Acromegaly_Chad
Offical Surgery Consultant
- Joined
- Apr 16, 2020
- Posts
- 2,128
- Reputation
- 5,438
TLDR: See at the bottom
This thread is an absolute premiere in the PSL sphere because nobody has ever done anything like this before. This is the first complete guide on why blood pressure in anesthesia is so important and why it can destroy YOUR brain. Anesthesia is often mentioned in the connection with postoperative cognitive dysfunction and memory loss. However, a deeper look into the subject reveals that there is A LOT that can be done to reduce these effects. From my understanding, the 2 most important factors with regard to anesthesia that are often being overlooked are blood pressure and the use of opioids.
As some of you know I've recently been on the brink of collapsing as a result of badly performed anesthesia. I feared that I got permanent brain and cardiac damage from oxygen deficiency and even worse. Probably nothing happened, but I'm still in shock and am not sure if I will ever recover psychologically from it. Therefore, let's dive right into the matter: Why you need to watch out when you're getting maxillofacial surgery: risks, that nobody talks about.
Hypotensive anesthesia is considered a suitable anesthetic technique for patients undergoing [...] major maxillofacial operations (Barak et al., 2015). All the maxillofacial surgeries that are being discussed on Looksmax (Lefort 1-3, BSSO, Genioplasty, Chin Wing, wisdom teeth extraction, jaw implants, orbital box osteotomy and more) are being performed under hypotensive anesthesia. Surgical procedures on the head and neck have a propensity to bleed profoundly because the region's blood supply is rich (Barak et al., 2015).
Reducing blood pressure and thus perfusion of the tissue around the surgical area results in (1) less blood loss (2) improved view of the surgical field and (3) allogeneic blood transfusion becoming redundant.
However, Barak et al. (2015) note that the use of hypotensive anesthesia is associated with the risk of reduced perfusion to important organs and tissues, mainly the brain, heart, and kidneys. The majority of studies, with the exception of a few outliers, demonstrate that hypotension during a variety of noncardiac surgeries is associated with various unfavorable outcomes, including increased mortality, longer hospitalization, all-cause morbidity, acute kidney injury, myocardial injury, postoperative congestive heart failure, stroke, postoperative cognitive decline, postoperative delirium, poor liver and kidney graft function, and postesophagectomy anastomotic leakage (Meng et al., 2018).
In hypotensive anesthesia, the patient's baseline means arterial pressure (MAP) is reduced by 30% (Barak et al., 2015). Consequently, the systolic blood pressure values are about 80–90 mm Hg and the MAP (Mean arterial pressure) is reduced to 50–65 mm Hg.
MAP is calculated as [Systolic Blood Pressure + 2(Diastolic Blood Pressure)]/3
MAP is an important measure for the blood flow to your organs and therefore a crucial aspect of safe hypotensive anesthesia.
But what we have learned so far is that (1) maxillofacial surgery requires hypotensive anesthesia and (2) that in turn is associated with several serious risks.
So far, my research has resulted in 2 different strategies to deal with this issue:
1) Get minimally invasive maxillofacial surgery or have a surgeon willing to perform surgery with normotensive (normal blood pressure) anesthesia on you. The less invasive the surgery i.e. the less tissue is being cut and scars produced, the less bleeding will occur and consequently the higher the threshold for tolerable blood pressure. I'm in contact with Dr. Alfaros clinic to get a view into their anesthesia protocols because maybe the minimally invasive approach allows for higher blood pressure and all the advantages accompanied by it (faster recovery, no memory loss, no delirium).
2) IF you are about to get hypotensive anesthesia, consider the following:
The abscissa (horizontal line) shows MAP blood pressure while the ordinate shows blood flow to the brain. The grey area represents the range of MAP that is within the cerebral autoregulation, meaning where the brain can regulate blood supply nearly independently from blood pressure.
- MAP must not be lower than 50 mm Hg during surgery, ideally, it must not be lower than 60 mm Hg. Feel free to talk to your anesthesiologist about this very openly and directly, because there are many retarded anesthesiologists out there who go to the limit and go as low as 50 mm Hg when the incompetent maxfac tells them to do so. You will eventually notice that at the very latest when you awake after surgery as a retard.
If this is still not possible, consider the following: a person with an arterial partial pressure of carbon dioxide (PaCO2) of 40 mmHg (normal range of 38–42 mmHg) and a Cerebral Blood Flow (CBF) of 50 ml per 100g per min. If the PaCO2 dips to 30 mmHg, this represents a 10 mmHg decrease from the initial value of PaCO2. Consequently, the CBF decreases by 1ml per 100g per min for each 1mmHg decrease in PaCO2, resulting in a new CBF of 40ml per 100g of brain tissue per minute.
- Lower levels of PaCO2 are associated with increased tolerance for hypotensive blood pressure (pushing the 50 mm Hg barrier) and vice versa. So tell your anesthesiologist to make the fuck sure to get the PaCO2 levels as low as possible if hypotensive blood pressure is indeed required. Anesthesiologists are (in my opinion) not sensitized enough to the importance of this. Many are willing to accept cognitive decline in their patients just for the sake of a more comfortable/standardized anesthesia.
Furthermore, the MAP baseline may vary from person to person. Define your baseline by accurately measuring your blood pressure several times before surgery and on the day of surgery. If you are a hypertensive person (high blood pressure) the grey area in the graph above shifts to the left or the orange line to the right. You may get brain damage at as high as MAP 60 mm Hg. Tell your anesthesiologist your blood pressure levels therefore in advance so that he knows.
Concerning opioids:
In anesthesia, the use of painkillers such as opioids is of crucial importance to manage perioperative pain and reduce the amount of propofol to keep you asleep (good pain management allows to reduce propofol doses to as low as 4mg/kg/h while bad management can require doses as high as 12mg/kg/h). However, the use of opioids can cause fatigue, breath depression and apnea, as well as prolonged brain fog and synaptic inflammation.
The gold standard for pain management in maxillofacial surgery anesthesia is a multimodal analgesia approach (paracetamol, nonsteroidal antiinflammatory drugs, corticosteroids, lidocaine and other long-acting local anesthetics, ketamine, magnesium sulfate and dexmedetomidine, among others) as well as ultrasound-guided bilateral suprazygomatic maxillary nerve block with ropivacaine. With regards to multimodal analgesia Alfaro et al. (2022) note that "Our recommendation in orthognathic surgery therefore is to administer multimodal analgesia with non-opioid agents such as N-methyl-d-aspartate antagonists, local anesthetics and alpha-2-agonists, together with low-opioid anesthesia and monitoring of nociception. These additive and/or synergic combinations of analgesics and anesthetics are effective and safe in improving the postoperative outcomes of patients subjected to orthognathic surgery globally."
What does this mean for you? Again, ask your clinic which painkillers they use, and decide based on that for/against the clinic. They play a crucial role in the post-surgical process and how well you recover.
At the end of the day, considering these guidelines on blood pressure and opioids will allow you to have much more surgery with fewer side effects.
TLDR
The ideal for anesthesia in maxillofacial surgery
- Short surgery time
- normotensive (normal blood pressure)
- no hypotension (no MAP blood pressure below 65 mm Hg)
- minimally invasive approach to minimize bleeding and avoid allogeneic blood transfusion
- IF you have to get hypotensive anesthesia, consider:
- very low levels of PaCO2
- your baseline blood pressure
- Multimodal analgesia approach is superior to the use of opioids as painkillers
Sources:
Barak, M., Yoav, L., & Abu el-Naaj, I. (2015). Hypotensive anesthesia versus normotensive anesthesia during major maxillofacial surgery: a review of the literature. TheScientificWorldJournal, 2015, 480728. https://doi.org/10.1155/2015/480728
Meng, L., Yu, W., Wang, T., Zhang, L., Heerdt, P. M., & Gelb, A. W. (2018). Blood Pressure Targets in Perioperative Care. Hypertension (Dallas, Tex. : 1979), 72(4), 806–817. https://doi.org/10.1161/HYPERTENSIONAHA.118.11688
Molins-Ballabriga, G., Hernández-Alfaro, F., Giralt-Hernando, M., & Valls-Ontañón, A. (2022). Multimodal analgesia in orthognathic surgery. Journal Of Oral And Maxillofacial Anesthesia, 1. doi:10.21037/joma-22-1
Tagging some surgery niggas:
@RealSurgerymax @Sergio-OMS
This thread is an absolute premiere in the PSL sphere because nobody has ever done anything like this before. This is the first complete guide on why blood pressure in anesthesia is so important and why it can destroy YOUR brain. Anesthesia is often mentioned in the connection with postoperative cognitive dysfunction and memory loss. However, a deeper look into the subject reveals that there is A LOT that can be done to reduce these effects. From my understanding, the 2 most important factors with regard to anesthesia that are often being overlooked are blood pressure and the use of opioids.
As some of you know I've recently been on the brink of collapsing as a result of badly performed anesthesia. I feared that I got permanent brain and cardiac damage from oxygen deficiency and even worse. Probably nothing happened, but I'm still in shock and am not sure if I will ever recover psychologically from it. Therefore, let's dive right into the matter: Why you need to watch out when you're getting maxillofacial surgery: risks, that nobody talks about.
Hypotensive anesthesia is considered a suitable anesthetic technique for patients undergoing [...] major maxillofacial operations (Barak et al., 2015). All the maxillofacial surgeries that are being discussed on Looksmax (Lefort 1-3, BSSO, Genioplasty, Chin Wing, wisdom teeth extraction, jaw implants, orbital box osteotomy and more) are being performed under hypotensive anesthesia. Surgical procedures on the head and neck have a propensity to bleed profoundly because the region's blood supply is rich (Barak et al., 2015).
Reducing blood pressure and thus perfusion of the tissue around the surgical area results in (1) less blood loss (2) improved view of the surgical field and (3) allogeneic blood transfusion becoming redundant.
However, Barak et al. (2015) note that the use of hypotensive anesthesia is associated with the risk of reduced perfusion to important organs and tissues, mainly the brain, heart, and kidneys. The majority of studies, with the exception of a few outliers, demonstrate that hypotension during a variety of noncardiac surgeries is associated with various unfavorable outcomes, including increased mortality, longer hospitalization, all-cause morbidity, acute kidney injury, myocardial injury, postoperative congestive heart failure, stroke, postoperative cognitive decline, postoperative delirium, poor liver and kidney graft function, and postesophagectomy anastomotic leakage (Meng et al., 2018).
In hypotensive anesthesia, the patient's baseline means arterial pressure (MAP) is reduced by 30% (Barak et al., 2015). Consequently, the systolic blood pressure values are about 80–90 mm Hg and the MAP (Mean arterial pressure) is reduced to 50–65 mm Hg.
MAP is calculated as [Systolic Blood Pressure + 2(Diastolic Blood Pressure)]/3
MAP is an important measure for the blood flow to your organs and therefore a crucial aspect of safe hypotensive anesthesia.
But what we have learned so far is that (1) maxillofacial surgery requires hypotensive anesthesia and (2) that in turn is associated with several serious risks.
So far, my research has resulted in 2 different strategies to deal with this issue:
1) Get minimally invasive maxillofacial surgery or have a surgeon willing to perform surgery with normotensive (normal blood pressure) anesthesia on you. The less invasive the surgery i.e. the less tissue is being cut and scars produced, the less bleeding will occur and consequently the higher the threshold for tolerable blood pressure. I'm in contact with Dr. Alfaros clinic to get a view into their anesthesia protocols because maybe the minimally invasive approach allows for higher blood pressure and all the advantages accompanied by it (faster recovery, no memory loss, no delirium).
2) IF you are about to get hypotensive anesthesia, consider the following:
The abscissa (horizontal line) shows MAP blood pressure while the ordinate shows blood flow to the brain. The grey area represents the range of MAP that is within the cerebral autoregulation, meaning where the brain can regulate blood supply nearly independently from blood pressure.
- MAP must not be lower than 50 mm Hg during surgery, ideally, it must not be lower than 60 mm Hg. Feel free to talk to your anesthesiologist about this very openly and directly, because there are many retarded anesthesiologists out there who go to the limit and go as low as 50 mm Hg when the incompetent maxfac tells them to do so. You will eventually notice that at the very latest when you awake after surgery as a retard.
If this is still not possible, consider the following: a person with an arterial partial pressure of carbon dioxide (PaCO2) of 40 mmHg (normal range of 38–42 mmHg) and a Cerebral Blood Flow (CBF) of 50 ml per 100g per min. If the PaCO2 dips to 30 mmHg, this represents a 10 mmHg decrease from the initial value of PaCO2. Consequently, the CBF decreases by 1ml per 100g per min for each 1mmHg decrease in PaCO2, resulting in a new CBF of 40ml per 100g of brain tissue per minute.
- Lower levels of PaCO2 are associated with increased tolerance for hypotensive blood pressure (pushing the 50 mm Hg barrier) and vice versa. So tell your anesthesiologist to make the fuck sure to get the PaCO2 levels as low as possible if hypotensive blood pressure is indeed required. Anesthesiologists are (in my opinion) not sensitized enough to the importance of this. Many are willing to accept cognitive decline in their patients just for the sake of a more comfortable/standardized anesthesia.
Furthermore, the MAP baseline may vary from person to person. Define your baseline by accurately measuring your blood pressure several times before surgery and on the day of surgery. If you are a hypertensive person (high blood pressure) the grey area in the graph above shifts to the left or the orange line to the right. You may get brain damage at as high as MAP 60 mm Hg. Tell your anesthesiologist your blood pressure levels therefore in advance so that he knows.
Concerning opioids:
In anesthesia, the use of painkillers such as opioids is of crucial importance to manage perioperative pain and reduce the amount of propofol to keep you asleep (good pain management allows to reduce propofol doses to as low as 4mg/kg/h while bad management can require doses as high as 12mg/kg/h). However, the use of opioids can cause fatigue, breath depression and apnea, as well as prolonged brain fog and synaptic inflammation.
The gold standard for pain management in maxillofacial surgery anesthesia is a multimodal analgesia approach (paracetamol, nonsteroidal antiinflammatory drugs, corticosteroids, lidocaine and other long-acting local anesthetics, ketamine, magnesium sulfate and dexmedetomidine, among others) as well as ultrasound-guided bilateral suprazygomatic maxillary nerve block with ropivacaine. With regards to multimodal analgesia Alfaro et al. (2022) note that "Our recommendation in orthognathic surgery therefore is to administer multimodal analgesia with non-opioid agents such as N-methyl-d-aspartate antagonists, local anesthetics and alpha-2-agonists, together with low-opioid anesthesia and monitoring of nociception. These additive and/or synergic combinations of analgesics and anesthetics are effective and safe in improving the postoperative outcomes of patients subjected to orthognathic surgery globally."
What does this mean for you? Again, ask your clinic which painkillers they use, and decide based on that for/against the clinic. They play a crucial role in the post-surgical process and how well you recover.
At the end of the day, considering these guidelines on blood pressure and opioids will allow you to have much more surgery with fewer side effects.
TLDR
The ideal for anesthesia in maxillofacial surgery
- Short surgery time
- normotensive (normal blood pressure)
- no hypotension (no MAP blood pressure below 65 mm Hg)
- minimally invasive approach to minimize bleeding and avoid allogeneic blood transfusion
- IF you have to get hypotensive anesthesia, consider:
- very low levels of PaCO2
- your baseline blood pressure
- Multimodal analgesia approach is superior to the use of opioids as painkillers
Sources:
Barak, M., Yoav, L., & Abu el-Naaj, I. (2015). Hypotensive anesthesia versus normotensive anesthesia during major maxillofacial surgery: a review of the literature. TheScientificWorldJournal, 2015, 480728. https://doi.org/10.1155/2015/480728
Meng, L., Yu, W., Wang, T., Zhang, L., Heerdt, P. M., & Gelb, A. W. (2018). Blood Pressure Targets in Perioperative Care. Hypertension (Dallas, Tex. : 1979), 72(4), 806–817. https://doi.org/10.1161/HYPERTENSIONAHA.118.11688
Molins-Ballabriga, G., Hernández-Alfaro, F., Giralt-Hernando, M., & Valls-Ontañón, A. (2022). Multimodal analgesia in orthognathic surgery. Journal Of Oral And Maxillofacial Anesthesia, 1. doi:10.21037/joma-22-1
Tagging some surgery niggas:
@RealSurgerymax @Sergio-OMS
Last edited:
