2/ PPCs are extremely common and associated with a high rate of morbidity and mortality following surgery.
While no one agrees on which conditions we should include in PPCs, most agree that atelectasis (collapsed lung tissue) is the most common PPC.
3/ Though it's common, the significance of postoperative atelectasis isn't always clear.
While there is no evidence to support the dogma that atelectasis causes early postoperative fever, atelectasis frequently accompanies more serious complications including pneumonia & death.
4/ As early as the 1920s doctors debated the pathophysiologic causes of postoperative atelectasis and even whether mild cases were "normal".
The uncertainty of the significance of atelectasis triggered even more debate about best to treat it.
5/ Postoperative atelectasis inspired many creative treatments to re-inflate the lung including bronchoscopic aspiration, cocainization of the airway, and CO2 inhalation.
One doctor even promoted direct tracheal injections to stimulate coughing and reduce collapse.
6/ Early on doctors recognized the importance of positional changes and deep breathing exercises in reducing atelectasis. They soon developed devices to assist patients with deep breaths including blow bottles and intermittent positive pressure breathing (IPPB) machines.
7/ In the 1970s Bartlett introduced the incentive spirometer as a means to reverse atelectasis via alveolar recruitment. When compared with IPPB (the standard of the day), IS improved atelectasis in patients undergoing cardiac surgery.
IS soon spread rapidly!
8/ Despite widespread adoption and 50 years of use, however, there is little data to support the use IS over other methods for preventing PPCs. There is also no agreement about the best frequency, duration, and target volumes to prescribe for IS.
9/ Two Cochrane reviews with thousands of patients undergoing upper abdominal (UAS) and cardiac surgery show that IS is no more effective than standard physical therapy, deep breathing exercises, or even no intervention in preventing PPCs.
10/ Even randomized control trials of high-risk cohorts undergoing bariatric or thoracic surgery show no benefit to IS in preventing PPCs. Yet despite a lack of evidence it's estimated that the US healthcare system spends >$1 Billion annually on IS.
11/ In 2011 The American Association for Respiratory Care published guidelines recommending against using IS alone to prevent PPCs in UAS and cardiac surgery patients . They recommend IS only as a part of a multimodal approach to care.
13/ So if IS doesn't work to prevent PPCs, what should we do instead? Until there's better data, it's not clear we need to do anything instead. Early mobilization and telling patients to take deep breaths on a schedule without a device appear to work just as well as IS.
14/ Are there times where we should use IS?
For patients at particularly high-risk for PPCs, the benefits of IS for the individual may outweigh the risks since there's both little benefit and little risk.
15/ IS may also be beneficial as a preoperative intervention along with inspiratory muscle training in helping high-risk patients prepare for scheduled surgery. IS has a role in helping with recovery from rib fractures and in vaso-occlusive crisis in Sickle Cell Disease
16/ So what are the key takeaways?
🫁Atelectasis is common after surgery
🫁There is little evidence supporting the routine use of incentive spirometry in reducing postoperative pulmonary complications
🫁Consider early mobilization or deep breathing exercises as alternatives
For more details read our newest publication in @JHospMedicine Things We Do for No Reason: Routine use of incentive spirometry to reduce postoperative pulmonary complications!
1/ Why is metformin associated with lactic acidosis? Do we need to routinely stop metformin when admitting patients with Type 2 Diabetes Mellitus (T2DM) to the hospital?
Let's explore these questions by looking at the history of metformin in the following #histmed#tweetorial.
2/ Metformin, a biguanide, works by decreasing hepatic glucose production and increasing insulin sensitivity.
It is a first-line therapy in T2DM because it's inexpensive, well-tolerated, helps with weight loss, and has very low risk of hypoglycemia.
1/ Did you know that you can import an Excel spreadsheet schedule into Google Calendar?
This thread is designed for new chief residents or any folks who schedule conferences/events and want to convert a spreadsheet into individual calendar events.
2/ During my time as a @uclaimchiefs we shared a google calendar to track tasks during the week. We also scheduled conferences via shared spreadsheets.
Importing the spreadsheet allowed me to view what conference was scheduled without constantly referencing the spreadsheet.
3/ To start we’ll need a basic spreadsheet to schedule events.
For this tweetorial we’ll use an example of a Noon Conference spreadsheet and include “Day", “Date", “Title", “Speaker", and “Notes" as headers though for this spreadsheet the headers are not critical.
This thread is designed for new chiefs residents (and faculty!) on a topic I got very little coaching on before my chief resident year: Email Management.
2/
My transition to chief year was abrupt. I went from being a decent doctor to a crappy administrator overnight. In this new role I went from receiving a few junk emails/day to hundreds of emails at all hours. The following tips are strategies that helped me survive my inbox.
3/
1️⃣ Set boundaries.
It's easy to be on your email 24 h/day- but it's okay not to be.
Unless I was chief on call I tried not reply to email past 6pm as that is family time. I also limited checking on weekends and vacation. Setting Do-Not-Disturb and downtime can be helpful.
1/ Why are hypodermic needles and IV catheters referenced by gauge numbers?
And why does the needle diameter get smaller as the gauge number increases?
Let's explore the obscure history of IV sizing in the following #histmed#tweetorial.
2/ The gauge numbers on modern hypodermic needles are adapted from the Birmingham Wire Gauge (BWG), a system developed during the Industrial Revolution in the early 1800s to standardize the British cottage industry of iron and steel wire manufacturing.
3/ As early as the 1200s wire was made through the process of wire-drawing, which involved pulling iron rods through a conical hole in a draw-plate or gauge.
The resultant wires could then be drawn through successively smaller diameter gauges to produce thinner wire.
3/ BNP is a hormone secreted in response to ventricular wall stretch. It binds to natriuretic peptide receptor A (NPR-A) which ⬆️ cGMP in various tissues to exert MANY effects including:
⬆️ Natriuresis
⬇️ RAAS
⬇️ sympathetic tone
& so much more!
1/ "Who feels comfortable evaluating a tracheostomy?"
Today on the wards we talked trachs. Though we see patients with trachs regularly I find it is a topic that few learners are comfortable with.
The following 🧵 is my "Hospitalists' Guide to Tracheostomies"
2/
Where are trachs placed anatomically?
Trachs are placed between the cricoid cartilage and the sternal notch around the 2nd to 4th tracheal ring. These can be placed surgically or percutaneously at the bedside.
3/ Anatomy of a Trach
When evaluating a trach, I find it helpful to consider the following:
🔹 Diameter - Is there an inner cannula or single lumen?
🔹 Length - Is it regular size or an Extended Length Trach (XLT)?
🔹 Cuffed or cuffless?
🔹 Fenestrations present?