Wednesday, February 21, 2007

JAMA: Off-Pump vs On-Pump CABG and Cognitive Decline

Five years after surgery, there is no difference in cognitive decline between on-pump and off-pump CABG.

Cognitive and Cardiac Outcomes 5 Years After Off-Pump vs On-Pump Coronary Artery Bypass Graft Surgery

"Results After 5 years, 130 patients were alive in each group. Cognitive outcomes could be determined in 123 and 117 patients in the off-pump and on-pump groups, respectively. When using a standard definition of cognitive decline (20% decline in performance in 20% of the neuropsychological test variables), 62 (50.4%) of 123 in the off-pump group and 59 (50.4%) of 117 in the on-pump group had cognitive decline (absolute difference, 0%; 95% confidence interval [CI], –12.7% to 12.6%; P>.99). When a more conservative definition of cognitive decline was used, 41 (33.3%) in the off-pump group and 41 (35.0%) in the on-pump group had cognitive decline (absolute difference, –1.7%; 95% CI, –13.7% to 10.3%; P = .79). Thirty off-pump patients (21.1%) and 25 on-pump patients (18.0%) experienced a cardiovascular event (absolute difference, 3.1%; 95% CI, –6.1% to 12.4%; P = .55). No differences were observed in anginal status or quality of life.

Conclusion In low-risk patients undergoing CABG surgery, avoiding the use of cardiopulmonary bypass had no effect on 5-year cognitive or cardiac outcomes."
[free full text]

Sunday, February 18, 2007

Keeping Patients Warm Means Generating Heat

Once anesthetized with a general anesthetic, patients are largely defenseless. The anesthesiologist is responsible for protecting the patient from their environment--an environment that can be increasingly hostile. One key facet of that environment is temperature, but control of it has never been more contested in the operating room than it is today.

My perspective may be skewed because I do so much anesthesia for orthopedic surgery--a surgery in which the surgeon is physically working hard under an OR gown, gloves, and hot lights. Certainly in pediatric rooms no one ever complains during times when we make the room hot. That's not true, actually. They complain, but they know full well that we are all there to keep the pediatric patient safe and keeping them warm is part of that. They don't expect us to drop the room temperature until we have the child anesthetized and covered.

But why does room temperature matter? It matters because it can affect patient body temperature, and patient body temperature matters for the following reasons:

  1. Mild hypothermia (1-3 deg. C) reduces resistance to surgical wound infection.
  2. Mild hypothermia prolongs hospital stay.
  3. Even mild hypothermia can cause shivering and be a very uncomfortable feeling after surgery.
  4. Shivering increases stress on the heart. In patients with heart disease this may cause ischemia.

Under anesthesia, our normal mechanisms for keeping warm are limited. Anesthetics significantly impair our ability to control blood flow to the skin. Although there are five mechanisms of heat loss from the body in the operating room, 90 percent occurs through the skin via radiation and convection

For those wanting a detailed review article and that have a NEJM subscription, see: Mild Perioperative Hypothermia by Daniel Sessler, M.D. in the Department of Anesthesia at UCSF.

I'm sure patients would be gratified to know that it's not the person with the most knowledge and training in patient temperature management that decides in most cases, but the person that whines the most (or is the sneakiest).

For example, last year I was scheduled to provide anesthesia for a 16 year old athlete having an ACL reconstruction. This was not the first case in that room, so the room was already as cold as a meat locker--64 degrees. I reset the room thermostat to 72 degrees, and placed a sticky note saying 'Please Do Not Change,' printed my name, and went to go see the patient.

When I came back to the room several minutes later, the note was gone and thermostat reset to 64 degrees. I replaced the note and reset the thermostat two more times. Both times the note was gone and thermostat reset. The final time there was a note from the charge nurse asking me to come see her.

What did I do? I did what any self-respecting anesthesiologist would do--I told the OR nurses the case was on hold until the room temperature came up and went to get some coffee. Not long after that the charge nurse paged me to discuss the issue. (Nothing gets management's attention more than a case delay.)

Why had she reset it? Because, she claimed, biomedical engineering (some guy with a Bachelor's Degree) said that bringing surgical instruments into a 72 degree room would cause them to sweat and possibly impair sterility. I thought back to my years of doing anesthesia for burn surgery in 85 degree operating rooms and found this explanation novel and fascinating. 'So', I asked her, 'you're taking the advice of a four year college graduate over that of a board certified anesthesiologist?'

Well, you can guess how the conversation went after that. These days, if someone in the OR is feeling hot they either turn the thermostat down themselves or ask the circulating nurse to do it. If all this done without asking me when I'm in the room, I point out to them that they should have asked me before making that decision and ask instead that the room temperature be increased several degrees. If they do ask me if they can turn the room temperature down, provided the patient is reasonably warm and covered, I'll oblige and say 'Thank for asking me. The patient appreciates it. You may set the room temperature to whatever you like.'

In days past everyone acknowledged room temperature was the anesthesiologists choice. These days I have to fight to control it, as I do for every other shred of professional respect. What I'm working on is to get a ruling from the OR committee that states room temperature is my bailiwick. With impending pay for performance measures that will include patient temperature on arrival to the recovery room, this issue has been forced to a head.

Friday, January 5, 2007

What Primary Care Physicians Really Do

From a recent JAMA section called A Piece of My Mind is an excerpt that gives a good summary of what primary care physicians spend a lot of time doing. The author describes what she will no longer be doing after moving to a new practice:

"No more primary care. No more forms to fill out for workers comp, disability, SSI, student loan forgiveness, longer-term-care insurance coverage, FMLA, or temporary suspension of billing for credit card or mortgage or rental furniture payments owing to customer illness.

No more forms for nebulizers, commodes, handrails, oxygen, home health nurses, adult diapers, wheelchairs, cock-up splints, lift chairs, physical therapy, or the dreaded power wheelchair/scooter doctoral dissertation.

No more forms to attest that someone can enter a nursing home, play soccer, work out at a gym, be in an assisted living facility, do chair exercise at the senior center, train to become a medical assistant, wrestle, teach school, or that he or she is, above all else, free from communicable diseases. "

The list of non-direct patient care tasks goes on for several more paragraphs, but you get the picture.


Friday, November 24, 2006

Anesthesia is safer than ever (even in France)

Anesthesiology--Survey of Anesthesia-related Mortality in France.

" Conclusion: In comparison with data from a previous nationwide study (1978-1982), the anesthesia-related mortality rate in France seems to be reduced 10-fold in 1999. Much remains to be done to improve compliance of physicians to standard practice and to improve the anesthetic system process."

Sunday, July 30, 2006

Risks of Epidural Analgesia for Labor

Anesthesiology has a nice article which attempt to quantify some of the less common risks of having an epidural during labor: epidural hematoma, infection, and neurologic injury.

Epidural hematoma 1 in 168,000 6 per million
Deep epidural infection 1 in 145,000 7 per million
Persistent neurologic injury 1 in 240,000 4 per million
Transient neurologic injury
[< 1 year]
1 in 6,700 180 per million

It contains an interesting tidbit others might find interesting, too. There are 4 million births in the United States each year and 2.4 million involve epidural analgesia. Wow. That's three fifth of all live birth get an epidural! (And some call nights, it seems every single one does...)

Friday, April 21, 2006

Archives of Surgery: Incidence, Patterns, and Prevention of Wrong-Site Surgery

Incidence, Patterns, and Prevention of Wrong-Site Surgery [free]
"Results Among 2 826 367 operations at insured institutions during the study period, 25 nonspine wrong-site operations were identified, producing an incidence of 1 in 112 994 operations (95% confidence interval, 1 in 76 336 to 1 in 174 825). Medical records were available for review in 13 cases. Among reviewed claims, patient injury was permanent-significant in 1, temporary-major in 2, and temporary-minor or temporary-insignificant in 10. Under optimal conditions, the Joint Commission on Accreditation of Healthcare Organizations Universal Protocol might have prevented 8 (62%) of 13 cases. Hospital protocol design varied significantly. The protocols mandated 2 to 4 personnel to perform 12 separate operative-site checks on average (range, 5-20). Five protocols required site marking in cases that involved nonmidline organs or structures; 6 required it in all cases."

The facilities I work at use 'Time Out' and are gradually standardizing on the use of the word 'yes' to mark the site (which I believe to be the best). Administrators tend to add things to the Time Out so they can say they did something about a problem. Our time outs now require confirmation of a negative pregnancy test before GYN surgery as well as 'Implants Available' for cases that will use implants; a list which will no doubt get longer as more errors occur.

The article contains this jewel from a well known author on errors in medicine--James Reason:

"First, written checklists, although designed for easy use, are prone to several types of error: skipped steps due to interruptions and distractions and stating that an item has been completed (checking the box) when in fact it has not. Second, redundant checks can achieve an exponential decrease in risk of error but only if each checkpoint is independent. Third, increasing the number of involved caregivers can foster routine violations because the multiple checks begin to seem like "busy work." Finally, efforts to keep up with the pace of patient flow may lead to viewing violations of protocol as acceptable or necessary. Simplification of protocols would improve adherence and efficiency and allow surgical teams to focus their limited time and energy on prevention of more common or harmful errors."

Tuesday, April 11, 2006

Pet Peave: popular press articles that don't link to their sources

The New York Times Online has an article titled 'Blasting of Kidney Stones Has Risks, Study Reports'. The article mentions the journal (The Journal of Urology) and the first author (Dr. Amy Krambeck). Would it have been so difficult to link to the abstract in the online version?

" SWL has revolutionized the management of nephrolithiasis and it is a preferred treatment for uncomplicated renal and proximal ureteral calculi. Since its introduction in 1982, conflicting reports of early adverse effects have been published. However, to our knowledge the long-term medical effects associated with SWL are unknown. We evaluated these adverse medical effects associated with SWL for renal and proximal ureteral stones.

Materials and Methods
Chart review identified 630 patients treated with SWL at our institution in 1985. Questionnaires were sent to 578 patients who were alive in 2004. The response rate was 58.9%. Respondents were matched by age, sex and year of presentation to a cohort of patients with nephrolithiasis who were treated nonsurgically.

At 19 years of followup hypertension was more prevalent in the SWL group (OR 1.47, 95% CI 1.03, 2.10, p = 0.034). The development of hypertension was related to bilateral treatment (p = 0.033). In the SWL group diabetes mellitus developed in 16.8% of patients. Patients treated with SWL were more likely to have diabetes mellitus than controls (OR 3.23, 95% CI 1.73 to 6.02, p <0.001). Multivariate analysis controlling for change in body mass index showed a persistent risk of diabetes mellitus in the SWL group (OR 3.75, 95% CI 1.56 to 9.02, p = 0.003). Diabetes mellitus was related to the number of administered shocks and treatment intensity (p = 0.005 and 0.007).

At 19 years of followup SWL for renal and proximal ureteral stones was associated with the development of hypertension and diabetes mellitus. The incidence of these conditions was significantly higher than in a cohort of conservatively treated patients with nephrolithiasis. "

Before people panic (or call lawyers), please consider that this is one study, retrospective, with a 59% response rate, using older lithotripsy technology (as the NYT article points out, modern machines use less energy and are able to focus it more precisely.

Sunday, March 5, 2006

Vaccines, Mercury, and Autism--New Data

My smart wife tells me that this article is really big news: Early Downward Trends in Neurodevelopmental Disorders Following Removal of Thimerosal-Containing Vaccines (pdf). I've quoted the entire abstract below:

"Contemporaneously with the epidemic rise in neurodevelopmental disorders (NDs), first observed in the United States during the 1990s, the childhood immunization schedule was expanded by the U.S. Centers for Disease Control and Prevention (CDC) to include several additional thimerosal-containing vaccines (TCVs). On July 7, 1999, a joint recommendation was made by the American Academy of Pediatrics (AAP) and the U.S. Public Health Service (PHS) to remove thimerosal from vaccines. A two-phase study was undertaken to evaluate trends in diagnosis of new NDs entered into the Vaccine Adverse Event Reporting System (VAERS) and the California Department of Developmental Services (CDDS) databases on a reporting quarter basis, from 1994 through 2005. Significant increasing trends in newly diagnosed NDs were observed in both databases 1994 through mid-2002. Significant decreasing trends in newly diagnosed NDs were observed in both databases from mid-2002 through 2005. The results indicate that the trends in newly diagnosed NDs correspond directly to the expansion and subsequent contraction of the cumulative mercury dose to which children were exposed from TCVs through the U.S. immunization schedule."

The big news is the last sentence: trends in newly diagnosed ND's [ed: autistic spectrum disorders] correspond directly to the expansion and subsequent contraction of the cumulative mercury dose to which children were exposed from TCVs through the U.S. immunization schedule.

There were suspicions during the time that vaccines contained Thimerisol that it was responsible for an associated increase is the so-called autistic spectrum disorders. The suspicion was based on reports of increases in autism in the community. These were explained away by the observation that diagnosis had become much better during the same time period and the fact that scientific data supporting such a link were of very poor quality. Nonetheless, many parents chose to forgo immunization of their children out of concern that vaccination would increase their risk of autism or related disorders. Skipping immunization did not increase their risk of infectious disease because of herd immunity, up until enough members of a population are unprotected and disease can once again propagate among the non-immunized.

There are ongoing flame wars among blogs about this issue, but his article should cause many of those involved to rethink their position.

Tuesday, February 28, 2006

MAC: Maximum Anesthesia Care?

Injury and Liability Associated with Monitored Anesthesia Care: A Closed Claims Analysis.:

"Analysis of closed malpractice claims associated with monitored anesthesia care showed a high severity of patient injuries, comparable to claims associated with general anesthesia. Severe respiratory depression from an absolute or relative overdose of medications used for sedation was the most common damaging mechanism. Burn injuries due to fires from the use of electrocautery in the presence of supplemental oxygen represented a surprisingly high proportion of all monitored anesthesia care claims (17%)."

[Via Anesthesiology]

Tuesday, February 7, 2006

Smoking Cessation Before Surgery Encouraged

"According to a new comprehensive review of existing studies in the February issue of Anesthesiology, surgical patients who are nonsmokers, or who stop smoking prior to surgery, tend to fare better in the recovery period than smokers. This is in addition to the benefit seen during the actual surgery, when anesthesia is safer and more predictable in nonsmokers due to better functioning of the heart, blood vessels, lungs and nervous system.

Add to all of this another bonus: smokers who have quit around the time of surgery may have fewer problems with nicotine withdrawal after the operation than they would have if they had tried to quit at other times. This may be due to medications and therapies commonly used during surgery and recovery, which may suppress nicotine withdrawal symptoms. Even if patients do have problems with nicotine withdrawal after surgery, they can safely receive help such as nicotine patches."

I think this is noteworthy because, in terms of complications, we used to think that one would need to quit smoking for at least six weeks before surgery for there to be any benefit. Though that may still be true, this review seems to indicate that if someone were to quit around time of surgery, their chances of success are better.

[via Newswise]
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