bloody or watery diarrhea and is usually associated with the ingestion of seafood.

When is microbiologic evaluation of stool indicated?
Microbiologic evaluation of stool is not usually indicated for most travelers with acute watery diarrhea, such as this patient, since the illness is usually self-resolving or can be treated empirically with hydration, agents that control symptoms, or antimicrobial agents. In contrast, microbiologic evaluation of stool is usually indicated for patients with evidence of an invasive enteropathy, those with persistent diarrhea, and those whose illness is part of an outbreak that has potential public health importance and has an uncertain cause.

What is the recommended treatment for travelers’ diarrhea?
Azithromycin is an agent of choice for the treatment of persons with cholera and those with travelers’ diarrhea. Many strains of campylobacter are now resistant to fluoroquinolones, and the Haitian strain of cholera has reduced susceptibility to ciprofloxacin, a pattern associated with clinical and microbiologic failure in cholera patients.

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NEJM Teaching Topics
June 30, 2011

2011年5月27日 星期五

急診留觀可減少小兒頭部外傷病患做斷層掃描

Emergency Department Observation of Children with Minor Head Injury Reduces Use of Computed Tomography
But does not impair identification of clinically important traumatic brain injuries

In a secondary analysis of data from the Pediatric Emergency Care Applied Research Network, researchers evaluated whether observing children (age, less than 18 years) with minor head injury before deciding whether to obtain a head computed tomography (CT) scan affects use of CT and diagnosis of traumatic brain injury (TBI). Data on duration of observation were not collected.

Of 40,113 patients (median age, 5.6 years), 5433 (14%) were observed. Observed patients were significantly less likely to undergo CT than patients who were not observed (31% vs. 35%). After adjustment for clinical covariates, the likelihood of CT scanning remained lower for patients who were observed (adjusted odds ratio, 0.53). Rates of clinically important TBI (defined as intracranial injury resulting in death, neurosurgical intervention, intubation for more than 24 hours, or hospital admission for 2 or more nights) were similar between groups (0.75% and 0.87%, respectively).

The authors conclude that observing intermediate-risk patients would result in approximately 39 fewer CT scans per 1000 children who present to the emergency department with blunt head trauma; intermediate-risk children were defined as those with normal mental status and no evidence of skull fracture and at least one of the following: loss of consciousness, severe mechanism of injury, vomiting, not acting normally per parents (children less than 2 years), or severe headache (children above 2 years).

Comment: The lack of data on duration of observation makes practical application of these findings difficult. However, neurologically normal children with a history of loss of consciousness, transient vomiting, or headache can be observed before deciding about CT. Children with persistent symptoms or any sign of clinical deterioration should undergo immediate CT.


Katherine Bakes, MD
Published in Journal Watch Emergency Medicine May 27, 2011

Citation(s): Nigrovic LE et al. The effect of observation on cranial computed tomography utilization for children after blunt head trauma. Pediatrics 2011 Jun; 127:1067.

2011年5月20日 星期五

視神經超音波可以評估腦壓

Optic Nerve Ultrasound Predicts Elevated Intracranial Pressure
In a small meta-analysis, ultrasound measurement of optic nerve sheath diameter had a sensitivity of 90% for predicting elevated ICP.

Bedside emergency department ocular ultrasound is increasingly used to detect retinal detachment, but does it also have other uses? Researchers performed a meta-analysis of six prospective studies (231 patients) in which researchers compared intracranial pressure (ICP) monitoring and ultrasound measurement of optic nerve sheath diameter (ONSD) in consecutive adult patients with suspected elevated ICP. ONSD was measured 3 mm behind the globe; ICP and ONSD measurements were performed within 1 hour of each other.

The pooled sensitivity for ONSD detection of elevated ICP was 90% and the pooled specificity was 85%. The pooled diagnostic odds ratio was 51, meaning that patients with elevated ICP were 51 times more likely to have a positive ONSD test than those without elevated ICP.

Comment: With a 90% sensitivity for ruling out elevated intracranial pressure, bedside ultrasound measurement of optic nerve sheath diameter shows promise as a new tool to guide decision making, including prioritizing patients for diagnostic studies and determining whether computed tomography is needed before an unstable polytrauma patient is taken to the operating room.


Kristi L. Koenig, MD, FACEP
Published in Journal Watch Emergency Medicine May 20, 2011

Citation(s): Dubourg J et al. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure: A systematic review and meta-analysis. Intensive Care Med 2011 Apr 20; [e-pub ahead of print]. (http://dx.doi.org/10.1007/s00134-011-2224-2)

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【實際做法】
http://emj.bmj.com/content/26/9/630.full.pdf

2011年5月6日 星期五

外傷急救新觀念:術中血壓不必keep太高!

Hypotensive Resuscitation in Trauma Patients Lessens Transfusion Needs
Also reduces incidence of postoperative coagulopathy and associated death.



The authors report an interim analysis of the first prospective randomized trial of intraoperative hypotensive resuscitation in patients. At a single level I trauma center, 90 patients with at least one episode of in-hospital systolic blood pressure ≤90 mm Hg who were undergoing laparotomy or thoracotomy for blunt (6 patients) or penetrating (84) trauma were randomized at entry to the operating room to have their mean arterial pressure (MAP) maintained at a target minimum of 50 mm Hg (low MAP) or 65 mm Hg (high MAP). Methods of achieving target levels were at the discretion of the anesthesiologist. MAPs that rose above the target were not lowered.

The low-MAP group received a significantly smaller amount of blood products (packed red blood cells, fresh frozen plasma, platelets) than the high-MAP group (1594 mL vs. 2898 mL) and had significantly lower mortality within 24 hours of admission to the intensive care unit (2.3% vs. 17.4%) and significantly lower mortality due to coagulopathy-associated postoperative hemorrhage (0 of 6 vs. 7 of 10). Mortality at 30 days did not differ significantly between the two groups (23% and 28%, respectively).

Comment: This interim analysis suggests that maintaining a low MAP during intraoperative resuscitation in seriously ill trauma patients is safe, reduces use of blood products, and decreases the incidence of postoperative coagulopathy and the related consequence of death. If these promising findings hold in the final analysis, similar approaches should be undertaken in the field and the emergency department.


John A. Marx, MD, FAAEM
Published in Journal Watch Emergency Medicine May 6, 2011

Citation(s): Morrison CA et al. Hypotensive resuscitation strategy reduces transfusion requirements and severe postoperative coagulopathy in trauma patients with hemorrhagic shock: Preliminary results of a randomized controlled trial. J Trauma 2011 Mar; 70:652.

2011年4月22日 星期五

治敗血症休克用Levophed比Dopamine好

Norepinephrine Outperforms Dopamine in Adults with Septic Shock
Use of norepinephrine was associated with a 9% reduction in mortality compared with dopamine.

According to the Surviving Sepsis Campaign guidelines, norepinephrine or its precursor, dopamine, are both recommended as first-line treatments to improve organ perfusion in patients with septic shock. To determine which vasopressor is better, researchers conducted a meta-analysis of six randomized trials that compared the two agents in patients with septic shock and that reported in-hospital or 28-day mortality.

The trials included a total of 995 patients randomized to norepinephrine and 1048 randomized to dopamine. Overall, mortality was significantly lower in the norepinephrine group than in the dopamine group (48% vs. 53%). Arrhythmias were significantly less common with norepinephrine than with dopamine (relative risk, 0.43).

Comment: This study suggests that norepinephrine is superior to dopamine for adult patients with refractory septic shock. The finding that dopamine is associated with more arrhythmias might explain the higher mortality, as arrhythmias can impair cardiac function, thereby leading to worse outcomes.


Kristi L. Koenig, MD, FACEP
Published in Journal Watch Emergency Medicine April 22, 2011

Citation(s): Vasu TS et al. Norepinephrine or dopamine for septic shock: A systematic review of randomized clinical trials. J Intensive Care Med 2011 Mar 24; [e-pub ahead of print].
http://dx.doi.org/10.1177/0885066610396312

2011年4月8日 星期五

Midazolam plus Ketamine

Adding Midazolam to Ketamine for Procedural Sedation Reduces Emergence Reactions in Adults
Coadministration significantly reduced incidence of emergence reactions, and route of ketamine administration had no effect on incidence of adverse events.

Ketamine is associated with untoward emergence reactions after procedural sedation, including nightmares and hallucinations. Coadministration of midazolam to mitigate this reaction is ineffective in children. Researchers assessed the effect of midazolam on incidence of ketamine emergence reactions and the effect of route of ketamine administration on incidence of adverse events in adult patients undergoing procedural sedation. In a prospective, double-blind, placebo-controlled study, 182 patients (age range, 18–50) at an academic emergency department in Turkey were randomized to receive ketamine either intravenously (1.5 mg/kg) or intramuscularly (4.0 mg/kg), either with or without intravenous midazolam (0.03 mg/kg).
Recovery agitation occurred significantly less frequently when midazolam was coadministered with ketamine (8% vs. 25%). Incidence of adverse events (recovery agitation, respiratory events, nausea and vomiting) was similar with the two routes of ketamine administration; no patient had respiratory compromise.

Comment: Coadministration of midazolam with ketamine in adults seems to mitigate emergence reactions with no significant downside.

Richard D. Zane, MD, FAAEM
Published in Journal Watch Emergency Medicine April 8, 2011

CITATION(S): Sener S et al. Ketamine with and without midazolam for emergency department sedation in adults: A randomized controlled trial. Ann Emerg Med 2011 Feb; 57:109.e2.

2011年4月5日 星期二

硬幣卡食道不必每個都要插endo處理!

Rapid Sequence Intubation for Esophageal Coin Removal in Kids
Rapid sequence intubation by emergency physicians resulted in coin removal in 95% of patients, but 10% of procedures lasted more than 30 minutes and half the patients had complications.

Esophageal coins pass spontaneously in children about 25% of the time, but most coins must be actively removed. Methods of removal in the emergency department (ED) include bougienage, Foley catheter, and Magill forceps. Endoscopy under general anesthesia typically is not performed in stable patients and, in stable patients, is delayed until patients have fasted and intubation can be performed in a more controlled setting than the ED. These authors report a 4-year retrospective review of 101 children (age range, 4 months–13 years) who underwent rapid sequence intubation (RSI; usually with succinylcholine and etomidate) for coin removal by emergency physicians at a pediatric ED in California.

Median time from ingestion to presentation was 5 hours. Coins were successfully retrieved in 96 patients, with Magill forceps alone (56 patients) or Magill forceps plus a Foley catheter (40 patients). Complications occurred in 46 patients and included minor bleeding (13 patients), lip lacerations (7), multiple attempts (5), hypoxia (2), accidental extubation (3), dental injuries (3), and bradycardia (2) despite pretreatment with atropine in 84 cases. Median ED length of stay was 5 hours (range, 1.5–45 hours), and median time from intubation to extubation was 15 minutes (range, 2–93 minutes); nine procedures lasted more than 30 minutes.

Comment:
Even at this tertiary referral center, almost 10% of procedures lasted longer than 30 minutes and nearly half the patients had complications. Faster, safer, simpler, less-expensive, and less resource-intensive techniques are more appropriate for removal of esophageal coins in most children. Why this aggressive RSI approach was used in the children in the study is unclear; however, it should be reserved for difficult cases and performed in an area of the hospital with dedicated resources.


Kristi L. Koenig, MD, FACEP
Published in Journal Watch Emergency Medicine April 1, 2011

CITATION(S): Bhargava R and Brown L. Esophageal coin removal by emergency physicians: A continuous quality improvement project incorporating rapid sequence intubation. CJEM 2011 Jan; 13:28.