Airway Management in Austere Environments




CASE PRESENTATION



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As an anesthesia practitioner, you have been deployed with your national disaster response team to a low-income country (LIC) that has just experienced an earthquake. Some surgical infrastructure did exist in the region prior to the earthquake, limited by too few anesthesia and surgical practitioners, too few safety monitors, and unpredictable access to essential medicines, including oxygen.



You are on the initial team as the only anesthetist, with a general surgeon, an orthopedic surgeon, seven nurses, and two technicians. There is no biomedical technician on the team. The team will be in country at least 2 weeks, and the mandate is to operate on any urgent or emergency surgical conditions. There will be capacity for basic ongoing postoperative care by local surgeons after the departure of the surgical team.



Just a few days after arrival, an otherwise healthy 22-year-old women presents with recent facial burns following a domestic cooking accident. She can no longer close her eyes effectively because of worsening contractures, corneal ulcers are developing, and she is becoming blind. The surgeon states that she can perform some small split skin grafts that will save her sight (Figure 59–1).




FIGURE 59–1.


Twenty-two-year-old woman with burn contractures.





On examination the patient has limited mouth opening and a full set of healthy teeth. Her Mallampati score is III and she has a normal thyromental distance and normal neck extension. There is some scarring over her anterior neck but you can easily palpate airway structures.




INTRODUCTION



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In the high-income countries (HIC), about 1:50 general anesthesia cases will present difficult tracheal intubation, 1:75 will result in a failed intubation, and a failure to intubate and to ventilate will occur in 1:1000 to 1:12,000 anesthetics. Obstetrical anesthesia is particularly challenging in this regard, as the airway (AW) may be complicated by soft-tissue edema related to toxemia or prolonged labor (see section “How Common Are the Difficult and Failed Airway?” in Chapter 1). Although the principles of AW management are similar worldwide, the anesthesia practitioner in the LIC can expect to face challenges both unrelated and related, to difficult AW anatomy (Table 59–1). A variety of difficult conditions will be encountered, often in later stages of evolution, and often presenting greater challenges. Diseases and conditions less familiar to the average practitioner can also be expected. Pediatric and obstetrical patients make up a higher proportion of anesthetic practice in an LIC.




TABLE 59–1.

Expected Developing Country Conditions with the Potential for Difficult Airway Management





What Are the Risks Inherent in AW Management in Austere Environments?



Forty years of intense commitment has greatly reduced avoidable anesthesia-related mortality in wealthy countries to a rate of about 1/56,000 anesthetics (1/180,000 when anesthesia is the sole cause of mortality and morbidity), and AW misadventure is no longer the primary reason for seriously adverse outcomes.1,2 Training in AW management has advanced, guidelines and standards have been introduced, technology has evolved immensely, and a culture of safety is in place.3,4 Sadly, such benefits have been largely restricted to the few who live in relatively privileged societies. Published mortality due to AW misadventure in less-resourced areas can vary from 100 to 1000 times that in affluent societies.58 Indeed, in one report, the avoidable mortality from AW-related causes was 1/183 anesthetics.8 Obstetric anesthesia is a particular risk in this regard.9



The challenges facing developing countries are far more profound than the unavailability of the latest aids for tracheal intubation. Many barriers to improving difficult AW management exist in LICs, including minimal education and training on the difficult AW for local physicians and non-physician practitioners. Additional factors involve limited functionally advanced AW equipment and safety monitoring, unpredictable access to essential medicines (including oxygen), and a lack of emphasis on vigilance, sustainable organizational structure, and a modern system of quality review.10 One major priority, universal pulse oximetry, is still often lacking in 77,000 operating rooms globally,11 but so too are vigorous educational support, mentorship, and team building.




AW EQUIPMENT IN AUSTERE ENVIRONMENTS



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What Are the Equipment Considerations for Difficult AW Management in the Developing World?



Aggressive attention to the needs of the developing world has been paid by the international anesthesia community since 1989,12 and a series of standards have evolved.4,13 Sadly, most of the 1st Referral Hospitals in at least 82 countries cannot meet even the basic standards of the World Federation of Societies of Anaesthesia (WFSA) at this time. Appropriate low-resource strategies, equipment, and approaches must be considered, and local input from government, hospital systems, and on-the-ground practitioners must be considered and included.14



Equipment Prescribed for Level 1 Facilities, Also Known As (AKA) Small Hospitals, Community Clinics, or Health Centers4,15


Level 1 facilities are expected by the World Health Organization (WHO) to provide emergency and basic surgery, resuscitation, stabilization, and normal obstetric delivery.15 It must be emphasized that, in LICs, there are frequently only non-physician practitioners, many of whom have limited training and very few advanced skills. AW management in these settings should be trained for and provided by a team of the most skilled individuals. General anesthesia in these settings should be avoided whenever possible, but this is often not possible. Indeed, it may not be possible to refer a seriously ill patient to a higher-level treatment center. In many environments, the supply of compressed gases is unreliable, frequently not available, and expensive. Under such circumstances, oxygen concentrators and draw-over anesthesia offer significant advantages.16 WFSA guidelines for medication and equipment availability in Level 1 facilities appear in Tables 59–2 and 59–3. Once again, it must be recognized that these medications and equipment may not be available.14




TABLE 59–2.

Medications Prescribed by the WFSA for Level 1 Facilities4






TABLE 59–3.

Equipment Prescribed by the WFSA for Level 1 Facilities4





Equipment Recommended for 1st Referral Hospitals AKA Level 2 Facilities, and District or Provincial Hospitals


Level 2 referral facilities undertake procedures such as caesarean section, laparotomy, and internal fixation of fractures that do not require a high level of specialization and technology.15 The term 1st Referral Hospital is usually applied to this level of capacity (DCP3),4 though some authors refer to Level 1 facilities as District Hospitals.15 While there may be an expectation that there will be at least one trained anesthesiologist, one or more trained surgeons, obstetricians, visiting specialists, district medical officers, senior clinical officers, nurses, and midwives, many such facilities will still lack physician anesthesia practitioners and anesthesia care will be delivered by clinical officers and nurse anesthetists. Additional drugs and equipment are expected to be available to supplement those in Level 1 facilities (Tables 59–4 and 59–5), but these also might not, in fact, be available.14,17




TABLE 59–4.

Additional Medication Prescribed by the WFSA for Level 2 Facilities4






TABLE 59–5.

Additional Equipment Prescribed by the WFSA for Level 2 Facilities4





Equipment Recommended for 2nd Referral Hospitals AKA Level 3 Facilities: National Referral Centers, University Hospitals


Level 3 facilities usually have the capacity to undertake facial surgery, intracranial surgery, bowel resection surgery, pediatric and neonatal surgery, thoracic surgery, major eye surgery, major gynecological surgery, and the management of critically ill patients.15 Personnel include surgical, anesthesia, and critical care subspecialists. International guidelines clearly define required medications and equipment for such referral centers,4 but once again such prescriptions are well beyond the reach for many LICs.



What Equipment Should Volunteers Traveling to LICs Bring with Them?



There is a variance in the needs for practice in an austere environment, depending on the nature of the mission. Longer-term teaching missions generally involve educating local practitioners to use equipment already present (or easily obtained) and maintained in the specific environment. In contrast, in the case of short-term service missions, a traveling team arrives to directly provide medical care, and AW equipment is generally transported in and out with the team.18



AW Equipment and an Associated Consideration for Longer-Term/Teaching Missions


A fundamental premise of longer-term missions, especially if there is a teaching component, is to teach and use AW equipment that is “locally sustainable.” A locally sustainable device is defined as one that is already present in the environment or can readily be obtained . In addition, it must be easily disinfected, and should be simple to maintain or repair if broken. If electronically powered, the device should have a reliable power source, batteries, or otherwise, and in this context, it must be stressed that electrical power (and compressed gases), are often unreliable in disadvantaged countries. Generally, equipment must be reusable, and it must be assumed that any single-use items will be reused.



Even if a device can be obtained and maintained, other factors must be considered. Introducing devices which are difficult to use, or with complex storage or disinfection needs, should be discouraged. Donation of equipment that is fragile or requires frequent servicing (e.g., a flexible bronchoscope with a video tower), while well meaning, can be counterproductive in an austere environment. If such a device is presented, it helps to designate one local practitioner as champion for the product, charged with responsibility for ensuring it is used, cleaned, and stored appropriately.



One related important consideration. Non-physician anesthesia practitioners in Level 1 or 2 hospitals are often held in low esteem in the capital cities in which they are trained and have had little basic intubation training and so appreciate a chance to learn. Every short-term mission should be a teaching mission for the providers who will be there the rest of the year—emphasizing an over-zealous approach when offering help at their local teaching hospitals.



Equipment Considerations for Short-Term Surgical Missions (STSM)


AW equipment considerations differ for a short-term service mission (Table 59–6). Under these conditions, routine and difficult AW equipment is transported by the team, such equipment being limited only by its portability and durability. This “kit” should ideally be available in adult and pediatric versions, given the high occurrence of pediatric cases. If battery-powered, sufficient batteries should also be available for the equipment, and disinfection requirements should be straightforward. Thankfully, portable oximetry and capnography units (ideally combined) are now quite affordable. If logistics permit, disposable equipment would be of value.




TABLE 59–6.

Sample Airway Equipment for a Short-Term Service Mission


Jan 20, 2019 | Posted by in ANESTHESIA | Comments Off on Airway Management in Austere Environments
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