Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1002_Библиотеки_им_академика_М_И_Перельмана
.pdf
19 Method ofAnesthesia: Gas Selection andAdjunct Medications
O
6
F
2
H
3
O C
7
F
3
H
4
O C
5
CIF
2
H
3
C
Low: 0.65 Very low: 0.45
1.40
Low: 18.7
42.0
Dose-dependent
Dose-dependent
later vasodilation
hypotension
hypotension
hypotension
negative
197
(continued)
Tachycardia
MAC
3
HBrCIF
2
O C
2
Chemical formula N
Brand name N/A Fluothane Forane Ultane Suprane
Inhalation anesthetic agents
Table 19.3 Types of inhalational gas agents
Generic name Nitrous oxide Halothane Isourane Sevourane Desurane
Odor Slightly sweet Sweet Sweet Sweet Sweet
Very high: 2.40 Moderately high:
Very low:
Solubility:blood:gas partition
Pungency None Moderate High Low Very high
Color Colorless Colorless Colorless Colorless Colorless
1.1 1.9 1.6 1.7 1.3
0.46
Redistribution:brain:blood partition
coefcient
coefcient
105.0% 0.8% 1.2% 2.0% 6.0%
for response to
50
Minimu alveolar concentration
Potency:oil:gas partition coefcient Very low: 1.4 Very high: 224.0 High: 97.0 Moderately high:
(MAC)=ED
surgery
68.0% 0.4% 0.5% 0.6% 2.5%
50
MAC-awake/MAC-awake=ED
Blood pressure effect Negligible Dose-dependent hypotension Dose-dependent
for response to voice/touch
Chronotropic effect Negligible Bradycardia Tachycardia Tachycardia >1
Inotropic effect Negligible Negative Slightly negative Slightly negative Initial positive, later
Vascular effect Negligible Negligible Vasodilation Vasodilation Initial vasoconstriction,
198
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Nausea/emesis; airway
irritation; initial
sympathomimetic
Nausea/emesis;
inhalational
induction
Nausea/emesis;
potentially
signicant
tachycardia
A. Samir
Nausea/emesis; bradycardia/
asystole; inhalational
induction; no longer used in
US
emesis
© 2021 UpToDate, Inc. and/or its afliates
bottled gas
How delivered Flowmeter Vaporizer Vaporizer Vaporizer Electric heated vaporizer
Non-ammable Non-ammable Non-ammable Non-ammable
combustion
Notes Nausea/
Fire risk Supports
Bottled liquid Bottled liquid Bottled liquid Bottled liquid
Inhalation anesthetic agents
How supplied Pressurized
Table 19.3 (continued)
19 Method ofAnesthesia: Gas Selection andAdjunct Medications
199
19.4 Drug Dosing forObese Patients
Dosing guidelines are not very clear and therefore it is important to titrate medications to effects. Drug clearance is usually higher in obese vs non-obese patients.
Medications are classied based on their required dose into ideal body weight dosing, lean body weight dosing, and adjusted body weight dosing. The latter is calculated by AdjBW=IBW+0.4 [TBW−IBW].
Volume of distribution of lipophilic medications is increased in obese patients
due to increase up by the adipose tissue while is decreased for hydrophilic drugs.
Drug clearance is slightly higher in obese patients due increased renal and hepatic
metabolism. Elimination of drugs depends on both the volume of distribution and
clearance and since both are altered by obesity, elimination is altered as well.
19.5 Emergence fromInhalational Anesthesia
Patient should be completely awake, following command, with no residual muscle
relaxant effect. Deep extubation is relatively contraindicated as patients have an
increased risk of aspiration as well as difcult ventilation and reintubation. The
head should be elevated to avoid aspiration and improve the tidal volume. Prolonged
surgical procedures may be associated with airway edema and narrowing of the
airway and careful removal of the endo tracheal tube should be done after performing a leak test and with available personnel and equipment in case reintubation is
necessary.
19.5.1 Adjunct Medications
(a) Succinylcholine: Obesity is one of the leading causes of difcult intubation.
Therefore rapid sequence intubation should be considered to avoid the possibility of “cannot intubate, cannot ventilate” scenario. Succinylcholine provides
rapid muscle relaxation that allows for quick security of the airway and thus
preventing that scenario as well as helping prevent aspiration that is associated
with obesity.
(b) Induction agents such as Propofol, ketamine, etomidate, and thiopental are best
doses based on the adjusted body weight to avoid over or under dosing of
those drugs.
(c) Narcotics that tend to be highly lipophilic are better dosed based on ideal body
weight to avoid excess adipose tissue uptake and redistribution back into the
blood at later time.
(d) Fluid management with euvolemic is the target. Judgement on volume status
should be done through multiple monitors such blood pressure, central venous
pressure, urine output, and stroke volume variation [11].
200
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
A. Samir
References
1. Hanley MJ, Abernethy DR, Greenblatt DJ.Effect of obesity on the pharmacokinetics of drugs
in humans. Clin Pharmacokinetic. 2010;49(2):71.
2. Blouin RA, Warren GW.Pharmacokinetic considerations in obesity. J Pharm Sci. 1999;88(1):1.
3. Bazurro S, Ball L, Pelosi P. Perioperative management of the obese patient. Curr Opin Crit
Care. 2018;24(6):560–7.
4. Yap JC, Watson RA, Gilbey S, Pride NB.Effects of posture on respiratory mechanics in obesity. J Appl Physiol. 1995;79:1199–205.
5. Dunlop C, Whyte P. 8—Is oxygen toxic? In: Deutschman CS, Neligan PJ, editors. Evidencebased practice of critical care. W.B.Saunders; 2010. p.45–50.
6. van Amsterdam J, Nabben T, van den Brink W. Recreational nitrous oxide use: prevalence and risk. Regul Toxicol Pharmacol. 2015;73(3):790–6. https://doi.org/10.1016/j.
yrtph.2015.10.017. Epub 2015 Oct 22.
7. Campagna JA, et al. Mechanisms of actions of inhaled anesthetics. N Engl J Med.
2003;348:2110.
8. Rampil IJ.Anesthetic potency is not altered after hypothermic spinal cord transection in rats.
Anesthesiology. 1994;80:606.
9. McKay RE, Malhotra A, Cakmakkaya OS, Hall KT, McKay WR, Apfel CC.Effect of increased
body mass index and anaesthetic duration on recovery of protective airway reexes after sevourane vs desurane. Br J Anaesth. 2010;104(2):175–82. Epub 2009 Dec 26.
10. Bardoczky GI, Yernault JC, Houben JJ, d’Hollander AA. Large tidal volume ventilation
does not improve oxygenation in morbidly obese patients during anesthesia. Anesth Analg.
1995;81(2):385–8.
11. Jain AK, Dutta A.Stroke volume variation as a guide to uid administration in morbidly obese
patients undergoing laparoscopic bariatric surgery. Obes Surg. 2010;20(6):709–15. Epub
2010 Mar 9.
Further Reading
1. Dikmen Y, Eminoglu E, Salihoglu Z, Demiroluk S. Pulmonary mechanics during isourane,
sevourane and desurane anaesthesia. Anaesthesia. 2003;58(8):745.
2. Sigston PE, Jenkins AM, Jackson EA, Sury MR, Mackersie AM, Hatch DJ. Rapid inhala-
tion induction in children: 8% sevourane compared with 5% halothane. Br J Anaesth.
1997;78(4):362–5.
3. Janmahasatian S, Duffull SB, Ash S, Ward LC, Byrne NM, Green B.Quantication of lean
bodyweight. Clin Pharmacokinet. 2005;44(10):1051.
Chapter 20
Regional Anesthesia inBariatric Surgery
AndreTeixeira, AdamEl Kommos, andMarisabelLinaresBolsegui
20.1 Introduction
Pain following bariatric surgery can be quite troublesome, causing suffering, prolonged recovery, and increased healthcare costs [1, 2]. There are several comorbidities common in patients with obesity, such as obstructive sleep apnea (OSA),
associated metabolic syndrome, and increased susceptibility to opioid medication,
that lead to difculties in pain management [2, 3]. The rst goal of regional anesthesia is to cover the nociceptive and adrenergic stimulation originating from the
manipulation of the gastrointestinal tract and the abdominal wall. Decreasing the
pain in the immediate postoperative period has substantial importance for the
management of patients undergoing bariatric surgery [2, 3], as it may decrease the
need for opioids at the critical times of emergence from general anesthetic, extubation, and immediate management in the Post Anesthetic Care Unit (PACU) [1, 3, 4].
The second goal is to guarantee adequate postoperative analgesia without inter-
ference with bowel motility, allowing early alimentation and mobilization, and
recovery, in the same way, reducing the risk of thrombosis and respiratory infections [2]. Achieving these goals can promote an early return to normal life for the
patient, allowing the early start of the postoperative weight loss program [2, 3, 5].
The complexity of the bariatric patient dictates the choice of safe anesthetic strategies for pain control. One popular approach includes regional anesthetic tech-
niques, which are mainly in neuraxial form (spinal and epidural); or a combination
of peripheral nerve blocks [1], such as transversus abdominis plane (TAP) block,
rectus sheath block, thoracic paravertebral block, erector spinae block, local
A. Teixeira (*)
Orlando Health Bariatric surgery and Weight-Loss Institute, Orlando, FL, USA
A. El Kommos · M. L. Bolsegui
Department of Anesthesia, Orlando Health Anesthesia, Orlando, FL, USA
© The Author(s), under exclusive license to Springer Nature
Switzerland AG 2023
A. Teixeira et al. (eds.), Duodenal Switch and Its Derivatives in Bariatric and
Metabolic Surgery, https://doi.org/10.1007/978-3-031-25828-2_20
201
202
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
A. Teixeira et al.
anesthetics administered at the surgical ports or via wound inltration, and intraperitoneal local anesthetic administration are also possible as a part of multimodal
analgesia therapy [5, 6].
A combination of general anesthesia and epidural analgesia can improve analgesia. A combination of general anesthesia and spinal analgesia is another option for
open bariatric surgery, continuous spinal analgesia, although rarely performed now,
was seen to be effective in intra- and postoperative pain management in patients
undergoing open vertical banded gastroplasty (VBG), allowing for earlier mobilization. In some selected patients, even neuraxial anesthesia alone can be a reasonable
alternative (e.g., in patients with severe respiratory impairment or with a history of
difcult airway) [1].
The potential benets of regional anesthesia are substantial and have increased
the interest in these techniques for obese patients undergoing bariatric surgery [2].
Several metanalysis and systematic clinical trial reviews [4–6] have shown that the
implementation of regional anesthesia provides many advantages and allows
minimal airway manipulation, avoidance of anesthetic drugs with cardiopulmonary
depression, attenuated sympathetic responses caused by the surgical insult, and
reduced postoperative nausea and vomiting (PONV) [3, 5].. Therefore, patients
develop fewer pulmonary complications and achieve greater postoperative pain
control than those under general anesthesia, and in turn may decrease the level of
stress, hospital stay, and length of recovery after surgery [1]. This likely improves
postoperative outcomes and accelerated baseline function return [5]. Regional anesthesia may also reduce perioperative and postoperative opioid requirements, as well
as interference with the gastrointestinal tract, allowing the surgical interventions to
show their biological effects [1, 3, 6]. Regional anesthesia has also been shown to
preserve immune function better than traditional techniques and opioids.
Additionally, the risk of deep venous thrombosis and pulmonary embolism is lower
with epidural anesthesia than with general anesthesia [6].
It is recommended to perform neuraxial blocks at least 12h after the administration of low molecular weight heparin (LMWH) to reduce the risk of hematoma.
Removal of indwelling catheters should also occur at least 12h after administration
of LMWH [1]. Obese patients require less local anesthetic in their epidural and
subarachnoid spaces in order to achieve the same level of block when compared
with non-obese controls. This dose requirement is due that obese patients have
smaller cerebrospinal uid volumes than non-obese individuals [3, 5, 6].
20.2 Regional Block
As an alternative to epidural analgesia, inltrative techniques have gained increasing attention in recent years as they can be safely and easily applied [2, 6]. In the
current times, there are several discussions about all the regional techniques in
regional anesthesia, two of the most popular are TAP and ESP block.
20 Regional Anesthesia inBariatric Surgery
203
20.3 Transversus Abdominal Plane Block (TAP Block)
Over the last two decades, regional neuromuscular blocks have gained clinical relevance. Especially TAP block, this technique has been increasingly employed in
the multimodal postoperative pain management after various types of minimally
invasive surgeries, including colorectal, biliary, gynecologic, and bariatric surgery
[1, 2, 4, 7], First described by Ra etal. in 2001 [3, 4, 7, 8], the TAP block is the
injection of local anesthetics in the transversus abdominis plane, a compartment that
can be found between the transversus abdominis and internal oblique muscles [7]
contains the T6-L1 thoracolumbar nerves, responsible for the sensitivity of the
anterior abdominal wall [8, 9]. Additionally, these nociceptive impulses are responsible for initiating segmental spinal reex responses, increasing skeletal muscle
tone, inhibition of phrenic nerve function, and decreasing gastrointestinal motility
[6, 10].
This compartment can be accessed through several approaches and anatomical
sites: subcostal (between anterior abdominal wall between xiphoid process and
anterosuperior iliac spine, the anesthetic is deposited between rectus abdominis and
transversus abdominis muscles), lateral (between the mid-axillary and anterior
axillary lines), and posterior (at the level of lumbar triangle of Petit the area conned within iliac crest, latissimus dorsi, and external abdominal oblique muscle [7,
11], or at the level of the anterolateral aspect of the quadratus lumborum muscle).
See Figs.20.1, 20.2, and 20.3, respectively. Subcostal and posterior approaches are
generally preferred over the lateral approach. Because an increased number of dermatomes is anesthetized (4 vs. 3) and higher peak of sensory blockade (T8 vs. T10)
[7, 8] (source: Tran, D.Q., Bravo, D., Leurcharusmee, P., & Neal, J.M. (2019).
Fig. 20.1 TAP Block US landmark. Ultrasound probe position, needle puncture site, and sonographic image of the subcoastal transversus abdominis plane block. Asterisk indicates needle target; RA rectus abdominis muscle; TA transversus abdominis muscle
204
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Fig. 20.2 TAP block US landmark. Ultrasound probe position, needle puncture site, and sonographic image of the lateral transversus abdominis plane block. Asterisk indicates needle target;
EO external oblique muscle; IO internal oblique muscle: TA transversus abdominis muscle
A. Teixeira et al.
Fig. 20.3 TAP block US landmark. Ultrasound probe position, needle puncture site, and sonographic image of the posterior transversus abdominis plane block. Asterisk indicates needle target;
EO external oblique muscle; IO internal oblique muscle; LD latissimus dorsi muscle; QL quadratus lumborum muscle; TA transversus abdominis muscle. Source: Tran, D. Q., Bravo, D.,
Leurcharusmee, P., & Neal, J. M. (2019). Transversus Abdominis Plane Block. Anesthesiology,
131(5), 1166–1190. https://doi.org/10.1097/ALN.0000000000002842
Transversus Abdominis Plane Block. Anesthesiology, 131(5), 1166–1190. https://
doi.org/10.1097/ALN.0000000000002842) [7].
TAP can be identied with landmarks, USG, or intraoperatively by surgeons
(Figs.20.1, 20.2, and 20.3). The landmark guided technique has been used only for
the posterior approach (identication of the lumbar triangle of Petit and recognition
of the intermuscular plane between the internal oblique and transversus muscles
with tactile pops) [1, 9, 12]. When TAP block was rst described, obesity was
20 Regional Anesthesia inBariatric Surgery
205
thought to be one of the contraindications to perform the block because it is difcult
to identify the triangle of Petit and other landmarks in obese patients [3, 5, 6], and
there was a high risk of visceral injury [7, 9], this fact has led many authors to favor
the use of ultrasound guidance (USG) that allowed identication of the layers of
the abdominal wall even in obese patients, where landmarks are often obscured by
the body habitus [7, 8]. Due to the depth of the abdominal wall structures, a lowfrequency curved transducer is used to guide needle placement.
Several clinical trials suggest, according to the current knowledge that USG-TAP
block must be performed bilaterally by injecting between 0.2 to 0.5% of bupiva-
caine or 0.2 to 0.25% of ropivacaine and volumes of at least 15mL per side
(usually 20–40mL) [7–9]. It has been described that the use of adjuvants such as
dexamethasone, dexmedetomidine, magnesium, and in some cases buprenorphine
has increased the duration of the anesthesia, nevertheless, further research is
required to better knowledge about dosing, mode of administration, and combination [12].
Considering the pharmacokinetics of the short-acting local anesthetics used,
notably bupivacaine (which means elimination half-life is around 9–10h) and ropivacaine have longer analgesic effectiveness. The impact of TAP block during the
postoperative period decreasing the opioid consumption is predicted to be signicant mainly in the rst 24 h. Recently the relatively long-acting liposomal
bupivacaine [4, 9] has been employed for TAP block in bariatric surgery patients,
which offers the advantage of extended duration of analgesia for up to 72h [2, 4, 7].
Furthermore, surgeons can perform TAP in the set of a laparotomy or laparoscopic incision, with the deposition of local anesthetic into the TAP under direct
vision of the laparoscope. A few trials have compared surgeon- and anesthesiologistperformed TAP blocks, where the surgical technique resulted to be faster, the pain
scores were similar but there was lower IV postoperative morphine consumption
compared with their anesthesiologist-performed counterpart [7, 9, 12].
20.3.1 Outcomes
USG-TAP block has shown to be a practical, effective, and safe technique for
postoperative analgesia in morbidly obese patients having SPSG with a minimal incidence of complications [12].
Several clinical trials and meta-analysis review in patients undergoing bariatric
surgery has demonstrated a strong association between TAP block and improved
perioperative and postoperative early (0–3 h), and late (3–24 h) pain scores
(either at rest and on movement) during the rst 24h after surgery [4, 7], reduced
24-h postoperative opioid consumption (cumulative IV morphine) and, consequently decreased incidence of related side effects at 24 and 48h, [1, 7] shorter time
to ambulation and reduced incidence of postoperative nausea and vomiting (PONV)
[1, 4]. Less need for biphasic intermittent positive airway pressure (BIPAP) ventilation support and lower Richmond Agitation and Sedation Score in the rst 6h [2].
206
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
A. Teixeira et al.
A 2013 systematic review meta-analysis in patients going through laparoscopic
sleeve gastrectomy and Roux Y gastric bypass showed that the posterior TAP block
has a greater reduction in opioid consumption and in rest and dynamic pain scores
compared with the lateral approach [1, 2, 4, 7]. Moreover, postoperative TAP block
administration resulted in greater effects decreasing opioid consumption at
24h compared with preoperative block administration [1, 4, 7, 9]. The literature
evaluation has shown statistically signicant difference improvement in time to
postoperative bowel recovery, lower sedation score, shortened time to ambulate, [13] reduced number of complications of immobilization higher satisfaction scores compared to the control group [2–4, 7], with very low rate incidence
of complications related to the TAP block procedure (e.g., hematoma, visceral
injury), symptoms of local anesthetic toxicity or any signicant adverse event [4, 7].
All those factors help the faster recovery of patients [2] and likely shorter length
hospital stay [10].
20.3.2 Erector Spinae Plane Block (ESPB)
The erector spinae plane block (ESPB) Fig.20.4 is a relatively new procedure, rst
described in 2016 [14] as another alternative to conventional thoracic regional anesthetic techniques such as thoracic epidural and paravertebral injections [15, 16].
Clinical studies have demonstrated that the block targets both the ventral and dorsal
spinal rami, and sympathetic chain. Exploration of the anatomical basis of the block
has shown that cranio-caudal local anesthetic spread allows for anesthesia of most
of the thoracic cavity [17, 18].
One of the advantages of ESPB compared to more conventional techniques is
that this block targets a plane that is far removed from the pleura and neuraxial
structures, improving its safety prole Fig.20.5 [11]. The mechanism of action of
ESPB has also been shown to involve both transforaminal and epidural spread, giving the technique an advantage over direct intercostal nerve blockade. In delivery of
ESPB, local anesthetic is injected into the fascial plane, deep to the erector spinae
muscle group, to achieve analgesia of the thoracic and abdominal wall.
Anatomically, ESPB targets the tips of the transverse processes, giving it a distinct
advantage over retrolaminar block, which targets the laminae and involves injection
over the thick spinalis and transversospinalis muscle groups. ESPB can be performed at the level of T5, T6, T7, or T8 transverses processes [14] to target the
thoracoabdominal area Fig.20.6. Since the erector spinae muscle extends inferiorly
to the lumbar spine, injection at the lower vertebral level spreads to the lower thoracoabdominal nerves Fig.20.7. Anatomically, the relatively supercial location of
the ESP block, distant from any major blood vessels and nervous structures, also
minimizes concerns regarding anticoagulation and the development of a clinically
signicant hematoma [16].
Соседние файлы в папке Библиотека им академика М.И. Перельмана