Hemodynamic Changes During Operative Hysteroscopy

Operative hysteroscopy has become a standard surgical treatment for abnormal uterine bleeding unresponsive to conservative medical management since it was shown as a safe and effective alternative to hysterectomy.(2,3) Monopolar resectoscope necessitates an irrigating fluid that should be a non-conductive and salt free solution such as glycine 1.5% or sorbitol 3%.(4) Physiologic irrigating fluids (e.g. saline 0.9%) are contraindicated with these instruments since electric current generated by any monopolar electro surgical unit is preferentially conducted through low impedance fluid rather than through tissue and consequently it's difficult to initiate cutting and impossible to create significant tissue coagulation with these devices The clinical drawback of non-conductive irrigating solution (e.g. glycine 1.5%) is the risk of excessive fluid absorption leading to symptomatic dilutional hyponatremia and for hypotonic solutions, hypo-osmolarity and secondary cerebral oedema as Glycine is metabolized to carbon dioxide, water and ammonia, and may lead to intra-cellular over hydration and neurotoxicity which is clinically reflected as hypoxemia, agitation, nausea and hypertension.(5).Although rare, irreversible neurologic damage and death have been reported after excessive absorption of salt free irrigating solutions during routine operative hysteroscopy(6)Theoretically, distension with 0.9% saline as a distension medium avoids most of the above mentioned risks associated with hyper absorption of non electrolytic distension media(7) However, there is no doubt that excessive absorption of normal saline can be fatal(8).

Recently , it has been suggested that the type of anesthesia could modify fluid absorption(9). General anaesthesia has been associated with less Glycine absorption than epidural anaesthesia: the latter being associated with systemic vasodilatation(9).