2009年10月29日 星期四

TPA for stroke 可延長至 4.5 小時

Stroke treatment with alteplase given 3.0-4.5 h after onset of acute ischaemic stroke (ECASS III).

Conclusion:
Our results support the use of alteplase up to 4.5 h after the onset of stroke symptoms across a broad range of subgroups of patients who meet the requirements of the European product label but miss the approved treatment window of 0-3 h.

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Lancet Neurol. 2009 Oct 20.
http://linkinghub.elsevier.com/retrieve/pii/S1474-4422(09)70264-9

HIV risk of percutaneous inoculation

What is the risk of HIV transmission after percutaneous inoculation?
The overall rate of HIV transmission through percutaneous inoculation (i.e., by means of a needle or other instrument that pierces the skin) is widely reported to be 0.3% (95% confidence interval [CI], 0.2 to 0.5); features of exposure that are associated with a higher rate of transmission include a needle that was used to cannulate a blood vessel in the source patient, advanced HIV disease in the source patient, a deep needlestick, and visible blood on the surface of the instrument. Theoretically, any exposure that involves piercing of the skin may transmit infection, but clinical judgment is required to assess the likelihood that the inoculum is sufficient to pose a credible threat of transmission; many clinicians use a puncture that draws blood as a general threshold. Splashes of infectious material to mucous membranes (e.g., conjunctivae or oral mucosa) or broken skin also may transmit HIV infection (estimated risk per exposure, 0.09% [95% CI, 0.006 to 0.5]).

HIV risk of sexual exposure

What is the risk of HIV transmission after sexual exposure?
The per-contact risk of HIV transmission from sexual exposure varies according to the nature of the exposure. The estimated risks are 1 to 30% with receptive anal intercourse, 0.1 to 10.0% with insertive anal intercourse and receptive vaginal intercourse, and 0.1 to 1.0% with insertive vaginal intercourse. As compared with other forms of intercourse, oral intercourse is considered to pose a lower risk of HIV transmission, although good risk estimates are lacking. The risks of sexual transmission are difficult to quantify; the wide ranges reported for the risks of per-contact transmission derive from observational studies and are influenced by many factors, including the presence or absence of concomitant genital ulcer disease, other disease states, and cervical or anal dysplasia; circumcision status; the viral load in the genital compartment; and the degree of viral virulence.

2009年10月26日 星期一

誰說OHCA低溫治療一定要買昂貴儀器?

Cold saline infusion and ice packs alone are effective in inducing and maintaining therapeutic hypothermia after cardiac arrest

Aim of the study
Hypothermia treatment with cold intravenous infusion and ice packs after cardiac arrest has been described and used in clinical practice. We hypothesised that with this method a target temperature of 32–34°C could be achieved and maintained during treatment and that rewarming could be controlled.

Materials and methods
Thirty-eight patients treated with hypothermia after cardiac arrest were included in this prospective observational study. The patients were cooled with 4°C intravenous saline infusion combined with ice packs applied in the groins, axillae, and along the neck. Hypothermia treatment was maintained for 26h after cardiac arrest. It was estimated that passive rewarming would occur over a period of 8h. Body temperature was monitored continuously and recorded every 15min up to 44h after cardiac arrest.

Results
All patients reached the target temperature interval of 32–34°C within 279±185min from cardiac arrest and 216±177min from induction of cooling. In nine patients the temperature dropped to below 32°C during a period of 15min up to 2.5h, with the lowest (nadir) temperature of 31.3°C in one of the patients. The target temperature was maintained by periodically applying ice packs on the patients. Passive rewarming started 26h after cardiac arrest and continued for 8±3h. Rebound hyperthermia (>38°C) occurred in eight patients 44h after cardiac arrest.

Conclusions
Intravenous cold saline infusion combined with ice packs is effective in inducing and maintaining therapeutic hypothermia, with good temperature control even during rewarming.

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Resuscitation - 23 October 2009
(10.1016/j.resuscitation.2009.09.012)

2009年10月24日 星期六

【新知】Cardiocerebral Resuscitation

Researchers at the University of Arizona created a new protocol for the management of OHCA that they termed "cardiocerebral resuscitation." CCR consists of 3 major parts: (1) continuous chest compressions with no early ventilations preshock and postshock; (2) delayed intubation; and (3) early use of epinephrine. A recent study that compared CCR with standard CPR in patients with shockable rhythms demonstrated that both survival (47.2% vs 19.6%) and percentage of survivors with good neurologic outcome (83.3% vs 77.8%) were significantly improved in those who underwent CCR.

http://www.medscape.com/viewarticle/707616


Summary

Ewy and Kern, both leaders in the field of cardiac resuscitation, reviewed CCR and described ideal postresuscitation care. The "3 pillars" of CCR were described:

A. Compression-only CPR by anyone who witnessed the event.
B. CCR by emergency medical service personnel, assumed to be arriving > 5 minutes postarrest.
  1. 200 chest compressions (at 100/minute), delay intubation; second person to apply defibrillation pads and initiate passive oxygen insufflation (eg, 100% oxygen via facemask)
  2. Single shock if indicated, immediately followed by 200 more chest compressions (no pulse check after shock)
  3. Check for pulse and rhythm; note that this pulse check occurs 4 minutes after the CCR has begun
  4. EPI intravenously or intraosseously as soon as possible to improve central circulation, coronary circulation, and diastolic blood pressure
  5. Repeat (2) and (3) 3 times; intubate if no return of spontaneous circulation after 3 cycles; note that neither bag-valve-mask ventilation nor intubation occurs until 12 minutes after the CCR has begun
  6. Continue resuscitation efforts with minimal interruptions of chest compressions until resuscitation is successful or the person is pronounced dead
Viewpoint

In summary, the traditional mantra in emergency medicine of "A-B-C" has been turned upside-down by CCR. Aggressive management of the airway in those who have cardiac arrest is being relegated to a far lower priority. Good chest compressions and early EPI administration are the most important interventions when ventricular fibrillation is present in the circulation phase of cardiac arrest. Future studies will need to evaluate whether these concepts are applicable to nonshockable rhythms as well, although intuitively this seems reasonable. Finally, those who survive cardiac arrest should be treated with induced hypothermia, and pending more studies, they may benefit from early coronary angiography and PCI as well.

2009年10月23日 星期五

新版的「用力壓、快快壓」果然有效!

Compress the Chest: Better CPR Improves Survival from Out-of-Hospital Cardiac Arrest
Implementation of the 2005 AHA CPR guidelines that focus on uninterrupted chest compressions nearly doubled the odds of survival among patients with out-of-hospital cardiac arrest.

In 2005, the American Heart Association (AHA) released updated evidence-based guidelines for cardiopulmonary resuscitation and emergency cardiovascular care, but does adherence to the revised protocol improve outcomes? Investigators compared rates of survival from out-of-hospital cardiac arrest among 606 adult patients treated before and 1021 treated after implementation of the 2005 AHA guidelines in a single large emergency medical services system.

Review of a convenience sample of 69 electronic electrocardiogram recordings showed significant improvement in CPR quality after guideline implementation, including improvements in mean chest-compression rate, proportion of time that patients received chest compressions, and median preshock and postshock pause times for compressions. Unadjusted rates of survival to hospital discharge were significantly higher after implementation of the guidelines than before (9.4% vs. 6.1%). Among patients with witnessed arrest whose initial rhythm was ventricular fibrillation on EMS arrival, survival rates improved significantly from 24% (19 of 78) before implementation to 30% (34 of 112) after. Multivariate regression analysis that adjusted for initial rhythm, sex, arrest location, and witnessed arrest showed 1.8 greater odds of survival in the postintervention period.

Comment: The promising results of this large study suggest the AHA was on the right track with its renewed focus on basic CPR, including the importance of providing uninterrupted chest compressions.


Kristi L. Koenig, MD, FACEP
Published in Journal Watch Emergency Medicine October 23, 2009

Citation(s): Sayre MR et al. Impact of the 2005 American Heart Association cardiopulmonary resuscitation and emergency cardiovascular care guidelines on out-of-hospital cardiac arrest survival. Prehosp Emerg Care 2009 Oct-Dec; 13:469.

AMI 之症狀表現:性別差異

Symptoms of a first acute myocardial infarction in women and men

Background: Many studies have compared women and men for symptoms of acute myocardial infarction (AMI), but findings have been inconsistent, largely because of varying inclusion criteria, different study populations, and different methods.

Objective: The purpose of this study was to analyze gender differences in symptoms in a well-defined, population-based sample of women and men who experienced a first AMI.

Methods: Information on symptoms was collected from the medical charts of all patients with a first AMI, aged 25 to 74 years, who had taken part in the INTERGENE (Interplay Between Genetic Susceptibility and Environmental Factors for the Risk of Chronic Diseases) study. INTERGENE was a population-based research program on risk factors for cardiovascular disease. Medical charts were reviewed for each patient to determine the symptoms of AMI, and the prevalence of each symptom was compared according to sex.

Results: The study included 225 patients with a first AMI: 52 women and 173 men. Chest pain was the most common symptom, affecting 88.5% (46/52) of the women and 94.8% (164/173) of the men, with no statistically significant difference between the sexes. Women had significantly higher rates of 4 symptoms: nausea (53.8% [28/52] vs 29.5% [51/173]; age-adjusted odds ratio [OR] = 2.78; 95% CI, 1.47–5.25), back pain (42.3% [22/52] vs 14.5% [25/173]; OR = 4.29; 95% CI, 2.14–8.62), dizziness (17.3% [9/52] vs 7.5% [13/173]; OR = 2.60; 95% CI, 1.04–6.50), and palpitations (11.5% [6/52] vs 2.9% [5/173]; OR = 3.99; 95% CI, 1.15–13.84). No significant gender differences were found in the proportions of patients experiencing arm or shoulder pain, diaphoresis, dyspnea, fatigue, neck pain, abdominal pain, vomiting, jaw pain, or syncope/lightheadedness. No significant differences were found in the duration, type, or location of chest pain. The medical charts listed numerically more symptoms in women than in men; 73.1% (38/52) of the women but only 48.0% (83/173) of the men reported >3 symptoms (age-adjusted OR = 3.26; 95% CI, 1.62–6.54).

Conclusions: Chest pain is the most common presenting symptom in both women and men with AMI. Nausea, back pain, dizziness, and palpitations were significantly more common in women. Women as a group displayed a greater number of symptoms than did men.

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Gender Medicine. Volume 6, Issue 3, September 2009, Pages 454-462
http://dx.doi.org/10.1016/j.genm.2009.09.007

類固醇治偏頭痛無效

Steroids for migraine headaches: a randomized double-blind, two-armed, placebo-controlled trial

Background:
Recurrence of migraine headache after treatment in the emergency department (ED) is common. Conflicting evidence exists regarding the utility of steroids in preventing migraine headache recurrence at 24–48 h.

Objective:
To determine if steroids decrease the headache recurrence in patients treated for migraine headaches in the ED.

Methods:
Double-blind placebo-controlled, two-tailed randomized trial. Patients aged >17 years with a moderately severe migraine headache diagnosed by treating Emergency Physician were approached for participation. Enrollees received either dexamethasone (10 mg i.v.) if intravenous access was utilized or prednisone (40 mg by mouth × 2 days) if no intravenous access was obtained. Each medication was matched with an identical-appearing placebo. Patients were contacted 24–72 h after the ED visit to assess headache recurrence.

Results:
A total of 181 patients were enrolled. Eight were lost to follow-up, 6 in the dexamethasone group and 2 in the prednisone arm. Participants had a mean age of 37 years (±10 years), with 86% female. Eighty-six percent met the International Headache Society Criteria for migraine headache. Of the 173 patients with completed follow-up, 20/91 (22%) (95% confidence interval [CI] 13.5–30.5) in the steroid arm and 26/82 (32%) (95% CI 21.9–42.1) in the placebo arm had recurrent headaches (p = 0.21).

Conclusion:
We did not find a statistically significant decrease in headache recurrence in patients treated with steroids for migraine headaches.

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http://www.jem-journal.com/article/PIIS0736467909007471/abstract

2009年10月22日 星期四

Management of Necrotizing Fasciitis

There are four general principles that guide the management of a necrotizing soft-tissue infection: (1) early identification, (2) source control, (3) antibiotics, and (4) supportive care. Early identification of a serious necrotizing soft-tissue infection may not be straightforward. The typical signs are erythema, purplish discoloration of the skin with bullae, edema, crepitus, and pain that seems disproportionate to the findings on examination. Since in many cases, not all these signs are present, practitioners may underestimate the extent of the disease process. Surgical control of the source of the infection is a lifesaving maneuver. Because of this, emphasis is placed on removing affected tissue, regardless of possible resultant cosmetic defects. Removal of the necrotic tissue and the bacterial load allows antibiotics to control the spread of bacteria more effectively. Because of the rapidity with which necrotizing fasciitis spreads, time is of the essence when dealing with source control. Despite early aggressive surgical débridement, mortality rates range from 16 to 45%.

New England Journal of Medicine - Vol. 361, No. 17, October 22, 2009

Epidemiology of Necrotizing Fasciitis

Necrotizing soft-tissue infections can be divided into two types: type I (polymicrobial) and type II (monomicrobial). Approximately 70% of infections are type I; type II infections usually involve group A streptococci. The incidence of necrotizing fasciitis is difficult to determine, since the classification and coding of these infections is poor; a conservative estimate is 1500 severe cases per year in the United States.

Risk factors for the development of these infections include diabetes, renal failure, liver failure, advanced age, behavior risks (e.g., intravenous drug abuse), and obesity. However, more than 20% of cases have no known risk factors. The patient in the case had recently given birth by means of a surgical procedure, and the wound could have been contaminated by organisms from the patient's skin or from a health care worker.

New England Journal of Medicine - Vol. 361, No. 17, October 22, 2009

2009年10月15日 星期四

Bacterial Diarrhea

Diagnosis of Bacterial Diarrhea
Most bacterial and nonbacterial enteropathogens produce nonspecific acute watery diarrhea. The rate of underreporting of cases of acute watery diarrhea that are caused by detectable enteric pathogens, including most cases of diarrhea caused by bacteria such as salmonella and campylobacter is substantial. Indications for stool culture include the presence of severe diarrhea (passage of six or more unformed stools per day), diarrhea of any severity that persists for longer than a week, fever, and multiple cases of illness that suggest an outbreak. Dysentery, with passage of blood and mucus in stools, suggests possible bacterial colitis, and stool samples are recommended. Stool cultures are not routinely recommended in most cases of watery diarrhea or traveler's diarrhea because of a low yield of bacterial pathogens.

Recommended treatment for bacterial diarrhea
For all cases of diarrhea, attention to fluid and electrolyte replacement is fundamental. Available data in children with acute diarrhea do support the continuation of oral feeding during the illness. Antimotility drugs such as loperamide and diphenoxylate hydrochloride, can reduce the number of stools passed and may be useful in controlling the stool rate with watery diarrhea. They should not be used without concomitant antibacterial therapy in patients with fever or dysentery in whom the drug may lead to increased contact time of the enteropathogen with the gut mucosa. Therapy with antimicrobial agents is important in most cases of diarrhea caused by invasive or inflammatory bacterial pathogens and is useful in other noninvasive forms of bacterial diarrhea.

Food poisoning

What characterizes the term “food poisoning”?

Food poisoning is the term used when a preformed toxin in food is ingested, resulting in intoxication rather than an enteric infection. Staphylococcus aureus causes vomiting within 2 to 7 hours after the ingestion of improperly cooked or stored food containing a heat-stable preformed toxin. Clostridium perfringens causes watery diarrhea without vomiting within 8 to 14 hours after the ingestion of contaminated meat, vegetables, or poultry. Strains of Bacillus cereus from contaminated fried rice, vegetable sprouts, or other food items produce one of two toxins that may result in disease resembling that caused by S. aureus or C. perfringens, depending on the toxin produced. Most cases of food poisoning are of short duration, with recovery occurring in 1 to 2 days. Although it is possible to confirm the cause of food poisoning by microbiologic methods, these are rarely used, and the diagnosis is made in nearly all cases clinically without laboratory confirmation.

New England Journal of Medicine - Vol. 361, No. 16, October 15, 2009

2009年10月8日 星期四

Top 10 Mistakes Made in Clinical Rotations

Top 10 Mistakes Made in Clinical Rotations
Kendra Campbell, Medical Student, Emergency Medicine, 10:38AM Oct 4, 2009

Last week, I watched a med student argue for 20 minutes with a patient about whether or not they were ambulating enough. His actions inspired me to make a top 10 list of mistakes that I've seen students make during their clinical rotations:

1. Arguing with a patient.
This is an exercise in futility, and is very unprofessional.

2. Reporting a physical finding without actually observing it.
I've even seen a student get in trouble for documenting a physical finding on a patient who had been discharged already.

3. Pimping your resident or attending.
Med school is similar to the military when it comes to respecting your place in the chain of command. Attendings pimp residents and med students. Residents pimp med students. Thou shalt not pimp up the chain.

4. Disrespecting the nurses.
Seriously, this is a huge no-no. If you want to make your life miserable, make the nurses hate you. If you want to enjoy your time at the hospital, befriend every nurse you meet.

5. Dressing inappropriately.
I've seen this rule broken many times, and yet it never fails to shock me. We've probably all seen at least one female wearing 4-inch stiletto heels, or showing so much cleavage that you could use their chest to make an anatomical drawing. There's a time and a place for everything, and the hospital is not a place to dress provocatively.

6. Documenting an important positive finding without alerting your resident or attending.
If you discover that a patient has rebound tenderness, or a temperature of 103.7, don't write this in a note and walk away. You must always alert your higher-ups to significant findings, or else you will find yourself getting chewed out for a good while.

7. Showing up late.
This is a particular pet peeve of mine, and one that some students seem to think is insignificant. People notice when you're late. It's unprofessional and disrespectful to the rest of the group. Traffic is not an excuse. Leave your residence early enough to get to the hospital with plenty of time to spare.

8. Performing a procedure without having been authorized to do so.
If the resident walks in on you placing a central line on a patient without their authorization, you will find yourself in deep trouble with the doctor, hospital, and potentially a courtroom.

9. Forgetting you are in a hospital.
This is something that is easier said than done. We spend so many hours in the hospital that it's easy to forget that we are surrounded by very ill people. It's not a high school football game; it's a hospital, people.

10. Being a slacker.
We all have seen students who try to get by with the bare minimum in everything they do. If you want to throw away a ridiculous amount of money, not learn anything, and end up being a crappy doctor, then by all means slack off during your clinical years. If you want to learn a lot and become an incredible doctor, then put in the time and effort.

2009年10月7日 星期三

何謂 DCS?

What is meant by “damage-control surgery”?

If a patient had hypothermia, acidosis, and diffuse bleeding during the first laparotomy, the surgical team will opt for a damage-control strategy. The term “damage control” originated in the U.S. Navy and referred to the ability of a ship to absorb damage while continuing to perform its mission. Damage-control laparotomy is widely practiced today in severely injured patients with trauma. The basic concept is to perform an abbreviated operation, focusing on controlling hemorrhage and contamination. This initial operation is followed by a period of resuscitation in the intensive care unit (ICU) to reverse the lethal triad of acidosis, hypothermia, and coagulopathy. The patients are taken back to the operating room for a definitive operation once the physiological disturbances have been corrected. Although used primarily for severely injured patients, this approach is equally useful for other critically ill patients who need an operation.

New England Journal of Medicine - Vol. 361, No. 15, October 8, 2009

外傷病患的死亡三角關係

What is the “lethal triad” in trauma patients?

The ominous trio of signs in trauma patients, including coagulopathy, acidosis, and hypothermia has been called the “lethal triad.” These factors perpetuate one another, thus creating a vicious cycle that is difficult to interrupt. Early development of coagulopathy is a well-recognized marker of the severity of an injury, and its presence is associated with a significantly increased risk of death.

New England Journal of Medicine - Vol. 361, No. 15, October 8, 2009