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African Health Sciences
Makerere University Medical School
ISSN: 1680-6905 EISSN: 1729-0503
Vol. 9, Num. 3, 2009, pp. 167-169
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African Health Sciences, Vol. 9, No. 3, Sept, 2009, pp. 167-169
Reactive airway and anaesthesia: challenge to the anaesthetist
and the way forward
Lawal I1*and Bakari AG2
1- Department of Anaesthesia, Ahmadu Bello Teaching Hospital, Zaria, Nigeria
2- Department of Medicine, Ahmadu Bello Teaching Hospital, Zaria, Nigeria
*Correspondence author: Lawal I Ibrahim, Department of Anaesthesia, Ahmadu Bello Teaching Hospital, Zaria, Kaduna State, Nigeria Email: dribrala@yahoo.com
Code Number: hs09037
Abstract
Background: Patients with concurrent medical conditions such as Reactive airway disease presenting for anaesthesia,
and surgery have potentially increased risk of perioperative morbidity and mortality if not well managed.
Objective: To highlight the need for adequate perioperative care and review the evidence for selection of techniques in
the anesthesia for such cases"
Materials and methods: An illustrative case is presented.
Conclusion: The main goal of the anaesthetist is to administer safe and sufficient anaestheia without
precipitating bronchospasm.
Keyword: Reactive airway, anaesthesia, presentation, management and constraints.
Introduction
Patients presenting for anaesthesia and surgery
may have with co-existing medical conditions 1-4. Bronchial asthma is one of such diseases 1. The co-existence of any medical condition in the
surgical patient has the potential to increase the risk
of morbidity and mortality in the perioperative
period, if inadequately managed 1-6. The main aim of
this article is to highlight this, and streamline the
steps necessary to be taken in the anaesthetic
management of patients with such condition. A case of
an asthmatic patient with prostatic hypertrophy requiring anaesthesia and surgical resection
is presented.
Case Report
A 60year old man presented with complaints
of frequent urination, urgency and poor urinary
stream for three months. There was no haematuria,
dysuria or urethral discharge. He was diagnosed as
asthmatic about twenty years before presentation. He
was allergic to cold, smoke and dusts. The disease
was brought under control using salbutamol tablets
8mg 6 hourly and salbutamol inhaler when required.
He was admitted on three occasions because of
severe asthmatic attacks and was treated with
intravenous fluids, antibiotics, aminophylline, steroids and
other drugs he could not recall. His last attack was about two months prior to presentation. There was
no history of cough and had been able to maintain
his normal daily activities up to the time he presented.
On examination, he was clinically stable
not in respiratory distress. Air entry was vesicular.
The cardiovascular system was stable with pulse rate
of 84 beats per minute and blood pressure of 150/90mmHg. There were no lesions on any part of
the vertebral spine. Rectal examination revealed a palpably enlarged prostate. A diagnosis of
benign prostatic hypertrophy in a known asthmatic (controlled) was made. He was scheduled
for prostatectomy.
Blood biochemistry and haematological
tests were normal. Chest X-ray and E.C.G were all normal. Three units of blood were
screened, grouped and cross-matched. He was assessed
as ASA III and graded Mallampatti II. He was consented for epidural anaesthesia.
While in the theatre, emergency
drugs including aminophylline, hydrocortisone,
ephedrine, etc were kept within reach. A vein was
cannulated with size 18G cannula and a litre of normal
saline set up.
The patient was positioned sitting on
the operation table with his feet supported on a
stool and hands on the opposite shoulders. The
fourth lumbar space (L4/L5 inter-space) was located
and infiltrated with 1.0ml of 1.0% plain lignocaine.
A size 18G Tuohy epidural needle was inserted with the bevel facing upward. On piercing the
interspinous ligament, the stylet was removed and a
20mls resistance-free glass syringe half full of air,
attached to the epidural needle. A gentle continuous
pressure was applied to the plunger as the needle was advanced. A give and later a sudden loss of
resistance to the plunger was felt as the epidural space
was entered. The glass syringe was removed and a
syringe containing 15mls of 0.5% plain bupivacaine connected to the extradural needle. A test dose
of 5mls of the solution was administered after aspiration. Five minutes later, the remaining
solution was slowly administered while verbal contact
was maintained with the patient. The needle, together
with the syringe, was removed and small gauze
plastered to the site. He was then positioned supine with a
10° head down tilt. After about 15minutes, the
Bromage scale was used to assess the extent of the block.
The patient could neither raise his legs nor flex his
knees or ankle joints. This confirmed the block to be
up to the level of the umbilicus (corresponds to
T10).
Intra-operative course was uneventful.
The pulse rate and blood pressure were fairly stable.
The respiratory rate and air entry were frequently
checked. Arterial oxygen saturation was monitored by
using pulse oximeter. There were no episodes of
coughs or secretions. The operation lasted 2hours
15minutes. Post operatively the patient was closely
monitored in the recovery room. Oxygen saturation
remained good while on room air. He was discharged to
the ward after 30minutes of observation in the recovery.
Discussion
A mild tonic constriction exists in all normal
human airways. This is mainly maintained by the
efferent vagal activity and easily abolished by
antimuscarinic drugs like atropine. In some individuals,
intense bronchoconstriction is provoked following
airway stimulation with low level of stimulus as
compared to normal persons. This bronchial hyper-responsiveness is termed "reactive airways".
The commonest disease condition that falls into this
entity is bronchial asthma. Others include chronic bronchitis, emphysema, allergic rhinitis and
upper/lower respiratory tract infections 1. This category of patients constitutes a problem to the
anaesthetist especially when the airway has to be tempered with.
Preoperative identification of patients
with reactive airways is important in planning a
rational approach for proper anaesthetic care. So far,
there is no single best test available for identifying
or evaluating airway hyper-responsiveness. Often, precise testing is not practicable preoperatively
and clinicians have to rely on history to identify
factors suggesting an increased likelihood for
perioperative bronchospasm. One of the most important is
history of recent upper respiratory tract
infection characterized by cough and fever.
Respiratory symptoms like nocturnal dyspnoea, chest
tightness on awakening, associated breathlessness
and wheezing in response to various respiratory
irritants, appear highly predictive of increased bronchial reactivity. The case being presented is a
diagnosed case of controlled bronchial asthma requiring
surgery on the perineum.
Anaesthetizing patients with reactive
airway disease is a challenge to the anaesthetist; he has to
be selective in the choice of technique and the use
of drugs on such patients to avoid the provocation
of bronchospasm. Such patients could present in controlled or acute state of the disease for
either elective or emergency surgery. Patients presenting
in controlled state and for elective surgery present
less problems. The operation could proceed while precautions need to be taken to
prevent bronchospasm. The case being presented falls
under this group. In the case of uncontrolled disease
coming for elective surgery, the anaesthetist might
be compelled to postpone the operation to such a
time that would be safe for anaesthesia/surgery.
The challenge in compounded when the uncontrolled/untreated patient presents as a surgical
emergency. In such a case, the anaesthetist is compelled
to anaesthetize the patient using available
resources considered safe, within his reach. Sometimes
the drugs considered safe might not be available for
use when urgently needed. This has been a
constraint and a major challenge to the anaesthetist in
the management of such patients.
Asthma is a disease of the airways that
is characterized by increased responsiveness of
the tracheobronchial tree to multiple stimuli 2. It is manifested by widespread narrowing of the
air passages and may be relieved spontaneously or as
a result of therapy 3, 4, 5. The decreased airway
caliber associated with bronchoconstriction affects
the distribution of gases within the lungs. The
major effect of this is under ventilation of many lung
units leading to low ventilation perfusion ratio. This
results in arterial hypoxaemia predisposing the patient
to non-specific bronchial reactivity 6. This calls for
the need to administer high concentration of oxygen
in the perioperative management of such patients. Oxygen was administered by face mask to our
patient up to the early postoperative period. Drugs
that could be needed in the treatment of acute
asthmatic attack had to be made available before
anaesthesia commences. Such drugs were available in the
theatre and within reach before anaesthesia started for
our patient.
In the case being presented
established diagnosis of asthma had already been made.
The disease condition is also under controlled.
The challenge to us was in the choice of technique
and the use of drugs/equipment free of provoking bronchospasm.
Options available included the use
of general anaesthetics devoid of stimulating the
airways or employing the use of regional anaesthesia. Being a perineal surgical case, epidural anaesthesia
was choosen for the patient. This eliminates the need
for instrumentation and drugs administration,
including anaesthetic gases that could trigger
bronchospasm 7, 8.
Olsson 9 in a retrospective analysis
of bronchospasm during anaesthesia, found an incidence of 1.7 per 1000 patients (1 case per
634 anaesthetics). He also confirmed a higher
incidence in the presence of pre-existing airway
obstruction, especially during airway instrumentation.
Avoiding the airways help in preventing of bronchospasm
in our patient. Intraoperative bronchospasm is diagnosed by ventilatory difficulties characterized
by increased peak airway pressure and expiratory wheezing. The key to therapy is inhalation
of sympathomimetics such as albuterol. These drugs produce more rapid and effective
bronchodilation than intravenous aminophylline.
Intravenous lignocaine (1.5-2 mg/kg), hydrocortisone (4
mg/kg) or glycopyrrolate (1 mg) may also help in reversing the reflex response to
bronchoconstriction. Glycopyroolate may also be administered
directly through the endotracheal tube. These dugs are
likely to be more effective before the stimulus.
Lignocaine has been shown to prevent such bronchospasm
by blockade of the airway response to
irritation10 and direct attenuation of smooth muscle response
to irritation 11. Its use could therefore be
employed when endotracheal intubation and some drugs
likely to trigger bronchospasm are indicated.
Inhalational anaesthetic agents like halothane
produce bronchodilatation and appear to prevent
the development of bronchospasm 12. If
inhalation anaesthesia is indicated, halothane has
been considered the agent of choice; but its
myocardial depressant and arrhythmic effects in the
presence of catecholamines may limit its use. At high
MAC (>1.5), both enflurane and isoflurane prevent
vagally mediated bronchospasm 13. These agents could
hence be considered useful for inhalation anaesthesia in
the asthmatics. However in 1997, Rooke et al 13 observed clinically in humans that sevoflurane at 1.1 MAC
may be more efficacious than both iso- and
enflurane. The beta- adrenergic aerosols like salbutamol,
when inhaled before induction of anaesthesia
prevents bronchospasm 14. Our patient did not suffer
any asthmatic attack throughout the perioperative period.
Conclusion
Identification of "at risk patients" and
adequate preoperative preparation are essential for
the administration of safe anaesthetics to patients
with reactive airway disease. Careful selection
of anaesthetic technique and drugs will reduce
morbidity and mortality during the perioperative period.
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