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[psycho-matic]

---

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Let me preface this post by saying that I am a RN and anaspiring anesthesiologist. I am not supportive of independent CRNA practice –it is not in the best interest of the patient.

I frequently read this board but rarely post. My experiencetoday gave me some food for thought and I wanted to share.

I had a lap chole and hiatal hernia repair today. It is thefirst surgery I’ve had as an adult. It was at the outpatient surgery centerattached to the hospital where I work. I was concerned about the level ofanesthesiologist oversight of the CRNA’s at the surgi center. Theanesthesiologist himself came in to do the preop eval. He took 10 min or moreexplaining everything that would happen during the intraoperative period. Becauseof this, I knew what to expect and was really put at ease. He took the time toanswer all of my questions and address my concerns. Admittedly, my questionsprobably aren’t what the typical patientasks..i.e. LMA vs ETT, choice of induction agent (I still get sick if I thinkabout the smell of the gas induction agent used on me during 4thgrade, and I want to make sure I get an IV agent.) I asked him if he would besupervising the CRNA and if he would be there during emergence and induction.He assured me he would be, as well as checking in the room frequently. Theanesthetic did such a good job that I have no memory of emergence (I was afraidof waking up with a tube in my mouth). Nor do I remember the propofol beinginjected – something else I was afraid of as I know it can burn. He told me hewould mix it with lidocaine.

I share all of this because I believe that the patient’sperception of the role of the anesthesiologist is important. I feel the levelof understanding he demonstrated in explaining the procedure and the way inwhich he addressed my concerns set him apart from the CRNA’s. I was really putat ease that a physician would be the one supervising my care. He appeared notonly competent and knowledgeable but demonstrated caring and compassion aswell. I hope that in other facilites the MD is filling this important role andnot allowing the CRNA to do it.

I would also like to ad that I work on a surgicalintermediate care unit of an 800+bed tertiary hospital. We take care of some verysick patients on my floor. Probably half of my patients have an epidural or PCAfor post-op pain management. The anesthesiologists maintain a very strongpresence on my floor as they manage most of the pain pumps. Everyone knows therole they play and it sets them apart from the CRNA’s. They are in-house 24/7and always available for an emergency – and this is not a teaching hospital.The surgeon personalities are hit or miss but the anesthesiologists are alwaysvery professional and polite to work with. They work hard but have very chilland have laid-back personalities. It seems like a wonderful profession.

I would like to ask a question for my own knowledge. I’m ahealthy 29 year-old ASA 1 patient. The procedure was only about an hour long.What is the attending’s rationale for selecting an ETT instead of a LMA? Thanks.

 

[gasattack3]

Let me preface this post by saying that I am a RN and anaspiring anesthesiologist. I am not supportive of independent CRNA practice –it is not in the best interest of the patient.

I frequently read this board but rarely post. My experiencetoday gave me some food for thought and I wanted to share.

I had a lap chole and hiatal hernia repair today. It is thefirst surgery I've had as an adult. It was at the outpatient surgery centerattached to the hospital where I work. I was concerned about the level ofanesthesiologist oversight of the CRNA's at the surgi center. Theanesthesiologist himself came in to do the preop eval. He took 10 min or moreexplaining everything that would happen during the intraoperative period. Becauseof this, I knew what to expect and was really put at ease. He took the time toanswer all of my questions and address my concerns. Admittedly, my questionsprobably aren't what the typical patientasks..i.e. LMA vs ETT, choice of induction agent (I still get sick if I thinkabout the smell of the gas induction agent used on me during 4thgrade, and I want to make sure I get an IV agent.) I asked him if he would besupervising the CRNA and if he would be there during emergence and induction.He assured me he would be, as well as checking in the room frequently. Theanesthetic did such a good job that I have no memory of emergence (I was afraidof waking up with a tube in my mouth). Nor do I remember the propofol beinginjected – something else I was afraid of as I know it can burn. He told me hewould mix it with lidocaine.

I share all of this because I believe that the patient'sperception of the role of the anesthesiologist is important. I feel the levelof understanding he demonstrated in explaining the procedure and the way inwhich he addressed my concerns set him apart from the CRNA's. I was really putat ease that a physician would be the one supervising my care. He appeared notonly competent and knowledgeable but demonstrated caring and compassion aswell. I hope that in other facilites the MD is filling this important role andnot allowing the CRNA to do it.

I would also like to ad that I work on a surgicalintermediate care unit of an 800+bed tertiary hospital. We take care of some verysick patients on my floor. Probably half of my patients have an epidural or PCAfor post-op pain management. The anesthesiologists maintain a very strongpresence on my floor as they manage most of the pain pumps. Everyone knows therole they play and it sets them apart from the CRNA's. They are in-house 24/7and always available for an emergency – and this is not a teaching hospital.The surgeon personalities are hit or miss but the anesthesiologists are alwaysvery professional and polite to work with. They work hard but have very chilland have laid-back personalities. It seems like a wonderful profession.

I would like to ask a question for my own knowledge. I'm ahealthy 29 year-old ASA 1 patient. The procedure was only about an hour long.What is the attending's rationale for selecting an ETT instead of a LMA? Thanks.

Spontaneous ventilation under laparoscopic surgery is difficult. With an LMA, you'd be expected to be breathing on your own, generating your own tidal volumes. With insufflation pressures (as well as a hiatal hernia fix which would compress and irritate the diaphragm) making manual ventilation very difficult and even dangerous if you were to cough or "buck" during the procedure. Use of a paralytic (required in your case) means an ETT as well. So, multiple reasons for using an ETT versus an LMA.

I'm sure you'll get at least a few case studies comparing LMA versus ETT for laparoscopic surgical procedures, but the majority of anesthesiologists in practice would do the ETT for sure. I bet someone could also quote a 5 patient study in China where they used accupunture for such a thing, but the reality is GA with ETT and keeping some paralytic on board throughout most of the case.

 

[psycho-matic]

Spontaneous ventilation under laparoscopic surgery is difficult. With an LMA, you'd be expected to be breathing on your own, generating your own tidal volumes. With insufflation pressures (as well as a hiatal hernia fix which would compress and irritate the diaphragm) making manual ventilation very difficult and even dangerous if you were to cough or "buck" during the procedure. Use of a paralytic (required in your case) means an ETT as well. So, multiple reasons for using an ETT versus an LMA.

I'm sure you'll get at least a few case studies comparing LMA versus ETT for laparoscopic surgical procedures, but the majority of anesthesiologists in practice would do the ETT for sure. I bet someone could also quote a 5 patient study in China where they used accupunture for such a thing, but the reality is GA with ETT and keeping some paralytic on board throughout most of the case.

Thank you for the explanation Gasattack.

 

[Dejavu]

Thank you for the explanation Gasattack.

And thank you for taking the time to send your kind words about MD anesthesiology.

We all aspire to be the guy who you had as your anesthesiologist. I just hope we reach that goal as often as possible.

 

[dhb]

With an LMA, you'd be expected to be breathing on your own, generating your own tidal volumes.

Not true you can use an LMA for PPV and some actually fancy using them for laparoscopic procedures.

To OP glad you had a positive experience.

 

[europeman]

I'm a surgeon....

Here in USA the standard of care is ett for lap chole.

In many European countries however, many of the anesthesiologists routinely use LMA instead. How they get away with it is beyond me.

 

[dhb]

How they get away with it is beyond me.

Easy:

I'm a surgeon....

😉

 

[WholeLottaGame7]

I'm a surgeon....

Here in USA the standard of care is ett for lap chole.

In many European countries however, many of the anesthesiologists routinely use LMA instead. How they get away with it is beyond me.

Honestly, I'm surprised more attendings don't use LMA for those cases over here. Assuming the patient is fasted appropriately, the pt isn't overly obese, and your LMA seats well, why couldn't you use an LMA? Even a crappy-fitting LMA you can usually get pressures up to 15 or so before you leak; in a normal size person that's usually plenty to adequately ventilate, especially with some reverse T-burg helping you out.

 

[G-Man82]

Honestly I think the answer as to why more people do not use LMAs for cases like this lies in the realm of defensive medicine. CYA medicine is pretty much becoming the norm. I know if I even suggested an LMA for this case at my hospital, my attendings would give me the look that says, "you need to go back to CA-1 orientation upstairs, stat!". Most of my attendings are big believers in the notion that LMA stands for "Lady Must Aspirate" or "Let Me Aspirate."

It's funny, because right now in peds (at a different hospital), I used an LMA for a 5 hour ortho ACL reconstruction in a 16 year-old ASA 2 (for RAD on 3 meds) girl, in which the orthopods were continuously pulling on the patient's leg (which caused her head to move and my HR to bump a little each time I saw the LMA jostle). At my home institution, they'd all be scandalized.

 

[foxtrot]

Let me preface this post by saying that I am a RN and anaspiring anesthesiologist. I am not supportive of independent CRNA practice –it is not in the best interest of the patient.

I frequently read this board but rarely post. My experiencetoday gave me some food for thought and I wanted to share.

I had a lap chole and hiatal hernia repair today. It is thefirst surgery I’ve had as an adult. It was at the outpatient surgery centerattached to the hospital where I work. I was concerned about the level ofanesthesiologist oversight of the CRNA’s at the surgi center. Theanesthesiologist himself came in to do the preop eval. He took 10 min or moreexplaining everything that would happen during the intraoperative period. Becauseof this, I knew what to expect and was really put at ease. He took the time toanswer all of my questions and address my concerns. Admittedly, my questionsprobably aren’t what the typical patientasks..i.e. LMA vs ETT, choice of induction agent (I still get sick if I thinkabout the smell of the gas induction agent used on me during 4
thgrade, and I want to make sure I get an IV agent.) I asked him if he would besupervising the CRNA and if he would be there during emergence and induction.He assured me he would be, as well as checking in the room frequently. Theanesthetic did such a good job that I have no memory of emergence (I was afraidof waking up with a tube in my mouth). Nor do I remember the propofol beinginjected – something else I was afraid of as I know it can burn. He told me hewould mix it with lidocaine.

I share all of this because I believe that the patient’sperception of the role of the anesthesiologist is important. I feel the levelof understanding he demonstrated in explaining the procedure and the way inwhich he addressed my concerns set him apart from the CRNA’s. I was really putat ease that a physician would be the one supervising my care. He appeared notonly competent and knowledgeable but demonstrated caring and compassion aswell. I hope that in other facilites the MD is filling this important role andnot allowing the CRNA to do it.

I would also like to ad that I work on a surgicalintermediate care unit of an 800+bed tertiary hospital. We take care of some verysick patients on my floor. Probably half of my patients have an epidural or PCAfor post-op pain management. The anesthesiologists maintain a very strongpresence on my floor as they manage most of the pain pumps. Everyone knows therole they play and it sets them apart from the CRNA’s. They are in-house 24/7and always available for an emergency – and this is not a teaching hospital.The surgeon personalities are hit or miss but the anesthesiologists are alwaysvery professional and polite to work with. They work hard but have very chilland have laid-back personalities. It seems like a wonderful profession.

I would like to ask a question for my own knowledge. I’m ahealthy 29 year-old ASA 1 patient. The procedure was only about an hour long.What is the attending’s rationale for selecting an ETT instead of a LMA? Thanks.

I appreciate you taking the time to write up such a complementary post. This is what makes me glad that I went into medicine.

 

[fakin' the funk]

Honestly, I'm surprised more attendings don't use LMA for those cases over here. Assuming the patient is fasted appropriately, the pt isn't overly obese, and your LMA seats well, why couldn't you use an LMA? Even a crappy-fitting LMA you can usually get pressures up to 15 or so before you leak; in a normal size person that's usually plenty to adequately ventilate, especially with some reverse T-burg helping you out.

Let's not forget that the LMA is a mask -- an unsealed, nondefinitive airway.

It provides little to no protection against aspiration, is **** for positive-pressure ventilation, can get dislodged far more easily than an ETT, and in most cases requires the patient to spontaneously ventilate.

For any "routine" laparoscopic procedure (especially an upper-airway procedure -- are you freaking kidding?!) the choice of an LMA over an ETT is totally insane. It is an inferior airway device without demonstrable benefit vs an ETT for "all comers." If you tell me that the surgeons want to do a brief foregut procedure on someone with severe asthma, OK, now I'm listening. But for "all comers" the risk-benefit ratio decidely favors the ETT.

 

[dhb]

Let's not forget that the LMA is a mask -- an unsealed, nondefinitive airway.

Let's trach everybody: definitive airway done

It provides little to no protection against aspiration, is **** for positive-pressure ventilation, can get dislodged far more easily than an ETT, and in most cases requires the patient to spontaneously ventilate.

What are people dislodging all the time? never happens to me... and if it did big deal put it back in

It is an inferior airway device without demonstrable benefit vs an ETT for "all comers."

But for "all comers" the risk-benefit ratio decidely favors the ETT

So not superior or inferior? Make up your mind, if it's inferior you should be tubing everyone. Do you have scientific proof?

If you tell me that the surgeons want to do a brief foregut procedure on someone with severe asthma, OK, now I'm listening.

What's the big deal with asthma if a patient is actively weezing i won't put him to sleep but if i had to for an emergency i'd definitely tube him (depending on procedure) what gives?

Mucho dogma here

 

[Mman]

Honestly, I'm surprised more attendings don't use LMA for those cases over here. Assuming the patient is fasted appropriately, the pt isn't overly obese, and your LMA seats well, why couldn't you use an LMA? Even a crappy-fitting LMA you can usually get pressures up to 15 or so before you leak; in a normal size person that's usually plenty to adequately ventilate, especially with some reverse T-burg helping you out.

Considering the abdomen is insufflated to a pressure of 15-18, is generating an inspiratory pressure of 15 with an LMA really sufficient? I mean at that level you are just stemming the tide of exhaled breath from the abdominal insufflation. Generally need inspiratory pressures of 25-40 to get adequate tidal volumes during laparoscopy.

Now if surgeons could get by with only inflating the abdomen to 8-10, then you might have a case for using an LMA. But not much of one IMHO. It offers no benefit. You still get a sore throat and you aren't protected from aspiration.

 

[BLADEMDA]

The use of the laryngeal mask airway (LMA) in laparoscopic surgery remains controversial due to the increased risk of aspiration and difficulties encountered when trying to maintain effective gas transfer while delivering the higher airway pressures required during pneumoperitoneum. Despite these concerns, there have been several randomized controlled trials assessing the use of Proseal LMA (PS-LMA) vs COTT with data advocating the PS-LMA as effective and efficient for pulmonary ventilation in laparoscopic surgery.6

 

[BLADEMDA]

Risk of pulmonary aspiration with laryngeal mask airway and tracheal tube

Risk of pulmonary aspiration with laryngeal mask airway and tracheal tube: analysis on 65,712 procedures with positive pressure ventilation



Anaesthesia 2009;64:1289-1294



Bernardini A, Natalini G

Abstract

Purpose The purpose of this study was to test the hypothesis that pulmonary aspiration of gastric contents was more likely when the airway was managed with an LMA than an endotracheal tube when patients were mechanically ventilated.

Background The Laryngeal Mask Airway (LMA) has a number of advantages over an endotracheal tube and it can be useful in the management of a difficult airway when ventilation through a facemask is difficult. Nevertheless, the LMA does not seal the trachea against entry of gastric contents as well as an endotracheal tube (ETT). Positive pressure ventilation may result in gastric inflation and increase the risk of regurgitation and aspiration during LMA use. There is, however, little evidence about the actual risk of pulmonary aspiration with an LMA vs. an ETT during mechanical ventilation. Criteria considered to contraindicate the use of an LMA are based primarily on opinion and not on evidence.

The overall incidence of pulmonary aspiration (all types of airway management) has been reported to be between 1 in 3,216 and 1 in 14,139 general anesthetics.

Methodology This retrospective study examined data in a preexisting quality improvement database. Data had been collected over a 10+ year period. Records were included in the analysis if either an LMA or ETT was used during a general anesthetic with mechanical ventilation. The selection of an LMA for airway management was driven by locally accepted contraindications to LMA use including: patients who were not NPO, intestinal obstruction, pregnancy, procedures involving the airway, and prone position. An LMA was occasionally used when one or more of these contraindications were present in a difficult airway situation.

Default volume controlled ventilator settings were tidal volume 8 – 10 mL / kg with respiratory rate adjusted according to the end tidal CO2. Surgical procedures included major abdominal, urologic, gynecologic, retroperitoneal, and laparoscopic surgery. Pulmonary aspiration of gastric contents was defined as the presence of gastric contents or bilious fluid in tracheal aspirate; bilious fluid on the LMA or in the oropharynx; or postoperative dyspnea, hypoxia, or "auscultatory abnormalities." When a case of aspiration was identified in the quality improvement database the original chart was reviewed to verify the data.

Result Slightly over 1,000,000 cases were contained in the database. Of those, 65,712 met the criteria for inclusion; general anesthesia and mechanical ventilation with either an LMA or ETT. Of those, 2,517 were major abdominal surgery or laparoscopy performed with an LMA. The airway was managed with an LMA in 1.7% of cases in which a contraindication to LMA use was present.

Aspiration occurred in 10 cases. Of these, 4 occurred during an elective procedure; 2 with an LMA and 2 with an ETT. The other 6 occurred during a non-elective procedure; 1 with an LMA. Only 2 of these patients were admitted to intensive care due to aspiration related problems; 1 of the ICU admissions was an LMA patient and 1 was an ETT patient. The occurrence of pulmonary aspiration in patients whose airway was managed with an LMA and mechanical ventilation was no different than those whose airway was managed with an ETT (odds ratio 95% confidence interval 0.09-1.4; P=0.141). The power of the study (the probability of rejecting the hypothesis when it is false) was calculated after the fact to be 0.69.

The primary factor associated with pulmonary aspiration was emergency surgery, not the airway management device. The overall incidence of aspiration was 1 in 6,571 anesthetics.

Conclusion The incidence of pulmonary aspiration was no greater when an LMA was used than when an ETT was used during general anesthesia with mechanical ventilation. Institutional contraindications to LMA use may have influenced the results.


http://felipeairway.sites.medinfo.ufl.edu/files/2009/11/sga-and-aspiration.pdf

 

[BLADEMDA]

The ProSeal laryngeal mask airway (PLMA) achieves a more effective seal than the LMA classic (cLMA) and isolates the glottis from the oesophagus when correctly placed123 .We describes a case where a correctly placed PLMA prevented aspiration.
A 22 year old female ASA-I (weight 50Kg, height 160cms) was scheduled for diagnostic laparoscopy for infertility under general anaesthesia. She was fasted overnight and premeditated with tab. alprazolam 0.25mg and tab. ranitidine 150mg at bed time and 2 hours preoperatively. In the operating room an IV line was started and monitors attached. Anaesthesia was induced with injection thiopentone sodium 250mg and injection tramadol 50mg IV and injection atracurium 25mg IV was given to facilitate airway placement. A size 3 PLMA was inserted easily on the first attempt using the introducer tool technique, the cuff inflated with 25ml of air to obtain an intracuff pressure of 60cmH2O and the lungs were ventilated easily with a tidal volume of 8mlkg-1. Correct placement of the mask was determined by testing absence of gas leak up the drainage tube at an airway pressure of <20 cmH2O, exhaled tidal volume > 8ml kg-1 and passage of gastric tube of 14FG. Airway seal pressure of 36cmH2O was recorded. The laparoscopic surgery was done in lithotomy position with a head down tilt.
Half way down the operative procedure a yellowish fluid was noticed in the drain tube of the mask. On suction the fluid was 10-15ml in amount and tested positive for acid. There was no difficulty in ventilation or any evidence of coughing or retching. All other respiratory and hemodynamic parameters remained constant. The PLMA was left in place and the procedure was allowed to continue. At the end of the procedure neuromuscular blockade was reversed and PLMA was removed when the patient was fully awake. The PLMA was examined for any secretions and both the ventral and dorsal surfaces of the bowl of PLMA were tested with a litmus paper, which had a pH of six thus there was no soiling of the bowl with the gastric contents. The postoperative course was uneventful.

 

[BLADEMDA]

Let's trach everybody: definitive airway done



What are people dislodging all the time? never happens to me... and if it did big deal put it back in





So not superior or inferior? Make up your mind, if it's inferior you should be tubing everyone. Do you have scientific proof?



What's the big deal with asthma if a patient is actively weezing i won't put him to sleep but if i had to for an emergency i'd definitely tube him (depending on procedure) what gives?

Mucho dogma here

DHB,

In Europe the use of a ProSeal or Classic LMA for Laparoscopic Surgery is fairly common. There is ample Scientific evidence that an LMA (Proseal better than a Classic LMA) is both safe and effective for Laparoscopic surgery provided the usual contraindications for LMA use are followed.

In the USA our medico-legal climate is different; hence, I (and most Anesthesiologists) utilize an ETT for all Laparoscopic surgeries. I simply can't afford the 1 in 1,000 patients who may develop an aspiration pneumomia and I end up in court. It isn't worth it.
Until the ASA or Anesthesia patient safety foundation states "the use of a Proseal LMA is safe for Laparoscopic Surgery" I'll stick with ETT for Lap. Surgeries.

You have a different legal climate. If I was in your situation then I predict over 50% of my patients would get a Proseal LMA instead of an ETT.

Peace,
Blade

 

[BLADEMDA]

Let's not forget that the LMA is a mask -- an unsealed, nondefinitive airway.

It provides little to no protection against aspiration, is **** for positive-pressure ventilation, can get dislodged far more easily than an ETT, and in most cases requires the patient to spontaneously ventilate.

For any "routine" laparoscopic procedure (especially an upper-airway procedure -- are you freaking kidding?!) the choice of an LMA over an ETT is totally insane. It is an inferior airway device without demonstrable benefit vs an ETT for "all comers." If you tell me that the surgeons want to do a brief foregut procedure on someone with severe asthma, OK, now I'm listening. But for "all comers" the risk-benefit ratio decidely favors the ETT.

We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery.

http://www.ncbi.nlm.nih.gov/pubmed/17697218


We conclude that the frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements is lower for the ProSeal LMA than the tracheal tube in females undergoing breast and gynaecological surgery.
http://www.ncbi.nlm.nih.gov/pubmed/17617554

 

[Mman]

We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery.

http://www.ncbi.nlm.nih.gov/pubmed/17697218


We conclude that the frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements is lower for the ProSeal LMA than the tracheal tube in females undergoing breast and gynaecological surgery.
http://www.ncbi.nlm.nih.gov/pubmed/17617554

When a study claims a greater reduction in nausea with LMA compared to ETT than any antiemetic in use, you have to question it's validity.

 

[WholeLottaGame7]

Considering the abdomen is insufflated to a pressure of 15-18, is generating an inspiratory pressure of 15 with an LMA really sufficient? I mean at that level you are just stemming the tide of exhaled breath from the abdominal insufflation. Generally need inspiratory pressures of 25-40 to get adequate tidal volumes during laparoscopy.

Now if surgeons could get by with only inflating the abdomen to 8-10, then you might have a case for using an LMA. But not much of one IMHO. It offers no benefit. You still get a sore throat and you aren't protected from aspiration.

Granted, it would have to be the right sort of circumstances. But I've had normal-sized individuals that have only required 25 of pressure during laparoscopy, and I've had LMAs with good seals up to 30+, so conceivably there's some overlap there. Or the surgeons could make do with less insufflation pressure, but good luck with that.

I'm certainly not advocating putting in LMAs for laparascopic procedures willy-nilly; just stating that I don't think it's as sacrilegious as most of my attendings make it sound.

 

[Mman]

Granted, it would have to be the right sort of circumstances. But I've had normal-sized individuals that have only required 25 of pressure during laparoscopy, and I've had LMAs with good seals up to 30+, so conceivably there's some overlap there. Or the surgeons could make do with less insufflation pressure, but good luck with that.

I'm certainly not advocating putting in LMAs for laparascopic procedures willy-nilly; just stating that I don't think it's as sacrilegious as most of my attendings make it sound.

Oh I agree there is some overlap. The problem is you won't be able to predict those situations accurately enough at the time of induction in order to put the LMAs in only the patients you can get away with it in. And if it's not working 1/2 way through the case, the surgeon isn't going to appreciate you requesting they deflate the abdomen so you can change out the LMA to an ETT.

I mean it could be done in some patients, but to what benefit? The potential harm far outweighs the potential benefit IMHO. Especially when you'd have a lineup of witnesses claiming you were insane in a malpractice trial.

 

[slunk]

Risk of pulmonary aspiration with laryngeal mask airway and tracheal tube

Risk of pulmonary aspiration with laryngeal mask airway and tracheal tube: analysis on 65,712 procedures with positive pressure ventilation



Anaesthesia 2009;64:1289-1294



Bernardini A, Natalini G

Abstract

Purpose The purpose of this study was to test the hypothesis that pulmonary aspiration of gastric contents was more likely when the airway was managed with an LMA than an endotracheal tube when patients were mechanically ventilated.

Background The Laryngeal Mask Airway (LMA) has a number of advantages over an endotracheal tube and it can be useful in the management of a difficult airway when ventilation through a facemask is difficult. Nevertheless, the LMA does not seal the trachea against entry of gastric contents as well as an endotracheal tube (ETT). Positive pressure ventilation may result in gastric inflation and increase the risk of regurgitation and aspiration during LMA use. There is, however, little evidence about the actual risk of pulmonary aspiration with an LMA vs. an ETT during mechanical ventilation. Criteria considered to contraindicate the use of an LMA are based primarily on opinion and not on evidence.

The overall incidence of pulmonary aspiration (all types of airway management) has been reported to be between 1 in 3,216 and 1 in 14,139 general anesthetics.

Methodology This retrospective study examined data in a preexisting quality improvement database. Data had been collected over a 10+ year period. Records were included in the analysis if either an LMA or ETT was used during a general anesthetic with mechanical ventilation. The selection of an LMA for airway management was driven by locally accepted contraindications to LMA use including: patients who were not NPO, intestinal obstruction, pregnancy, procedures involving the airway, and prone position. An LMA was occasionally used when one or more of these contraindications were present in a difficult airway situation.

Default volume controlled ventilator settings were tidal volume 8 – 10 mL / kg with respiratory rate adjusted according to the end tidal CO2. Surgical procedures included major abdominal, urologic, gynecologic, retroperitoneal, and laparoscopic surgery. Pulmonary aspiration of gastric contents was defined as the presence of gastric contents or bilious fluid in tracheal aspirate; bilious fluid on the LMA or in the oropharynx; or postoperative dyspnea, hypoxia, or “auscultatory abnormalities.” When a case of aspiration was identified in the quality improvement database the original chart was reviewed to verify the data.

Result Slightly over 1,000,000 cases were contained in the database. Of those, 65,712 met the criteria for inclusion; general anesthesia and mechanical ventilation with either an LMA or ETT. Of those, 2,517 were major abdominal surgery or laparoscopy performed with an LMA. The airway was managed with an LMA in 1.7% of cases in which a contraindication to LMA use was present.

Aspiration occurred in 10 cases. Of these, 4 occurred during an elective procedure; 2 with an LMA and 2 with an ETT. The other 6 occurred during a non-elective procedure; 1 with an LMA. Only 2 of these patients were admitted to intensive care due to aspiration related problems; 1 of the ICU admissions was an LMA patient and 1 was an ETT patient. The occurrence of pulmonary aspiration in patients whose airway was managed with an LMA and mechanical ventilation was no different than those whose airway was managed with an ETT (odds ratio 95% confidence interval 0.09-1.4; P=0.141). The power of the study (the probability of rejecting the hypothesis when it is false) was calculated after the fact to be 0.69.

The primary factor associated with pulmonary aspiration was emergency surgery, not the airway management device. The overall incidence of aspiration was 1 in 6,571 anesthetics.

Conclusion The incidence of pulmonary aspiration was no greater when an LMA was used than when an ETT was used during general anesthesia with mechanical ventilation. Institutional contraindications to LMA use may have influenced the results.


http://felipeairway.sites.medinfo.ufl.edu/files/2009/11/sga-and-aspiration.pdf

Usefulness limited from being a retrospective study as well as the mentioned institutional limitations in LMA use. The fact is that a prospective study would never pass an IRB.

 

[BLADEMDA]

When a study claims a greater reduction in nausea with LMA compared to ETT than any antiemetic in use, you have to question it's validity.

New study showing the safety and efficacy of Proseal LMA for Lap Gastric banding Surgery in our Journal this month. By the way, less nausea and vomiting and postop pain in this study as well. In addition, insuffation pressure were about 25 on average. Plus this study passed the IRB easily in its home country.

As usual DHB and his European colleagues are ahead of us in many areas due to our ridiculous malpractice system.

 

[BLADEMDA]

Usefulness limited from being a retrospective study as well as the mentioned institutional limitations in LMA use. The fact is that a prospective study would never pass an IRB.

Wrong. This study published in Anesthesiology this month (August 2012) was prospective and IRB approved in Italy. The fact is the Europeans use Proseal LMA safely for a whole variety of laparoscopic cases.



Display Settings:AbstractSend to:
Anesthesiology. 2012 Aug;117(2):309-20.
Hemodynamic and Hormonal Stress Responses to Endotracheal Tube and ProSeal Laryngeal Mask AirwayTM for Laparoscopic Gastric Banding.
Carron M, Veronese S, Gomiero W, Foletto M, Nitti D, Ori C, Freo U.
Source
* Assistant Professor of Anesthesiology, &#8224; Staff Anesthesiologist, # Professor of Anesthesiology, Department of Pharmacology and Anesthesiology, University of Padova, Padova, Italy. &#8225; Research Technician, Department of Medical Sciences, University of Padova. &#8214; Professor of Surgery, § Staff Surgeon, Bariatric Unit, Department of Surgical and Oncological Sciences, University of Padova, and Padova City Hospital, Padova, Italy.
Abstract
BACKGROUND:
: The stress responses from tracheal intubation are potentially dangerous in patients with higher cardiovascular risk, such as obese patients. The primary outcome objective of this study was to test whether, in comparison with the endotracheal tube (ETT), the Proseal&#8482; Laryngeal Mask Airway (PLMA&#8482😉 (Laryngeal Mask Airway Company, Jersey, United Kingdom) reduces blood pressure and norepinephrine responses and the amounts of muscle relaxants needed in obese patients.
METHODS:
: We assessed hemodynamic and hormonal stress responses, ventilation, and postoperative recovery in 75 morbidly obese patients randomized to receive standardized anesthesia with either an ETT or the PLMA&#8482; for laparoscopic gastric banding.
RESULTS:
: In repeated-measures ANOVA, mean arterial blood pressure and plasma norepinephrine were significantly higher in the ETT group than in the PLMA&#8482; group. In individual pairwise comparisons, blood pressure rose higher in ETT than PLMA&#8482; patients after insertion and removal of airway devices, and after recovery. In ETT compared with PLMA&#8482; patients, plasma norepinephrine was higher after induction of carboperitoneum (mean ± SD, 534 ± 198 and 368 ± 147 and pg/ml, P = 0.001), after airway device removal (578 ± 285 and 329 ± 128 pg/ml, P < 0.0001), and after recovery in postanesthesia care unit (380 ± 167 and 262 ± 95 and pg/ml, P = 0.003). Compared with use of the ETT, the PLMA&#8482; reduced cisatracurium requirement, oxygen desaturation, and time to discharge from both the postanesthesia care unit and the hospital.
CONCLUSIONS:
: PLMA&#8482; reduces stress responses and postoperative complaints after laparoscopic gastric banding.
PMID: 22614132 [PubMed - in process]
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[Mman]

New study showing the safety and efficacy of Proseal LMA for Lap Gastric banding Surgery in our Journal this month. By the way, less nausea and vomiting and postop pain in this study as well. In addition, insuffation pressure were about 25 on average. Plus this study passed the IRB easily in its home country.

As usual DHB and his European colleagues are ahead of us in many areas due to our ridiculous malpractice system.

The burden of proof for anybody claiming an LMA leads to reduced PONV and reduced pain is extremely high and unlikely to be reach in any single trial. I mean I can run 100 trials of the exact same thing and 5 of them will show a statistically significant difference in anything I want regardless of the true effect.

LMAs cause sore throats just like ETTs. They don't prevent PONV. They don't prevent post op pain. They are a device to maintain a patent airway. It's a glorified oral airway. I use them all the time for minor elective things so it's not like I'm an LMA hater.

 

[BLADEMDA]

The burden of proof for anybody claiming an LMA leads to reduced PONV and reduced pain is extremely high and unlikely to be reach in any single trial. I mean I can run 100 trials of the exact same thing and 5 of them will show a statistically significant difference in anything I want regardless of the true effect.

LMAs cause sore throats just like ETTs. They don't prevent PONV. They don't prevent post op pain. They are a device to maintain a patent airway. It's a glorified oral airway. I use them all the time for minor elective things so it's not like I'm an LMA hater.

plasma norepinephrine were significantly higher in the ETT group than in the PLMA&#8482;

So, you know the all the interactions high NorePi levels has on human Physiology?
Perhaps, higher Norepi levels influence post op pain and post op nausea?

Adrenergically modulated vasoactive and smooth muscle responses to norepinephrine can result in nausea/vomiting

 

[Mman]

plasma norepinephrine were significantly higher in the ETT group than in the PLMA™

So, you know the all the interactions high NorePi levels has on human Physiology?
Perhaps, higher Norepi levels influence post op pain and post op nausea?

Adrenergically modulated vasoactive and smooth muscle responses to norepinephrine can result in nausea/vomiting

The burden of proof for a relatively outrageous claim is far higher than that trial can provide.