Prior to induction of anesthesia, the bariatric patient should be positioned on a ramp (Fig. 2) on the operating table so that the neck can be optimally extended for direct laryngoscopy. A slight head-up or reverse Trendelenburg position for preoxygenation can be helpful in recruiting additional functional residual capacity, in conjunction with CPAP [25]. The ramp for intubation can be made with multiple blankets; there are also commercially available foam and inflatable ramps. The ramp should be easily removable after the patient is anesthetized to provide good operating position; ideally the ramp should also be easily repositioned at emergence in the event of a need for reintubation. If the plan for airway management is an awake fiberoptic intubation, the patient may be placed in a sitting position for optimal oxygenation; adequate space must be available for the anesthesiologist and the necessary equipment. The patient’s extremities should be properly padded and positioned to avoid positional neuropathy; patients at extremes of weight are known to be at higher risk of developing perioperative neuropathies.

Induction of anesthesia should begin with ample time for preoxygenation to optimize the patient’s apneic reserve and minimize hypoxemia during the apneic period. Excessive premedication should be avoided as the patient should be able to cooperate fully with preoxygenation. The operating room staff, including the surgeon, should be available to assist with securing the airway, especially in the event of unanticipated difficult airway. Bariatric operating room personnel should be educated on the basics of the difficult airway algorithm and the location of various airway devices in order to assist the anesthesiologist should such a situation arise. In addition to various direct laryngoscopy blades, an assortment of laryngeal mask airways (LMA) should be available. LMAs provide a means for manual ventilation as a rescue device and can also act as a conduit for intubation using an intubating LMA or via fiberoptic intubation using the Aintree catheter. Video laryngoscopes such as the GlideScope and the McGrath have become popular airway management alternatives to awake fiberoptic intubation. Though most commonly used after induction of anesthesia, successful awake GlideScope intubations have also been reported [26]. As a last resort in the difficult airway algorithm, cricothyrotomy kits should be available to the surgeon and the anesthesiologist. In our institution, the bariatric operating room has a dedicated difficult airway cart with some of the aforementioned devices, and cricothyrotomy kits are stocked in every anesthesia workstation.

Communication between the surgeon and the anesthesiologist is of utmost importance in minimally invasive bariatric surgery, particularly at several critical points in the procedure. Peritoneal insufflation can lead to sudden dysrhythmias, with severe bradycardia being the most common [27]. Instrumentation of the esophagus—such as the removal of the nasogastric tube and esophageal temperature probe, or insertion of sizing bougies—should also be a concerted effort between the surgeon and the anesthesiologist. In addition, any concerns of bleeding on the surgical field should immediately be relayed to the anesthesiologist, as obtaining additional IV access may be difficult in the bariatric patient. An unanticipated conversion to open laparotomy will significantly change the postoperative course of the patient, including postoperative pain management and possibly continued mechanical ventilation in the immediate postoperative period. While many anesthesiologists in high-volume bariatric surgery centers are familiar with the steps in the surgical procedure and the usual duration, it is helpful for the surgeon to communicate with the anesthesiologist at these critical junctures. The anesthesiologist should ideally provide maximal neuromuscular blockade but still maintain the ability to adequately reverse the neuromuscular blockade at the end of the procedure. The repeat dosing of neuromuscular blockade agents at proper intervals should be guided by the use of the aforementioned peripheral nerve stimulators or acceleromyography as well as direct communication with the surgeon. A lack of peripheral nerve response to stimulation reflects greater than 90 % of neuromuscular junction acetylcholine receptor blockade, and reversal with an acetylcholinesterase inhibitor at that point is deemed to be ineffective. Such a situation at the end of the procedure may lead to inadequate neuromuscular recovery and therefore unnecessarily prolonged mechanical ventilation in the postoperative period.

Postoperative concerns after general anesthesia include pulmonary complications such as hypoxemia and hypercarbia, hemodynamic instability, hypothermia, nausea and/or vomiting, and inadequate analgesia. Of these, pulmonary complications and proper analgesia are of particular concern for bariatric patients. It has been demonstrated that obese patients, with and without OSA, experience frequent desaturations in the postoperative period after laparoscopic bariatric surgery [28]. For those with OSA, symptoms of apnea may be exacerbated by both residual anesthetic and opioid analgesics.

Bariatric patients should be extubated awake with intact airway reflexes to avoid upper airway obstruction or aspiration events that can lead to hypoventilation and hypoxemia. If the patient has a diagnosis of sleep apnea and uses CPAP or NIPPV at home, the home unit should be brought to the recovery room and applied post-extubation; the device settings should be noted so that hospital devices can be used if needed. CPAP therapy should also be considered in those patients who do not have a formal diagnosis of OSA but are suspected of such during the perioperative course. Supplemental oxygen should be administered to all patients after laparoscopic bariatric surgery, and can be discontinued when patients are able to maintain their baseline oxygen saturation on room air. Some patients who fulfill all post-recovery room discharge criteria but have a mild degree of hypoxemia may be discharged to an inpatient ward with low-flow supplemental oxygen and proper monitoring, with the goal of weaning the oxygen therapy over a longer period of time. In our institution, patients with OSA who do not experience apneic episodes in the recovery room can be discharged to the inpatient ward once the standard discharge criteria are met, while those who do experience apneic episodes are kept in the recovery room until they can demonstrate at least a 30-min continuous period without apnea when left undisturbed. The ASA task force recommends continuous pulse oximetry monitoring for patients with OSA who continue to be at increased risk of respiratory compromise after discharge from the recovery room [29]; such arrangements should be readily available in facilities providing bariatric surgical services.

Because bariatric patients may be more susceptible to the respiratory depressive effects of opioid analgesics, an opioid-sparing, multimodal analgesic plan is the standard model of care [30]. Surgical port sites should be infiltrated with long-acting local anesthetics such as bupivacaine either prior to incision or during closure. The use of patient-controlled intravenous opioid analgesia (PCA) should be initiated in the post-anesthesia recovery unit so that hypoxemic, hypopneic, or apneic events can be quickly identified and the PCA regimen can be adjusted. Non-opioid analgesics should include acetaminophen; the intravenous formulation that has recently become available in the United States should facilitate the administration of acetaminophen as scheduled doses (usually 1 g every 6 h and not to exceed 4 g/day). Though long-term use of NSAID such as ibuprofen is discouraged due to the risk of peptic ulcer disease in the post-bariatric surgery population, short-term and limited use of intravenous NSAID such as ketorolac should be seriously considered in the immediate postoperative period. For the bariatric patients with a history of chronic pain or neuropathic pain, other non-opioid analgesics such as gabapentin can be incorporated into the analgesic plan, if not already previously prescribed by other physicians. Other agents such as intravenous ketamine infusion and transdermal clonidine can be useful adjuncts in patients experiencing difficulty with pain management; expert pain consultation should be sought in these circumstances. Lastly, regional analgesic techniques such as epidural analgesia should be considered in patients with pain that is poorly controlled by parenteral means, and in patients who have undergone open bariatric procedure, bearing in mind that the procedure may be more challenging in these patients due to body habitus and patients’ difficulty with cooperation given their level of discomfort in the postoperative period.