Saudi Journal of Anaesthesia

LETTERS TO EDITOR
Year
: 2020  |  Volume : 14  |  Issue : 4  |  Page : 559--560

Different standards of the variable pitch for oxygen saturation with pulse rate and heart rate monitoring: An avoidable complication


Tanya Aysha Edathodu, Renu Sinha, Thilaka Muthiah, V Yokasekar 
 Department of Anesthesiology, All India Institute of Medical Science, New Delhi, India

Correspondence Address:
Dr. Thilaka Muthiah
Department of Anesthesiology, Room Number 5011, All India Institute of Medical Science, Ansari Nagar, New Delhi - 1110029
India




How to cite this article:
Edathodu TA, Sinha R, Muthiah T, Yokasekar V. Different standards of the variable pitch for oxygen saturation with pulse rate and heart rate monitoring: An avoidable complication.Saudi J Anaesth 2020;14:559-560


How to cite this URL:
Edathodu TA, Sinha R, Muthiah T, Yokasekar V. Different standards of the variable pitch for oxygen saturation with pulse rate and heart rate monitoring: An avoidable complication. Saudi J Anaesth [serial online] 2020 [cited 2022 Jun 29 ];14:559-560
Available from: https://www.saudija.org/text.asp?2020/14/4/559/295996


Full Text



Sir,

After installing the new multipara monitor Drager infinity C700 in our operation theatres, during anesthetic management of a 6-month-old infant, oxygen desaturation from 98% to 80% went unnoticed as the anesthesiologist was busy positioning the infant and there was no change in the pitch of pulse tone during desaturation. After scrutinizing the features of the Drager infinity C700 monitor, we found that the monitor's default pulse tone source was from electrocardiography (ECG) and in case of desaturation, there would be no change in the pitch of pulse tone. The monitor gives an audible alarm only when the oxygen saturation (SpO2) falls below the set lower alarm limit for SpO2.

Variable pitch pulse tone will be active if pulse tone source is manually changed to SpO2, as it is not a default setting in the Drager infinity C700 monitor. Hence, one has to manually change the source of the pulse tone to pulse oximeter after switching on the monitor every time, to have the audible pulse tone change during variation of SpO2. In case the pulse tone source is not changed to SpO2 after switching on the monitor, it can lead to unnoticed desaturation during intubation or any procedure, especially if a single anesthesiologist is managing the case.

Although we are trained to differentiate variable pitch of SpO2 during anaesthesia management,[1] we propose that the Drager infinity C700 monitor manufacturers should consider changing the monitor's default pulse tone source from ECG to SpO2 and may incorporate the variable pitch pulse tone for the ECG source as well. This will ensure the safety of the patient in the operating room as per the American Society of Anesthesiologists (ASA) standard of basic monitoring during anesthesia.[2]

Declaration of patient consent

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

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Loeb RG, Brecknell B, Sanderson PM. The sounds of desaturation: A survey of commercial pulse oximeter sonifications. Anesth Analg 2016;122:1395-403.
2ASA. Standards For Basic Anesthetic Monitoring. Schaumburg, IL: American Society of Anesthesiologists, 2010. Available from: http://www.asahq.org/~/media/sites/asahq/files/public/resources/standards-guidelines/standards-for-basic-anesthetic-monitoring.pdf. [Last accessed on 2015 Jul 16].