Uses of Sugammadex in Bariatric Surgery

Abstract

Obesity is defined as a body mass index (BMI) 30 kg/m2, whereas those with a BMI 35 and 55 kg/m2 are considered ‘morbidly’ obese and ‘super morbidly’ obese, respectively.

Obesity-related medical conditions include hypertension, coronary artery disease, sudden (cardiac) death, restrictive lung disease, obstructive sleep apnea (OSA), diabetes mellitus, gallstones, a range of cancers (breast, gynecological, and gastrointestinal), degenerative joint disease, and socioeconomic and psychosocial impairment.

The preoperative assessment facilitates the appropriate selection of patients suitable for bariatric surgery, enables timely identification and treatment of pre-existing medical conditions, and determines how and where each patient should be managed post operatively.

OSA is strongly associated with obesity. Because OSA is undiagnosed in an estimated 60-70% of patients, screening for OSA should be part of routine preoperative evaluation. Because morbid obesity is one of the major risk factors for the development of pulmonary embolism, prophylaxis for DVT with low dose heparin in combination with intermittent pneumatic compression, are recommended. Also prophylaxis against acid aspiration is commonly used.

Most intravenous anesthetic drugs and opioids should be dosed according to lean body weight (not actual body weight), except for neuromuscular blocking drugs, which should be dosed according to ideal body weight. Sugammadex is the first and only selective relaxant binding agent (SRBA), which selectively binds steroid relaxants (rocuronium, vecuronium) and reverses the neuromuscular blockade. The drug is a modified gamma-cyclodextrin, which encapsulates and inactivates molecules of steroid ring compounds, including relaxants, forming complexes, which are subsequently excreted by kidneys.

The introduction of Sugammadex has potentially changed how anesthetists use NMBA in everyday practice. More particularly it has allowed us to re-evaluate the use of neostigmine, the use of suxamethonium, how we can avoid post-operative residual curarisation (PORC) and the reversal of deep NMB.

Obese patients are at increased risk of presenting a difficult airway and avoidance of PORC is a priority. Sugammadex, either electively or in the emergency CICV situation, may offer benefits over neostigmine.

Any degree of neuromuscular block produced by rocuronium or vecuronium can be rapidly and completely reversed without autonomic effects. Because sugammadex is optimized for reversing rocuronium it is most likely to be used in conjunction with this drug.

Moreover, sugammadex is currently sold in a 200 mg or 500 mg vial, and is not to be divided among patients. Unless a smaller dose vial is available, the cost reduction will not be realized.

It has been licensed for reversal of rocuronium and vecuronium induced neuromuscular blockade (NMB) since July 2008. European Union had approved sugammadex for marketing in Europe by European Medicines Agency (EMEA).