by standard corrugated one-inch diameter plastic tubing to a home-heated humidifier unit with water bath placed in an unsecure manner on a table . The volume of the water bath was approximately 300 mL . The humidifier unit was connected by the same type of tubing to standard Y-connector that was connected via a short standard flex tubing to a tracheostomized infant mannequin in an infant bouncer on the floor . During reenactments , the flex tubing was connected to a 500 mL test lung . On three separate occasions , the humidifier unit was quickly displaced onto its side and within less than two seconds 175- 200 mL of water was rapidly dumped into the inspiratory limb of the ventilator circuit with approximately 25-50 mL entering the test lung .
Discussion :
To our knowledge , this is the first case report that identifies accidental displacement of a homeheated humidifier unit as a preventable cause of tracheostomy-related death in a child on long-term mechanical ventilation . Contributing factors to this unfortunate incident include unsecured placement of the home humidifier unit and location of the unit above the level of the child . These factors allowed the unit to be accidentally displaced and catastrophically spill water into the ventilator circuit and tracheostomy tube . During reenactment , we found that when the humidifier unit was quickly displaced onto its side , 175-200mL of water from a full water chamber rapidly filled the inspiratory tubing and 25- 50mL of water entered the test lung . We believe this volume of water to be sufficient to cause a tracheostomized small child on long-term mechanical ventilation significant distress and possible fatal outcome , as in our patient .
A brief phone survey revealed families were not consistently instructed by our institution or their local home durable medical equipment ( DME ) company to secure the home-heated humidifier unit so it could not be displaced or to ensure the heated humidifier unit was situated below the level of the patient . These instructions were not included in a recent respiratory care practice guideline , 7 but a warning that the humidifier should always be mounted and positioned lower than the patient was found in the technical manual for a commonly used home-heated humidifier unit . 8 Review of United States Food and Drug Administration ( FDA ) safety communications for heated humidifiers revealed only one public health notification that concerned the risk of fire or electrical injury . 9
Based upon this incident , we strongly recommend the following : 1 ) heated humidifier units should be secured to a non-tipping medical pole via
Secured correctly placed heated humidifier
Figure 2 : Home ventilator and heated humidifier unit showing correct setup : a ) heated humidifier unit mounted as low as possible on non-tipping medical pole , and b ) close up posterior view of mounting bracket and heated humidifier unit .
appropriate mounting clamp or bracket ( see Figure 2 ) or the device should be clamped or bolted to a flat table or sturdy non-tipping stand ; 2 ) heated humidifier units should always be below the level of the child ; 3 ) local and national DME and home nursing companies should be made aware of this potential hazard ; 4 ) appropriate verbal and written safety instructions should be given to all families who have a child with a tracheostomy on long-term mechanical ventilation ; 5 ) a heat and moisture exchanger ( HME ) should be utilized when the child is on the floor or below the level of the heated humidifier unit ; and 6 ) appropriate methods of securing and safe use of heated humidifier units in the hospital should be modelled . Since this incident , we have incorporated additional heated humidifier safety information into our in-hospital tracheostomy training , provided verbal and written education to families with children who are already at home , and notified our local DME and home nursing companies of this potential hazard .
References :
1 . Wallis C , Paton JY , Beaton S , Jardine E . Children on long-term ventilator support : 10 years of progress . Arch Dis Child 2011 ; 96:998-1002 .
2 . Amin R , Sayal P , Syed F , Chaves A , Moraes TJ , MacLusky I . Pediatric long-term home mechanical ventilation : twenty years of follow-up from one Canadian center . Pediatr Pulmonol 2014 ; 49 : 816-824 .
3 . Edwards JD , Kun SS , Keens TG . Outcomes and causes of death in children on home mechanical ventilation via tracheostomy : an institutional and literature review . J Pediatr 2010 ; 157:955-959 .
4 . Com G , Kuo DZ , Bauer ML , Lenker CV , Melguizo- Castro MM , Nick TG , Makris CM . Outcomes of children treated with tracheostomy and positivepressure ventilation at home . Clin Pediatr 2013 ; 52:54-61 .
5 . Wilcox LJ , Weber BC , Cunningham TD , Baldassari CM . Tracheostomy complications in institutionalized children with long-term tracheostomy and ventilator dependence . Otolaryngol Head Neck Surg 2016 ; 154:725-730 .
6 . Sherman JM , Davis S , Albamonte-Petrick S , Chatburn RL , Fitton C , Green C , Johnston J , Lyrene RK , Myer III C , Othersen HB , Wood R , Zach M , Zander J , Zinman R . Care of the child with a chronic tracheostomy . Am J Respir Crit Care Med 2000 ; 161:297-308 .
7 . Restrepo RD , Walsh BK . Humidification during invasive and noninvasive mechanical ventilation : 2012 . Resp Care 2012 ; 57:782-788 .
8 . MR850 Respiratory humidifier technical manual ( Revision J ). 2005 Fisher & Paykel Healthcare Ltd . Accessed at : www . nbngroup . com / manuals / machine / V-MR850TechManual . pdf ( last accessed May 29 , 2017 ).
9 . Burlington B . Hazards of volume ventilators and heated humidifiers . FDA Public Health Notification September 15 , 1993 . Accessed at : https :// wayback . archive-it . org / 7993 / 20170111190812 / http :// www . fda . gov / MedicalDevices / Safety / AlertsandNotices / PublicHealthNotifications / ucm238179 . htm ( last accessed May 29 , 2017 ).
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