Local anesthetic news

Summer was once again approaching and while unlike the anticipation and eagerness I usually enjoyed each November, as I journeyed to my
Caribbean retreat for my fix of ultra violet rays, yet there was something almost homeopathic and  calming about the aging hammock with a good book and the almost deathly silence of summer by the lake.

On my usual November trip south, the captain would put us through  the “g force” as he challenged the physics of gravity prior to lift-off. I often thought how Albert Einstein could have ever imagined what it would have been like to travel along side the speed of light when my main concern was focused on whether this de-iced 700,000 lbs monster would continue to gain altitude. However as true to form the falling leaves of red and gold faded into white fluffy cumulus which seemed to be void of density as the shining machine sliced through them as effortless as a knife through butter. There you go.  

Life above the 49^th parallel had lasting memories for me. I lived the best of both worlds. Snow shoveling was replaced by an early walk where I summonsed my younger balancing skills at playing hopscotch through the sharp edged seashells being caressed by each gentle wave. In contrast, summer was spent mostly reclining in a hammock which over the years had formed itself like a large latex glove around my girth with each increasing year.  This posture allowed me together with my book of the day to blend in with the sparsely placed pine furniture in the large and opened verandah which surrounded the cottage on three sides. open and almost oblivious to the distant hum of a power boat on the lake.

Winter, albeit relaxing and therapeutic, was in deep contrast to the silence one experienced on most lakes north of the 49^th parallel. The mere experience for most northern tourists to afford a
Caribbean vacation was seen as a right of passage to gave way to any Freudian inhibition which may have not been completely resolved. In addition, there was the cooling and refreshing rum punch mixtures added to the rhythmic sound of the “steel band” made it a powerful prescription of feeling entitled to shed not only one’s pent-up stress, but at times parts of their already skimpy apparel. This resulting atmosphere is what most scholars of psychology refer to as the emerging passive-aggressive behavior. There you go.

In preparation for my summer retreat during the month of June, I was like the proverbial bull in the china store as I maneuvered my mini shopping cart from aisle to aisle through my favorite book store. This store offered an atmosphere not unlike a trade show with rows and rows of draped individual small tables throughout the aisles which seemed to add that much more square footage to advertise and promote authors and new releases. These arcades and display tables were managed independently by their own sales associates, a title by which they preferred to be addressed. There you go. 

It was noticeably busy for a mid week morning in June. I carefully rechecked my BlackBerry organizer which for the most part tagged along with me like a faithful poodle with its unconditional love. From to time it would vibrate or other times it would emit a childlike whine to inform me of some event I had previously entered and may have completely forgotten about it. I lovingly referred to it as my dementia levee which faithfully protected any memory cells from overflowing my aging brain’s levee. A tap or two on  the sensitive touch screen revealed  nothing exceptional or urgent other than a memo to remind me to make a date to see the movie “Sex and the City” With Sarah Jessica Parker, Kim Cattrall. There you go. 

Why then was this excessive marketing atmosphere so evident throughout the store? Did the book industry secretly generate a Tiger Woods’ moment of mass marketing?  This certainly would have been the best kept secret, yet the solution was facing me right between the eyes. Historically, increased activity at book stores and movie houses has proven to be an accurate and reliable early leading indicator of impending recession as people at large have more free time. Ironically some business benefit from recession in the same way as the demand for steel increases during periods of war. 

Suspense novels are my passion and among others there were two on my short  list – namely “A prisoner of birth” by Jeffrey Archer and “The Pillars of the Earth” by Ken Follet. I also keep in touch and have a burning desire to be current with professional journals and especially editorials which, with some basic writing skills and strategetly placed references can be confused as scientific material. 

Over the many years of reading, I have developed an almost Sherlock Holmes analytical personality for articles. No more so than dentists are impulsively attracted to “the work” on one’s teeth or an architect inspecting the symmetry of a well placed keystone. These editorials/articles can often be detected by the format of their presentation, which is usually in the form of a question rather than the more accepted form of peer reviewed scientific study complete with investigating phenomena or purpose, an accepted methodology protocol and a conclusion. The pure sciences are becoming more and more diluted as such editorials begin their long “hear-say” or gossip walk through the hallowed corridors of famed teaching institutions.  Such articles presented under the guise of scientific material are for the most part self serving and do little to advance clinical efficacy with less unforeseen mishaps.  

However, there are the pundits of an evolving world where analytic jurisprudence is popular and where asking questions like, “What is law?” “What are the criteria for legal validity?” or “What is the relationship between law and morality?” and other such questions that legal philosophers may engage. (Wiki). 

An article this summer caught my attention under the heading of ethics and jurisprudence.  Here goes that question format - “Informed consent for Local Anesthesia - is it necessary?” There is implied dictum which takes the blame away from the operator and places it on a compound (amides) which dentists have been using successfully since 1947 to induce local anesthesia. If ever there was a case for longitudinal and sample size data, our stats people would have a heyday.   

Life styles through all aspects has changed and dental offices were no exception. I was as attentive to my oral health as I was to my physical health and over the  years I had noticed gradual subtle changes such as more pre clinical involvement with hygienists but perception is reality. I also noticed the office in greater detail. The Italian leather couches, slate tile floors and backlit etched glass in the patient lounge, exuded a definite warmth and elegant atmosphere. My dentist was considered to be one of the best, hence the ambience to go with her status. 

From the patient lounge I  was taken into a room with soft music and current magazines like Ophra, Vogue, Sports Illustrated, which all appeared to have been delivered that very morning. The dentist greeted me and after some small talk, asked me to place a tiny pill under my tongue which she explained would dissolve in a few minutes. Her assistant returned in about half an hour and led me into the operatory. By this time I was feeling very relaxed and comfortable.The local anesthetic solution was delivered through a computer-like electric tooth brush (minus the brush tip) and I felt absolutely nothing…no stick, not anything. I felt very relaxed throughout the procedure.  

This is where, in my humble opinion, and together with my graduate degree in pharmacy, may leave room for a clinical study to determine the use of oral or even intravenous sedation in general dentistry. The question is whether to circumvent the pain associated with what some dentists refer to as “pumping”. Is there need for added pharmacological interventions ( use of muscle relaxants) when a slower delivery ( 60 seconds) would have proven just as effective and with reduced cost to the office?  The term “ Infants practicing on mom’s high heels’ is probably not inappropriate here.  

To suggest a case for advocating informed consent for the use of local anesthetics after 60 years of successful clinical use in dentistry appears less substantive phenomena to identify such rare sequellae such as temporary amaurosis, paresthesia and even death which would seem to be classified as operator error rather than of a biochemical origin.  All clinical evidence would seem to beg the question. “Does this track record reasonably qualify to put local anesthetics (amides) under curfew or to “throw them under the bus?”

There is without doubt in general dentistry, a need to address the needle phobic patient, however a sudden move to give patients a “high” may increase patient traffic  prone to chemical addictiveness as the word get around, but with consequences not every dentist is willing to spend time, effort, legal and peer review in their selective associations. 

Anesthetics and aesthetics — they even sound as though they work together. Informed consent seems rather like infants practicing on mom’s high heels.  However for general dentistry with limited experience of these  powerful opioid analgesic with a potency approximately 81 times that of morphine (wiki) may increase the traffic you may live to regret.

Comments to author.  mailto:localanesthetics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.Anestheticnews.com

Steven lost his taste for The Big Mac after a visit to his dentist. Dentist unable to explain: Could this be Dr. Watson’s first case of unexplained paresthesia? I was entering my sophomore year of engineering. This transition year would be taking me from broad-based general education to a more highly-focused mechanical engineering course through advanced studies in mathematics, science and systems. By all measurements, I was well positioned with my peers and my grades were above average. My freshman year was now over and I was literally pacing myself for the complexity of projects which eventually would see my skills put into practice. At this stage in my studies, I was like a sponge in the ocean soaking up all and every lecture I attended. Being pulled and pushed with every movement of the tide around me. No clear route was calculated on my internal GPS; however there was a steady wind which seemed to be pushing me on a definite course. Or so it appeared to me.

It was difficult to conceal my identity; I was from a small Midwestern town and attended a private high school with my siblings where we enjoyed a comfortable life as children of parents who were both professionals. My mother was a restorative hygienist and my dad, Dr. Watson, owned a well established dental practice.

I was now off campus and was fortunate to share a modest third story attic-like apartment with Steven, a student who was also in engineering, one year ahead of me. Our apartment was no more than 500 sq.ft. but comfortable and spotlessly clean, with a clear view across town where one could see the familiar Golden arches and where many a university student caught up on notes, while enjoying the special burger of the day. Steven was no exception. He loved to eat at the MacDonald’s; He was hooked on their Big Mac and ate there at least four or five tines a week. Our apartment consisted of a sitting area, a kitchen, a washroom and one bedroom with two single beds. I was beginning to feel more in charge of my life and free to come and go as I pleased. My room mate was friendly but somewhat quiet and deep within his thoughts, or so it appeared to me.

Our schedules were quite different, and we did not have a lot of time together other than the occasional small talk while having a coffee. We were not big on booze but enjoyed the odd beer. He had a part time job at a small computer repair store and would be home usually by midnight. The tempo and the anonymity of the North East were very fascinating and everyday I could feel maturity seeping into every move I made. I was at ease with myself and happy, especially when I heard from my folks.

Although it was never overtly pushed on me, the atmosphere at home during high school was subtlety an expectation of going on to undergraduate school in the East. I was the oldest of my siblings and now that I can reflect, both my parents were lovingly using me as their flagship.  “If Jim sets the pace, the others will follow”. I was fortunate in that I did not have to work during my semesters away from home. My mother saw to that. There were to be no excuses for failing grades. I lacked for nothing. However in no way was I pretentious. In fact I was often seen and not heard. Deep within me I knew I was popular albeit, shy. I was no “Brad Pitt”, but confident was I, or so it appeared to me.

It was during our second semester of my sophomore year that I started to have some concern about my room mate. He suffered from bruxism, commonly known as grinding of the teeth, typically accompanied by the clenching of the jaw. It is an oral para functional activity which is common in many humans. Bruxism  (Wiki) is caused by the activation of reflex chewing activity; it is not a learned habit. Through osmosis, I had picked up many dental terminologies over the years from both of my parents. This condition (grinding) was not unknown to me; however the situation was causing me restless nights. I talked to my dad during one of our weekly “how are you” conversations and he suggested that Steven should see a local dentist, because of possibly damage to his teeth. It was not difficult to share my concern with Steven, because his girlfriend also thought he should see a dentist.

We (Steven, his girlfriend Veronica and I) had now become much closer. Steven opened up a bit more and at times could be quite comical. I was seeing the other side of him. We started to hang out on a more regular basis. Steven had appreciated my father’s professional advice and did in fact go to see a dentist associated to our engineering faculty. The diagnosis was confirmed. There was some small initial damage which had started to erode the enamel of his molars. The dentist was able to have a guard fitted in Steven’s mouth with which he could sleep comfortably at night. A follow-up appointment was scheduled in a couple of weeks to make sure the protective appliance was fitting comfortably. However the dentist noticed there was an old amalgam filling on his LR bi-cuspid which was overhung and was a floss shredder. The dentist advised Steven it should be replaced with a more modern white filling. Amalgams are for the most part now dated. The trend is to natural color composite fillings. This was good news for Steven because the silver amalgam was a nuisance and unsightly for a youngster. The date was set for the replacement filling and all would be well, or so it appeared to me.

Steven showed up for his 9:00 AM dental appointment which would have given him ample time to get back to class and by noon the anesthetic would have worn off giving him sufficient time to enjoy his big Mac. However things did not go as was planned. Steven still had a numb jaw and although he tried to disregard this persistent strange feeling, it was apparent that he had indeed lost all taste for his favorite Big Mac and fries.  On the third day Steven called his dentist to explain jokingly that he had lost all taste for any food and in particular, his craving for a Big Mac fix. The dentist reassured him that some people react that way to local anesthetics but the numbness and tingling sensation would soon disappear and normal full sensitivity would be back. Steven apprehensively took his word, but after day five, the condition had not improved and Steven was in a panic and wanted another opinion.

Without knowledge of the total situation, my father was privileged only to “hear-say” and cautioned me that it could be a case of paresthesia, which is a potentially serious pitfall for which dentists hope never to encounter during the life of their practice. My dad did not want to be involved for obvious reasons. I was now on the horns of a dilemma. After-all Steven was my trusted friend and room mate.

Unexplained paresthesia:

Steven was now withdrawn and depressed. He had lost weight and his essays were suffering. Veronica accompanied him to the guidance counselor and a decision was made that he should see a neurologist. Paresthesia was in fact the diagnosis. This condition was explained to Steven and the prognosis was good because he had a simply and uncomplicated infiltration of the anesthetic and was not exposed to a full nerve block. There were still unanswered questions. Why would this occur? There was no truma to any neres.

Steven did his research and discovered that around this time a new local anesthetic called Septocaine had been approved by FDA for dental use in the U.S. Unlike most other anesthetic solutions which have a concentration of 2%, this new one was a 4% concentration. In other words, theoretically and pharmacologically speaking, all things being equal, or as the scientists would say, in vitro, one could use half the volume of the 4% solution to achieve what the 2% was capable of. Each one of us can have slight anatomical variations in the oral cavity, hence different responces.

For some unknown reason, dentists are in the habit of referring to volume (cartridges) used rather than by mg/ml. (actual mg given).As it turned out, Steven awoke now in its tenth day, to discover the paresthesia had been miraculously reversed and full sensitivity had returned to his tongue and soft tissue around his lip. No point of mentioning where he headed after he discovered there were no more pins and needles. All therapeutic compounds are accompanied with an index. The lesson to be learnt is that the product monographs included in any medication by FDA and are intended to be read. The term Minimal Effective Dose is alive and well. Following these instructions may avoid expensive and time consuming litigation.

Comments to author.  mailto:localanesthtics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.AnestheticsNews.com

 http://tinyurl.com/2bsqsz

References: Haas DA, Lennon D   J Can Dent Assoc. 1995  

Steven lost his taste for The Big Mac after a visit to his dentist. Dentist unable to explain: Could this be Dr. Watson’s first case of unexplained paresthesia?

 I was entering my sophomore year of engineering. This transition year would be taking me from broad-based general education to a more highly-focused mechanical engineering course through advanced studies in mathematics, science and systems. By all measurements, I was well positioned with my peers and my grades were above average. My freshman year was now over and I was literally pacing myself for the complexity of projects which eventually would see my skills put into practice. At this stage in my studies, I was like a sponge in the ocean soaking up all and every lecture I attended. Being pulled and pushed with every movement of the tide around me. No clear route was calculated on my internal GPS; however there was a steady wind which seemed to be pushing me on a definite course. Or so it appeared to me.

It was difficult to conceal my identity; I was from a small Midwestern town and attended a private high school with my siblings where we enjoyed a comfortable life as children of parents who were both professionals. My mother was a restorative hygienist and my dad, Dr. Watson, owned a well established dental practice.

I was now off campus and was fortunate to share a modest third story attic-like apartment with Steven, a student who was also in engineering, one year ahead of me. Our apartment was no more than 500 sq.ft. but comfortable and spotlessly clean, with a clear view across town where one could see the familiar Golden arches and where many a university student caught up on notes, while enjoying the special burger of the day. Steven was no exception. He loved to eat at the MacDonald’s; He was hooked on their Big Mac and ate there at least four or five tines a week. Our apartment consisted of a sitting area, a kitchen, a washroom and one bedroom with two single beds. I was beginning to feel more in charge of my life and free to come and go as I pleased. My room mate was friendly but somewhat quiet and deep within his thoughts, or so it appeared to me.

Our schedules were quite different, and we did not have a lot of time together other than the occasional small talk while having a coffee. We were not big on booze but enjoyed the odd beer. He had a part time job at a small computer repair store and would be home usually by midnight. The tempo and the anonymity of the North East were very fascinating and everyday I could feel maturity seeping into every move I made. I was at ease with myself and happy, especially when I heard from my folks.

Although it was never overtly pushed on me, the atmosphere at home during high school was subtlety an expectation of going on to undergraduate school in the East. I was the oldest of my siblings and now that I can reflect, both my parents were lovingly using me as their flagship.  “If Jim sets the pace, the others will follow”. I was fortunate in that I did not have to work during my semesters away from home. My mother saw to that. There were to be no excuses for failing grades. I lacked for nothing. However in no way was I pretentious. In fact I was often seen and not heard. Deep within me I knew I was popular albeit, shy. I was no “Brad Pitt”, but confident was I, or so it appeared to me.

It was during our second semester of my sophomore year that I started to have some concern about my room mate. He suffered from bruxism, commonly known as grinding of the teeth, typically accompanied by the clenching of the jaw. It is an oral para functional activity which is common in many humans. Bruxism  (Wiki) is caused by the activation of reflex chewing activity; it is not a learned habit. Through osmosis, I had picked up many dental terminologies over the years from both of my parents. This condition (grinding) was not unknown to me; however the situation was causing me restless nights. I talked to my dad during one of our weekly “how are you” conversations and he suggested that Steven should see a local dentist, because of possibly damage to his teeth. It was not difficult to share my concern with Steven, because his girlfriend also thought he should see a dentist.

We (Steven, his girlfriend Veronica and I) had now become much closer. Steven opened up a bit more and at times could be quite comical. I was seeing the other side of him. We started to hang out on a more regular basis. Steven had appreciated my father’s professional advice and did in fact go to see a dentist associated to our engineering faculty. The diagnosis was confirmed. There was some small initial damage which had started to erode the enamel of his molars. The dentist was able to have a guard fitted in Steven’s mouth with which he could sleep comfortably at night. A follow-up appointment was scheduled in a couple of weeks to make sure the protective appliance was fitting comfortably. However the dentist noticed there was an old amalgam filling on his LR bi-cuspid which was overhung and was a floss shredder. The dentist advised Steven it should be replaced with a more modern white filling. Amalgams are for the most part now dated. The trend is to natural color composite fillings. This was good news for Steven because the silver amalgam was a nuisance and unsightly for a youngster. The date was set for the replacement filling and all would be well, or so it appeared to me.

Steven showed up for his 9:00 AM dental appointment which would have given him ample time to get back to class and by noon the anesthetic would have worn off giving him sufficient time to enjoy his big Mac. However things did not go as was planned. Steven still had a numb jaw and although he tried to disregard this persistent strange feeling, it was apparent that he had indeed lost all taste for his favorite Big Mac and fries.  On the third day Steven called his dentist to explain jokingly that he had lost all taste for any food and in particular, his craving for a Big Mac fix. The dentist reassured him that some people react that way to local anesthetics but the numbness and tingling sensation would soon disappear and normal full sensitivity would be back. Steven apprehensively took his word, but after day five, the condition had not improved and Steven was in a panic and wanted another opinion.

Without knowledge of the total situation, my father was privileged only to “hear-say” and cautioned me that it could be a case of paresthesia, which is a potentially serious pitfall for which dentists hope never to encounter during the life of their practice. My dad did not want to be involved for obvious reasons. I was now on the horns of a dilemma. After-all Steven was my trusted friend and room mate.

Unexplained paresthesia:

Steven was now withdrawn and depressed. He had lost weight and his essays were suffering. Veronica accompanied him to the guidance counselor and a decision was made that he should see a neurologist. Paresthesia was in fact the diagnosis. This condition was explained to Steven and the prognosis was good because he had a simply and uncomplicated infiltration of the anesthetic and was not exposed to a full nerve block. There were still unanswered questions. Why would this occur? There was no truma to any neres.

Steven did his research and discovered that around this time a new local anesthetic called Septocaine had been approved by FDA for dental use in the U.S. Unlike most other anesthetic solutions which have a concentration of 2%, this new one was a 4% concentration. In other words, theoretically and pharmacologically speaking, all things being equal, or as the scientists would say, in vitro, one could use half the volume of the 4% solution to achieve what the 2% was capable of. Each one of us can have slight anatomical variations in the oral cavity, hence different responces.

For some unknown reason, dentists are in the habit of referring to volume (cartridges) used rather than by mg/ml. (actual mg given).As it turned out, Steven awoke now in its tenth day, to discover the paresthesia had been miraculously reversed and full sensitivity had returned to his tongue and soft tissue around his lip. No point of mentioning where he headed after he discovered there were no more pins and needles. All therapeutic compounds are accompanied with an index. The lesson to be learnt is that the product monographs included in any medication by FDA and are intended to be read. The term Minimal Effective Dose is alive and well. Following these instructions may avoid expensive and time consuming litigation.

Comments to author.  mailto:localanesthtics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.AnestheticsNews.com

 http://tinyurl.com/2bsqsz

References: Haas DA, Lennon D   J Can Dent Assoc. 1995  

Questions re dosage of local anesthetics is in our top 10 list. We therefore think it is appropriate to clear up what is meant by this important subject…relative and absolute maximum dose.  For lighter weight individuals, the relative maximum dose can be calculated by mg/kg. This can be less than the “absolute” maximum dose.  However for heavier weight individuals, the volume, i.e. mg/kg of the local anesthetic cannot exceed the absolute maximum for that particular local anesthetic. We at www.anestheticsnews.com  go into great detail in our lecturers especially when articaine is used in children . As usual your comments are valued. You may respond directly or mail us at localanesthetics@yahoo.ca  (M.Sc. Phm. CCPE) 

Current posts and anecdotal reports indicate an exponential rise of unexplained paresthesia in the dental community. This rise seems to have coincided with the introduction of the thiophene molecule articaine. Fortunately these episodes all seem to be reversible within 3 - 7 days.  Historically, a dentist will more often refer to the number of cartridges given to any one patient,as opposed to mg/kg. One should bear in mind that articaine is a 4% solution and contains approximately 70 mg in one cartridge compared to lodocaine which contains approximately 35 mg in one cartridge. As busy clinicians who are trained to diagnose and treat, the imposition of having to get into pharmacology is beyond your already hectic day. Let us at www.anestheticsnews.com  take the load off your shoulder. You can e-mail us at localanesthetics@yahoo.ca