In 2014, SPECT embarked on an ambitious project - to design and manufacture a sterilizer that could be produced and maintained in resource-constrained settings. Adapting equipment to the needs of rural healthcare facilities in Sub-Saharan Africa, along with staff training on sterile processing practices, ensured that surgical instruments could be sterilized, reducing the patients risk of infection.
Broken temperature gauges, unpredictable electrical surges, and unavailable spare parts are just some of the barriers preventing sterilization equipment from functioning properly and jeopardizing the safety of surgical instruments.
This blog post is based on an unpublished paper written by Dan Fast, with contributions from Christina Fast, Olive Fast and Lauren Welch.
During site assessments in both Madagascar and Benin, SPECT identified that healthcare facilities had a very limited number of functioning sterilization equipment [Table 1]. Urban hospitals primarily used dry heat sterilizers (DHS), verticle gravity steam sterilizers and tabletop autoclaves, while smaller rural clinics included table top autoclaves, DHS, pressure cookers (PCs), propane stoves to boil instruments (not achieving sterilization) and occasionally dosing instruments in alcohol before lighting them on fire, locally known as the ‘flambé’ method.
Given the variability of equipment, SPECT confirmed sterilization parameters by testing the equipment with chemical and biological indicators. As outlined in the WHO Guidelines for Safe Surgery 2009, “the physical parameters of sterilization, such as temperature, pressure and length of exposure to the sterilizing agent, must be measured for every sterilization cycle and load. For automatic equipment, this is frequently measured and documented by the equipment itself. Manual equipment should be operated by trained personnel, and calibrated thermometers, barometers, clocks and load sensors should be used”.
SPECT found facilities in Benin and Madagascar were not using indicators to confirm that sterilization parameters were met. Only 1 of the 10 facilities assessed in Benin regularly used a Bowie-Dick air removal test and had external chemical indicators.
Health care workers demonstrated how the equipment turned on/off. Most facilities had a piece of paper taped to the wall which outlined recommended times and temperatures, though no functioning monitors were available to confirm that these parameters were met. Staff frequently put surgical instruments into a DHS and ran the machine for 1-2 hours. When the temperature dial was broken at one facility, staff reported a technician had manually programmed it so that the sterilizer would always operate at the recommended temperature. Another facility reported that their sterilizer would heat up with no temperature regulation. In all facilities, there were no written records of when the equipment was last serviced.
As part of site assessments, SPECT function tested sterilization equipment. Due to time constraints, testing was limited to 7 autoclaves and 37 DHS at 18 healthcare facilities. Of those tested, 38% (14/37) of the DHS and 14% (1/7) of the autoclaves failed [Table 2]. In cases where staff adjusted the functioning temperature dials some DHS passed, though most did not. Facility managers were aware of the risks with improperly functioning equipment and lamented the lack of support or resources available to repair or replace the equipment.
Recognizing these challenges, SPECT began to search for a low resource sterilization alternatives and discovered research suggesting success in using pressure cookers as a way to sterilize surgical instruments. Development parameters for the sterilization system included: low cost; ability to heat with electricity, gas, wood or charcoal, reducing the need for consistent electricity; minimal parts and easy-to-use; and portability as some facilities would transport equipment for use between departments.
SPECT ran repeated CI and BI tests on a larger model pressure cooker which verified that conditions to achieve sterility were reached after 25 minutes, with a consistent pressure of 15 psi. Other issues, however, had been identified with using a pressure cooker to sterilize instruments. Surgical instruments were placed horizontally on the shallow tray provided with some pressure cookers and left there for varying lengths of time. This practice resulted in trapped moisture and prevented some surfaces from being completely exposed to steam. To address this issue SPECT designed a steel mesh basket with hooks where instruments could be suspended vertically in open position, allowing them to drip dry and ensuring steam could come in contact with the entire surface.
SPECT consulted with an engineer to develop a prototype and used marine-grade stainless steel where perforated sheets were cut to size and used for the sides of the basket while a fine mesh was used for the base. At the top of the basket, a solid ring was attached to which hooks were then welded. Inside the main basket a smaller basket was suspended on a metal bracket, which was welded to each side. Under the main basket, metal legs were welded to elevate the basket above the water level [Appendix I].
In 2014, SPECT collaborated with a local metalworker in Antananarivo, Madagascar, using stainless steel from the Africa Mercy (Mercy Ships) and sourcing component parts from Canada to replicate the initial basket prototype. A second iteration of the instrument basket was developed in 2016 by a metal manufacturing company in Canada, and 60 of these baskets were produced by a company in India [Appendix 2].
In 2015/16, after confirming functionality, SPECT distributed 26 sterilization units, including instrument baskets and heating sources, to healthcare facilities in Madagascar. And in 2017, with the support of additional funding from Mercy Ships Canada and revisions to the original prototype, SPECT provided 59 units to healthcare facilities in Benin. Facilities were chosen based on input from the Ministry of Health and additionally met one or more of the following criteria: availability of electricity; current availability of functioning sterilization equipment; the number of daily procedures performed (busier facilities were given a higher priority) and staff receptivity to trial the sterilization system as well as attend SPECT's training program.
Once the recipient facilities were selected, all were required to send 1-2 representatives for training on the fundamentals of sterile processing and safe operation of the pressure cooker units. Laminated step-by-step illustrated instruction sheets were provided to every site, both in English and in the local language.
Both SPECT and local partnering facilities gained valuable insights into the challenges that contribute to improper sterilization of surgical instruments in low-resource settings. The project required frequent adjustments and significant collaboration. These are a few of the more notable lessons learned:
Some facilities had a single fuse box with amperage less than 15, rendering it impossible to operate electric pressure cookers as designed.
In India the pressure cookers were designed to operate with an M type plug (3 round pins in a triangular pattern) and were wired for 230 volt 50 Hz. The supplier was informed of the plug type used in Benin and tested the units in India with different plug types, but encountered electrical problems they were unable to resolve prior to shipment. The supplier attached a type G plug (3 rectangular blades in a triangular pattern) and included a universal adapter designed to adapt G to plug type C or E, the commonly used plugs in Benin. When the universal adapters were tested in Benin, they became extremely hot, to the extent that the plastic casing melted and they were no longer usable. Subsequently, all the type G plugs were exchanged with locally available type E plugs.
Pre-Vacuum Steam Sterilizers are designed with a drying cycle intended to remove all moisture from the instruments. If moisture remains, the instrument pack is considered contaminated and must be reprocessed. The pressure cookers have a vacuum release valve on the side, which allowed all moisture above the immersion heater coil to escape. The valve then closed, creating a vacuum in the chamber that allowed the sterilized material to dry. Tests showed that small droplets of moisture remained on some instruments if the lid of the pressure cooker was removed shortly after completion of the cycle (approximately 5-10 minutes); however, if the lid was left on for a longer period of time (i.e., overnight), the instruments dried completely. As bacteria requires moisture for growth and survival, damp instruments are at risk of bacterial growth once exposed to the environment. To minimize exposure of the instruments, health care workers were advised to keep the lid on the pressure cooker until shortly before the instruments were needed and if possible, to transport the pressure cooker to the point-of-use area and remove the lid in a sterile environment.
During the rainy season in Madagascar, recipient healthcare facilities were only accessible by motorcycle on narrow dirt tracks, so delivery was delayed by several months. In Benin, motorcycles were also used to deliver the pressure cooker units and innovative ways of strapping the units to the motorcycle were noted.
Follow up visits to facilities in Benin one month after distribution revealed that many were not yet using their units. Several explanations were given for the delay, but it appeared the main reason was due to the lack of staff confidence in assembling and training their co-workers on its use. To rectify this, SPECT spent additional time at each facility training additional staff members on the safe operation of the units, which increased self-reported knowledge and confidence.
Only a handful of staff had prior training in sterile processing, and only two of the 65 facilities employed staff specifically as sterilization technicians. In the majority of healthcare facilities, staff responsible for sterile processing were generally nurses, cleaners, or nursing students with additional responsibilities. As a result, staff were often called in different directions, making it challenging to monitor the pressure cooker cycle. Staff were trained to record the sterilization start time and the time that the needle on the pressure gauge reached the green zone. Timing is a critical component as tests proved that the process would only be successful if the temperature and pressure were maintained for at least 25 minutes. With different heating sources in use, monitoring also meant ensuring that the heat source would be consistent (e.g. if wood stoves were used, they may need to stoke the fire; if charcoal, they may need to resupply if the charcoal burned too quickly; if gas, they might need to adjust the valve). With multiple responsibilities it was challenging for staff to ensure these instructions were accurately followed.
Observations at nearly all facilities in Benin and Madagascar found few instruments were packaged with protective barriers during sterilization due to lack of availability. Likewise, the instruments in the pressure cooker would not be protected with wrapping materials and therefore subject to contamination the moment the lid was removed. It was common to sterilize several small sets of instruments, then remove the lid of the pressure cooker and place each set of instruments into separate metal boxes, before using or transferring to different departments. This practice raised concerns as to the sterility of the storage boxes and sterility of the gloves or device used to remove the instruments from the basket. SPECT recommended instruments be left in the pressure cooker with the lid on until needed.
In September - October 2017, follow up contact was attempted with all recipient facilities in Madagascar and Benin to obtain feedback on use of the pressure cookers and instrument baskets [Table 3 and Table 4, respectively].
* Unable to reach contacts at six facilities due to changed phone number or staff transfers.
** This number may be higher as units could be in use at six unreached facilities. Five units confirmed not used for the following reasons: 1 was stolen, 1 needed a new gasket, 1 never reached a remote facility, 1 staff person trained on its use was transferred out of the facility before training anyone else, 1 had misplaced a part and was unable to locate or replace it.
* Unable to reach contact at one facility.
** This number may be higher as 1 unit could be in use at the unreached facility. Of the 14 units that were confirmed not in use: 1 was not used because the facility generator had broken down, 1 was missing a part at shipment, 2 were only used as backup if the facilities autoclaves broke down, 2 were unused as staff were awaiting completion of renovations, and 8 were not used due to inadequate electricity.
“Very useful as it decreases risk of infection”
“Now we are confident in using sterile instruments”
"Staff attitude has changed, especially concerning hand washing"
"Wounds are healing quicker"
"Now staff regularly use Personal Protective Equipment when handling instruments"
"Now patients and staff are protected against infection"
The use of pressure cookers and instrument baskets can offer healthcare facilities in resource constrained settings an affordable and effective method of sterilizing their surgical instruments. For larger urban facilities, the pressure cooker units could provide a viable option to sterilize smaller instrument sets when autoclaves break down, while smaller rural facilities who have no sterilizing equipment or poorly functioning equipment are presented with an option that would allow them to use a tested and proven method of sterilizing when operated according to manufacturer’s instructions and following SPECT’s reprocessing guidelines.
The initial prototype basket was constructed of highly rust resistant and durable 316L marine grade perforated stainless steel. Sheets were cut to size and formed into a circular basket measuring approximately 25 cm (10”) high with a diameter of 21 cm (8.5”). These dimensions allowed the basket to fit comfortably into a 38L pressure cooker with a height of 41 cm (16”) and diameter of 30 cm (12”) and ensured that at least 4 cm (1.5”) of space remained on all sides for steam to readily penetrate all surfaces. A smaller basket, designed to hold short instruments such as scalpels, was then placed inside the larger basket and supported by a metal bracket welded to each side. The small basket measured approximately 11 cm (4.5”) high with a diameter of 9 cm (3.5”). The larger basket had a solid ring at the top to which hooks were welded for suspending and opening the ring handled instruments. Collapsible handles were attached to each side of the basket allowing ease in removing it from the pressure cooker while avoiding any contact with the sterilized instruments. Metal strips measuring 4 cm (1.5”) in height were welded to the base of the basket to ensure that it was elevated above the water level in the pressure cooker.
Development of a second prototype was initiated for the following reasons: the metal thickness and weight of the first prototype was excessive to support the instruments; the cost could be significantly reduced with less and lighter metal; by attaching metal rings to 4 posts with tiny screws, the whole unit could be collapsible for easier shipping, by perforating the metal rings with small holes slightly larger than the hooks, the hooks could be spaced as needed to ensure all ring handled instruments were fully opened, the small inner basket could be suspended on a threaded central pole allowing the basket to spin up or down, the development of metal “wings” at the base of the small inner basket provided dividers for supporting and separating longer instruments and provided a base for the small basket if it was removed.
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