Complications of intravascular injection or anesthetic overdose include allergy, neurologic effects, and impaired myocardial conduction. Allergy is characterized by the typical symptoms of agitation, palpitations, pruritus, coughing, shortness of breath, urticaria, bronchospasm, shock, and convulsions. Treatment measures include administration of oxygen, isotonic intravenous ﬂuids, intramuscular or subcutaneous adrenaline, and intravenous prednisolone and aminophylline. Cardiac effects related to impaired myocardial conduction include bradycardia, cardiac arrest, shock, and convulsions. Emergency treatment measures include the administration of oxygen, intravenous atropine (0.5 mg), and intravenous adrenaline and the initiation of appropriate cardiac resuscitation. The most common central nervous system manifestations are paresthesia of the tongue, drowsiness, tremor, and convulsions. Options for therapy include intravenous diazepam and respiratory support.
Carbon dioxide is highly soluble in blood; consequently such emboli as occur are usually clinically insignificant; however, in rare instances, CO2 emboli may result in serious intra-operative morbidity and even death (221–223). These risks can be eliminated by avoiding the use of CO2 with operative procedures, by ensuring that the insufﬂation pressure is always lower than 100 mm Hg, and that the ﬂow rate is lower than 100 mL per minute. The insufﬂator used must be especially designed for hysteroscopy; it is difficult to set laparoscopic insufﬂator ﬂow rates below 1,000 mL per minute.
Dextran 70 is a hyperosmolar medium that, rarely, can induce an allergic response or coagulopathy (224,225). Similar to other types of distention media, if sufficient volumes are infused, vascular overload and heart failure can occur (226,227). Because dextran is hydrophilic, it can draw six times its own volume into the systemic circulation. Consequently, the volume of this agent should be limited to less than 300 mL.
The low-viscosity ﬂuids—1.5% glycine, 3% sorbitol, and 5.0% mannitol—are used commonly because of their low cost, compatibility with standard electrosurgery, and availability in large-volume bags. However, should these electrolyte free and usually hypotonic media be absorbed to excess in the systemic circulation, they can create serious ﬂuid and electrolyte disturbances, a potentially dangerous complication that can result in pulmonary edema, hyponatremia, heart failure, cerebral edema, and even death. There are a number of published guidelines describing the steps required to reduce the risk of ﬂuid overload at the time of hysteroscopy (228).
1.
Before undertaking anything but simple operative procedures using these agents, baseline serum electrolyte levels should be measured. Women with cardiopulmonary disease should be evaluated carefully. The selective preoperative use of agents such as GnRH agonists may reduce operating time and media absorption. Intracervical injection of 8 mL of a dilute vasopressin solution (0.01 U/mL) immediately prior to surgery is effective at reducing the amount of systemic absorption of distending media (229). The duration of this effect may be limited to approximately 20 to 30 minutes, so repeat dosing may be useful for optimal effect.
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In the operating room, media infusion and collection should take place in a closed system to allow accurate measurement of the “absorbed” volume. The volume should be measured continuously with a device specifically designed for the purpose or, if such a system is not available, calculated every 5 minutes by support staff who are trained in these calculations and unencumbered by duties that may interfere with this task.
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