Discussion:
Pulmonary air embolism is a serious medical emergency with significant clinical outcome that can result in death. It represents one of the deadly complications of central venous line insertion and removal [6]. The patient once suspected of having venous air embolism should be placed in the left lateral decubitus position with head down or Trendelenburg position to allow air bubbles to stay in the upper most part of the right ventricle which avoids further movement of the air bubbles into the pulmonary trunk and hence causing less embolization [11,12].Further management should include providing supplemental oxygen to increase the partial blood oxygen pressure and decrease the partial blood nitrogen pressure which will cause the nitrogen to diffuse from the air bubbles which has a high nitrogen pressure into the blood where it has a low pressure and thereby decreasing the air bubble size [13].Treatment with hyperbaric oxygen has been known to drop the mortality rate for severe cases particularly if used within 3 hours of onset of air embolism [9,15,16]. Preventive measures to be taken when inserting or removing a central venous line has been known for proper positioning of the patient in the Trendelenburg position especially for jugular and subclavian venous lines or supine for femoral lines, in addition to taking care of the patient volume status, and instructing the patient to do Valsalva maneuver or exhale during removal of the line [14]. In this paper, we are describing a case of suspected multiple sclerosis who presented with bilateral optic neuritis and was initially managed with pulsed steroids with no improvement then shifted to plasma exchange through a right jugular venous catheter through which he received 7 sessions of plasma exchange and upon removal of the jugular venous catheter in the sitting position he immediately developed shortness of breath with severe hypoxia and was found to have air bubbles in the left side of his heart due to a patent foramen ovale. He also developed acute respiratory distress syndrome and was shifted to the intensive care unit on high flow nasal canula. Within six hours of the event, he was started on hyperbaric oxygen and showed significant improvement. With extensive literature review on Pubmed, multiple cases were reported on the development of air embolism particularly causing cerebral air embolism through paradoxical air embolism following the removal of central venous catheters [17-20].Cases of pulmonary air embolism have also been reported following venous catheterization or removal [21-23]. Physician awareness of this potentially lethal complication of central venous catheterization or removal has been reported to be inadequate in a study done by Ely et.al. where it was found that around 42% of the 140 physicians who were surveyed did not show concern for air embolism when inserting a central venous line, although, 91% chose the Trendelenburg position during insertion, only 26% of the physicians reported concern for air embolism during central venous line removal , and around 13.9% of the physicians admitted elevating the head of the bed during central venous line removal which can potentially increase the risk of air embolism [24].
The main purpose of this paper is to emphasize on the importance of taking preventive measures to prevent air embolism when inserting or removing a central venous line and to increase the awareness among physicians to keep a high index of suspicion for such a serious complication. This paper also discusses the importance of commencing hyperbaric oxygen therapy in severe cases as it has shown effectiveness in reducing the size of air embolism and related morbidity. To conclude, Pulmonary air embolism related to central venous catheters insertion or removal, although uncommon, has been reported in the literature and physicians should keep in mind certain preventive measures when dealing with central venous catheters to prevent such a serious complication.