Why hasn’t dad woken up after his heart surgery?

January 26, 2008

Sedation helps patients tolerate the uncomfortable bodily invasions of high tech intensive care. But when dad isn’t “waking up”, or just “isn’t himself”, many family members want to know whether sedatives are responsible for the prolonged problems with wakefulness, memory, and cognition seen in a significant number of patients who have received care in the Intensive Care Unit (ICU).

Benzodiazepines like lorazepam (Ativan)(cousin:Valium) are inexpensive, effective and safe sedatives for this purpose, with very little impact on organ systems other than the brain (that’s a good thing).Flowers

Dexmedetomidine is a new sedative drug marketed as the more easily pronounceable Precedex™. It is cousin to clonidine, a blood pressure medicine that’s been around for many years, which also has sedative properties. Precedex has pain-relieving properties and can cause the heart to slow and the blood pressure to drop in some patients.

Because Precedex works in a different way to the standard sedatives (it blocks alpha-adrenergic receptors) there is hope that it represents a better option for some conditions and procedures. Could it have less long term effect than other drugs on the brain?

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How to Avoid (One Type of) Hospital Infection

January 24, 2008

Peter Pronovost is a different kind of medical hero. An anesthesiologist who is making an impact on hospital care far greater than almost any new pharmaceutical or high-tech surgical technique.

Implementation of Pronovost’s simple checklist for prevention of catheter-related bloodstream infection – the infection that can arise from intravenous lines inserted into the central circulation – has resulted in a dramatic reduction in these infections in a large group of Michigan hospitals. In many hospitals, the incidence, quite astonishingly, dropped to ZERO, sustained over a period of months.

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Surgery – A Good Time to Quit Smoking

January 17, 2008

Quitting smoking is just about the best thing anyone can do for their health.

Are there any benefits to smoking, now that it no longer has much sex appeal, and the French have even banned it in the cafes of the Champs Elysees? The only medical benefit of smoking I know of is a reduction in the risk of postoperative nausea and vomiting (PONV). The cause is not certain, but numerous studies have shown this to be true. Although PONV isn’t much fun this is not, I hasten to add, a good reason to take up the noxious weed before your next operation.

No SmokingSmoking creates added risk for people having surgery and anesthesia. For instance, smoking increases your risk of respiratory complications, and your risk of wound infection.

The perioperative period (before and immediately after surgery) creates forced abstinence – try lighting up in the surgical ward these days and you will pretty soon find yourself surrounded by irate nurses, fellow patients and possibly the security staff. So surgery represents a perfect opportunity to quit.

A new meta-analysis (study of studies) in the Canadian Journal of Anesthesia confirms that the preoperative setting represents a “teachable moment”. Read the rest of this entry »


Does anesthesia cause sleep disturbance?

January 11, 2008

Sleep disturbance after major surgery is common, and some people assume anesthesia is the cause. That is probably wrong.

The “surgical stress response“, the body’s hormonal and metabolic response to the trauma of surgery, is quite profound and has an important effect on the subsequent amount and quality of sleep. The bigger the surgery, it seems, the more significant is the stress response and the accompanying sleep disturbance.

Sleep During the stress response, hormones from the pituitary gland are released, and the sympathetic nervous system is activated (adrenaline and its companion “fight or flight” hormones). Metabolic changes include increased blood sugar, and breakdown of body protein. Injured tissues release cytokines and other potent chemicals associated with inflammation.

Pain, and the medications used to treat pain, sedatives, food deprivation, fever, psychological factors, age, and a person’s usual sleep profile all affect sleep after surgery.

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The Cost of Anesthetic (Anaesthetic) Gases

January 8, 2008

In South Africa, controversy has arisen over the cost of anesthetic gases charged by private hospitals.

According to the Board of Healthcare Funders (BHF), which represents medical schemes (insurers), hospitals are overcharging for anesthetic gases because they charge by the minute rather than for each milliliter of anesthetic agent consumed.

For those unfamiliar with the intricacies of anesthetic pharmacology I will attempt to explain the problem, without delving into the political aspects of this issue.

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Help Avoid Mistakes in Your Surgery

January 7, 2008

Speakup

In 2002 the Joint Commission initiated a campaign to improve patient safety called SpeakUp. Many of the materials produced and distributed are copyright free. Here I reproduce a brochure titled “Help Avoid Mistakes in Your Surgery”. I highly recommend that anyone about to undergo surgery read, and take action on, these suggestions. You can download the brochure (free) here.

Preparing for your surgery

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Video games treat pain

January 2, 2008

Immersive virtual reality (VR)

Pain has been declared the “fifth vital sign”, signifying its importance to patients and health care providers. A common therapeutic goal in American hospitals is to ensure that patients have a pain score of 4 or less (out of ten) after surgery .

Unfortunately, all pharmaceutical pain treatments have potential side-effects. The aggressive treatment of postoperative pain with standard pain killers may lead to a range of complications, including gastro-intestinal side-effects (nausea, vomiting, constipation), over-sedation, hematological problems (bleeding or thrombosis), and even death from respiratory depression. Non-pharmacological approaches to the treatment of pain, such as hypnotherapy, acupuncture and music, are therefore an attractive option.

A recent study of immersive Virtual Reality (VR) published in the journal Anesthesia & Analgesia (Dec 2007) adds to the evidence that this technology can be useful in the treatment of pain.

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Does anesthesia “fry” the elderly brain?

December 30, 2007

One of the most common fears of people undergoing anesthesia and surgery is that anesthesia will cause harm, even permanent damage, to the brain. The traditional view is that anesthetic agents are rapidly metabolized (broken down) and/or excreted from the body, their effects are readily reversed, and anesthesia is therefore unlikely in the long run to cause neurologic injury.

We know that anesthetic agents affect many aspects of brain physiology, altering blood supply to the brain, metabolism, neurotransmitters, cerebrospinal fluid production, and more. These effects are being investigated in the laboratory and through the use of special imaging techniques. The picture that emerges is as complex as the brain itself, and is sometimes surprising. For instance, certain anesthetic agents seem to protect, not injure, the brain – at least in animal experiments.

Your Brain on Drugs

More than 50 years ago, it was reported that some older people have brain problems after surgery, and recent research challenges the belief that a well-conducted anesthetic and complication-free surgical procedure is totally neurologically benign.

The term postoperative cognitive dysfunction (POCD) has been coined to describe the mental changes, (in the areas of thinking, attention and memory) that do occur in some patients after anesthesia and surgery.

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“Shock treatment” reduces postoperative nausea and vomiting

December 30, 2007

Nausea and vomiting after anesthesia, known as PONV (postoperative nausea and vomiting) is still common, despite new anesthetic agents and anti-nausea medications tested in hundreds of clinical studies. Acupuncture, and related techniques that use pressure (acupressure) or electrical pulses (transcutaneous electrical nerve stimulation) instead of needles, are fairly well studied in the prevention of PONV. These prevention measures seem to be as effective as the standard drugs. There are commercial bracelet devices that exploit this effect. The standard acupuncture point is called Nei guan, or P6, and is located on the inside of the wrist, between two tendons. These systems also appear to be effective in the prevention of motion sickness.

Neuromuscular blocking agents, also known as muscle relaxants (they are in fact reversible, paralyzing drugs), are used routinely in anesthesia for certain surgical procedures. The effect of these drugs is monitored with nerve stimulators, portable devices that deliver small electrical pulses via adhesive electrode patches applied to the skin. As the paralysis wears off, muscles supplied by the nerve that is stimulated begin to twitch in response to the electrical stimulation. Electrodes used for nerve stimulation are usually placed on the face (facial nerve monitoring) or on the wrist (ulnar nerve monitoring).

The Study:

In a simple but clever clinical study done in hospitals in Switzerland and Austria and published in the flagship specialty journal Anesthesiology, investigators have combined nerve stimulation for monitoring of muscle relaxation, with the effects of acupuncture.

By moving one of the wrist electrodes about 2 cm from its usual (ulnar nerve) location toward the center of the wrist, corresponding with the location of both the median nerve and the P6 point, investigators guessed they might achieve both goals – that is, monitor paralysis while providing an anti-nausea effect. The stimulator was set at 1Hz, that is one electrical impulse per second, for the duration of each case.

Placing the electrodes for monitoring and prevention of PONV

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Welcome to the SurgiPrep Blog

December 11, 2007

I’m an anesthesiologist. About 8 years ago I started answering questions about anesthesia on an excellent and popular consumer health website called NetWellness. NetWellness is linked to Case Western Reserve University, where I am a faculty member. Answering over 350 questions, most of which can be found on SurgiPrep, my site dedicated to preoperative evaluation, or in their original form on NetWellness, has taught me a lot.

I’ve learned that many people are more worried about anesthesia than they are about their surgery. It’s particularly anxiety provoking when a loved one – a child say, or a parent, is about to “go under”. It’s also a huge concern when things don’t turn out the way people expect. Sometimes, complications, like a breathing problem, a nerve injury, or an allergic reaction, are clearly attributable to the drugs or techniques that are part of anesthesia. People want these problems explained and they want to know how to avoid them in the future.

I’ve discovered to my surprise and fascination that some people will attribute almost any new symptom to a recent anesthetic (examples: curly hair, loss of hair, oily skin, decreased energy, increased energy, bad dreams, bad breath, loss of taste, loss of concentration). Either we anesthesiologists are missing some weird and possibly important stuff happening right beneath our face masks, or we’re not doing a good job of informing and listening to our patients. (It’s probably some of both).

I’ve heard from people angry with the way they’ve been treated by their doctors. Often all they’ve wanted is a bit of time and a simple explanation from their doctors. Problem is, time is a commodity most medical practitioners are short of. I’ve taken time to explain how anesthesia works, how it’s administered, and by whom, what the choices are (when choices exist), and what outcomes, good or bad, can be expected, in the simplest terms possible. (This is despite the reality that general anesthesia, like consciousness itself, is a rather mysterious process and the science underlying it is still being explored).

Why do I care to do this? Most anesthesiologists don’t go into their field because they like to chat, but during my earlier professional career I was forced to do a lot of it – first during a 6 month stint as a psychiatry house officer (in Harare, Zimbabwe!) and later as a family physician (in Saskatchewan, Canada). I recognized the power of talk, as an expression of caring and a mechanism of healing. Perhaps something rubbed off. I am not the most garrulous individual (pardon the pun) but I do like to write and I enjoy trying to make scientific and medical concepts more understandable.

In this blog I hope to explore, in a little more depth, some of the issues, weird and commonplace, expected and unexpected, that my NetWellness correspondents have brought to light. This blog does not replace an interview with your friendly local anesthesiologist, or surgeon, but reading the articles I post here may help you to have an informed conversation with your doctors when its your time to undergo a medical or surgical procedure requiring anesthesia.

Please join me on this journey.

Gary Kantor, MD