Venous air embolism associated with removal of central venous catheter.

Abstract

Tumurs <5 cm in diameter and at the anal margin have a more favourable prognosis. PrognosisFor prognostic purposes most information of clinical value is obtained by distinguishing tumours arising at the anal margin from those in the anal canal and separating them into those greater or less than 5 cm in diameter. The tumour is relatively uncommon so there have been relatively few large follow up studies, but the five year survival rate is about 50%. The need to avoid air embolism when inserting and manipulating central venous catheters is widely appreciated but the risk after catheter removal is less widely known. This has implications regarding the delegation of practical procedures.' Case report A 73 year old man was admitted for elective repair of an 8 cm abdominal aortic aneurysm. The past history included a myocardial infarction complicated by ventricular fibrillation eight years previously and an episode of acute left ventricular failure one year before when mitral incompetence was noted. The preoperative echocardiogram showed minimal mitral regurgitation and an ejection fraction of 54%. The aneurysm repair was uneventful, lasting 90 minutes. An episode ofpulmonary oedema on the first day was easily treated with diuretics and oxygen. Thereafter, he had an uneventful course, returning from the intensive care unit to the ward on the second postoperative day.A pulmonary flotation catheter (7 5 French gauge) had been inserted into the right internal jugular vein at the time of operation and the catheter sheath was removed by the houseman on the fifth day. About two minutes later the patient collapsed and became unresponsive with no palpable cardiac output. Cardiac massage was begun. On arrival the arrest team noted a spontaneous respiration rate of 18/min with good ventilatory efforts. Pulse was 120/min, regular, and in sinus rhythm. Blood pressure was 90/60 mm Hg and there was good colour and no cyanosis. The patient was sweating profusely. He was unresponsive to painful stimuli. Pupils were of normal size and reacting symmetrically. There were no focal neurological signs. Chest sounds were normal but examination of the heart disclosed widespread loud, harsh, crunching sounds throughout systole and diastole over the whole precordium. The originally recorded murmur of mitral incompetence could not be heard.Examination of abdomen and legs showed nothing abnormal apart from the recent incision. Blood glucose concentration was 6-7 mmol/l, and haemoglobin and Prevention Central venous catheters must be removed with the patient supine or in slight Trendelenberg position and the entry site covered by an air occlusive dressing.

Cerebral Air Embolism after Central Venous Catheter Self-Extraction

“…Firstly, with regards to positioning, the upright posture after our patient removed the catheter not only increased the risk of introducing air into the venous circulation but also the likelihood of air bubble transit "upwards" into the cerebral vessels. 8,9 Secondly, paradoxical embolism may occur in the absence of cardiac defects. 3,4,7,10 Although a trans-esophageal echocardiogram or a trans-thoracic echocardiogram with Valsalva is more sensitive in diagnosing intra-atrial shunts 11 , the absence of cardiac defects in this patient lead us to suspect the paradoxical embolism was related to transpulmonary passage of air bubbles.…”

Massive Air Embolism After Central Venous Catheter Removal

“…2 Air aspiration through the residual perfusion channel during or after central venous catheter removal is a probably not-so-rare and well-known complication. 3 This is, to the best of our knowledge, the first real-time documentation of air arrival in the right side of the heart. …”

Venous Air Embolism

“…64,67 Malfunction of the introducer valve 68,69 and disconnection of the two-part sheath and side-port/valve mechanism 70 have been implicated in reports of massive VAE. Despite the subsequent manufacture of one-piece introducers 70 and standard self-sealing valves, 64 some still recommend that an introducer is not left in place after the removal of the SG or pacing catheter.…”

“…There are numerous reports of VAE after the removal of CVCs. 7,[65][66][67][71][72][73][74] Surveys of physicians-in-training and critical care nurses have shown a lack of awareness of the potential for VAE after catheter removal. 66,72 Formation of a fibrin sleeve has been shown within 24 h of CVC placement, 75 providing a potentially patent tract for VAE to occur.…”

“…Possible contributing factors for VAE after CVC removal include upright patient position during or immediately after removal, coughing or straining, coagulopathy, and the use of a non-occlusive dressing. 7,[65][66][67][72][73][74] Clinical Presentation…”