Page 39 - JSOM Spring 2021

Use of a Pressure Cooker to
Achieve Sterilization for an Expeditionary Environment

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Ross K. Cook, DMD, MS *; Jason McDaniel, DDS ;
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Manuel Pelaez, DMD, MS ; Thomas A. Beltran, MA ; Ollie Webb 5
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ABSTRACT
Background: Sterilization of healthcare instruments in an ex- 90kg and have a power requirement of 1.5 to 3kW. The cost
peditionary environment presents a myriad of challenges in- of tabletop units, ranging from $1,500 to $2,000, combined
cluding portability, cost, and sufficient electrical power. Using with the cost and weight of the generators needed to power
pressure cookers to sterilize instruments presents a low-cost the autoclaves, can also be prohibitive. Forgoing the use of
option for sterilization in prehospital settings. This project’s an autoclave and opting for single-use medical and dental
objective was to determine if sterility can be achieved using instruments can be helpful in expeditionary or austere envi-
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a commercially available pressure cooker. Methods: Presto ronments. However, the packing and transport of single use
4-quart stainless steel pressure cookers were heated using items can be impractical in scenarios of high patient volume or
Cuisinart CB-30 cast-iron single burners. One 3M Attest separation from a supply chain.
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1292 Rapid Readout Biological Indicator and one 3M
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Comply SteriGage integrator strip were sealed in a Henry Liquid chemicals for sterilization come with a comparatively
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Schein Sterilization Pouch and placed in a pressure cooker lower cost than tabletop autoclaves and no power requirement
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and brought to a pressure of 103.4kPa. Sterility was verified for use. The use of liquid chemicals for “cold sterilization” have
after 20 minutes at pressure. The Attest vials were incubated the drawbacks of requiring contact times from 3 to 12 hours
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in a 3M Attest 290 Auto-Reader for 3 hours with a control and the inability to verify sterility using a biological indicator.
vial. Results: Sterility using the pressure cooker was achieved Shorter contact times are considered high-level disinfection,
in all tested bags, integrator strips, and Attest vials (n = 128). meaning they eliminate all pathogenic microorganisms, except
The mean time to achieve the necessary 103.4kPa was 379 bacterial spores and prions, on inanimate objects. Alcohol
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seconds (standard deviation (SD) = 77). Neither the ambient lacks sporicidal action and cannot penetrate protein-rich ma-
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temperature nor humidity were found to affect the pressure terials found on instruments. Chemicals such as chlorine and
cooker’s time to achieve adequate pressure, nor the achieved glutaraldehyde have sporicidal activity, but the World Health
depth on the integrator strip (all p > .05). Conclusion: This Organization (WHO) does not recommend their use for steril-
study provides evidence that sterilization is possible with off- ization due to the risk of contamination while rinsing. These
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the-shelf pressure cookers. Though lacking US Food and Drug chemicals have other concerns in addition to the long con-
Administration (FDA) approval, the use of this commercially tact times required and potential risk of not achieving sterility.
available pressure cooker may provide a method of steriliza- Chlorine is corrosive to metal instruments in high concentra-
tion requiring minimal resources from providers working in tions and, similar to formaldehyde and glutaraldehyde, can
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expeditionary environments. be dangerous or hazardous to transport. As with single-use
instruments, the use of chemicals also makes a provider or
Keywords: disinfection; sterilization; dental instruments; facility dependent on a supply chain.
health personnel
The World Dental Relief advocates for the off-label use of
pressure cookers as portable alternatives to autoclaves in aus-
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tere environments. Off-the-shelf pressure cookers only re-
Background quire a consistent source of heat to operate, weigh less than
Sterilization of medical and dental instruments allows health- 4.5kg, and cost less than $50. The objective of this project was
care providers to minimize the transmission of HIV, hep- to determine if sterility can be achieved using a commercially
atitis C virus, hepatitis B virus, or bacterial infections from available Presto 4-quart stainless steel pressure cooker.
one patient to another. The Centers for Disease Control and
Prevention (CDC) defines sterilization as a process that de- Methods
stroys or eliminates all forms of microbial life and is carried
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out in healthcare facilities by physical or chemical methods. Two Presto 4-quart stainless steel pressure cookers were filled
Sterilization in an expeditionary environment presents a myr- with 355mL of tap water. The metal grates included with the
iad of logistical challenges including weight, cost, and power pressure cookers (National Presto Industries, https://www
requirement. Table top autoclaves can weigh between 27 and .gopresto.com) were placed at the bottom of each pressure
*Correspondence to Smoke Bomb Hill Dental Clinic, BLDG H-3817 Gruber Dr., Fort Bragg, NC 28310
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1 MAJ Cook is a comprehensive dentist at Fort Bragg, NC. MAJ McDaniel is an endodontist at Fort Bragg, NC. COL Pelaez is a periodontist at
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Fort Stewart, GA. Mr Beltran provides statistical support in the Department of Research at Womack Army Medical Center at Fort Bragg, NC.
5 Ms. Webb is a sterilization technician at the Smoke Bomb Hill Dental Clinic at Fort Bragg, NC.
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