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Stupid question, because I never understood this. Anesthetics seems like a mostly mechanical process with little room to deviate from the established procedures

by a_imho 6y ago

Stupid question, because I never understood this. Anesthetics seems like a mostly mechanical process with little room to deviate from the established procedures both for medical and legal reasons. What am I missing, what makes anesthesiologist that highly paid?

Peradine 6y ago
A common comparison is drawn to flying a plane - its a proceduralised and mechanical process for a lot of the time, but occasionally unexpected things happen and you need knowledge and skills to react quickly and prevent serious injury and death. Its like flying a plane but if every plane was built differently with no instruction manual, some of the planes are badly broken before you take off, and someone's trying to repair the engines in mid air. I'm currently revising for my anaesthetics exams. The things I'm meant to know include: * The physics and mechanical principles of all the equipment I use, from the ventilator to the pulse oximiter - so that I can identify when and how it might fail and how to respond * The pharmacokinetics, pharmacodynamics, and mechanism of all the drugs I might use - so I can understand their effects, side-effects, and interactions * The physiology and function of the human body, including the respiratory, circulatory, neurological, renal, gastrointestinal, musculoskeletal, and immune systems - so I can understand how anaesthesia effects these systems, and how diseases and disorders of the systems will interact with the anaesthetic and how problems can be identified and treated * The anatomy of the body, with particular focus on the head and neck anatomy to aide in intubation and airway procedures, and neuro-anatomy to aide in regional anaesthetic techniques * The anatomical, phsiological, and pharmacological consequences of pregnancy, childhood, old-age, and a huge variety of acute and chronic diseases - so I can understand and adapt anaesthetics to these conditions
rleigh 6y ago
You would have to read up on the science of anaesthesiology for a full understanding. I'll describe just a few of the subtleties I've encountered. About two decades back, I was a medical researcher who did all the vetinary qualifications for animal research including general anaesthesia, all the different types of analgesics and dissociatives, and I subsequently spent a few months working with mice and injectable liquid anaesthetics. You're playing a fine balance between keeping the animal under, and killing it. You have to continually observe and balance the degree of anaesthesia which you can test with pain reflexes and core reflexes, and adjust the dosage accordingly. Too much and you depress the core functions to the point breathing stops. Too little and the animal retains consciousness along with pain reflexes. With larger animals you can use similar equipment to what you would use with humans. Small ones require direct physical observation. There's a simple dosage rule: n ml anaesthetic per gram bodyweight. So you would weigh the mouse, calculate the dose and then inject it. Sounds easy enough. Not so. It also depends upon the percentage of fat tissue. If the mouse is fat, the fat tissue will absorb the anaesthetic and then slowly release it. This changes the dynamics of how fast the anaesthetic takes effect, and how deep and how long lasting the anaesthesia will be. Skinny mice would go under almost immediately. Fat mice might take 10 minutes. But if you topped up the dose, you would risk the dosage reaching fatal levels a few minutes down the line as the fat tissue released its stored anaesthetic. You would learn to adapt the formula by experience, but this is just one factor to consider. Now imagine how difficult this is with obese human patients. Or anorexic patients. Or sick patients. Patients on various drugs. Or patients with different metabolic rates. There are dozens of factors, making each case unique. Anaesthesiologists have a huge responsibility, and taking great care and skill to keep their patients alive. We think of this as routine, and it is, but that doesn't make it simple or easy to do. This stuff looks simple on paper. Doing it in practice is far, far more difficult and demanding.
- mnw21cam 6y ago
  There's also the difficulty that unexpected things happen, and the anaesthesiologist has to know how to keep a patient alive and well when they do. There are tricky genetic conditions such as malignant hyperthermia https://en.wikipedia.org/wiki/Malignant_hyperthermia https://en.wikipedia.org/wiki/Malignant_hyperthermia that can cause serious reactions to certain anaesthetics with no warning.
- a_imho 6y ago
  Thanks for the explanation, but I'm not sure whether I'm 100% convinced by the example. Monitoring multiple signals and reacting to them is what machines good at, in fact, a human in the control loop can be a liability for many industrial processes.
  - rscho 6y ago
    Anesthesia is not a problem for machines because of signal complexity. The problem lies in the everchanging environment and the practical aspects of the job. Things are not fixed enough for machines to perform well. Just as in surgery. For example, venous catheterization is a very difficult task for machines while it's pretty simple for humans.
  - Peradine 6y ago
    There's a role for a human-machine hybrid, and indeed there are also quite complicated control systems in work in anaesthesia. As an example, syringe pumps which perform pharmacokinetic calculations: you enter the patient's height, weight, sex, and age, then set a target plasma drug concentration and the pump uses complex pharmacokinetic models to determine how much drug to deliver to acheive that goal and maintain it. I can imagine more elegant systems coming in the future - ie a pump that can adjust drug delivery rates to maintain a given blood pressure. But the overall process of safely delivering an anaesthetic, from pre-operative assessment to post-operative recovery and discharge, is far beyond automating at the moment.
  - rleigh 6y ago
    The problem is the unpredictability and the nature of the feedback. Living creatures are not industrial processes. Each one is unique and will behave differently. So while you can draw some generalisations, you can't safely put a machine in ultimate control, or even in a position to provide unreliable feedback. Even industrial processes aren't usually automated in their entirety and usually have 24/7 oversight; "simple" PID loops can misbehave, and this is far more complex with many more variables. The consequences here are death at one extreme and extreme suffering at the other, and so the stakes are too high to delegate it to a machine. This isn't some theoretical problem--a life is literally on the line and machines can not hold responsibility for a life. Also note that answering the questions of "is the animal conscious", "is the animal in respiratory distress", "is the animal in pain", "are the core reflexes functioning" or "have the core reflexes stopped functioning" all require complex assessment, which a machine can't do. And if any of those are true or false, the complex dynamics make the decision of giving more or less anaesthetic dose a very complex question to answer. If anything goes wrong, it requires intelligent and informed decisions to be made. In some circumstances that includes killing with an overdose for ethical and legal reasons. It would be unethical and cruel to let a machine make decisions of such consequence. Having another life in your hands is a huge burden. It's both humbling and scary to be given such power and responsibility over another living being, and having done it I'd have to say I find the notion of giving a machine control or even moderate influence over the process grossly irresponsible. Automating every last aspect of our existence is a horrifying concept. Some things need humans in absolute control, and this is one of them. And I say this as someone who eventually became an software engineer for embedded medical diagnostic devices. Think about the ethics of what you are suggesting.
rscho 6y ago
In many countries, if you're from any other specialty and you've got any kind of complication that puts the patient at immediate serious risk, you'll call anesthesia to handle it. Surgery, resuscitation, airway problem, paediatrics, obstetrics, you name it... there will be an anesthesiologist around for your own protection (not only to put you under). That should give you an idea of the breadth of anesthesia.

by a_imho 6y ago

Peradine 6y ago

A common comparison is drawn to flying a plane - its a proceduralised and mechanical process for a lot of the time, but occasionally unexpected things happen and you need knowledge and skills to react quickly and prevent serious injury and death. Its like flying a plane but if every plane was built differently with no instruction manual, some of the planes are badly broken before you take off, and someone's trying to repair the engines in mid air. I'm currently revising for my anaesthetics exams. The things I'm meant to know include: * The physics and mechanical principles of all the equipment I use, from the ventilator to the pulse oximiter - so that I can identify when and how it might fail and how to respond * The pharmacokinetics, pharmacodynamics, and mechanism of all the drugs I might use - so I can understand their effects, side-effects, and interactions * The physiology and function of the human body, including the respiratory, circulatory, neurological, renal, gastrointestinal, musculoskeletal, and immune systems - so I can understand how anaesthesia effects these systems, and how diseases and disorders of the systems will interact with the anaesthetic and how problems can be identified and treated * The anatomy of the body, with particular focus on the head and neck anatomy to aide in intubation and airway procedures, and neuro-anatomy to aide in regional anaesthetic techniques * The anatomical, phsiological, and pharmacological consequences of pregnancy, childhood, old-age, and a huge variety of acute and chronic diseases - so I can understand and adapt anaesthetics to these conditions

rleigh 6y ago

You would have to read up on the science of anaesthesiology for a full understanding. I'll describe just a few of the subtleties I've encountered. About two decades back, I was a medical researcher who did all the vetinary qualifications for animal research including general anaesthesia, all the different types of analgesics and dissociatives, and I subsequently spent a few months working with mice and injectable liquid anaesthetics. You're playing a fine balance between keeping the animal under, and killing it. You have to continually observe and balance the degree of anaesthesia which you can test with pain reflexes and core reflexes, and adjust the dosage accordingly. Too much and you depress the core functions to the point breathing stops. Too little and the animal retains consciousness along with pain reflexes. With larger animals you can use similar equipment to what you would use with humans. Small ones require direct physical observation. There's a simple dosage rule: n ml anaesthetic per gram bodyweight. So you would weigh the mouse, calculate the dose and then inject it. Sounds easy enough. Not so. It also depends upon the percentage of fat tissue. If the mouse is fat, the fat tissue will absorb the anaesthetic and then slowly release it. This changes the dynamics of how fast the anaesthetic takes effect, and how deep and how long lasting the anaesthesia will be. Skinny mice would go under almost immediately. Fat mice might take 10 minutes. But if you topped up the dose, you would risk the dosage reaching fatal levels a few minutes down the line as the fat tissue released its stored anaesthetic. You would learn to adapt the formula by experience, but this is just one factor to consider. Now imagine how difficult this is with obese human patients. Or anorexic patients. Or sick patients. Patients on various drugs. Or patients with different metabolic rates. There are dozens of factors, making each case unique. Anaesthesiologists have a huge responsibility, and taking great care and skill to keep their patients alive. We think of this as routine, and it is, but that doesn't make it simple or easy to do. This stuff looks simple on paper. Doing it in practice is far, far more difficult and demanding.

mnw21cam 6y ago
There's also the difficulty that unexpected things happen, and the anaesthesiologist has to know how to keep a patient alive and well when they do. There are tricky genetic conditions such as malignant hyperthermia https://en.wikipedia.org/wiki/Malignant_hyperthermia https://en.wikipedia.org/wiki/Malignant_hyperthermia that can cause serious reactions to certain anaesthetics with no warning.
a_imho 6y ago
Thanks for the explanation, but I'm not sure whether I'm 100% convinced by the example. Monitoring multiple signals and reacting to them is what machines good at, in fact, a human in the control loop can be a liability for many industrial processes.
- rscho 6y ago
  Anesthesia is not a problem for machines because of signal complexity. The problem lies in the everchanging environment and the practical aspects of the job. Things are not fixed enough for machines to perform well. Just as in surgery. For example, venous catheterization is a very difficult task for machines while it's pretty simple for humans.
- Peradine 6y ago
  There's a role for a human-machine hybrid, and indeed there are also quite complicated control systems in work in anaesthesia. As an example, syringe pumps which perform pharmacokinetic calculations: you enter the patient's height, weight, sex, and age, then set a target plasma drug concentration and the pump uses complex pharmacokinetic models to determine how much drug to deliver to acheive that goal and maintain it. I can imagine more elegant systems coming in the future - ie a pump that can adjust drug delivery rates to maintain a given blood pressure. But the overall process of safely delivering an anaesthetic, from pre-operative assessment to post-operative recovery and discharge, is far beyond automating at the moment.
- rleigh 6y ago
  The problem is the unpredictability and the nature of the feedback. Living creatures are not industrial processes. Each one is unique and will behave differently. So while you can draw some generalisations, you can't safely put a machine in ultimate control, or even in a position to provide unreliable feedback. Even industrial processes aren't usually automated in their entirety and usually have 24/7 oversight; "simple" PID loops can misbehave, and this is far more complex with many more variables. The consequences here are death at one extreme and extreme suffering at the other, and so the stakes are too high to delegate it to a machine. This isn't some theoretical problem--a life is literally on the line and machines can not hold responsibility for a life. Also note that answering the questions of "is the animal conscious", "is the animal in respiratory distress", "is the animal in pain", "are the core reflexes functioning" or "have the core reflexes stopped functioning" all require complex assessment, which a machine can't do. And if any of those are true or false, the complex dynamics make the decision of giving more or less anaesthetic dose a very complex question to answer. If anything goes wrong, it requires intelligent and informed decisions to be made. In some circumstances that includes killing with an overdose for ethical and legal reasons. It would be unethical and cruel to let a machine make decisions of such consequence. Having another life in your hands is a huge burden. It's both humbling and scary to be given such power and responsibility over another living being, and having done it I'd have to say I find the notion of giving a machine control or even moderate influence over the process grossly irresponsible. Automating every last aspect of our existence is a horrifying concept. Some things need humans in absolute control, and this is one of them. And I say this as someone who eventually became an software engineer for embedded medical diagnostic devices. Think about the ethics of what you are suggesting.

rscho 6y ago

In many countries, if you're from any other specialty and you've got any kind of complication that puts the patient at immediate serious risk, you'll call anesthesia to handle it. Surgery, resuscitation, airway problem, paediatrics, obstetrics, you name it... there will be an anesthesiologist around for your own protection (not only to put you under). That should give you an idea of the breadth of anesthesia.