Ambulatory Care for the Obese Patient

By Adaora M. Chima, MBBS, MPH, from the IARS, AUA and SOCCA 2019 Annual Meetings*

The rising prevalence in obesity has increased the occurrence of electively scheduled procedures for obese patients in ambulatory surgical centers. As obesity is known to be associated with increased perioperative risks, it is important to reassess the suitability of ambulatory center resources for obese patient care. The International Society for the Perioperative Care of the Obese Patient (ISPCOP) held a review course lecture on Monday, May 20 titled, Ambulatory Surgery in Morbid Obesity: Quo Vadis?, to discuss future approaches to anesthesia care for obese patients in the ambulatory setting. Naveen Eipe, MD, faculty at University of Ottawa, presented the lecture, which was moderated by Satya Ramachandran, MD, FRCA, Harvard University.

Although BMI is a misleading metric, it has been used in many clinical studies regarding obese patients, thus remains relevant in clinical evaluation. Weight to height ratio proposed by the Society for Obesity and Bariatric Anesthesia United Kingdom (SOBA UK) has been shown to be a better indicator of obesity. A simple assessment of abdominal girth and patient shape (e.g., apple/pear shape) can also provide some information about weight status.

A preoperative assessment of the obese patient is necessary for identification of potential risks and assignment to the appropriate location for surgery. Ambulatory centers are designed for efficiency hence the selection of surgeries and candidates that are unlikely to require higher level of care. Post-operative complications not only disrupt the schedule of the center, but also put patients at significant risk. Complications are also associated with significant cost to the hospital and the patient in the form of case delays and/or cancellations and ambulance service costs respectively if patients are transferred to an emergency department of intensive care unit (ICU).

Preoperatively, patients should be educated, engaged and empowered to participate in optimizing their health through smoking cessation, obstructive sleep apnea (OSA) diagnosis and treatment, and treatment and control of comorbidities. OSA is problematic in the ambulatory setting and can delay extubation and discharge, and even cause significant complications necessitating transfer to higher level of care. The triad of obesity, OSA and opioids can be deadly, more so in an outpatient surgical center. Sedation can be treacherous in these patients because of the risk of respiratory obstruction and retention of carbon dioxide in the presence of OSA. High-flow oxygen therapy, and creative use of oral and nasal airways have been useful in managing obese patients without resorting to advanced airway interventions.

A multimodal approach to anesthesia care is necessary for management of the obese patient to minimize the risks. Opioid sparing techniques such as regional anesthesia, non-opioid analgesic medications will prevent the opioid-related postoperative nausea and vomiting, and respiratory events, expediting discharge.  

Important factors to determining appropriateness for an ambulatory center are BMI, type of procedure, comorbidities such as OSA, location of ambulatory center (proximity to hospital and ICU and higher level of care), pain associated with procedure, anesthesia plan (i.e., regional anesthesia).

Considerations for future directions that were discussed include:

• Screen for BMI and identify a hard cutoff for ambulatory assignments.
• The Obesity Surgery Mortality Risk Score (OSMRS) is a validated tool that could be useful as part of a decision-making matrix regarding appropriateness for an ambulatory center.
• Consider emulating enhanced recovery protocols, which have been used successfully in bariatric surgery, and applying these principles to optimizing obese patients, prior to ambulatory surgery. This will require buy-in from our surgical colleagues.
• Encourage the use of opioid sparing techniques when appropriate.
• Promote innovation in monitoring end tidal carbon dioxide, measuring apnea and/or ventilation.
• A consensus statement regarding ambulatory care for obese patients may become necessary in the future. Caution should be taken however in ensuring that these are not prohibitive to ambulatory centers with limited resources.

Obese patients can present unique challenges to perioperative care in the ambulatory setting. As the prevalence of obesity rises, conscientious efforts should be made to ensure that these patients are taken care of in settings with appropriate resources for their care. This will require patient and staff education, clinical protocols and guidelines, and multimodal approaches to anesthesia delivery.

*Coverage from ISPCOP Review Course Lecture: Ambulatory Surgery in Morbid Obesity: Quo Vadis? at the IARS 2019 Annual Meeting