Hysteroscopy and IUD insertion in Patient with BMI 77

PIG Meeting: 1st July 2021

56-year-old lady with endometrial hyperplasia for hysteroscopy, D&C, Mirena


  • Obesity Hypoventilation syndrome – on home BiPAP, compliant
  • Asthma – recent admission with exacerbation of asthma and type 2 respiratory failure
  • Spirometry; FEV1 = 0.8 (33%) and FVC = 1.4 (42%)
  • AF – Apixaban and metoprolol. Rate-controlled.
  • Hyperthyroidism


  • Super-morbid obesity
  • Dyspnoea on minimal exertion
  • No previous cardiac investigations despite AF and multiple risk factors


Perioperative optimisation

  • Dyspnoea – likely multifactorial due to obesity, respiratory disease, and deconditioning.
  • Regular review by respiratory physician ongoing
  • Should we exclude cardiac causes? Not required preoperatively for this procedure, but prudent to begin process of investigations as will likely require repeated procedures and ultimately, a hysterectomy.
  • Discussed at cardiology meeting – advised proceed as planned, should have BNP and if significantly raised then organise an Echocardiogram

Anaesthetic Management

  • Opioid-sparing anaesthetic options discussed: sedation with THRIVE/BiPAP, spinal.
  • Similar cases discussed that have been performed under ketamine sedation and using THRIVE
  • Difficult to perform as a day case if opioids administered.
  • ANZCA document PS15 ‘Guideline for the perioperative care of patients selected for day stay procedures.’ advises that patients with confirmed or suspected OSA should have minimal post-operative opioid requirement and ideally discharge analgesia should not include opioids.

BNP as a diagnostic tool

  • Increases in Plasma BNP can indicate a diagnosis of HFpEF or HFrEF
  • Also used as a biomarker in pulmonary hypertension
  • Differentiate between pulmonary cause of dyspnoea and undiagnosed Heart Failure
  • The Breathing not properly study (attached article) showed low plasma concentrations of BNP had a negative predictive value of 96%
  • Suggested in this case as an Echocardiogram would be technically difficult and may not be required if BNP normal
  • Affected by obesity – lower plasma concentrations seen in obese patients


  • Discussed with procedural anaesthetist – aim to perform procedure with BiPAP and sedation
  • BNP to be done on admission to hospital as patient has no way to travel to pathology, results to be discussed at cardiology meeting if required