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  Table of Contents 
Year : 2018  |  Volume : 19  |  Issue : 2  |  Page : 99-100

Detachment of the externally reinforced wire from the circuit tubing: Cause of circuit kinking

Department of Anaesthesia, All India Institute of Medical Sciences, Patna, Bihar, India

Date of Web Publication15-Nov-2018

Correspondence Address:
Dr. Ajeet Kumar
112, Block 2, Type 4, All India Institute of Medical Sciences Residential Complex, Khagaul, Patna - 801 505, Bihar
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/TheIAForum.TheIAForum_41_18

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How to cite this article:
Kumar A, Kumar A, Sinha C, Kumari P. Detachment of the externally reinforced wire from the circuit tubing: Cause of circuit kinking. Indian Anaesth Forum 2018;19:99-100

How to cite this URL:
Kumar A, Kumar A, Sinha C, Kumari P. Detachment of the externally reinforced wire from the circuit tubing: Cause of circuit kinking. Indian Anaesth Forum [serial online] 2018 [cited 2023 Jun 7];19:99-100. Available from: http://www.theiaforum.org/text.asp?2018/19/2/99/245548


The breathing circuits of a noninvasive ventilator are designed to provide low resistance kink free ventilation of the patients. Here, we report a case of obstruction due to the shrinking of inner tubing from the external reinforced wire.

A 45-year-old male chronic obstructive pulmonary disease patient with lower respiratory tract infection was admitted in our high dependency unit with breathlessness. He was on antibiotics and nebulization. Noninvasive ventilation was started with bi-level positive airway pressure (Respironics BiPAP machine with reusable flexible tubing) settings of 12/7 which he was tolerating well as seen in the arterial blood gas findings 1 h after starting ventilation.

After a few hours, there was a progressive decrease in peripheral oxygen saturation, which had decreased to 85%. The monitor of the NIV showed inadequate tidal volume being generated. On auscultation, the chest was clear. On inspecting the ventilator circuit, it was found that the externally reinforced wire had detached from the tubing, which had shrunk as shown in [Figure 1]. We immediately changed the ventilator circuit, after which the patient s saturation improved.
Figure 1: Circuit twisted after its detachment from wire

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Reinforcement of the tube is required to prevent tube kinking, tube collapse, tube expansion during positive pressure ventilation. Reinforcement can be done either intramural (wire inside wall of the tube) or extramural (wire outside the tube). The main purpose of external wire is to prevent tube expansion during positive pressure ventilation and to prevent tube kinking. However in this case, the internal tube got detached from wire and was twisted on its self thereby preventing ventilation.

Kinking of the disposable tubing of circle system causing difficulty in ventilation has been reported.[1] Thereafter, kink resistant tubes with silicone rings were introduced. A case of crowding of the rings and kink in silico n-reinforced nonkinkable tubes has also been reported.[2] The disposable corrugated plastic tubes are still in use, especially in peripheries as they are economical.

We conclude that the intramural reinforcement or use of corrugated plastic tube is more beneficial than using an extramural reinforced tube which may be life-threatening for the patient if not detected early.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Vohra SB. Kinking of disposable anaesthetic circuits. Anaesthesia 2006;61:721.  Back to cited text no. 1
Desai S, Torgal S, Rao R. Breathing circuit obstruction caused by kink in the reinforced kink-resistant circle system tube. Indian J Anaesth 2013;57:96-7.  Back to cited text no. 2
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