Keywords
macro-aspiration - aspiration pneumonia - bronchoscopy in neurotrauma
The most common cause of death following severe brain injury is the associated aspiration
pneumonitis progressing to pneumonia. All efforts to prevent aspiration and any strategy
to minimize aspiration pneumonia in patients with severe brain injury will significantly
improve the course of treatment of such patients and decrease the financial burden
on limited resources. Management of road traffic–related head-injury patients has
several logistic shortcomings and it is rarely possible to prevent aspiration in comatose
patients. Hence, the possibility of decreasing the severity of aspiration was contemplated
by developing a protocol for early bronchoscopic evaluation and retrieval of the aspirated
products. This study presents the observations made during the management of 30 patients
with suspected macro-aspiration following severe brain injury among whom bronchoscopy
was performed as a part of initial management protocol.
Materials and Methods
This study includes patients with severe brain injury treated in a single institute
during the period of 2010 to 2012. All patients were deeply comatose with Glasgow
Coma Scale (GCS) of 8 or less either directly brought to the center or primarily managed
at another center. The protocol ([Fig. 1]) involved primary assessment of patients for poly trauma including thoracic injury.
Exclusion criteria included those with thoracic injury, age less than 18 years or
greater than 60 years, associated diabetes mellitus and chronic obstructive pulmonary
(COPD) or other chronic pulmonary illness, and patient not requiring intubation and
ventilation ([Table 1]). Patients who satisfied the inclusion criteria were then screened for presence
of maxilla-facial injury, skull base injury, and cerebrospinal fluid (CSF) rhinorrhea.
Preadmission triage care was reviewed with regard to the predictors of macro-aspiration
and aspiration pneumonitis, and measures taken for prevention of the same. Considering
the available resources in the semirural and rural section of India where this study
was based, an attempt to predict the patients who are likely to have macro-aspirated
was made by the use of a self-developed scoring system ([Table 2]). The Predictor of Macro Aspiration at Trauma site [PMAT] score defines multiple
parameters that are crucial in airway protection. The score ranged from −3 to 23.
The score was conceptualized based on the parameters in favor or against the upper
airway safety of patients. Early intubation, transport by trained personnel, and transport
by equipped ambulance were given negative scores. All other parameters can be broadly
divided into (1) type of brain injury reflecting the immediate loss of consciousness,
(2) associated upper airway obstruction and injury such as maxilla-facial injury and
CSF rhinorrhea, and (3) those parameters affecting respiration indirectly such as
abnormal posturing, seizures, and quadriplegia. All these parameters were found to
make a difference in the patient's ability to clear his airway and compound the effect
if present together. The distribution of favorable as negative and unfavorable as
positive scores was interpreted into a direct proportionality relationship to the
expected possibility of macro-aspiration. Hence, the lower the score, the lesser the
chance of a macro-aspiration. Score above 6 was considered to have significant bolus
of aspiration to warrant a check bronchoscopy. Such a lower limit was purely matter
of choice based on the clinical presentation of our study cohort. All patients underwent
check bronchoscopy within 6 hours of injury and often after stabilization with ventilator
support using an Olympus BF type P10 (Olympus America Inc., Pennsylvania, United States)
bronchoscope. The findings were noted with regard to the extent of particulate matter,
blood products, and inflammation in the tracheobronchial tree. In all cases, a bronchial
lavage with normal saline was given using 15 to 20 mL total lavage volume. End goals
of the study were considered with regard to two aspects: (1) at seventh day for presence
of evidence of aspiration pneumonia considering available data that aspiration pneumonia
incidence peaks between fifth and seventh day posttrauma and (2) survival at 3 weeks
to evaluate the overall effect of this intervention on survival. Swabs from endotracheal
tube were taken on day 4 from all patients ([Table 3]). Stringent bronchoscope sterilization procedures were maintained before and after
each procedure. Cleaning of the bronchoscope requires recommended enzymatic cleaning
with reprocessor (Olympus). This is impractical in most centers. In this study, an
alternative low-cost procedure for cleaning bronchoscope was used ([Table 4]). The bronchoscope was cleaned after changing procedure gloves with cetrimide and
chlorhexidine gluconate soapy solution (Savlon) using a gauze pad and the channels
using a flexible biopsy forceps for 5 minutes by the clock. Thereafter, the flexible
section of the bronchoscope was immersed in the chlorhexidine solution 2 to 3% for
5 minutes and then liberally cleaned with boiled water. The process of drying by holding
in hand suspension was important. Thereafter it was wrapped in a sterile polyethylene
sheet and stored in the transportation unit. The eye piece and control section in
addition to the light guide and universal cord were wiped with soaks of mecetronium
metilsulfate in propranolol solution (Sterillium). This procedure cannot be stated
to be better than other established automated systems; however; it remained effective
as preprocedure swabs taken in two instances from the initial 10 cm of the scope did
not grow bacteria on culture.
Fig. 1 Protocol for check bronchoscopy after polytrauma.
Table 1
Patient selection criteria
|
Inclusion criteria
|
Exclusion criteria
|
|
1
|
GCS < 8
|
GCS > 8
|
|
2
|
Altered sensorium due to road traffic injury
|
Associated thoracic injury.
|
|
3
|
Age > 18 y and < 60 y
|
Preexisting pulmonary disease (COPD, tuberculosis, etc.)
|
|
4
|
Patients requiring intubation and ventilation
|
Diabetes mellitus
|
|
5
|
PMAT score > 6
|
Associated spine injury
|
Abbreviations: COPD, chronic obstructive pulmonary disease; GCS, Glasgow Coma Scale;
PMAT, Predictor of Macro-Aspiration at Trauma site.
Table 2
Predictors of PMAT
|
Allotted score
|
Patient score
|
|
Type of trauma
(at least 1)
|
High velocity (>40 km/h Indian roads)
|
1
|
0
|
|
Tangential or rotational injury
|
1
|
1
|
|
Thrown out or off vehicle
|
1
|
0
|
|
GCS
|
5–8
|
1
|
1
|
|
<5
|
2
|
0
|
|
Extent of injury
(at least 1)
|
Maxilla-facial injury
|
2
|
2
|
|
Fracture mandible
|
2
|
0
|
|
Decerebrate posturing
|
2
|
0
|
|
Quadriplegia
|
1
|
0
|
|
CSF rhinorrhea
|
2
|
0
|
|
Convulsions
|
2
|
0
|
|
Primary triage care
|
Vomiting during transport
|
2
|
0
|
|
Suspected aspiration during transport
|
2
|
0
|
|
Intubated
|
−2
|
−2
|
|
Hypovolemic shock managed
|
−2
|
−2
|
|
Under the influence of alcohol
|
Alcohol in vomitus
|
2
|
0
|
|
Rescue team
|
Untrained citizen
|
1
|
|
|
Trained citizen
|
−1
|
−1
|
|
Transport team
|
Untrained ambulance
|
1
|
|
|
Trained 108 service
|
−1
|
−1
|
Abbreviations: GCS, Glasgow Coma Scale; PMAT, Predictor of Macro-Aspiration at Trauma
site.
The greater the score, the higher is the chance of macro-aspiration. Maximum score
being 23 and minimum being −3. In the present study, all patients were placed between
6 and 23.
Table 3
Microbial findings in our patients
|
Organism[a]
|
Number of patients (days 3–4 swab) (n = 21)
|
Swab collected on days 7–8 (n = 30)
|
|
Acinetobacter spp.
|
0
|
4
|
|
Klebsiella pneumoniae
|
2
|
9
|
|
Escherichia coli
|
0
|
1
|
|
Pseudomonas aeruginosa
|
0
|
9
|
|
Streptococcus
|
0
|
1
|
|
No growth
|
19
|
–
|
a The specimens were collected between the third and fourth day. Culture patterns were
different in patients who were diagnosed with VAP.
Table 4
Protocol used for bronchoscope maintenance
|
Step
|
Procedure
|
|
1
|
Change procedure gloves
|
|
2
|
Manual scrubbing of the flexible section of the bronchoscope with gauze soaked with
Savlon solution for 5 min
|
|
3
|
Soak in 2–3% chlorhexidine solution for 5 min; use available forces to clean the channel
|
|
4
|
Wipe the lens unit and control section, light guide and universal light cable with
Sterillium
|
|
5
|
Wash with distill water or boiled water
|
|
6
|
Dry the scope
|
|
7
|
Wrap in sterile disposable polyethylene sheet and preserve
|
Results
Patients sustained injury following high-velocity road traffic accident in 26 of 30
cases. A brief epidemiologic profile of the patients is presented in [Table 5]. Most patients were young to middle-aged males who had fallen off their two wheelers.
None of the victims were using protective gear such as helmets. Most patients were
transferred to the nearest health facility where basic procedure such as intubation
could not be done. Unfortunately in most cases, the need for CT scan of the brain
was considered more important than securing airway. In 14 of 30 (46.6%) patients,
the primary procedure for securing the airway was possible within 60 minutes of injury
and 16 of 30 (53.3%) patients were received within an interval of 1 to 4 hours. The
most common cause noted was the nonavailability of competent staff, delayed pickup
from the site of injury (usually an isolated road), and nonavailability of basic equipment.
A total of 23 out of 30 (76.6%) patients had vomited large quantity of gastric content,
and 18 of 30 (60%) patients had suffered injury in full stomach and 26 of 30 (86.6%)
patients had consumed alcohol prior to the trauma.
Table 5
Relevant clinical profile of patients included in study
|
1
|
Average age
|
39.6 y
|
|
2
|
Male
|
28/30 (93%)
|
|
3
|
Female
|
2/30 (7%)
|
|
4
|
Two-wheeler accidents
|
23/30 (76.6%)
|
|
5
|
Three-wheeler accidents
|
2/30 (7%)
|
|
6
|
Four-wheeler accidents
|
5/30 (16.6%)
|
|
7
|
Primary care at PHC/other hospital
|
22/30 (73%)
|
|
8
|
Primary care at neurosurgical center
|
8/30 (26.6%)
|
Abbreviation: PHC, primary health center.
Bronchoscopy procedure was successfully completed within 6 hours of the trauma in
all patients with the average time of 4.06 hours from the time of injury. The procedure
was free of any complications in all the 30 patients. Gross aspiration was noted in
28 of 30 (93.3%) patients with bilateral bronchial contamination with clots, fresh
blood, altered blood, and foreign material. Rice particles were aspirated in 5 of
30 (16.6%) patients and vegetable material in 2 of 30 (6.6%) patients, in addition
to the altered blood. CSF flooding of the airway was noted in 1 of 30 (3.3%) patients
who was intubated in the hospital. Grit-stone dust was noted to be present in 1 (3.3%)
patient. Gentle normal saline lavage was administered to all the patients.
Outcome assessment after 7 days: A total of 6 out of 30 (18%) patients developed clinical pneumonia and required continued
ventilator support because of pulmonary indications. Right lower lobe was affected
alone in two of the six patients and bilateral affection was observed in four of six
patients. Seven of 30 (23.3%) patients developed ventilator-associated pneumonia (VAP)
that was observed after the initial period of 7 days.
Survival at 3 weeks: A total of 5 out of 30 (16.6%) patients died. Three patients died primarily due to
the severity of the brain injury. Two patients were diagnosed with VAP required prolonged
ventilation. Both patients succumbed to infection. Remaining 25 patients survived
this period of 3 weeks at various stages of neurologic recovery.
Bacteriology (
[Table 3]
): In 2 of 21 (9.5%) patients, early samples (within 48 hours and taken by sterile suction
tip) were sent and pathologic microorganisms were isolated. Both patients had Klebsiella spp. isolated from the tracheal swab collected on day 3 to 4 of admission. Samples
were sent in the cases of 19 other patients and were reported as no growth. The bacteriologic
pattern changed on the day 7 to 8 specimens, and Pseudomonas spp. and Klebsiella spp. were found in 9 of 30 (30%) patients and Acinetobacter spp. in 4 of 30 (13.3%) patients.
Bronchoscope hygiene (
[Table 4]
): Cetrimide and chlorhexidine gluconate Savlon solution washing with a gauze wipe by
the surgeon for 5 minutes was the most crucial step in cleaning. Immersion in chlorhexidine
solution for another 5 minutes and wiping with liberal amounts of normal saline preserved
the protective layer of the scope. All three products were easily available and affordable
at any surgical unit. Time taken for the cleaning procedure takes on the average approximately
20 minutes accommodated between the writing notes by the surgeon. The bronchoscope
needs to be dried and sterile polyethylene sheet was used to wrap the scope before
keeping in the transport unit.
Discussion
The guidelines to manage severely traumatized patient with brain injury have been
well established.[1]
[2]
[3]
[4] The importance attributed to securing of the airway and avoiding hypoxia cannot
be overstated. Patients are required to be transported in specific well-defined, pre-hospital
procedural code. Yet much of this is not possible in low-resource, rural sectors of
the world. Race against time often comes to a complete standstill due to the many
reasons stated previously. It has been established that leaving behind particulate
aspirated material in the airway is detrimental, especially in the presence of positive
pressure ventilation.[5]
[6]
[7] Several inflammatory markers are known to rise immediately following the aspiration
of the particulate matter, including tumor necrotic factor-α, macrophage inflammatory
protein 2 and cytokine-induced neutrophil chemoattractant-1.[8] A monocytic response peaks at the interval of 48 hours postaspiration. Experiments
on mice have confirmed the additive effect of gastric acid and small nonacid particle
aspiration to be more severe than the sum of individual events.[9] If so, then an obvious follow-up of this is the question: How do we choose the appropriate
candidate for any procedure related to extrication of aspirated particulate material?
This observational study proposes to answer such a question. This study proposes that
check bronchoscopy and lavage with normal saline among selected patients with neurotrauma
predicted to have macro-aspiration can decrease the burden of contaminants and hence
prevent or decrease the severity of pneumonia.
Most studies to date comment on the lack of scientific proof for any benefit following
routine check bronchoscopy.[1]
[2]
[3] However, systematic literature search does not identify any study with the necessary
inclusion criteria, leading to the selection of a cohort of patients who logically
may have higher chance of particulate contaminants in the airway. Such particles are
likely to get further pushed in or impacted with positive-pressure ventilation.
Another concern expressed in multiple studies and guidelines is related to the possibility
of scope-induced infection. However, these studies were not related to trauma but
to long-term ventilation or procedures including bronchoalveolar lavage. This issue
needs to be addressed with serious attention to the process of cleaning. The author
in the present study maintained single-person handling of equipment so that the process
of cleaning was stringent. No procedures other than bronchial lavage with 15 to 20
mL of normal saline containing either gentamycin (80 mg in 100 mL) or Chloromycetin
(500 mg in 100 mL) were done, thereby reducing the source of infection.
Hence the benefits of check bronchoscopy and lavage should be discussed. If appropriate
care is taken to prevent complications such as hypoxia and iatrogenic infection, the
removal of particulate matter from the airway of a comatose patient on positive-pressure
ventilator support should help. These particulate materials, if left behind in the
airway, will result in increased bacterial burden. Removal of clots and decomposable
material will improve the immediate progress of patient. This study identifies the
practical feasibility of such intervention without increasing the existing risk. The
clinical progress observed in this study is encouraging and certainly makes a point
for considering a randomized comparative study between those patients who were given
the benefit of bronchoscopy and others without it. Such a study should not only consider
the mortality but other comorbidity of prolonged antibiotic therapy, antimicrobial
resistance, and cost of therapy.
Conclusion
-
The observations made in this study emphasize the possible scope of further improvement
in the survival of brain-injured patients, especially in rural sectors of the world
working with limited resource.
-
Neurologic outcome may improve indirectly if prolonged ventilation and antibiotic
therapy can be eliminated.
-
This center has been continuing the study by developing a comparison group where check
bronchoscopy is withheld. Similar such studies from developing countries on the lines
of the mentioned protocol could allow us to better assess the benefits of the intervention.
-
Shortcomings of the present study: PMAT scoring is not validated and the study lacks
a comparison group.
