2008年8月29日 星期五


Acute Phosphate Nephropathy after Colonoscopy
Preparation for colonoscopy may involve the administration of an oral phosphate solution, which can result in acute hyperphosphatemia and hyperphosphaturia. (Note that the Food and Drug Administration issued a warning about the potential for acute renal failure after ingestion of such solutions in 2006.) A patient with baseline impairment of kidney function undergoing this “prep” may have volume contraction due to related decreased oral intake, diarrhea or vomiting, or both or may develop acute phosphate nephropathy because of diffuse intratubular injury from calcium-phosphate deposition, given the high phosphate intake from the preparation itself. The other risk factors for acute phosphate nephropathy include preexisting kidney disease, hypertension, advanced age, female sex, antecedent volume depletion, and use of angiotensin-converting–enzyme inhibitors or angiotensin-receptor blockers, diuretics, or nonsteroidal anti-inflammatory drugs.

New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008


What guidelines may distinguish acute tubular necrosis from prerenal azotemia?
Ans: In acute tubular necrosis, the fractional excretion of sodium (FENa) is >2, the fractional excretion of urea nitrogen is >50, the urinary sodium is >20 mmol/liter, and the ratio of urinary creatinine to plasma creatinine is <15.

In contrast, in prerenal azotemia, the fractional excretion of sodium (FENa) is <1,>20.

New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008

Pancreatitis Definition

There is a tendency to overdiagnose acute pancreatitis. A reasonable threshold for a diagnosis of acute pancreatitis is a serum level of amylase (or lipase) that is at least three times the upper limit of the normal range, plus a history of characteristic abdominal pain. If amylase (or lipase) does not reach this threshold, it is best not to make the diagnosis of acute pancreatitis unless findings on computed tomography or MRI reveal characteristic changes of acute pancreatitis.

New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008

UGI bleeding - rebleeding

Repeat Endoscopy
Repeat endoscopy may be considered on a case-by-case basis if there are clinical signs of recurrent bleeding or if there is uncertainty regarding the effectiveness of hemostasis during the initial treatment. However, planned second-look endoscopy that is performed within 24 hours after initial endoscopic therapy is generally not recommended. Even though such a procedure was shown to be efficacious in two meta-analyses, it provided only a limited reduction in the rate of rebleeding. Also, the procedure may not be cost-effective when medical therapy leading to profound acid suppression is initiated.

What test should be included in the long-term management and treatment of patients after acute peptic ulcer bleeding?
Ans: Testing for and treatment of H. pylori infection are critical considerations in the long-term management and treatment of patients after acute peptic ulcer bleeding.

What is the precise definition of postural changes or orthostatic hypotension?
Ans: Postural changes or orthostatic hypotension is defined as an increase in the pulse of ≥20 or more beats per minute or a drop in systolic blood pressure of over 20 mm Hg on standing after the patient has been in a recumbent position for at least five minutes.

New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008

UGI bleeding

Acute Upper Gastrointestinal Bleeding
The mortality associated with acute bleeding from a peptic ulcer remains high (5 to 10%), and the condition accounts for more than 400,000 hospital admissions per year in the United States. In most settings, the vast majority of acute episodes of upper gastrointestinal bleeding (80 to 90%) have nonvariceal causes, with gastroduodenal peptic ulcer accounting for the majority of lesions.

Nasogastric Tube
The insertion of a nasogastric tube may be helpful in the initial assessment of the patient (specifically, triage), although the incremental information such a procedure provides remains controversial. It has been suggested that the presence of blood in the nasogastric aspirate is an adverse prognostic sign that may be useful in identifying patients who require urgent endoscopic evaluation. However, the absence of bloody or coffee-ground material does not definitively rule out ongoing or recurrent bleeding, since approximately 15% of patients without bloody or coffee-ground material in nasogastric aspirates are found to have high-risk lesions on endoscopy. The use of a large-bore orogastric tube with gastric lavage (with the use of tap water at room temperature) appears to improve only the visualization of the gastric fundus on endoscopy and has not been documented to improve outcome.

New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008

Beware antipsychotics in dementia

Almost everyone with dementia has behavioural and psychiatric problems such as depression, agitation or delusions at some stage. They are often prescribed antipsychotic drugs to control their symptoms. Atypical antipsychotics (e.g. risperidone, olanzpine) increase the risk of death by 8% in a year compared with non-antipsychotic medication. The reason may be a direct effect of the drugs or that the disease that causes the symptoms also causes early death. Non drug treatments like behavioural therapy should be considered, say the authors.

Source: Evidence-Based Mental Health 2008;11:73. Abstracted from Am J Psychiatry 2007;164:1568-76.

Dangerous Sports

People across the world have been watching the Olympics this month, and many will be encouraged to do more sport. But no activity is completely risk-free, as this 10 year retrospective study of sports-related deaths points out. It notes that:
  • Sudden death most often happens in people with left ventricular hypertrophy from underlying coronary heart disease
  • Traumatic deaths from drowning or blunt trauma most often happen on holiday in unfamiliar surroundings
  • Medical screening for everyone before participation in sports won't prevent many of the unexpected death
  • The cause is often not apparent until a postmortem is carried out
Source: British Journal of Sports Medicine 2008;42:604-608

2008年8月25日 星期一

Ketamine 用於急診是安全的

Audit of the safety and effectiveness of ketamine for procedural sedation in the emergency department
Emergency Medicine Journal 2008;25:579-582; doi:10.1136/emj.2007.056200

Aim: To examine the effectiveness and safety of the sedative agents used in the emergency department following the introduction of ketamine as an agent for procedural sedation

Methods: A 2-year prospective audit of sedation practice was undertaken. This specifically examined the rationale behind a doctor’s choice of sedative agent, the depth of sedation achieved, adverse events and the time taken to regain full orientation.

Results: 210 patients were included of whom 85 (40%) were given ketamine, 107 (51%) midazolam and 18 (9%) propofol. The median time to full orientation was 25 min for ketamine, 30 min for midazolam and 10 min for propofol. Complications occurred in 15.9% of sedations overall (14.6% of those given ketamine, 15.8% given midazolam and 22.2% given propofol). Apnoea and hypoxia most often occurred with midazolam and propofol, while hypertension and hypertonicity were encountered more frequently with ketamine. In addition, 19.5% of patients given ketamine suffered the re-emergence phenomenon. The association between deep sedation with no response to pain and adverse events encountered with midazolam does not occur with ketamine.

Conclusions: Ketamine is both safe and effective and compares favourably with midazolam as an agent for procedural sedation in the emergency department. Although the re-emergence phenomenon occurred, no psychological sequelae were encountered after return to full orientation. Ketamine may be particularly useful in groups of patients at high risk of adverse effects with midazolam.

Appendicitis 止痛不會導致誤診

Morphine analgesia in patients with acute appendicitis: a randomised double-blind clinical trial
Emergency Medicine Journal 2008;25:586-589 ; doi:10.1136/emj.2007.050914

Background: The administration of analgesics to patients with acute abdominal pain due to acute appendicitis is controversial. A study was undertaken to assess the analgesic effect of morphine in patients with acute appendicitis.

Methods: A randomised double-blind clinical trial was conducted in Sina hospital, a general teaching hospital, from January 2004 to March 2005. Patients scheduled for appendectomy were randomised to receive 0.1 mg/kg morphine sulfate or saline (0.9%) to a maximum dose of 10 mg over a 5 min period. Patients were examined by surgeons not involved in their care before and after drug administration and their pain intensity and signs were recorded at each visit. The physicians were also asked to indicate their own treatment plan. The main outcome measures were pain intensity using a visual analogue scale (VAS) and signs of acute appendicitis. A favourable reduction in VAS score was defined as a change of >13 mm.

Results: Of the 71 patients enrolled in the study, 35 were allocated to receive morphine and 36 to receive placebo. One patient left the hospital before receiving morphine. No significant differences were seen between the two groups with regard to age, sex and initial VAS score. A more favourable change in VAS score was reported in the morphine group with a significantly greater reduction in the median VAS score than in the placebo group. Morphine administration did not cause significant changes in patients’ signs or in the physicians’ plans or diagnoses. No adverse events were seen in either group.

Conclusion: Morphine can reduce pain in patients with acute appendicitis without affecting diagnostic accuracy.

2008年8月22日 星期五


A Tool for Predicting the Need for Intensive Respiratory or Vasopressor Support in Community-Acquired Pneumonia

Clinical Infectious Diseases 2008;47:375–384

Existing severity assessment tools, such as the pneumonia severity index (PSI) and CURB-65 (tool based on confusion, urea level, respiratory rate, blood pressure, and age 65 years), predict 30-day mortality in community-acquired pneumonia (CAP) and have limited ability to predict which patients will require intensive respiratory or vasopressor support (IRVS).

The Australian CAP Study (ACAPS) was a prospective study of 882 episodes in which each patient had a detailed assessment of severity features, etiology, and treatment outcomes. Multivariate logistic regression was performed to identify features at initial assessment that were associated with receipt of IRVS. These results were converted into a simple points-based severity tool that was validated in 5 external databases, totaling 7464 patients.

In ACAPS, 10.3% of patients received IRVS, and the 30-day mortality rate was 5.7%. The features statistically significantly associated with receipt of IRVS were SMART-COP:
  • low systolic blood pressure (2 points),
  • multilobar chest radiography involvement (1 point),
  • low albumin level (1 point),
  • high respiratory rate (1 point),
  • tachycardia (1 point),
  • confusion (1 point),
  • poor oxygenation (2 points), and
  • low arterial pH (2 points) .
A SMART-COP score of 3 points identified 92% of patients who received IRVS, including 84% of patients who did not need immediate admission to the intensive care unit. Accuracy was also high in the 5 validation databases. Sensitivities of PSI and CURB-65 for identifying the need for IRVS were 74% and 39%, respectively.

SMART-COP is a simple, practical clinical tool for accurately predicting the need for IRVS that is likely to assist clinicians in determining CAP severity.

2008年8月20日 星期三

Statin-Induced Myopathy

Statin-Induced Myopathy
In rare cases, statins can cause muscle pain or weakness in association with elevated creatine kinase levels (i.e., myopathy), and, occasionally, this leads to muscle breakdown and myoglobin release (i.e., rhabdomyolysis), which confers a risk of renal failure and death. The mechanisms by which statins cause myopathy remain unknown but appear to be related to statin concentration in the blood. The incidence of frank myopathy is typically only about 1 case in 10,000 patients per year with standard doses (e.g., 20 to 40 mg of simvastatin daily) but it increases with higher doses (e.g., 80 mg of simvastatin daily) and with concomitant use of certain drugs (e.g., cyclosporine which can inhibit statin metabolism).

Increased Risk for Statin-Induced Myopathy
This study by The SEARCH Collaborative Group, reports small increases in the risk of myopathy among older participants and women, as well as among those with evidence of impaired renal function and those who were taking calcium antagonists at baseline. Amiodarone can increase the risk that a statin will cause myopathy, for example when amiodarone is taken with 80 mg of simvastatin daily the risk of statin-induced myopathy increases significantly.

New England Journal of Medicine - Vol. 359, No. 8, August 21, 2008

Hearing loss

Q: What type of hearing loss makes sound lateralize to the affected ear during the Weber test or when the patient hums?
A: In conductive hearing loss, sound lateralizes to the affected ear during the Weber test or when the patient hums.

Q: What bedside procedure can cause a transient bilateral sudden sensorineural hearing loss?
A: Transient bilateral sudden sensorineural hearing loss may result from a sudden drop in intracranial pressure, which can occur during a spinal tap.

New England Journal of Medicine - Vol. 359, No. 8, August 21, 2008

Sensorineural Hearing Loss

Causes of Sensorineural Hearing Loss (SNHL)
Approximately 1% of cases of sudden SNHL are due to retrocochlear disorders that may be related to vestibular schwannoma, demyelinating disease, or stroke. Another 10 to 15% are due to another identifiable cause such as Meniere's disease, trauma, autoimmune disease, syphilis, Lyme disease, or perilymphatic fistula. The remainder are idiopathic and almost exclusively unilateral.
Rare cases of bilateral sudden deafness most often reflect a psychiatric (functional) cause or a neurologic process (e.g., neoplastic dural infiltration of the posterior cranial fossa, paraneoplastic syndrome, or encephalitis).

Steroids to Treat Hearing Loss
Oral corticosteroids are routinely used for primary treatment of sudden sensorineural hearing loss, once primary causes are ruled out, although data are limited to support their use; there are also limited data to support the use of intratympanic corticosteroids for primary therapy or for treatment of those whose hearing did not improve with initial therapy. A clinical trail sponsored by the National Institutes of Health that compares oral with intratympanic corticosteroid treatment for primary therapy is under way.

New England Journal of Medicine - Vol. 359, No. 8, August 21, 2008

Neuroleptic malignant syndrome

What is neuroleptic malignant syndrome?
Neuroleptic malignant syndrome is a rare life-threatening neurological disorder most often caused by neuroleptic or antipsychotic drugs. Symptoms usually involve muscle rigidity, high fever, unstable blood pressure, and changes in cognition that can lead to delirium, and coma. Creatine kinase levels are elevated, which helps in making the diagnosis.

New England Journal of Medicine - Vol. 359, No. 8, August 21, 2008

Herpes Simplex Virus Encephalitis

Acute limbic encephalitis is seen in patients with herpes simplex virus infection. These patients have an acute onset, with fever, behavioral changes, and meningismus. MRI reveals swelling, often with hemorrhage, bilaterally but asymmetrically in the temporal lobes, cingulate gyri, insula, or subfrontal areas.

The virus usually cannot be cultured from the cerebrospinal fluid, but polymerase-chain-reaction analysis for viral DNA is reliably positive after the first 2 to 3 days.

Human herpesvirus 6 may cause more indolent limbic encephalitis, but HHV6 encephalitis is usually limited to patients with immunosuppression.

New England Journal of Medicine - Vol. 359, No. 8, August 21, 2008

2008年8月19日 星期二

Massive transfusion 要記得輸 FFP

結論似乎指 massive transfusion 時,FFP 給得不夠積極則預後差?。

Review of Current Blood Transfusions Strategies in a Mature Level I Trauma Center: Were We Wrong for the Last 60 Years?

Journal of Trauma-Injury Infection & Critical Care. 65(2):272-278, August 2008.

Background: Recent military experience reported casualties who receive >10 units of packed red blood cells (PRBC) in 24 hours have 20% versus 65% mortality when the fresh-frozen plasma (FFP) to PRBC ratio was 1:1 versus 1:4, respectively. We hypothesize a similar improvement in mortality in civilian trauma patients that require massive transfusion and are treated with a FFP to PRBC ratio closer to 1:1.

Methods: Four-year retrospective study of all trauma patients who underwent emergency surgery in an urban Level I Trauma Center. Patients were divided into two groups; those that received <=10 units or >10 units of PRBC during and after initial surgical intervention. Only patients who received transfusion of both FFP and PRBC were included in the analysis. The primary research question was the impact of initial FFP:PRBC ratio on mortality. Other variables for analysis included patient age, gender, mechanism, and Injury Severity Scale score. Both univariate and multivariate analysis were used to assess the relationship between outcome and predictors.

Results: A total of 2,746 patients underwent surgical intervention of which 1,985 (72.2%) received no transfusion. Of those that received transfusion, 626 (22.8%) received <=10 units of PRBC and 135 (4.9%) >10 units of PRBC. Out of the 626 patients that received <=10 units of PRBC, 250 (39.9%) received FFP and 376 (60.1%) received no FFP. All the patients that received >10 units PRBC received FFP. In univariate analysis, a significant difference in mortality was found in patients who received >10 units of PRBC (26% vs. 87.5%) when FFP:PRBC ratio was 1:1 versus 1:4 (p = 0.0001). Multivariate analysis in the group of patients that received >10 units of PRBC showed a FFP:PRBC ratio of 1:4 was consistent with increased risk of mortality (relative risk, 18.88; 95% CI, 6.32-56.36; p = 0.001), when compared with a ratio of 1:1. Patients who received <=10 units of PRBC had a trend toward increased mortality (21.2% vs.11.8%) when the FFP:PRBC ratio was 1:4 versus 1:1 (p: 0.06).

Conclusion: An FFP to PRBC ratio close to 1:1 confers a survival advantage in patients requiring massive transfusion.

2008年8月18日 星期一

Scapula Fractures 的意義

Scapula Fractures: A Marker for Concomitant Injury?
A Retrospective Review of Data in the National Trauma Database.
Upper extremity, thoracic, and pelvic ring injuries were associated with greater frequency in patients with scapular fracture.

Journal of Trauma-Injury Infection & Critical Care. 65(2):430-435, August 2008.

Background: Many series have found that certain associated injuries occur with greater frequency in patients with scapula fractures than in patients without scapula fractures. However, several of the published series were limited by lack of a control group, inclusion of a patient population limited to the catchment area of one hospital, or inadequate control for injury severity. The goal of this study was to determine whether there was a relationship between scapula fractures and concomitant injury and which injuries related simply to the increased injury severity observed in this patient population.

Methods: This series was a retrospective case control database analysis. Patients were identified through the National Trauma Database from 1994 to 2002 from trauma centers across the United States. Diagnosis code (ICD-9) 811.0 was used to identify 9,453 scapular fractures, whereas the 2,728 patients in the control group were selected by random number generation. After data extraction to a database, each patient was examined for concomitant diagnoses. The binomial distribution was used to compare cases and controls, as well as different diagnostic groups before adjusting for injury severity. The Bonferroni correction was applied to correct for the multiple null hypotheses. After univariate analysis, the data were analyzed with logistic regression using injury severity score as a covariate.

Results: After statistical adjustment for multiple tests, there was not a statistically significant difference in injury rates for patients with different types of scapula fractures. However, there were many injuries that showed increased frequency in patients with scapula fractures compared with patients without this injury. Interestingly, when injury severity was statistically adjusted for, many of these differences disappeared.

Conclusions: After adjustment for injury severity, upper extremity, thoracic, and pelvic ring injuries were associated with greater frequency in patients with scapular fracture. The majority of other injuries found to occur frequently in the unadjusted patient population were likely because the injury severity is higher in patients with scapula fractures.

Level of Evidence: III.

2008年8月12日 星期二

照 Lat C-spine 已經過時...

Is The Lateral Cervical Spine Plain Film Obsolete?
Journal of Surgical Research Volume 147, Issue 2, 15 June 2008, Pages 267-269

The objective of this study was to determine the utility of a lateral cervical spine plain film in the evaluation of blunt trauma patients.

We prospectively evaluated blunt trauma patients from February 2004 to September 2006 who had both a lateral cervical spine (LCS) film and a computed tomography of the cervical spine (CTC), comparing the diagnostic accuracy of the LCS to the CTC.

There were 1004 patients who met inclusion criteria. Eighty-four patients had a cervical spine fracture while 920 patients had no fracture on CTC. Of the 84 patients with fractures by CTC, 68 had a negative or incomplete LCS. Of the 920 negative CTC, there were 7 false positive LCSs. LCS compared with CTC showed a sensitivity of 19% (16/84) and positive predictive value of 69.6% (16/23). Of the 981 negative or incomplete LCS films, 96.9% were incomplete (951/981). Of the seven patients with a false positive LCS (negative CTC), none was subsequently found to have a cervical spine fracture on further evaluation. Elimination of the LCS would result in charge savings of $265,056.00 (LCS charges with interpretation, $264 each) and increase patient safety by eliminating error.

LCS has no value as a screening tool in the blunt trauma patient since most are either inaccurate or incomplete. It should be eliminated from the Advanced Trauma Life Support algorithm, and CTC should receive emphasis as the diagnostic gold standard.

2008年8月8日 星期五

Rocuronium 已有解藥!

Sugammadex Rapidly Reverses Rocuronium Paralysis
Full reversal of a 1.0 mg/kg dose of rocuronium takes less than 2 minutes.

Sugammadex is a novel agent designed to rapidly reverse rocuronium block (JW Emerg Med Mar 23 2007), but it has not been evaluated for reversal of the higher doses of rocuronium used for rapid sequence intubation (RSI). In a multicenter European study, investigators (including a clinical research scientist and statisticians employed by the manufacturer) randomized 168 patients who were undergoing elective anesthesia to receive one of five doses of sugammadex (2, 4, 8, 12, or 16 mg/kg) or placebo administered either 3 minutes or 15 minutes after administration of rocuronium (1.0 mg/kg or 1.2 mg/kg). Recovery of muscle function (to 90% of normal response to train-of-four stimulation, which permits normal breathing) was monitored continuously until recovery was noted and for at least 30 minutes after sugammadex administration to ensure that recovery was sustained.

When the highest dose of sugammadex (16 mg/kg) was administered 3 or 15 minutes after administration of 1.0 mg/kg of rocuronium, median recovery times were 1.6 and 0.9 minutes, respectively. Corresponding median recovery times in patients who received 1.2 mg/kg rocuronium were 1.3 and 1.9 minutes, respectively. Median times to recovery in patients who received placebo ranged from 91 to 124 minutes. Time to recovery was dependent on sugammadex dose. Twenty-two of 157 sugammadex recipients (14%) and none of 11 placebo recipients had drug-related adverse events, mostly nausea, vomiting, or anesthetic complications. Eleven patients in the sugammadex groups and one in the placebo group had serious adverse events, mostly QT interval prolongation, but the investigators considered this outcome to be related possibly to sugammadex in only one case.

Comment: The RSI dose of rocuronium (1.0 mg/kg) requires a larger dose of sugammadex for reversal than does the routine paralyzing dose of 0.6 mg/kg. The larger dose of sugammadex is effective and has few apparent adverse effects. The median reversal time of less than 2 minutes means that we could use rocuronium routinely for RSI, knowing that paralysis can be reversed if necessary. These findings might prove to be another significant nail in succinylcholine’s coffin.

Published in Journal Watch Emergency Medicine August 8, 2008

Citation(s): Puhringer FK et al. Reversal of profound, high-dose rocuronium–induced neuromuscular blockade by sugammadex at two different time points: An international, multicenter, randomized, dose-finding, safety assessor–blinded, phase II trial. Anesthesiology 2008 Aug; 109:188.

2008年8月7日 星期四


肋骨斷三根未照出 高市醫挨批 
誤診胸部挫傷 醫院:角度問題

2008/08/07 報導記者:居傳儀



切記:Rib fracture 為臨床診斷,不要依賴 false negative rate 極高的 chest X ray!


Melioidosis, caused by a gram-negative aerobic bacillus B. pseudomallei and endemic to Australia and parts of Southeast Asia, can be challenging to distinguish from tuberculosis both clinically and histologically.

Chronic melioidosis may produce necrotizing granulomas that are indistinguishable from those of tuberculosis; thus, this diagnosis should be considered, especially when the presentation or course of a chronic infection is atypical for tuberculosis.

The clinical manifestations of melioidosis range from localized cutaneous abscesses to multiorgan involvement to septic shock. Intravenous ceftazidime, imipenem, or meropenem can be used for the acute phase of treatment. Long-term treatment with high-dose bactrim, given together with doxycycline given for at least 20 weeks is recommended.

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

Vertebral Osteomyelitis

In the developed world, vertebral osteomyelitis is most commonly acquired hematogenously. Staphylococcus aureus is the most frequent isolate, followed by streptococcus and gram-negative organisms. Progressive pain over a period of months is typical of vertebral osteomyelitis. Spinal epidural abscesses are caused by the same organisms and may result from hematogenous seeding of the epidural space or extension from vertebral osteomyelitis.

For most patients who have vertebral osteomyelitis without epidural abscess, empirical antibiotic treatment can be delayed (but not by more than 24 hours) until biopsy is performed to obtain a microbiologic diagnosis; operative management is not required. If MRI and clinical findings are consistent with compression of the spinal cord by an epidural abscess, immediate neurosurgical consultation and possible mechanical decompression are warranted.

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

Schizonts and hypnozoites

What are schizonts and hypnozoites? What types of malaria produce them?
Schizonts are multinucleated stages of parasites that undergo mitotic division within white cells and are produced by all forms of malaria. Hypnozoites are specialized dormant forms of the malaria parasite within the liver and are produced only by two types of malaria, P. vivax and P. ovale. Hypnozoites reactivate spontaneously weeks or many months after the initial exposure to infective mosquitoes; their release into the blood-stream results in late-onset or relapsing clinical disease. Primaquine is the only available drug that acts on the hypnozoites of P. vivax and P. ovale in the liver.

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

Malaria prophylaxis for pregnant woman

What types of malaria chemoprophylaxis would be safe for a pregnant woman?
Malaria is more severe in pregnancy, and the risks of adverse outcomes (for both the mother and the fetus) are increased. No chemoprophylactic agent is 100% effective. The WHO and the CDC both recommend that pregnant women not travel to areas where malaria is endemic. Most women refrain from traveling to these areas during pregnancy, but for pregnant women who decide to travel or must travel, mefloquine is the drug of choice for chloroquine-resistant malaria. (Chloroquine can also be used during pregnancy.)

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

Chloroquine Resistance

The resistance of P. falciparum to chloroquine is nearly universal; chloroquine remains effective only in Mexico, areas of Central America that are west of the Panama Canal, the Caribbean, East Asia, and a few Middle Eastern countries. In all other areas where malaria is endemic, atovaquone–proguanil, mefloquine, or doxycycline is recommended by the CDC and WHO. Primary prophylaxis with chloroquine when appropriate and a choice of atovaquone–proguanil, mefloquine, or doxycycline for other areas according to traveler circumstances is recommended by these organizations.

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

Malaria Symptoms

Malaria in travelers is usually characterized by fever and influenza-like symptoms, including headache and back pain. Vomiting, diarrhea, abdominal cramping, and cough may occur and may be confused with symptoms associated with more common infections. Textbooks often describe the fever as occurring in discrete episodes lasting a few hours every 2 to 3 days; however, in travelers the fever usually has an irregular pattern throughout the day. Disease caused by P. falciparum in travelers most often occurs 9 to 14 days after an infectious bite, but it may occur up to months later, especially in patients who have received suboptimal prophylaxis.

New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008

2008年8月1日 星期五

Lumbar Puncture 後之頭痛

Lumbar Puncture and Post-Dural Puncture Headaches: Implications for the Emergency Physician

Volume 35, Issue 2, August 2008, Pages 149-157

Dural puncture procedures are commonly performed by various medical practitioners, including emergency physicians, for many reasons. Post-dural puncture headache (PDPH) is a relatively common complication. The degree of pain and disability caused by PDPHs is considerable. Appropriate use of smaller gauge, atraumatic needles is likely the single most important factor in reducing PDPH. Hydration and bed rest do little to prevent PDPH. Treatment of mild, nondebilitating headaches usually can be accomplished with limited activity, analgesics, and methylxanthine therapy until they resolve spontaneously. For more severe headaches, methylxanthine derivatives may be tried with epidural blood patch (EBP) as a first-line alternative or to be used if methylxanthines fail. It is helpful to use 24-gauge Sprotte spinal needles in all patients at risk for PDPH. For patients who have moderate to severe pain, cannot or do not want to remain on bed rest, and those in whom narcotic pain medication is not a practical treatment option, EBP is an appropriate first-line therapy. In general, EBP is safe, well tolerated and effective. Though the technique for epidural blood patch is not significantly more difficult than lumbar puncture, it is a procedure most commonly performed by anesthesiologists.

Bystander CPR 的重要性

Out-of-Hospital Unwitnessed Cardiopulmonary Collapse and No-Bystander CPR: A Practical Addition to Resuscitation Termination Guidelines

Journal of Emergency Medicine Volume 35, Issue 2, August 2008, Pages 175-179

AbstractCardiopulmonary resuscitation (CPR) provides possible survival from otherwise fatal cardiopulmonary collapse. Termination guidelines have been developed for use when resuscitation has no potential benefit for a victim. The purpose of this prospective cohort study was to determine if unwitnessed collapse combined with no-bystander cardiopulmonary resuscitation would support a decision to terminate attempted resuscitation. There were 541 patients analyzed during 6 months, with functional neurological survival the outcome of interest. There were no functional neurological survivors at hospital discharge among the 180 victims in the unwitnessed, no-bystander CPR subgroup (95% confidence interval [CI] 0.0%–2.1%). Functional neurological survival for witnessed collapse, bystander CPR was 6.0% (95% CI 2.8%–12.5%), for witnessed collapse, no-bystander CPR was 3.8% (95% CI 1.9%–7.7%), and for unwitnessed collapse, bystander CPR 1.3% (95% CI 0.2%–6.9%). With confirmation by further studies, unwitnessed collapse and lack of bystander CPR may be a practical addition to resuscitation termination guidelines.

牛源聚合血紅蛋白 - HBOC-201

HBOC-201: A Viable Alternative to Blood Transfusion
Use of hemoglobin-based oxygen carrier-201 avoided need for blood transfusion in nearly 60% of patients.

Despite strategies to conserve use of packed red blood cells (PRBCs), experts predict that availability will not meet the increasing demand by an aging population. Hemoglobin-based oxygen carrier-201 (HBOC-201) is a bovine–hemoglobin-based blood substitute that is approved in South Africa for clinical use. In a randomized, single-blind, controlled, multinational study, researchers (some of whom were affiliated with the manufacturer) assessed whether administration of HBOC-201 eliminates the need for PRBC transfusion in adult patients undergoing orthopedic surgery.

Overall, 688 patients (mean age, 61) with hemoglobin concentrations <10.5>7 mL/kg within 2 hours, oliguria, and significant weakness or dizziness. Patients in the HBOC group received a loading dose of 65 g of hemoglobin infused in 500 mL (a volume considered equivalent to 1 unit of PRBCs); additional doses were administered for up to 6 days to a maximum of 325 g (2500 mL), after which need for additional oxygen-carrying capacity was met by transfusion of PRBCs.

Overall, 59% of patients in the HBOC group did not require PRBC transfusion. The HBOC group had significantly higher rates of adverse events (e.g., elevated blood pressure) than the PRBC group (8.5 vs. 5.9 per patient) and serious adverse events (e.g., cardiac events and strokes; 0.34 vs. 0.25 per patient). Findings of a safety analysis led the authors to conclude that risk for adverse events from HBOC was greatest in patients who were older than 80, had volume overload, and were undertreated.

Comment: HBOC-201 does not require crossmatching and can be stored at room temperature for as long as 3 years. In this study, its use eliminated the need for transfusion of allogeneic PRBCs in 59% of patients. Its safety profile was inferior to that of PRBC transfusion, including a greater incidence of acute coronary syndromes and strokes, which the authors partially attributed to age older than 80, volume overload, and undertreatment. Overall, the authors suggest that patients younger than 80 with moderate clinical need for transfusion can be managed with up to 10 units of HBOC-201, thereby preserving the stockpile of PRBCs for other patients.

John A. Marx, MD, FAAEM, FACEP
Published in Journal Watch Emergency Medicine August 1, 2008

Citation(s): Jahr JS et al. HBOC-201 as an alternative to blood transfusion: Efficacy and safety evaluation in a multicenter phase III trial in elective orthopedic surgery. J Trauma 2008 Jun; 64:1484.