Why this is interesting...
In many ways, human albumin might be the perfect colloid fluid – and concentrated 20% albumin could be the ideal resuscitation fluid in the critical care setting, where fluid overload is otherwise a common consequence. Because of its high relative concentration, the intravascular expansion effect of 20% albumin is roughly double its infused volume, unlike 4% or 5% albumin.
In the SWIPE trial Mårtensson et al showed that even in the leaky-capillary state of critical illness, resuscitation with 20% albumin decreased fluid needs, lessened positive fluid-balance states, and was not associated with harm when compared to 4-5% albumin.
What did they do?
This was a well designed multicentre trial across three adult Australian & UK ICUs. 321 patients were randomized to either 20% or 4-5% albumin resuscitation during their first 48h in ICU.
Probably the most important takeaway is simply that resuscitation with 20% albumin is practical and results in no patient harm compared with 4-5%. The 576mL median lower difference in fluid balance is unlikely alone to be dramatically consequential.
Nonetheless an important first step before larger studies can look at morbidity and mortality outcomes.
Cautiously note though that for logistic reasons the trial was open label, so treating clinicians were well aware of which fluid they were using. Additionally, they were given free reign to choose additional resuscitation fluids (crystalloid or synthetic colloid) as the clinical situation required.
The intravascular expansion effect of 20% albumin is roughly double its infused volume, although 15% greater again in the healthy versus those with sepsis.
This update to their 2011 meta-analysis supports their conclusion that aspirin modestly reduces myocardial infarction when used for primary prevention, but at the expense of increased risk of intracranial and major bleeding.
Although daily low-dose aspirin reduces vascular events in those with diabetes but no cardiovascular history, it does this at the expense of major hemorrhage risk.
Daily low-dose aspirin does not reduce all-cause mortality in the healthy elderly.
Daily low-dose aspirin does not improve disability-free survival in the healthy elderly.
Daily low-dose aspirin for primary prevention in the healthy elderly offers no cardiovascular benefit but does increase the risk of major hemorrhage.
What's the big deal?
Low-dose daily aspirin is one of the most common drugs taken for cardiovascular disease prophylaxis. Although it's role in secondary prevention is well established, until now it's use for primary prevention in the fit and healthy was controversial – even though it was widely taken by patients and their family doctors alike!
What did they do?
The ASPREE trial (Aspirin in Reducing Events in the Elderly) enrolled 19,114 across the U.S. and Australia, randomizing to 100mg daily aspirin or placebo. Participants were 56% women, median age of 74 and had median follow-up for almost 5 years.
What did they find?
Aspirin did NOT improve either disease-free survival OR reduce cardiovascular disease, although it did increase risk of major hemorrhage. Similarly no benefit was seen for all-cause mortality (in fact, a surprising increase crept in...).
The one group that did see a drop in cardiovascular events were diabetics with no previous cardiovascualr history but who suffered a counteracting increase of major hemorrhage.
But... this study specifically targeted the elderly, who suffer higher rates of antiplatelet-related hemorrhage. Modest benefits have previously been reported in a recently updated meta-analysis though again with a simultaneous increase in major and intracranial bleeding.
Final word... daily aspirin likely causes net harm in the healthy elderly.
Pressure control ventilation is associated with lower surgical bleeding volume when compared to volume controlled ventilation during lumbar spine surgery.
Two thirds of anesthesia awareness occurs before or after surgery.