The use of TIVA in a super-morbidly obese woman for partial nephrectomy.

P Gillen, A Kapila

Department of Anaesthetics, Royal Berkshire Hospital, Reading, RG1 5AN, UK

Introduction:        

Mrs X, a super-morbidly obese patient (BMI 72, weight 198 Kg) presented for an urgent partial right nephrectomy. She also suffered from insulin dependent diabetes, hypertension and gastro-oesophageal reflux disease. Her exercise tolerance was limited to dyspnoea on 3 METS due, in part, to mechanical arthralgia. Examination of her airway, cardiovascular and respiratory systems were normal. Her medication included insulin and anti-hypertensives. All other tests were normal.

Methods:                               

Following careful discussion with the patient she consented to undergo a general anaesthetic, with intravascular monitoring and the provision of post-operative analgesia using a thoracic epidural, which were inserted under local anaesthesia pre-induction. The patient positioned herself in the semi-recumbent position. A remifentanil infusion, delivered via a Fresenius TCI System™, was commenced prior to the instigation of an awake fibre-optic intubation which, along with topical local anaesthesia, was achieved via effect-site remifentanil concentration of 1 ng.ml^-1. (Parameters inputted into the TCI system included the patient’s weight, height, age and gender.) On confirmation of placement of an endotracheal tube, general anaesthesia was instigated using the Fresenius TCI System™, with a combination of propofol and remifentanil, augmented with epidural anaesthesia and balanced analgesia. The patient was haemodynamically stable throughout the 90 minute surgery. Despite her supermorbid obesity, the emergence time for this lady to be fully awake, and able to protect her airway, was approx 5 minutes.

Results:                 

We found that the Fresenius TCI System™ was capable of administering a safe and appropriate TIVA technique to the super-morbidly obese with excellent clinical effects; this patient’s BMI being the highest recorded as having undergone a total-intravenous-anaesthetic in this institution.

Discussion:           

The choice of general anaesthetic technique in morbidly obese patients is controversial¹ with the increasing recognition of the influence of technique choice on post-operative recovery ². This clinical challenges of this case included super-morbid obesity, hypertension, gastro-oesphageal reflux, probable diabetic gastro-paresis with surgery performed via an abdominal incision, potentially impairing respiration. It was essential that she underwent an anaesthetic technique which could ensure a smooth induction, maintenance and rapid emergence from anaesthesia.

TIVA has been found to be an effective anaesthetic technique in the morbidly obese³. We believe that this case exemplifies some of the reasons why TIVA offers significant advantages over a volatile technique; including a potentially more haemodynamically stable, controlled anaesthetic in patients who poorly tolerate large and rapid changes in blood pressure and fluid shifts. Other advantages include the predictable, rapid emergence despite the very large adipose compartment which can delay the emergence from volatile anaesthesia.

References:  

1. Salihoglu et al (2001) “Total Intravenous Anesthesia versus Single Breath Technique and Anesthesia Maintenance with Sevoflurane for Bariatric Operations,” Obesity Surgery, 11, 4, 496-501(6)

2. Gaszynsk and Tomasz (2004) “Anesthetic complications of gross obesity,” Current Opinion in Anaesthesiology,17,3,271-276

3. Alvarez et al (2000) “Total Intravenous Anesthesia with Midazolam, Remifentanil, Propofol and Cisatracurium in Morbid Obesity,” Obesity Surgery, 10, 4, 353-360(8)