We would like to draw the attention of your readers to the outcome of a survey undertaken in Kettering General Hospital. We wanted to determine what methods clinicians use to confirm central line cannula/needle position before dilatation and what their removal plan would be for an accidental insertion of a central line (>7 Fr) into the carotid artery.
We performed a paper survey of 52 doctors in anaesthesia/intensive care at Kettering General Hospital. We achieved a 100% return rate. We asked the doctors to answer questions based on their practise over the previous year period. The majority of people surveyed were consultants (47%). The results of the survey revealed doctors mostly utilised ultrasound confirmation of guidewire before dilatation (89%) but only 19% utilised pressure transduction. A large proportion of doctors surveyed either did not know how to manage carotid artery cannulation with a >7 Fr central line (35%) or would ‘pull and press’ (40%). Only 5% of the doctors who would ‘pull and press’ would arrange computed tomography (CT) angiogram follow up.
We highlighted a lack of clarity, which may be widespread. It is advisable to seek a vascular surgeon or interventional radiology input to facilitate line removal due to the excessive complications related to the ‘pull and press’ technique (47% complication rate).1 Complications include pseudoaneurysm formation, airway compromising haematomas, arteriovenous fistula, stroke and death.1 If such lines are removed by the ‘pull and press’ technique it is recommended to arrange CT angiogram even if the patient is asymptomatic due to the possibility of pseudoaneurysm or arteriovenous fistula formation.1
We correctly utilised ultrasound confirmation of guidewire position before dilatation. However ultrasound alone has not eliminated accidental arterial dilatation. This still occurs despite ultrasound usage especially in cases involving inexperienced clinicians and the guidewire going through the vein and into the artery.2 The combined use of ultrasound and transduction may further reduce the incidence of carotid cannulation.3 This may prove invaluable in centres without vascular or interventional radiology support.
Our centre has reduced its usage of central venous pressure (CVP) monitoring. This may reflect our lack of transduction prior to dilatation for central line insertion. Hence we devised a novel use of the double male Luer lock connector. This connector allows the female connector end of an infusion line to connect to the female connector of the blood aspirating port of an arterial transducer. This will then allow transduction of a central line cannula, before dilatation, via the arterial transducer by turning the 3-way tap (Figure 1). This removes the need to set up a separate transducer and also prevents the need to disconnect connections in the arterial line to allow CVP confirmation, as this was considered an infection risk.
Figure 1: Double male Luer lock connector attached to the blood aspirating port of an arterial transducer, with a fluid line connecting this to the central venous cannula
Immediate postoperative care of patients undergoing nasal surgery, e.g. septoplasty or rhinoplasty, could be hazardous as desaturation happens frequently especially if the patient is not fully recovered struggling for nasal breathing while the nose is packed with gauze.1,2 Moreover, ice may be applied to the nose in the operating room to decrease swelling, and an external splint could be taped by the surgeon onto the patient’s face.3 All make it difficult to apply and fit a Hudson recovery face mask in the post-anaesthesia care unit (PACU) to maintain adequate oxygenation.
Figure 1
Facing this problem, we prepared an oral oxygenating airway device, to maintain an open unblocked airway in addition to adequate oxygenation, in the early recovery period for patients undergoing nasal surgery. Our device (Fig 1,2) is an oral airway size 4 or 5 with a siliconised soft endotracheal tube (ETT) size 5.5 mm fixed alongside the airway with its bevel directed laterally to provide easy insertion of the airway. The distal end of the ETT is cut 4-5 cm from the airway to be connected to a breathing circuit through a 15 mm connector or connected directly to tubing of oxygen flow-meter supplying humidified oxygen at a low flow rate of 1-2 L/minute to provide FIO2 35-40%. This device was tried successfully in 54 patients scheduled to septoplasty and rhinoplasty.
Figure 2
In conclusion, this device is simple, cheap, easily inserted, efficiently maintains adequate arterial oxygen saturation as long as the oral airway is tolerated in the early recovery period, reduces the oxygen flow rate and, in addition, an oxygen analyzer can be connected to the 15 mm connector to provide monitoring of the delivered FIO2.
