Fatal vascular air embolism during fluid resuscitation as a complication of pressure infuser bag

Dear Editor,

Vascular air embolism (VAE) is an unprecedented yet conceivably disastrous occasion that happens as a result of the entrance of air into the vasculature. Most reports on the topic of VAE deal primarily with surgical procedures where the operative site is above the level of the heart.[1] Accidental administration of air while using a pressure infuser bag is rare. We are reporting an unfortunate case of intra-operative air embolism leading to cardiovascular collapse.

A 55-year-old female diagnosed as a case of ovarian carcinoma and planned for debulking gynecological surgery. We did induction of anesthesia with thiopentone sodium 150 mg and trachea was intubated after succinylcholine 75 mg. Anesthesia was maintained with isoflurane 1-1.5% in O₂/N₂O and intravenous (IV) morphine was used in increments for intra-operative analgesia. Due to anticipated prolonged surgery and blood loss, another IV cannula was maintained with Ringer's Lactate on right foot. When sudden hemorrhage occurred, a pressure infuser bag was applied to the right foot infusion set to overcome the resistance of Tedd's stockings and to augment fluid resuscitation. Few minutes later, we noted desaturation to 85% and a sudden drop in end tidal carbon dioxide to 19 mmHg and then negligible trace on the monitor with associated bradycardia and circulatory collapse. Immediately, we realized that an un-noticed and an unknown amount of air went through the foot cannula, which was identified as a column of air in the infusion set and fluid bag was completely emptied [Figure 1]. Infusion set was immediately discontinued, call for help given and patient was put in the head down position, but quickly changed to head up to make heart level above the source of air entry which in our case is foot cannula. The resuscitative measures were started with fluid loading, adrenaline infusion 0.5 µg/kg/min and central venous catheter was inserted in the right internal jugular vein through which 250-300 ml blood mixed with air was aspirated. Cardiopulmonary resuscitation continued for 30 min and then she gradually stabilized. Surgeon was asked to complete rest of surgical procedure and patient shifted to intensive care unit for postoperative ventilation and further management.

Figure 1.

Pressure bag applied to plastic bottle with empty chamber and column of air in tubing

The two crucial elements deciding the morbidity and mortality of VAE are specifically identified with the volume of air entrainment and rate of accumulation. From case reports of accidental intravascular delivery of air, the adult lethal volume has been described as between 200 and 300 ml, or 3-5 ml/kg.[2] The incidence of VAE from a pressurized fluid may be underreported on the grounds that the conclusion is troublesome and generally made by exclusion. Gray and Glover reported two cases of VAE while infusing Haemaccel^® from a pressurized plastic bottle with a standard administration set. They demonstrated that up to 45 ml of air expelled from IV set could be infused into a patient.[3]

In conclusion, this case involved the accidental rapid embolism of air of the unknown amount through the peripheral venous catheter during the attempted volume resuscitation with the application of pressure infuser bag applied over the plastic infusion bottle. VAE is preventable critical medical emergency. Given the potential adverse outcome of iatrogenic air embolism, all staff involved in administering IV fluids need to be fully trained to remove air by venting prior to infusion. When infusing crystalloid under pressure, extra care must be taken to definitively expel air prior to placement of any pressurized infusion device and use of devices that incorporate automatic detection of air coupled with a shut-off mechanism.