Sunday, July 05, 2015

Point of care echo to evaluate patients with non shockable rhythm cardiac arrest


From a recent paper in Resuscitation:

Methods

This prospective and observational cohort study evaluated ICU patients with CPA in asystole or pulseless electrical activity (PEA). Intensivists performed TTE during intervals of up to 10 s as established in the treatment protocol. Myocardial contractility was defined as intrinsic movement of the myocardium coordinated with cardiac valve movement. PEA without contractility was classified as electromechanical dissociation (EMD), and with contractility as pseudo-EMD. The images, the rates of return of spontaneous circulation (ROSC) and the survival upon hospital discharge and after 180 days were evaluated.

Results

A total of 49 patients were included. Image quality was considered adequate in all cases and contributed to the diagnosis of CPA in 51.0% of the patients. Of the 49 patients included, 17 (34.7%) were in asystole and 32 (65.3%) in PEA, among which 5 (10.2%) were in EMD and 27 (55.1%) in pseudo-EMD. The rates of ROSC were 70.4% for those in pseudo-EMD, 20.0% for those in EMD, and 23.5% for those in asystole. Survival upon hospital discharge and after 180 days occurred only in patients in pseudo-EMD (22.2% and 14.8%, respectively).

Conclusions

TTE conducted during cardiopulmonary resuscitation in ICU patients can be performed without interfering with care protocols and can contribute to the differential diagnosis of CPA and to the identification of a subgroup of patients with better prognosis.




Friday, July 03, 2015

Comparison of temperature targets in patients with non shockable rhythm cardiac arrest


From a recent study:

Purpose

Despite a lack of randomized trials in comatose survivors of out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm (NSR), guidelines recommend induced hypothermia to be considered in these patients. We assessed the effect on outcome of two levels of induced hypothermia in comatose patient resuscitated from NSR.

Methods

Hundred and seventy-eight patients out of 950 in the TTM trial with an initial NSR were randomly assigned to targeted temperature management at either 33 °C (TTM33, n = 96) or 36 °C (TTM36, n = 82). We assessed mortality, neurologic function (Cerebral Performance Score (CPC) and modified Rankin Scale (mRS)), and organ dysfunction (Sequential Organ Failure Assessment (SOFA) score).

Results

Patients with NSR were older, had longer time to ROSC, less frequently had bystander CPR and had higher lactate levels at admission compared to patients with shockable rhythm, p less than  0.001 for all. Mortality in patients with NSR was 84% in both temperature groups (unadjusted HR 0.92, adjusted HR 0.75; 95% CI 0.53–1.08, p = 0.12). In the TTM33 group 3% survived with poor neurological outcome (CPC 3–4, mRS 4–5), compared to 2% in the TTM36 group (adjusted OR 0.67; 95% CI 0.08–4.73, p = 0.69 for both). Thirteen percent in the TTM33 group and 15% in the TTM36 group had good neurologic outcome (CPC 1–2, mRS 0–3, OR 1.5, CI 0.21–12.5, p = 0.69). The SOFA-score did not differ between temperature groups.

Conclusion

Comatose patients after OHCA with initial NSR continue to have a poor prognosis. We found no effect of targeted temperature management at 33 °C compared to 36 °C in these patients.




STEMI: now you see it, now you don't!


The STEMI versus non-STEMI distinction is unreliable in emergency decision making in patients with ACS for several reasons I have posted before. This study illustrates yet another reason:

Objective. To determine the prevalence and significance of ST-segment elevation resolution between prehospital and first hospital ECG...Results. We reviewed 24,197 prehospital ECGs and identified 293 cases of prehospital STEMI. Complete hospital and prehospital records were available for 83 cases (28%)...STR occurred in 18 cases (22%, CI 14–32%). There were no differences between STR and non-STR cases in prehospital vital signs or treatments. 95% of patients underwent cardiac catheterization with a mean door-to-needle time of 57 minutes (interquartile range 43–71). Comparing STR and non-STR cases, significant lesions (greater than or equal to 50%) were found in 94 and 97% of patients (p = 0.6), and subtotal or total lesions (greater than or equal to 95%) were found in 63 and 85% (p = 0.1), respectively. Conclusions. We found that ST-segment resolution occurred prior to catheterization in 1 of 5 patients with prehospital STEMI, emphasizing the necessity of prehospital ECG in risk stratification of patients with suspected coronary disease. Coronary lesions and intervention rates did not differ between STR and non-STR, suggesting that catheterization is warranted even when STEMI criteria are no longer met in-hospital.

Acute coronary syndromes, as we've known ever since studies involving coronary angioscopy in the 1980s, are dynamic states of thrombus, lysis and reformation. What presents as NSTEMI to the ER may have been a STEMI only moments prior.

Obesity and CKD: a newly emerging association


From a recent review:

Recent findings: It is well established that excessive caloric intake contributes to organ injury. The associated increased adiposity initiates a cascade of cellular events that leads to progressive obesity-associated diseases such as kidney disease. Recent evidence has indicated that adipose tissue produces bioactive substances that contribute to obesity-related kidney disease, altering the renal function and structure. In parallel, proinflammatory processes within the adipose tissue can also lead to pathophysiological changes in the kidney during the obese state.


Summary: Despite considerable efforts to better characterize the pathophysiology of obesity-related metabolic disease, there are still a lack of efficient therapeutic strategies. New strategies focused on regulating adipose function with respect to AMP-activated protein kinase activation, NADPH oxidase function, and TGF-β may contribute to reducing adipose inflammation that may also provide renoprotection.

Thursday, July 02, 2015

TIA: the essentials


A brief review in the American Journal of Medicine. Free full text.

Statins in the prevention of contrast induced acute kidney injury


Earlier I linked a couple of studies that showed promise. Now here's a new meta-analysis that shows benefit:

A systematic review and meta-analysis was performed including randomized controlled trials of short-term high-dose statins (compared with either low-dose statin or placebo) for CIAKI prevention in patients undergoing coronary angiography. Study-specific odds ratios (ORs) were calculated, and between-study heterogeneity was assessed using the I2 statistic. We used a random-effects model meta-analysis to pool the OR. Twelve RCTs, including 5,564 patients, were included. CIAKI occurred in 94 of 2,769 patients (3.4%) pretreated with high-dose statins and 213 of 2,795 patients (7.6%) in the low-dose or no-statin group (OR 0.43, 95% confidence interval [CI] 0.33 to 0.55, I2 = 19%, p less than 0.001). Subgroup analysis showed that the occurrence of CIAKI did not differ in patients with diabetes (OR 0.60, 95% CI 0.43 to 0.85, I2 = 0%, p = 0.004) or in patients with documented renal insufficiency (creatinine clearance les than 60 ml/min/m2; OR 0.66, 95% CI 0.45 to 0.96, I2 = 0%, p = 0.03). In conclusion, pretreatment with high-dose statins, compared with low-dose statins or placebo, in patients undergoing coronary angiography reduces the incidence of CIAKI. This benefit was seen irrespective of the presence of diabetes and chronic kidney disease. Future studies should identify optimum dosing protocols for each statin.

Statin-associated autoimmune necrotizing myopathy


This recently emerging entity is the topic of a review in the Cleveland Clinic Journal of Medicine.

Some points of interest:

The principal cause is autoantibody to HMG coenzyme A reductase, the site of action of statins.

Unlike other statin associated myopathies it does not resolve with stopping the drug and requires immunosuppression.

In the spectrum of statin associated myopathy three principal entities have emerged: 1) simple myalgias without CK elevation; 2) myositis with elevated CK which resolves on drug discontinuation; and 3) the autoimmune entity just described.


Another example of a “non-STEMI” that needed to go to the cath lab



Increased T wave amplitude was the only finding on the initial ECG and highlights the rule of proportionality.

Wednesday, July 01, 2015

Statins for the prevention of contrast associated AKI


Here's a systematic review that provides more evidence of benefit.

Acute porphyrias


Here is a case series recently published. From the article:

We report the largest group of subjects with well-documented and -characterized acute porphyrias thus far assembled in North America. Our emphasis is on acute intermittent porphyria, which is the most common and severe form of acute porphyria in the US. Among the important features are the following: 1) There is a substantial preponderance of females (83%) over males. 2) Fewer than half the subjects reported a parent with known acute porphyria, confirming the variable expression of the clinical phenotype, even within individual kindreds. 3) The onset of symptoms usually occurs during the second through fourth decades of life (81%). 4) Medications (37%) and weight loss diets (22%) are the most commonly reported triggers of acute attacks. 5) Eighteen percent feel they suffer from chronic, ongoing symptoms.

There are high prevalences of chronic medical conditions such as peripheral neuropathy (43%), systemic arterial hypertension (43%), chronic kidney disease (29%), and history of abdominal surgeries (appendectomy 13%, and cholecystectomy 15%). The prevalences of systemic arterial hypertension, psychiatric conditions, and seizures are significantly greater than that in the general population, matched for age and sex...

In conclusion, most patients with symptomatic acute porphyrias in the US are women who first develop symptoms in the second to fourth decades of life. The cardinal symptom is severe generalized abdominal pain, often with nausea and vomiting. There are significantly increased frequencies of systemic arterial hypertension, chronic renal and psychiatric disease, and seizures. Genetic analyses reveal diverse mutations in the genes underlying these disorders.

Patients report that the most effective therapy of acute attacks is intravenous hematin. Thus,2, 15 we believe that patients with acute porphyrias and with symptoms severe enough to come to the Emergency Department or to be hospitalized, should be treated as expeditiously as possible with intravenous hematin. In addition, prophylactic and repeated administration of intravenous hematin is of benefit to those prone to recurrent attacks,21 and hematin is safe for use in women who are pregnant. Hematin was the first drug approved under the Orphan Drug Act, and it should be readily available to all symptomatic patients with well-documented acute porphyrias.

The paper is available as free full text.



Aneurysmal subarachnoid hemorrhage


Here's a review from CCJM. I found this section of interest, on the initial diagnostic approach:

Emergency physicians should have a low threshold for ordering noncontrast computed tomography (CT) of the head in patients with even mild symptoms suggesting aneurysmal subarachnoid hemorrhage. Failure to order CT is the most common diagnostic error in this situation.6 CT performed within 6 hours of headache onset is nearly 100% sensitive for this condition,7 but the sensitivity falls to 93% after the first 24 hours and to less than 60% after 5 days.8 In patients who have symptoms highly suggestive of aneurysmal subarachnoid hemorrhage but a normal CT, lumbar puncture is the next diagnostic step.
There are two alternatives to CT followed by lumbar puncture: ie, noncontrast CT followed by CT angiography,9,10 and magnetic resonance imaging followed by magnetic resonance angiography. In patients with suspicious clinical symptoms but negative CT results, CT followed by CT angiography can rule out aneurysmal subarachnoid hemorrhage with a 99% probability.9,10 However, CT followed by lumbar puncture remains the standard of care and carries a class I recommendation in the American Heart Association guidelines for ruling out subarachnoid hemorrhage.5

NSAIDs and the risk of atrial fibrillation


NSAID use was a risk factor in this meta-analysis.

Tuesday, June 30, 2015

Yet another study on rapid response systems


The evidence in support of RRS is mixed. The RRS is favored in some before and after studies but not RCTs. This study, published in Resuscitation, is another before and after study but it does have some strengths compared to the older ones. From the paper:

Methods

For the period 2002–2009, we compared a teaching hospital with a mature RRS, with three similar teaching hospitals without a RRS. Two non-RRS hospitals began implementing the system in 2009 and a third in January 2010. We compared the rates of in-hospital cardiopulmonary arrest (IHCA), IHCA-related mortality, overall hospital mortality and 1-year post discharge mortality after IHCA between the RRS hospital and the non-RRS hospitals based on three separate analyses: (1) pooled analysis during 2002–2008; (2) before–after difference between 2008 and 2009; (3) after implementation in 2009.

Results

During the 2002–2008 period, the mature RRS hospital had a greater than 50% lower IHCA rate, a 40% lower IHCA-related mortality, and 6% lower overall hospital mortality. Compared to 2008, in their first year of RRS (2009) two hospitals achieved a 22% reduction in IHCA rate, a 22% reduction in IHCA-related mortality and an 11% reduction in overall hospital mortality. During the same time, the mature RRS hospital showed no significant change in those outcomes but, in 2009, it still achieved a crude 20% lower IHCA rate, and a 14% lower overall hospital mortality rate. There was no significant difference in 1-year post-discharge mortality for survivors of IHCA over the study period.

A related editorial makes some important points. First, the rationale and plausibility for the RRS are strong. In hospital arrests are often preceded by hours or even days of deterioration, presenting opportunities for intervention. Why can't the RRS be proven in high level studies? For one thing, says the editorial writer, the RRS is not a “clean intervention.” How it's used depends on the staffing and culture of the institution. It is one thing to say your hospital has a rapid response system but quite another to use it for all it's worth. What's most important is to recognize the signs of deterioration, then “have the big discussion” or pull out all the stops early. That, of course, is nothing more than a principle of clinical vigilance we've known for decades: when you smell a rat, get aggressive early.

Bottom line? A rapid response system can be beneficial in many ways depending on the needs and resources of the institution. However, general claims that these systems save lives cannot be justified.


Will this or that technology revolutionize education?


Throughout the history of education one innovation after another has failed to live up to the hype. Electronic media developed in recent years are no exceptions. It's really all about what happens in the mind of the learner and the social interaction with the teacher as explained in this video. (HT to Life in the Fast Lane). Individual learners have different styles. One size does not fit all.

NASH as an emerging indication for liver transplant


A study form an organ transplant database:

We queried 2,356 patients with nonalcoholic steatohepatitis, alcoholic cirrhosis (ETOH), and hepatitis C cirrhosis from the Ohio Solid Organ Transplantation Consortium who were listed for and/or received an orthotopic liver transplant from 2000 to 2012.
Results

The proportion of listed patients with nonalcoholic steatohepatitis increased from 0% to 26% and the proportion of transplanted patients increased from 0% to 23.4%.


Monday, June 29, 2015

Point of care ultrasound for hospitalists


From a review:

We review the literature on diagnostic point-of-care ultrasound applications most relevant to hospital medicine and highlight gaps in the evidence base. Diagnostic point-of-care applications most relevant to hospitalists include cardiac ultrasound for left ventricular systolic function, pericardial effusion, and severe mitral regurgitation; lung ultrasound for pneumonia, pleural effusion, pneumothorax, and pulmonary edema; abdominal ultrasound for ascites, aortic aneurysm, and hydronephrosis; and venous ultrasound for central venous volume assessment and lower extremity deep venous thrombosis. Hospitalists and other frontline providers, as well as physician trainees at various levels of training, have moderate to excellent diagnostic accuracy after brief training programs for most of these applications. Despite the evidence supporting the diagnostic accuracy of point-of-care ultrasound, experimental evidence supporting its clinical use by hospitalists is limited to cardiac ultrasound.

ST elevation in aVR and left main coronary syndromes: addressing the confusion


Here are a case presentation and a follow up on a patient with diffuse ST depression and ST elevation in aVR from the EMS 12-Lead blog.

A few learning points from the post:

Multi-lead ST depression with ST elevation in aVR suggest global subendocardial ischemia due to left main artery stenosis or its equivalent (multi-vessel) but not occlusion.

Rather than an unstable coronary plaque, the syndrome often reflects myocardial oxygen supply-demand imbalance in which case the troponin elevation represents a type 2 MI.

Treatment often consists of mitigating those factors causing supply-demand imbalance.


When should these patients go to the cath lab? Not always immediately, depending on clinical circumstances. That question is addressed further in this post from Dr. Smith's blog, which also discusses the much less common presentation of left main occlusion.


Sunday, June 21, 2015

American College of Physicians to practicing docs: we are your conscience


A post by Bob Doherty in the ACP Advocate Blog supports an increasingly popular narrative: the idea that the interests of the medical profession are necessarily opposed to those of patients and that some entity must advocate for patients against the profession. The ACP, as I read the post, would like to appoint itself as that entity by being the "conscience of medicine."

Can the conscience of medicine be collective? Conscience is naturally collective for certain general virtues such as being honest and being good to people. It's based on precepts that are innate and form what philosophers call the natural law. But as the collective conscience moves from general to specific, as defined by a community, government or an organization trouble may ensue as examples from history have shown. When it is defined by a particular side in political debate bad consequences can be taken for granted. But based on Doherty's remarks that's exactly how the ACP seems to be defining it.

In his post he traces the evolution of the ACP from an apolitical society that existed to represent the professional and educational interests of physicians to an activist organization involved in many facets of politics. Despite Doherty's empty disclaimer that it's only about the well being of patients the ACP has come down squarely in a partisan manner on a variety of issues. In order to support such a disclaimer you would have to stretch to absurdity the idea that the political process exists to serve people.

There's nothing new or shocking about a professional medical organization being involved in politics. It takes on a new dimension, though, when you articulate a partisan stand on multiple issues and imply in the same breath to physicians at large “we are your conscience.” It smacks of intolerance because it says in effect “if you disagree you're in the wrong and not putting patients first.”

But as long as we have this new conscience of medicine we should note that it is strangely selective given its silence on the ethical questions now swirling around the American Board of Internal Medicine. That's something the conscience should be screaming about.