AIRWAY AND ORAL CAVITY - PowerPoint Presentation

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AIRWAY AND ORAL

CAVITY CANCERS

Dr.H-Kayalha

Anesthesiologist

Mucositis

is a painful inflammation and ulceration of

the mucous

membranes of the digestive tract.

Oral

lesions

begin as mucosal

whitening

followed by

the development

of

erythema

and

tissue

friability

.

Oral

mucositis

is a

relatively common

adverse effect of

high-dose chemotherapy

and

radiation

to the head and neck.

Mucositis

can also occur

in the

context of

hematopoietic stem cell

transplantation

.

Chemotherapeutic drugs

associated with

mucositis

include:

-

anthracyclines

-

taxanes

-platinum-based compounds

-methotrexate

-

fluorouracil.

Mucositis

associated with chemotherapy often

begins during

the

first week

of treatment and typically

resolves

after treatment

is terminated

.

Mucositis

associated with

radiation therapy

usually has a more

delayed

onset.

Patients with

mucositis

are at risk of

infection

from spread of oral bacteria.

Narcotics

are frequently required to achieve adequate analgesia.

In its most

severe form

,

pseudomembrane

formation, edema

, and bleeding

may cause

airway compromise

or

risk of

aspiration

.

Radiation

to the head and neck can result in

permanent tissue

fibrosis

that may

limit mouth opening

and

neck

and

tongue

mobility

.

Airway

fibrosis

and

tracheal

stenosis

may result

in difficulty in ventilation and intubation that is not

recognized on

physical examination.

MANAGEMENT OF ANESTHESIA

Preoperative evaluation

of patients with cancer includes

consideration of

the

pathophysiologic

effects

of the disease

and recognition

of the potential

adverse effects of cancer

treatments

(Table

23-4).

In addition, the patient's

underlying

medical

comorbidities

must not

be overlooked

.

Correction of

nutrient

deficiencies, electrolyte abnormalities, anemia,

and

coagulopathies

may be needed preoperatively.

In most

cases, laboratory

evaluation should

include:

-complete

blood

count

-coagulation profile

-

serum electrolyte

concentrations

-transaminase

levels.

Chest radiography,

echocardiography, pulmonary

function evaluation

, and other specialized

testing should

be used if clinical suspicion warrants.

chemotherapeutic drugs

have

the

potential to

impair wound healing

, especially the

growth factor

and

angiogenesis

inhibitors

.

It

has been suggested that surgery

be

delayed

for 4 to 8 weeks

after treatment with

bevacizumab

because

of an increased

risk of bleeding

and

postoperative

wound

complications

.

Potential

pulmonary

or

cardiac toxicity

is a

consideration in

patients being treated with chemotherapeutic drugs

known to

be associated with these complications.

The

myocardialdepressant

effects

of anesthesia

can unmask cardiac

dysfunction related

to

cardiotoxic

chemotherapeutic drugs

such as

doxorubicin

.

Therefore

, when

major surgery

is

planned,

preoperative

echocardiography

may be indicated. Since

several chemotherapeutic

agents can cause

electrocardiographic abnormalities

such as

QT prolongation

, a baseline

electrocardiogram should

be reviewed.

A preoperative history of drug-induced

pulmonary

fibrosis

(

dyspnea

, nonproductive cough) or

congestive heart

failure will

influence the subsequent management of anesthesia

.

In patients

treated with

bleomycin

, it may be helpful to

perform

arterial

blood gas

monitoring in addition to

oximetry

and

to carefully

titrate intravascular fluid

replacement, since

these patients

are at risk of developing

interstitial pulmonary

edema

, presumably

because of

impaired lymphatic drainage

in

the lung

.

Bleomycin

-associated pulmonary injury may be

exacerbated by

high oxygen concentrations

; therefore, it is

prudent to

adjust the delivered

oxygen

concentration

to the

minimum

that

provides adequate

oxygen saturation

.

Nitrous

oxide

may augment

the toxicity of methotrexate, so it is best

avoided

.

The presence of

hepatic

or

renal

dysfunction

should

influence the

choice and dose of anesthetic drugs and muscle

relaxants

. the possibility of

a

prolonged response to succinylcholine

is a

consideration in

patients being treated with alkylating

chemotherapeutic drugs

like

cyclophosphamide

.

The

presence of

paraneoplastic

syndromes

such as

myasthenia gravis

and

Eaton-Lambert syndrome

may also affect the patient's response to

muscle relaxants

.

Attention to

aseptic technique

is important, because

immunosuppression

occurs

with most chemotherapeutic agents

and is

exacerbated by

malnutrition

.

Immunosuppression

produced by:

1-anesthesia,

2 -surgical

stress

,

3-

blood transfusion

during the

perioperative

period could have deleterious effects

on the

patient's subsequent response to his or her cancer.

Adrenal suppression

may be present in patients who are being

treated with

steroids

. Those who have been receiving

more than

20 mg

of prednisone

(or its equivalent) per day for

longer

than 3

weeks

are considered most at risk.

Recovery

of the

hypothalamic- pituitary-adrenal

axis may take

up to a year

.

A typical steroid

replacement regimen is

hydrocortisone 100 mg

IV

administered

at induction of anesthesia followed by 100 mg

IV every

8 hours for the first 24 hours after surgery.

Intubation

in the presence of oral

mucositis

may

cause bleeding

.

Patients with cancers of the head, neck, and

anterior

mediastinum

may exhibit

airway compromise

.

Patients with a

history of

radiation

exposure may have

airway

deformities

that

are difficult to recognize on physical examination

.

Recent evidence suggests that

anesthetics and

analgesics have

immunomodulatory

properties

.

Intravenous

opioids

tend to

blunt natural killer cell

activity, producing

an

immunosuppressive effect

that supports the

proliferation of

tumor cells.

The

use of

neuraxial

anesthesia

may

preserve

the host's intrinsic anticancer defenses better

than general

anesthesia

. However,

coagulopathies

may prevent

the use

of these techniques in some cancer patients.

Peripheral nerve

blocks may be utilized, but baseline

peripheral

neuropathies

related

to chemotherapeutic drugs such as

vincristine

and

cisplatin

should be well documented.

Postoperative care

must include adequate attention to

pain management

.

Many

cancer patients have been treated for

pain related

to their underlying diagnosis. Therefore,

narcotic

dosing must

be adjusted to account for possible drug

tolerance

.

Prophylaxis

against infection and

thromboembolism

must also

be considered

.

Have a nice day