Lactate clearance 和 ScvO2 一樣好

Lactate Clearance vs Central Venous Oxygen Saturation as Goals of Early Sepsis Therapy: A Randomized Clinical Trial.

Early goal-directed fluid resuscitation is the cornerstone of therapy for septic shock, but the optimal target for goal-directed resuscitation has not been well studied. The investigators sought to determine whether lactate clearance and central venous oxygen saturation (ScvO2) are equally effective as guides for early sepsis resuscitation. A cohort of 300 patients presenting to the emergency department with septic shock were randomly assigned to resuscitation guided either by normalization of ScvO2 (above 70%) or lactate clearance (at least 10% from baseline or remaining below 2 mmol/L), in addition to standard goals for mean arterial and central venous pressure. The 2 groups did not differ in the treatments that were administered during the 6 hours of goal-directed resuscitation or during the first 72 hours of hospitalization. Death occurred in 23% of patients managed with the ScvO2 protocol and in 17% of patients managed with the lactate clearance protocol, with no difference in adverse events between the 2 groups. The investigators concluded that early goal-directed fluid resuscitation of patients with septic shock can be safely guided by either ScvO2 or lactate clearance.

Hint:
A high ScvO2 cannot always be considered normal because dysfunctional tissue oxygen extraction (as in sepsis) may lead to increased ScvO2and thus falsely reassure the clinician about the health of the patient

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JAMA. 2010;303:739-746

聲音嘶啞(hoarseness)的注意事項

Hoarseness
A useful reminder about patients who complain of a hoarse voice:

• Red flag symptoms are persistent hoarseness for more than three weeks, difficulty or pain on swallowing, haemoptysis, earache with normal otoscopy, weight loss, and heavy smoking or alcohol intake
• Urgent ! chest x ray is needed if hoarseness persists for more than 3 weeks (especially if the patient is a heavy drinker, smoker, or over 50 years old)
• If the x ray is positive, refer urgently for suspected lung cancer. If it's negative, refer urgently for suspected head and neck cancer
• Routine ENT referral is advised for recurrent but non persistent (less than 3 weeks) hoarseness with no red flag symptoms
• Advise patients to stop smoking, reduce alcohol intake, and improve vocal hygiene
• Treat any exacerbating conditions such as oral thrush, asthma, or rhinitis

Source: BMJ 2010;340:c522

有5%的SAH是NE正常但已中線位移

Midline Shift or Herniation in Patients with Subarachnoid Hemorrhage and Normal Neurological Exams

In a retrospective study, 5% of patients with spontaneous SAH and normal neurological exams had computed tomographic findings that contraindicated lumbar puncture.

Controversy surrounds the issue of whether computed tomography (CT) is required before lumbar puncture (LP) in patients with suspected subarachnoid hemorrhage (SAH) and normal neurological examinations. These authors retrospectively reviewed records of 73 patients with final diagnoses of spontaneous SAH who underwent CT after presenting with sudden-onset severe headaches and normal neurological examinations.

Two neuroradiologists who were blinded to patient outcomes and original CT interpretations reviewed the scans for evidence of herniation or midline shift >2 mm. The radiologists agreed that brain herniation or midline shift was present in 4 of the 73 cases (5%); only 1 of these cases was identified in the initial radiology report. The radiologists disagreed with each other about the presence of herniation or shift in 4 cases (5%); in all 4 cases, CT scan results were considered negative for herniation or shift in the initial report.

Comment: The authors' recommendation that CT be routinely performed before LP in patients with suspected SAH is overreaching, given their study's limitations. However, new-generation CT scanning picks up most cases of SAH noninvasively, so the best approach is to obtain a CT scan first and follow with LP if the scan result is negative.

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Diane M. Birnbaumer, MD, FACEP
Published in Journal Watch Emergency Medicine April 23, 2010


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Citation(s):
Baraff LJ et al. Prevalence of herniation and intracranial shift on cranial tomography in patients with subarachnoid hemorrhage and a normal neurologic examination. Acad Emerg Med 2010 Apr; 17:423.

Abstract

OBJECTIVES: Patients frequently present to the emergency department (ED) with headache. Those with sudden severe headache are often evaluated for spontaneous subarachnoid hemorrhage (SAH) with noncontrast cranial computed tomography (CT) followed by lumbar puncture (LP). The authors postulated that in patients without neurologic symptoms or signs, physicians could forgo noncontrast cranial CT and proceed directly to LP. The authors sought to define the safety of this option by having senior neuroradiologists rereview all cranial CTs in a group of such patients for evidence of brain herniation or midline shift.

METHODS: This was a retrospective study that included all patients with a normal neurologic examination and nontraumatic SAH diagnosed by CT presenting to a tertiary care medical center from August 1, 2001, to December 31, 2004. Two neuroradiologists, blinded to clinical information and outcomes, rereviewed the initial ED head CT for evidence of herniation or midline shift.

RESULTS: Of the 172 patients who presented to the ED with spontaneous SAH diagnoses by cranial CT, 78 had normal neurologic examinations. Of these, 73 had initial ED CTs available for review. Four of the 73 (5%; 95% confidence interval [CI] = 2% to 13%) had evidence of brain herniation or midline shift, including three (4%; 95% CI = 1% to 12%) with herniation. In only one of these patients was herniation or shift noted on the initial radiology report.

CONCLUSIONS: Awake and alert patients with a normal neurologic examination and SAH may have brain herniation and/or midline shift. Therefore, cranial CT should be obtained before LP in all patients with suspected SAH.
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【EBM】App 做 CT 不必打顯影劑

http://www.annemergmed.com/article/S0196-0644(09)01140-8/abstract

Study objective
We seek to determine the diagnostic test characteristics of noncontrast computed tomography(CT) for appendicitis in the adult emergency department (ED) population.
Methods
We conducted a search of MEDLINE, EMBASE, the Cochrane Library, and the bibliographies of previous systematic reviews. Included studies assessed the diagnostic accuracy of noncontrast CT for acute appendicitis in adults by using the final diagnosis at surgery or follow-up at a minimum of 2 weeks as the reference standard. Studies were included only if the CT was completed using a multislice helical scanner. Two authors independently conducted the relevance screen of titles and abstracts, selected studies for the final inclusion, extracted data, and assessed study quality. Consensus was reached by conference, and any disagreements were adjudicated by a third reviewer. Unenhanced CT test performance was assessed with summary
receiver operating characteristic curve analysis, with independently pooled sensitivity and specificity values across studies.
Results
The search yielded 1,258 publications; 7 studies met the inclusion criteria and provided a sample of 1,060 patients. The included studies were of high methodological quality with respect to appropriate patient spectrum and reference standard. Our pooled estimates for sensitivity and specificity were 92.7% (95% confidence interval 89.5% to 95.0%) and 96.1% (95% confidence interval 94.2% to 97.5%), respectively; the positive likelihood ratio=24 and the negative likelihood ratio=0.08.
Conclusion
We found the diagnostic accuracy of noncontrast CT for the diagnosis of acute appendicitis in the adult population to be adequate for clinical decision making in the ED setting.

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Annals of emergency medicine Volume 55, Issue 1, Pages 51-59.e1

Vertebral osteomyelitis

Vertebral osteomyelitis can be complicated by direct seeding in different compartments, resulting in paravertebral, epidural, or psoas abscesses. In one series, vertebral osteomyelitis was complicated by epidural abscess in 17% of cases, paravertebral abscess in 26%, and a disk-space abscess in 5%. One fourth of patients developed motor weakness or paralysis, with particularly high rates among patients with cervical spine osteomyelitis. Neurologic complications have been reported in 38% of patients with vertebral osteomyelitis. In an analysis of 14 case series, vertebral osteomyelitis was complicated by relapse in 8% of cases, and death in 6%.

What organisms are most frequently implicated in pyogenic vertebral osteomyelitis?
Staphylococcus aureus is the most common microorganism implicated in pyogenic vertebral osteomyelitis, followed by E. coli. Coagulase-negative staphylococci and Propionibacterium acnes cause almost exclusively exogenous osteomyelitis after spine surgery, particularly if fixation devices are used. However, in case of prolonged bacteremia (e.g., pacemaker-electrode associated infection), hematogenous vertebral osteomyelitis due to low-virulence microorganisms (e,g., coagulase-negative staphylococci) has been described.

What tests are highly sensitive for the diagnosis of vertebral osteomyelitis?
Increased CRP is highly sensitive for the diagnosis of osteomyelitis, reported in 100% of cases. CRP is the preferred marker of infection, at least in postoperative spinal wound infection. Increased blood leukocyte counts or a high percentage of neutrophils (above 80%) are insensitive for the diagnosis of osteomyelitis. In a systematic review of studies of vertebral osteomyelitis, positive blood cultures were reported in 58% (range across studies, 30 to 78%).

What diagnostic step is recommended if vertebral osteomyelitis is suspected by imaging procedures and blood cultures show no growth?
If vertebral osteomyelitis is suspected by imaging procedures and blood cultures do not show growth, biopsy is generally warranted. Biopsy should be performed regardless of whether or not blood cultures are negative if polymicrobial osteomyelitis is suspected (e.g., intraabdominal sepsis). If the patient has a paravertebral, epidural, or psoas abscess, CT-guided drainage (with stain and culture of the specimen) may make bone biopsy unnecessary. Culture of a biopsy specimen, either CT-guided or open, has a higher overall yield than blood cultures (77%, range across studies 47 to 100%). Bone samples should be cultured for aerobic and anaerobic bacteria and for fungi. In patients with a suggestive history (e.g., stay in endemic region, subacute presentation), cultures should also be performed for mycobacteria and brucella species. In addition, analysis by histopathology is useful, because the presence of leukocytes in the specimens distinguishes infection from contamination.

EtCO2 已是 standard of care？

Does Capnography Add Benefit During Emergency Department Propofol Sedation?
All patients who became hypoxemic demonstrated respiratory depression by capnography before developing hypoxemia.

Capnography has been used as a real-time adjunct to procedural sedation monitoring in intensive care units and operating rooms for decades, yet it is not commonly used in the emergency department (ED) for this purpose. These authors determined whether adding capnography to standard monitoring (pulse oximetry, pulse rate, and blood pressure) during ED procedural sedation decreases the incidence of hypoxic events. In a prospective trial, 132 consecutive adults undergoing propofol sedation with standard monitoring and capnography at a single tertiary-care hospital ED were randomized to a study group, in which treating physicians could view the capnography monitoring screen, or to a control group, in which physicians could not view the screen.

Procedural sedation was initiated with a bolus of 1 mg/kg of propofol, followed by additional boluses of 0.5 mg/kg. All patients received opioids (0.5 µg/kg of fentanyl or 0.05 mg/kg of morphine) at least 30 minutes before administration of propofol. Hypoxia was defined as a pulse oximetry oxygen saturation (SpO2) level <93%.>/= 50 mm Hg, an ETCO2 absolute increase or decrease from baseline of >/= 10%, or loss of the waveform for >/= 15 seconds.

Patient characteristics were similar in the two groups. The rate of capnography-detected respiratory depression was similar between groups, but hypoxia was more frequent in the control group (42% vs. 25%). Capnographic evidence of respiratory depression was 100% sensitive for predicting hypoxia. Overall, 64% of patients with capnographic evidence of respiratory depression developed hypoxia.

Comment:
This study and myriad others from the anesthesia and intensive care literature provide convincing evidence that capnography is extremely useful for detecting respiratory depression and preventing hypoxia in patients undergoing procedural sedation. Its use should be standard for emergency department patients receiving deep procedural sedation.

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Richard D. Zane, MD, FAAEM
Published in Journal Watch Emergency Medicine March 12, 2010
Citation(s): Deitch K et al. Does end tidal CO2 monitoring during emergency department procedural sedation and analgesia with propofol decrease the incidence of hypoxic events? A randomized, controlled trial. Ann Emerg Med 2010 Mar; 55:258.

commotio cordis

Ventricular fibrillation and sudden death triggered by a blunt, nonpenetrating, and often innocent-appearing unintentional blow to the chest without damage to the ribs, sternum, or heart (and in the absence of underlying cardiovascular disease) constitute an event known as commotio cordis.

When does commotio cordis occur?
About 55% of occurrences of commotio cordis have been reported in young competitive athletes (mostly those between 11 and 20 years of age) participating in a variety of organized amateur sports — typically baseball, softball, ice hockey, football, or lacrosse — who receive a blow to the chest that is usually (but not always) delivered by a projectile that is used to play the game.

How should suspected commotio cordis be treated?
A public health strategy that incorporates a plan for making automated external defibrillators (AEDs) widely available is likely to result in the survival of more young people in the event of commotio cordis. Indeed, AEDs have also effectively terminated ventricular fibrillation in animal models of commotio cordis. However, even under optimal conditions, an AED can fail to restore the heart to normal rhythm after commotio cordis. Both clinical studies and experimental studies suggest that precordial thumps are unreliable in terminating ventricular fibrillation caused by chest blows.

What location of a blow can precipitate commotio cordis?
To precipitate commotio cordis, the blow must be directly over the heart, particularly at or near the center of the cardiac silhouette. Precordial bruises representing the imprint of a blow are frequently evident in victims. There is no evidence in humans or in experimental models that blows sustained outside the precordium (e.g., the back, the flank, or the right side of the chest) cause sudden death.

At what part of the cardiac electrophysiological cycle must the blow occur?
The blow must occur within a narrow window of 10 to 20 msec on the upstroke of the T wave, just before its peak (accounting for only 1% of the cardiac cycle) — that is, the blow must occur during an electrically vulnerable period, when inhomogeneous dispersion of repolarization is greatest, creating a susceptible myocardial substrate for provoked ventricular fibrillation.

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Teaching topics from the New England Journal of Medicine
Vol. 362, No.10, March 11, 2010