Wilderness medicine

Hemlock poisoning

Kratom

Securing a difficult airway

15month old 8kg weighing with bil TM joint ankylosis with moth closed completely.
what options are available to securing airway electively

1. be quiet and always have another colleague next to you. 
2. have a skilled ENT pediatric surgeon aside and prepped 
3. pediatric difficult airway cart in and ready 
4. volatile induction and spontaneous breathing. 
5. mask ventilation (SEV) and secure an i.v. 
6. nasal topical anesthesia (a few drops of 2% esracaine would be ok). 
7. CRITICAL: when inserting the FOB do it through a dedicated face mask with a special FOB port. While one nostril is obstructed by the FOB, you can hand ventilate the child through the second. In fact it may be best to deepen the child this way w/o paralyzing. Keep the tip of the FOB above the vocal cords. Thus you can ventilate w/o obstructing the larynx. 
8. the ETT must fit both the FOB and the airway (sorry for writing this stupid point but it's like a check list. never let anything unchecked). Also: warmed in water and well lubricated. 
9. start advancing the ETT. Some gentle rotation left-right may help especially at the nose-nasopharynx curve. 
10. once the tip of the ETT is beyond the tip of the FOB (t.i. you see it) keep the ETT still, advance the FOB between the vocal cords, or gently advance them both.advance the ETT until you see it again. then retract the FOB while keeping the ETT in position. 
11. Well, you're almost done. Don't forget that the narrowest part of the airway is still below the vocal cords in this age group. 
12. Check double lung ventilation. 
13. Fixation, listen again. 
14. If you're happy proceed. If in doubt stop and reassess. You're elective! 
15. Have drugs ready in case of laryngo/bronchospasm. 
Good luck


Ketamine, fentanyl, and rocuronium for RSI

Awake video laryngoscope intubation of a patient with a displaced free flap reconstruction obstructing the glottis

Intubation and Extubation Guidelines from the Difficult Airway Society

Elective Cricothyrotomy

This Month in Anesthesia History: March

This Month in Anesthesia History: March

1712 March 8: English physician John Fothergill was born in Wensleydale, Yorkshire. Among many other accomplishments, this devout Quaker was the first to accurately describe migraines, and recognized that hardening of the arteries could cause chest pain. In 1744 he published an account of mouth-to-mouth resuscitation to revive the apparently dead. Fothergill was also the first to recognize the symptoms of diphtheria and maintained an extensive botanical garden near Stratford which contained plants from all over the world. He died in London on December 26, 1780. 

John Fothergill, M.D. as painted by Gilbert Stuart

1733 March 13: Joseph Priestley was born in England. Among numerous other achievements as a Unitarian minister, author, and chemist, Priestley isolated nitrous oxide in the 1770s. Because of his support of the French and American revolutions, Priestley's home and laboratory were burned in the Birmingham Riots of July, 1791. In 1794 Priestley sailed for America and settled in Pennsylvania. He died on February 6, 1804, and was buried in Riverview Cemetery in Northumberland. Two recent books about Priestley are Isabel Rivers and David L. Wykes, Joseph Priestley, Scientist, Philosopher, and Theologian [2008], and Steven Johnson, The Invention of Air [2008].

Joseph Priestley by Ellen Sharples, 1794

1750 March 20: Dutch chemist Martinus van Marum was born. From about 1790 to 1808 Van Marumwas an active member of the Society of Dutch Chemists which studied gases--including nitrous oxide--and published some 35 papers based on that research. He is best known for the electrostatic machines he built and the discovery of ozone produced by electrical sparks. Van Marum died inHaarlem on December 26, 1837. For more information, see Defalque RJ, Wright AJ. The Society of Dutch Chemists (1790-1808): It’s Contribution to Anesthesia. Anesthesiology 91(3A):A1157, 1999.

Martinus van Marum by Charles Howard Hodges

1753 March 26: Benjamin Thompson, Count Rumford, was born in Massachusetts. During his life Thompson was an inventor, spy, government official, diplomat, physicist and philanthropist. Over a number of years he studied and wrote about gunpowder. Thompson was the first to propose what turned out to be the correct idea, that heat is a form of motion, not an invisible liquid known in his day as "caloric." He invented a photometer, calorimeter, and a new oil lamp. During the Revolution he spied on Americans for the British and naturally moved to England after the war. He was eventually knighted and later made a count. In 1800 he helped found the famed Royal Institution in London and hired a young Humphry Davy to become a lecturer in chemistry there. In March 1801 Davy left Bristol, where he had been experimenting with nitrous oxide and other gases at Thomas Beddoes' Pneumatic Medical Institution. For a year or two after moving to London, Davy continued to demonstrate the effects of nitrous oxide inhalation at the Royal Institution. The great English satiric artist James Gillray portrayed such a demonstration in one of his most famous works; both Davy and Rumford are caricatured in the scene. Count Rumford died in 1814, aged 61. You can learn more about Rumford at http://www.rumford.com/Rumford.html

Benjamin Thompson, Count Rumford

1815 March 5: German physician Franz Mesmer died at Lake Constance in what is now Germany. Mesmer, who was born on May 23, 1734, received his medical degree from the University of Viennain 1766. Mesmer developed a therapy that he called "animal magnetism" that supposedly used the influence of heavenly bodies on health. His techniques of suggestion were later developed by James Braid (1795-1860) into what we know as hypnotism. Although "Mesmerism" was used for surgical pain relief, especially in England and among the British in India, prior to the introduction of anesthesia in the late 1840s, it also became widely associated with quackery.

Franz Mesmer

1842 March 30: On this date, Dr. Crawford W. Long--using sulphuric ether--gave the first anesthetic for a surgical procedure--the removal of a tumor on the neck of James Venable in Jefferson, Georgia. This event is the first known administration of a gas for surgical pain relief. Long did not publish an account until 1849. For most of the years since that first anesthetic, Crawford W. Long received little recognition for his accomplishment. In the past two decades some credit has at last been granted for Dr. Long's role in introducing this important innovation in medicine. Doctor's Day--March 30-- is one tangible and important symbol of the restoration of Dr. Long to his rightful place in history.

1845 March 12: Francis Rynd first introduced fluids into the body by subcutaneous injections using a hypodermic syringe.

1847 March: French physiologist Marie Jean Pierre Flourens [1794-1867] determined that inhalation of chloroform caused the same temporary state in animals as did ether. Flourens is best known for proving that the respiratory center is in the medulla and the function of the cerebellum in muscular coordination; he also studied bone formation. He was a professor at the Collège de France for many years. In November 1847 Scottish physician James Young Simpson demonstrated the anesthetic properties of chloroform in humans. 

1847 March 11: Less than six months after William Morton's demonstration of ether anesthesia inBoston, the first ether anesthetic was administered in Latin America. Dr. Vincente Antonio de Castro, a surgeon at the Hospital San Juan de Dios in Havana, Cuba, performs a successful bilateralhydrocele on the anesthetized patient.

1850 March 30: The first issue of Household Words appeared in England. This publication was the first of two weekly newspapers Charles Dickens would edit. The author used Household Words to call attention to a number of social ills, and his novel Hard Times was first serialized in its pages. The paper lasted until 1859. In 1851 an issue included Percival Leigh’s “Some Account of Chloroform” [3: 151-155]. The publication of this essay may have reflected Dickens’ concerns about amputation and other surgical procedures; characters with wooden legs appear in many of his novels.

1852 March 26: "On this day Dr. William Mallett of Fayetteville, North Carolina, performed one of the first Cesarean sections in the southern United States where the mother survived. In most instances, the mother generally died of shock as a result of the surgery. Dr. Mallett performed the operation on a 17-year-old woman without the use of anesthesia. The mother had refused the use of chloroform and ether for religious reasons. Her child did not survive." Dr. Mallett, born in 1819, died in 1889[Source: Powell WS, ed. Dictionary of North Carolina Biography; for more about religious objections to anesthesia, see Swanson GA. The Religious Objections and Military Opposition to Anesthetics, 1846-1848. Bulletin of Anesthesia History 23(2): 1, 4-5, 14, April 2005]

1898 March: At a meeting of the Society of Anaesthetists in England Alfred Coleman described his technique for nasal administration of nitrous oxide and Stephen A. Coxon advocated continuousinsufflation of pure nitrous oxide into the pharynx.

1909 March 24: John Millington Synge, Irish dramatist and poet [Riders to the Sea, etc.] died. He was born April 16, 1871. In 1916 a fascinating account of his experiences under ether anesthesia was published posthumously: "I seemed to traverse whole epochs of desolation and bliss. All secrets were open before me...." he wrote. [Under ether. Personal experiences during an operation.Interstate Medical Journal 23:45-49, 1916]. Synge's account is part of a large body of literature related to anesthesia and mystical experiences.

1930 March 23: Russian surgeon Sergei Yudin performed the first transfusion of cadaver blood into a human.

1934 March 8: In Wisconsin, Ralph M. Waters administered the first use of thiopental in man.

Ralph M. Waters, M.D.
[Source: http://page2anesthesiology.org/ ]

1937 March 15: First blood bank was established in Chicago, Illinois.

1939 March 5: British actress Samantha Eggar was born in London. One of her earliest prominent film roles was Miranda Grey in the 1965 version of John Fowles' novel The Collector. That 1963 novel tells the story of Frederick Clegg, a meek clerk and butterfly collector who decides to elevate his collecting and kidnaps beautiful art student Grey as she is walking home from class. Clegg uses a rag soaked in chloroform to subdue her. The film version also featured Terence Stamp as Clegg. Both novel and film have extended scenes of the criminal use of chloroform. [For more information on such real-life uses of chloroform, see Payne JP. The criminal use of chloroform. Anaesthesia.1998 Jul;53(7):685-90]

1942 March 2: American author John Irving was born in Exeter, New Hampshire. His novels include<The World According to Garp and The Hotel New Hampshire. His 1985 novel The Cider House Rules is set in a Maine orphanage presided over by the kindly ether-addict Dr. Larch.

1948 March 8: The Alabama State Society of Anesthesiologists was founded by Drs. Alice McNeal, Hiram Elliott, Alfred Habeeb and E. Bryce Robinson, Jr., in Birmingham. Dr. Robinson was elected President, Dr. William May of Montgomery, Vice-President, and Dr. McNeal Secretary-Treasurer. Dr. Robinson was appointed Delegate and Dr. May, Alternate. [ASA Newsletter 12(5):7, May 1948] “Dr. Hiram Elliott recalled how the little group gave birth to organized anesthesiology in the state. ‘We got together—the four of us, Dr. McNeal, Dr. Robinson, Dr. Habeeb and I—at Dr. Robinson’s house one night, and we organized the Jefferson County Society of Anesthesiologists,’ said Elliott. ‘At the same time, we decided we might as well organize the State Society of Anesthesiologists. So we organized both of them that same night.’” [Anita Smith, The Boss: Lloyd Noland, M.D., 1986, p. 260] The application for a charter by the state society was approved by the ASA on May 4, 1948. [ASA Newsletter 12(6):3, June 1948] Dr. McNeal was Chief of Anesthesia in the of Surgery, University of Alabama School of Medicine; the others were anesthesiologists in private practice. Dr. McNeal was the first female anesthesiologist to practice in Alabama. Dr. Habeeb completed the first anesthesia residency in Alabama, at the urging of Dr. Lloyd Noland at the TCI Hospital in Fairfield in the late 1930s. Dr. Habeeb was also the first ABA Diplomate in Alabama.

MOCA, or the Maintenance of board certification, and the innumerable steps and exorbitant money needed to maintain

Debate of Maintenance of Certification


MOCA has become a time and financial burden without any clear real benefit. While I do advocate for board certification, I am board certified, I do believe the number of steps needed to continually maintain board certification is unnecessary.
A new board has been formed that will allow physicians who are already board certified by their specialities board, to have their certification continue with a new board.
Here is the website: NATIONAL BOARD OF PHYSICIANS AND SURGEONS

Neuraxial Anesthesia for Labor and Delivery: Epidurals

Background:

In obstetrics an epidural is usually placed for labor and delivery. It is placed for pain control. Typically the epidural is placed during active labor, however an epidural can be placed prior to active labor if the patient is committed to labor. In some cases an epidural may be placed not for labor and delivery but for use during a cesarean section (c/s). The reason is that an epidural can be used for a prolonged c/s.

An epidural differs from a spinal due to the anatomic placement and the resultant effects. An epidural needs a larger volume of local anesthetic to be as effective as a spinal anesthetic. An epidural is typically administered via a catheter which allows the anesthesiologist to titrate the anesthetic slowly, which isn't the case typically in a spinal anesthetic, and also allows for a continuous infusion of local anesthetics which is comforting during a labor. 

The diagram above will serve to conceptualize the anatomy of the epidural procedure. To the left on the illustration is the skin. To place an epidural a needle transverses the skin, next the interspinous ligament (between the spinous processes which are the knobby projections in the middle of your back), then the ligamentum flavum, and finally the epidural space. We do not want to enter the dura, because for an epidural we are using a much larger needle than what we typically use for a spinal procedure, so that means if you puncture the dura with an epidural needle the chances of a spinal headache after the procedure are very high.

The Procedure:

Above is a typical epidural kit. When you request an epidural you obstetrician will page for the anesthesiologist or nurse anesthetist. The anesthesiologist will interview you and do a history and physical. Basically we are ensuring you are an appropriate candidate to receive an epidural. Our main concerns are to rule out an bleeding abnormalities, neurological or cardiac issues. We also want to make sure the delivery is running smoothly, although the obstetrician will alert us prior to us seeing you if there are any issues. We will look to see if there is any pertinent blood work drawn and we will also ask about the pregnancy. Verifying that there are no issues during your pregnancy or with past pregnancies or with past epidurals. The main risks associated with epidural placement are causing a post epidural by inadvertently going through the dura as described above. We also inspect the back to ensure no skin infections in the area that we will be placing the epidural. We typically place the epidural in the lumbar area. Typically below the L2 area, although this isn't as stringent as with a spinal since we will not be going intrathecally (below the dura, and potentially injuring the spinal cord). Risks of dosing the epidurally are typically hypotension, or lowering of the blood pressure and causing fetal decelerations. I dose my epidurals slowly and make sure that my patients have received adequate fluid boluses. This has been highly effective for me. Other less common risks include seizure, paralysis, and death. These risks are a lot less common.

After we obtain consent, we prepare to place the epidural. We sterilize your back with a prep solution.  After doing this we wash our hands and don sterile gloves and draw up the local anesthetic. I find the spot that I will be placing the epidural and put local anesthetic in that area.

I allow the local time to take effect. In the picture above is a blue hubbed needle, this is the needle I use to infiltrate the skin with local anesthetic. Next I use the needle that is in the picture that has the silver and black demarcation. This is what is termed a Tuohy needle. This is the needle that will be used to place the epidural catheter. I slowly advance the Tuohy needle through the skin, the interspinous ligament, the ligamentum flavum (there is a characteristic popping sensation).

Once I am in the interspinous ligament area, I pull the plastic stylet that is in the middle of the Tuohy needle and place the syringe in the picture above onto the back of my Tuohy needle. This is my loss of resistance syringe, it is filled with sterile saline. The loss of resistance syringe allows me to judge when I am in the epidural space, once I pass through the ligamentum flavum, there is a potential space prior to reaching the dura. This potential space causes a loss of resistance, this is felt and the anesthesiologists thumb sits on the plunger of the loss of resistance syringe. Once the loss of resistance is reached, beyond the ligamentum flavum, the plunger gives way and the anesthesiologist injects the sterile saline into the epidural space. This injection of saline into the epidural space is itself useful as it decreases the likelihood of placing your epidural catheter into an epidural vein. This procedure is all done on feel and landmarks. So, final knowledge of correct placement of the epidural only occurs once the patient begins to feel appropriately comfortable.

In the picture above to the left is the sterile saline that is used for the loss of resistance syringe. The vial in the middle is the local anesthetic that is used at the beginning of the procedure. And the vial to the right is the test dose. I will get to that in a short while. Once I have loss of resistance, I next begin to thread the epidural catheter into the epidural space. The epidural catheter is a long flexible tube that is about the thickness of a strand of spaghetti. Once the catheter is in, you may experience a shooting pain down one or both of your legs, this is typically transitory. I next dose the catheter with the test dose, the reddish vial on the right. This test dose helps confirm the epidural catheter is not in an epidural vein or in the spinal space. The anesthesiologist will typically ask if you feel any funny taste to your mouth or ringing to your ears after the test dose, this would mean the catheter is in a vein, and would need to be repositioned.  The neurologic side effects are from the lidocaine in the test dose going into a vein. There is also epinephrine in the test dose and is a second signal that the catheter is malpositioned. If the patients heart rate goes up after the test dose, this means the catheter is in a vein. The lidocaine is a test to see if the catheter is in the spinal space, if after the test dose the patient becomes extremely comfortable or can't move their legs, then that means the catheter is probably intrathecal (in the spinal space).

Post epidural care:

Once the epidural is in and the test dose is done, the next thing I do is check the baseline blood pressure and start to slowly bolus the epidural catheter with Bupivacaine, a local anesthetic. I will be frequently monitoring the patient and the blood pressure to ensure each is stable. Hypotension can occur and if it does it will happen usually within the first half hour after dosing an epidural. Once I have bolused the catheter and ensured the patient is stable I begin a continuous infusion of bupivacaine and sufentanil into the epidural catheter from an external epidural pump.

Neuraxial Anesthesia for Labor and Delivery: Spinals

Background:

Neuraxial anesthesia comes in two forms, spinal and epidural (can also have a combined spinal/epidural).  For labor and delivery you will most likely only have a spinal anesthetic if you are going to have a cesarean section. Of course there are exceptions to every rule and there is an exception to this rule as well. Some anesthesiologists will place a low dose spinal if you ask for an epidural for labor. 

Some anesthesiologists perform spinals when they place an epidural for labor in order to deliver quick pain relief. The reason I choose to not do this is because I like to know my labor epidural is working.  If I place a spinal anesthetic and then I thread in an epidural catheter, I won't be able to know if my epidural catheter is working, here is why. The spinal that I placed prior to threading the epidural will make the patient comfortable. I rely on dosing my epidural and then having a comfortable patient 15 minutes later to verify that I have a working epidural, if the patient is already comfortable from a spinal I have placed, I cannot dose my epidural and have verification of correct placement because the patient is already comfortable.

You may be wondering, what is the difference between an epidural and a spinal, or is there any difference? The difference is based on anatomy and location. An epidural is above the dura. Eli- meaning on top of, and dura meaning tough ligament. So an epidural is a space on top of the ligament. A spinal, also know as intrathecal, is below the dura, or below the ligament. The dura is a tough ligament thats main function is to hold the cerebrospinal fluid; similar to a balloon that holds water. The cerebrospinal fluid in the dura is used to protect the brain and the spinal cord. So an epidural is above the dura and a spinal is below the dura.

The Procedure:

Start by obtaining the consent from the patient, letting them know the risks and the benefits. The benefits are obvious, pain relief. There is belief that decreasing the amount of pain will decrease the catecholamine response, which in turn will increase uteroplacental perfusion. Most spinals in obstetrics are done for cesarean sections. However, like I stated previously, some anesthesiologists will used a combined spinal/epidural technique for labor and delivery. Back to the main point, spinals are done for cesarean sections (c/s) because numerous studies have confirmed a spinal or an epidural technique is safer than a general anesthetic for c/s. An epidural would be used in a c/s if a mother is laboring and during the course of labor is administered an epidural and subsequently is taken to the operating room (o/r) for a c/s. An epidural is sometimes used in patients who have had numerous previous c/s or are morbidly obese. The reason being, an epidural allows the anesthetist to length the neuraxial anesthetic because a catheter is left in place when you do an epidural and commonly is not for a spinal anesthetic. The side effects are multiple. The main ones being hypotension. The hypotension has a cascade effect and can lead to nausea/vomiting and fetal decelerations if not treated quickly. The less common side effects are high spinal, when the anesthetic is too high, it may be hard for the mother to breath or she may not be able to breath at all, in which case the spinal is switched to a general anesthetic and we breath for the mom. Seizures and death being the other rare side effects of a spinal anesthetic. Another fairly rare side effect is a spinal headache. Spinal headaches have almost been entirely eliminated. Through research on the issue, we have been able to substantially decrease the occurrence of post spinal headaches. What we have learned is to use smaller needles and a needle with a pencil point tip.

We also will perform a history and a physical exam. The basis of the history is to ensure you are appropriate candidate for a spinal anesthetic, there are no bleeding disorders, neurologic disorders, or any cardiac valve abnormalities that may make us reconsider using a spinal as our anesthetic. Parturients typically have lab results, I will look at these results to ensure they are normal. We will also ask about the course of your pregnancy to ensure no serious issues are surrounding the course of your pregnancy, such as pregnancy induced hypertension, cardiomyopathy of pregnancy, placenta accreta, etc.

Next the anesthesiologist will prepare the spinal tray, seen in the picture above. Also we begin to prep the mothers back to sterilize the skin surface as much as possible. 

Once the prep is done, the time out is done, the anesthesiologist has wash their hands and they are set up, they will begin the spinal procedure.

We start by infiltrating your skin with 1% lidocaine, which is in the bottle on the left. This allows us to advance larger needles later on in the procedure without causing as much discomfort. We allow the lidocaine to take effect and then we go onto the next part of the procedure. For a spinal anesthetic we typically use the L3-L4 interspace to decrease the risk of injecting our solution into the spinal cord. A

To get to the spinal space, the anesthesiologist needs to put the spinal needle through multiple layers, the skin, adipose layer below the skin, interspinous ligament, ligamentum flavum, the epidural space, and then the dura, and then into the cerebrospinal fluid. Confirmation that one has reached the spinal space is the presence of cerebrospinal fluid (CSF) in the spinal needle hub.

The spinal needle is in the above picture. The spinal needle in the above picture is the blue hubbed longer needle. When you reach the spinal space you will see CSF in the hub of the blue spinal needle.  The hub is the blue portion of the needle. There is a stylet that goes into the center of the needle. The stylet is a thinner needle that delivers more strength and integrity to the spinal needle and also prevents tissue from clogging the spinal needle as the spinal needle is advanced through skin, fat, and ligament. If there were tissue in the core of the spinal needle then one would not be able to confirm proper placement of the spinal needle in the CSF as the tissue would prevent CSF from traveling into the core of the spinal needle and into the hub.

Once CSF is seen in the hub of the spinal needle the local anesthetic that will be used is injected in the spinal needle. I typically use 0.75% bupivacaine with dextrose mixed with fentanyl and morphine. There are a number of mixtures that anesthesiologists use, it is similar to a recipe, each has its own merits. I use bupivacaine, a local anesthetic, for the pain relief, the loss of motor (so you cannot move your legs while the operation is in progress), and its lack of painful aftereffects. I mix the local anesthetic with fentanyl for its quick action and synergistic action with bupivacaine. I add morphine because it lasts for 24 hours, offering you pain control once the operation is over. However, adding narcotics is not without deleterious effects. Nausea, vomiting, pruritus are all potential side effects of adding narcotics to the spinal mix.

Post spinal anesthetic:

Like I have stated previously, I never use a spinal anesthestic for laboring patients. So, I will briefly touch on the experience of a c/s from the anesthetic standpoint, after administering a spinal. 

After a spinal, unless contraindicated, I will typically administer a vasopressor, which will maintain the blood pressure. I have had good success with this approach in decreasing the number of hypotensive patients, thereby decreasing the number of patients retching after the spinal.

When the baby is being delivered, you will feel them pushing, as they will be pushing in the substernal area. This is uncomfortable. Throughout the procedure, mothers report sometimes feeling uncomfortable about not being able to move their legs, or may feel queasy when the obstetricians are pulling at different layers when they are operating. Mothers report feeling touch throughout, but you should very little pain. Most mothers also have shivering that lasts through the procedure. This is more a nuisance than anything else.