Page 93 - JSOM Summer 2018

be easy to handle and provide reliable protection against aspi- the manufacturer’s directions. After the initial cuffing of the
ration. The findings of multiple studies 16–30 support adequate tube with a fixed volume of air, a cuff pressure of 60cmH O
15
2
ventilation with the laryngeal tube (LT) and the LTS-D. Schalk was used.
et al. reported a high success rate of 98.2% with the LTS-D in
22
the prehospital setting. Gahan et al. reported an 87.8% success Medics
24
rate for with LT insertion by inexperienced airway providers. The medics were part of the Swedish Armed Forces, active
or Territorial Army. They were either team medics or first re-
We conducted a clinical study in which we allowed medics to sponders, who had received 3 weeks of medical training fo-
secure the airway of anesthetized, elective patients sequentially cused on combat trauma care, or combat life savers, who had
by using the adjuncts LTS-D and disposable LMA. The objec- received 5–7 weeks of training. In this study, participants with
tive of this study was to determine if inexperienced medical either of these types of training were called medics. Indepen-
personnel such as military medics could provide airway con- dent of their level of training, they all had a similar amount
trol using the LTS-D and LMA. of airway management training. This consisted of basic air-
way maneuvers: chin lift, jaw thrust, recovery position, use
of a pocket mask, and insertion of oral and nasal pharyngeal
Methods
airways. Before the study, the medics were given 4 hours of
Design training with the LMA and LTS-D, 2 hours of theory, and 2
This was a quantitative, structured observational study with hours of practical training with manikins. They performed 10
a crossover design. The study was performed in 19 patients interventions with each adjunct on a manikin. The training
undergoing surgery at the Uppsala University Hospital, Up- was conducted less than 30 days before the study. The medics
psala, Sweden, a tertiary care center. The patients were se- had limited previous clinical experience and no clinical experi-
lected consecutively and the inclusion criteria were American ence in airway management.
Society of Anesthesiologists (ASA) classification I–II, Mallam-
pati classification I–III, and planned for elective surgery with Laryngeal Tube Suction
general anesthesia via a supraglottic airway. Exclusion criteria The LT is available in a single-lumen version (LT + LT-D) and
were age younger than 18 years, Mallampati classification IV, a dual-lumen version (LTSII + LTS-D). They are both avail-
emergency status, ASA physical status III–VI, or inability to able in a disposable (D) or reusable version. In this study, we
give consent due to illness, drugs, or decreased cognitive func- focused on the LTS-D (Figure 1). The tube is polyvinyl chlo-
tion (please see Appendices 1–3 at https://www.jsomonline.org ride based and consists of two separate lumens, one each for
/References/201821Regner.php). ventilation and access to the gastric ventricle. There are two
cuffs: one proximal cuff that seals the oropharynx and one
Procedure distal cuff that blocks the esophagus. There is one primary
The airway adjuncts used in this study were the LTS-D and ventilation opening and multiple additional small orifices.
the Ambu AuraOnce Disposable Laryngeal Mask (https:// For releasing gastric pressure and content, the gastric lumen
™
®
www.ambu.com). The anesthesia was provided by a clinical ends in the distal tip of the tube. The manufacturer has color
team consisting of an anesthesiologist and a nurse anesthetist; coded the tube connector matching the size of the tube (e.g.,
the research data were collected by a researcher not involved red: length, 155–180cm; yellow: <155cm. The cuff syringe is
in providing the anesthesia. The researcher was responsible for equally coded (e.g., red is marked on the 80mlL syringe; yel-
seeing that the study protocol was followed and the following low is marked on the 60mL syringe). The manufacturer has
were recorded: overall success rate, number of attempts, time thereby set fixed volumes of air to the different sizes of tubes.
to verified ventilation, total drug dosage, cuff pressure, age, When using a red tube, the user fills the syringe to the red
sex, ASA and Mallampati classifications, tube length, patient mark and inflates the cuff with the set volume of air without
weight, and the possible cause of failure (i.e., complications). needing a cuff pressure gauge. This makes it easier to use in
environments where a cuff pressure gauge may be absent. The
Intraoperative monitoring included end-tidal CO pulse ox- medics in this study inflated the cuff according to color of the
2,
imetry, noninvasive blood pressure, and three-lead electro- tube connector, as taught by the manufacturer’s representative.
cardiography. After administration of oxygen (fraction of
inspired oxygen, 85% for longer than 1 minute) anesthesia
was induced with 1μg/kg fentanyl (more than 5 minutes before
airway intervention) and up to 2.5mg/kg propofol was given
intravenously. Two patients required 0.5mg of atropine. The
anesthesia was maintained with propofol during the airway
intervention.
When verifying adequate ventilation, the medic used a manual
technique consisting of look, listen, and feel: Look for chest FIGURE 1 Disposable
rise and fall, listen for free passage of air, and feel the chest laryngeal suction tube.
rising. The clinical anesthesia team simultaneously verified the
ventilation using return of end-tidal CO (ETco ), bilateral
2
2
chest sounds, and ease of manual ventilation. Each patient re-
ceived intervention with both airway adjuncts, according to
the crossover design of the study. The sequence in which the
adjunct was going to be used was randomized for each patient
using a manual technique. The LTS-D was cuffed according to

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