Introduction:
The National Institute of Clinical Excellence has suggested bariatric surgery to treat obesity. Bariatric treatments can help shed more than 50 % of excess weight. Bariatric surgery is generally considered safe, has a low morbidity and mortality rate, and can result in long-term weight loss with a marked improvement in co-morbidity and quality of life in patients who are morbidly obese. A multidisciplinary team is included in treating overweight patients and offers a comprehensive weight loss program that includes dietary and lifestyle changes and increased physical activity. Weight loss may also be aided by approved medication therapy. Unfortunately, the weight loss achieved with these non-invasive methods seldom lasts, which has led to a rise in the popularity of bariatric surgery as a treatment.
What Is Laparoscopic Bariatric Surgery?
Laparoscopic gastric bypass (GBP) surgery is a surgical treatment that involves the development of a gastric pouch and is used to help patients who are extremely obese lose a large amount of weight over the long term. The one-anastomosis (mini) gastric bypass is an alternative to the traditional laparoscopic Roux-en-Y gastric bypass (RYGB). By limiting food intake and reducing food absorption, RYGB promotes weight loss. A tiny pouch that is comparable in size to the adjustable gastric band restricts how much food may be consumed. Moreover, food is sent directly from the pouch into the small intestine, bypassing much of the stomach, duodenum, and upper intestine from coming into contact with it. This reduces the amount of food that is absorbed in the digestive tract.
How Is Laparoscopic Bariatric Surgery Performed?
A small scope with a video camera and surgical equipment is placed via the five to six small incisions made in the belly during the procedure, which is typically done laparoscopically. In order to divide the upper portion of the stomach from the bottom and form a small stomach pouch, the surgeon staples the stomach. Intake of food is restricted by this little pouch. Afterward, the jejunum, a portion of the small intestine, is joined to the little stomach pouch, allowing food to skip the duodenum at the bottom of the stomach. With this bypass, the body absorbs fewer calories and nutrients, a condition known as malabsorption.
What Is the Anesthetic Consideration for Laparoscopic Bariatric Surgery?
The anesthetic consideration for laparoscopic bariatric surgery is broadly distinguished into three modes of action:
1. Preoperative Consideration:
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The evaluation of indicators of systemic or pulmonary hypertension, ischemic heart disease, and heart failure are included in the preoperative consideration. In addition to a thorough history and examination, right ventricular hypertrophy may be apparent in an ECG (electrocardiogram). Cardiopulmonary exercise testing and stress echocardiography can be employed for further cardiac evaluations.
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Prophylaxis against aspiration has been recommended for all patients with or without heartburn or reflux symptoms. H2 blockers (such as ranitidine 150 mg orally) and prokinetics (such as metoclopramide 10 mg) are given 12 and 2 hours before surgery, respectively.
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Before surgery, patients who are scheduled for repeat bariatric or non-bariatric surgery must be assessed for long-term metabolic and nutritional deficiencies brought on by medication and a liver shrinking diet. They include hypoproteinemia, vitamin K deficiency, iron, folate, vitamin B12, and hypoproteinemia. Additionally, drug-protein-protein binding, drug metabolism and clearance, and coagulation affect the fluid compartment of the body and give rise to postoperative neuropathies. Hence, blood indices that should be examined before surgery include coagulation, folate, and vitamin B12.
2. Intra-operative Consideration:
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Laparoscopic bariatric surgery is typically performed in a modified Lloyd Davis position, severe reverse Trendelenburg position with legs wide apart and both arms out on arm boards. Due to the increased prevalence of pressure sores and nerve damage in this distinct patient population, more care should be directed toward protecting pressure areas. This increases the risk of strain or pressure injuries to the major nerves in the distal limb and raises the possibility of compartment syndrome, more common in Lloyd Davis's position.
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Although their volume of distribution (VD) is generally comparable between obese and normal-weight people, medications with weak or moderate lipophilicity can be taken in accordance with ideal body weight (IBW).
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Pneumoperitoneum is well tolerated by obese patients without causing a drop in cardiac output. The reverse Trendelenburg position has been demonstrated to be a straightforward and secure intraoperative posture for obese patients, and it may even have some cardiorespiratory benefits, such as improved respiratory compliance, recruitment of the alveolar unit, and an increase in the functional residual volume.
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Desflurane has been recommended for anesthesia maintenance because of its low blood: gas partition coefficient, which produces a more quick and more reliable recovery profile. Drugs that are simple to titrate, including remifentanil and propofol, have also been used successfully.
3. Postoperative Consideration:
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Following surgery, the patients can be successfully maintained in conventional surgical wards, the high dependency unit (HDU), or the intensive care unit (ITU). The Montefiore Obesity Surgery Score (MOSS), which recommends that the patients be watched in an HDU if they are older than 40 to 50 years or have a history of asthma or snoring, can be utilized to help choose the best site. MOSS advises reserving ICU for those who experience complications.
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Achieving the best analgesia lowers the chance of postoperative chest infections and provides proper pulmonary mechanics and breathing. With sufficient local anesthetic wound infiltration and patient-controlled analgesia hence resulting in minimal pain.
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Multimodal analgesia regimens like acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), or tramadol can be used for all bariatric procedures.
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Additional postoperative concerns should include suitable thromboprophylaxis, proton-pump inhibitors, and postoperative antibiotics in accordance with local regulations.
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Personal desires should be taken into account when managing fluids, and the input and outflow of fluids should be precisely monitored.
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The risk of postoperative chest infections is decreased by optimal analgesia, which also ensures proper ventilation and pulmonary mechanics. It has been demonstrated that the majority of laparoscopic bariatric patients experience minimal discomfort thanks to adequate local anesthetic wound infiltration and patient-controlled analgesia.
Conclusion:
According to a recent study, having bariatric surgery and experiencing significant weight loss appear to be independent risk factors for pulmonary aspiration during the induction of anesthesia. This might be due to diminished lower esophageal sphincter tone and decreased esophageal-gastric peristalsis. Anesthesiologists should be familiar with the clinical management of obese patients for all types of surgeries, especially for weight reduction procedures, because the risk of anesthesia and surgery is higher in obese patients than in the general population. These patients can present difficulties during the induction and maintenance of anesthesia, oxygenation, intubation, and pain management.
