|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 2 | Page : 66-67
Is it time for yet another new safety feature in workstations?
Bharat Paliwal, Pradeep Bhatia, Shilpi Verma, Manoj Kamal
Department of Anesthesiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
|Date of Web Publication||16-Dec-2016|
Dr. Bharat Paliwal
Sector-23, House-14, Chopasni Housing Board Colony, Pal Road, Jodhpur - 342 008, Rajasthan
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Paliwal B, Bhatia P, Verma S, Kamal M. Is it time for yet another new safety feature in workstations?. Indian Anaesth Forum 2016;17:66-7
Over the years, conventional anesthesia machines have evolved into the anesthesia workstations capable of providing finest care. This development is an evolving process and each time some new problem is encountered, it lays pathway for incorporation of additional safety features in these workstations.,,,, We report one such incidence that may require technical modification in machine mechanics.
A 65-year-old patient belonging to American Society of Anesthesiologists physical status II was posted for microlaryngeal surgery. Routine preuse check of Drager workstation (Fabius® GS premium) was performed and standard monitoring was attached to the patient. After giving premedication, the patient was preoxygenated using closed breathing circuit system (circle system). During induction with intravenous (IV) propofol, the patient developed apnea, so volume-controlled (VC) ventilation was started through face mask. After observing adequate chest expansion, atracurium 25 mg IV was given and isoflurane 1.2% was started. As the larynx was anterior, intubation took around 20 s. Meanwhile, the oxygen saturation (SpO2 ) dropped to 70%. VC ventilation was resumed through endotracheal tube, but the rise of SpO2 was very slow despite bilateral equal air entry, normal capnography, and 6 L/min fresh gas flow of oxygen. We noticed that the fraction of inspired oxygen (FiO2 ) displayed on anesthesia workstation was 21% which was initially thought to be due to malfunctioning of FiO2 sensor. A closer look at the machine revealed that the manually operated selector switch was accidently kept at open circuit mode [Figure 1]a and [Figure 1]b instead of circle system [Figure 1]c and [Figure 1]d. Hence, the ventilator continued to ventilate the patient with air alone and oxygen-isoflurane mixture was not being delivered to the patient. Although ventilation was not compromised due to the above-mentioned error, the patient could not be preoxygenated which led to rapid desaturation.
|Figure 1: (a) Ventilator continues to ventilate even with selector switch turned to open circuit. (b) Note fraction of inspired oxygen display of 21% even though oxygen flow is turned on. (c) Ventilator operating in closed circuit (d) with oxygen flow turned on. Note the fraction of inspired oxygen display of 98%|
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Following the above incidence, we suggest that the workstation may be equipped with an alarm to alert the machine user when fresh gas flow is not delivered to ventilator or to incorporate a mechanism that allows ventilator to be used only in closed system.
We would like to thank Dr. Anamika Purohit and Dr. Kamal Kishore for their assistance in preparing the manuscript.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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