If perforation is suspected, laparoscopy or laparotomy is necessary to clarify the cause of pain, unstable vital signs, or free fluid visualized by ultrasound.6
Exercise extra care and precautions in women who have had a prior cesarean section, myomectomy, or uterine perforation. Complete visualization of uterine landmarks is necessary during operative hysteroscopy to exclude uterine dehiscence, sacculation, and perforation. Prior uterine surgery may cause myometrial weakness and lead to possible perforation. Do not proceed if abnormal uterine morphology is detected. If uterine perforation occurs, injury to bladder and bowel is possible when electrical energy is applied to a uterine wall compromised by prior surgery. Strict visualization of uterine anatomy is critical in this population so that bowel or bladder burns can be avoided.
MEDIA-RELATED COMPLICATIONS
Notorious complications and several recent lawsuits have stemmed from fluid overload. A common element has been the physician’s lack of awareness of how rapidly complications can arise, and what signs and symptoms are specific to the fluid used.
Monitor fluids vigilantly
Operative hysteroscopy must be performed in a fluid medium. The type of fluid depends on the surgeon’s preference and the instrument utilized, but any fluid can be associated with complications. Fluid choices with monopolar instruments include glycine 1.5%, a mixture of sorbitol 3% and mannitol 0.54%, and mannitol 5%. These are frequently used with the continuous-flow resectoscope. Bipolar operative hysteroscopy can be performed using saline.
The solution to media-related complications is basic: vigilant monitoring of fluids. A cavalier attitude, poor fluid documentation, and failure to respond to complications can lead to trouble. If fluid overload occurs, comanagement and consultation with an intensive care specialist is advised.
Distention media
Among the options for distention media in operative and diagnostic hysteroscopy are high-viscosity dextran 70 and low-viscosity fluids such as hypotonic, electrolyte-free and isotonic, electrolyte-containing solutions. The popularity of dextran 70 is waning, however. While it is immiscible with blood, significant complications have been reported.
Signs of anaphylactic reactions to dextran 70 include acute hypotension, hypoxia, pulmonary edema, fluid overload, fulminant coagulopathies, and anemia. The surgeon must operate quickly, minimize endometrial trauma, use continuous pulse oximetry, and obtain a preoperative coagulation panel.
Dextran 70 also can ruin operative hysteroscopes if they are not cleaned promptly and thoroughly after use.
Hypotonic, electrolyte-free solutions. With hypotonic, electrolyte-free solutions such as glycine 1.5%, early recognition of possible complications, including hyponatremic hypervolemia, is vital. For example, when glycine and sorbitol are metabolized, free water accumulates and the body attempts to achieve homeostasis through compensatory mechanisms such as osmosis, which moves free water into extracellular and intracellular spaces. This can lead to increased free water in the brain, resulting in cerebral edema, rising intracranial pressure, and cellular necrosis.
The cerebral cation pump normally pumps osmotically active cations into the extracellular space, thereby minimizing cerebral edema. However, this pump is inhibited by estrogen, so the compensatory mechanism is diminished.
Classic clinical features of hyponatremic hypervolemia include apprehension, confusion, fatigue, headache, mental agitation, nausea, visual disturbances (including blindness), vomiting, and weakness. These complications are more readily apparent when regional anesthesia is used rather than general anesthesia.
If hyponatremic hypervolemia goes unrecognized, bradycardia and hypertension can ensue, followed rapidly by cerebral and pulmonary edema and cardiovascular collapse. In addition, glycine 1.5% is metabolized to glycolic acid and ammonia. Free ammonia is associated with central nervous system disorders. Recognition and prompt treatment by an intensivist may prevent permanent neurologic sequelae, death, and lawsuits.7
Isotonic, electrolyte-containing solutions. Mannitol 5% is electrolyte poor but isotonic, creating less risk for hypo-osmolality. However, dilutional hyponatremia (ie, low sodium levels) can still occur.
Advantages of bipolar instruments. To minimize complications from hypotonic, electrolyte-free solutions, manufacturers developed operative hysteroscopes that can function in a bipolar environment. Bipolar instruments can operate in isotonic, physiologic, electrolyte-containing media. Hyponatremia and hypo-osmolality cannot occur with normal saline or Ringer’s lactate, but fluid overload can. (Fluid overload with saline can cause pulmonary edema and congestive heart failure.)
How much fluid will be absorbed? The answer depends on factors including surface area of the surgical field, duration of surgery, opened venous channels, type of irrigation fluid used, and pressure of the delivery system. Modern gynecologic suites employ fluid irrigation systems that continuously measure input and output, with alarms that signal a predetermined fluid deficit. The alarm indicates the need to halt the procedure and quickly evaluate the patient. Careful attention to the recommendations of Loffer et al8 would lead to fewer complications from fluid mismanagement.
Appropriate use of CO2
High risk of embolism with CO2 in operative procedures. Although diagnostic hysteroscopic procedures often are performed with carbon dioxide (CO2), operative procedures never should be. The reason: the high risk of CO2 embolism that occurs with open venous channels and vascular endometrium. The choice between CO2 and fluid medium for diagnostic hysteroscopy often is determined by physician preference and the presence of uterine bleeding. Many gynecologists prefer CO2 for its optical clarity and patient comfort during insufflation.9