COMPLICATIONS&E.R. IN L.A.

L.A. is widely used in medical & dental (effective&safe).In spite of that :complications occasionally happen.Dentist thru knowledge reduces the incidence.You give many thousands of injections but one may lead to dangerous reaction.So diagnosis&management is clearly important. Dentist& his staff must practice&deal with ER.

Local complication

Failure to obtain anesthesia.

Pain during&after injection

hematoma

intra-vascular injection

Trismus

facial paralysis

prolonged impairment of sensation

needles

infection

lip trauma

visual disturbances

General complication.

Fainting: vaso-vagal shock

drugs interaction

serum hepatitis

sensitivity reaction

occupational dermatitis

cardio-respiratory ER.

1-failure to obtain anesthesia:

needs experience& competence. Dentine is sensitive but you can extract the adjacent tooth (anesthesia delayed and only analgesia obtained ).

Possible reasons:

1 - faulty technique .Repeat

2 - infection (pH change), alkaloids will not dissociate.

Also, it leads to spread of infection by destroying

barriers. Regional anesthesia or GA.

3 – solution expiration (store reasonable amount).

4 - individual resistance to certain drugs(use another

drug with different chemical composition).

2 - pain during & after injection:

a - patient attitude in life.(Previous experience).

b - dentist :methods of pain control (painless

& pleasant).

- Sharp needles at right angle to tense

tissue (rubber balloon).

- warm sol.& inject slowly.

- Non-isotonic or contaminated solution (use

reputable cartridge).

- nerve sheath penetration: otherwise numbness.

- Force to deposit solution in tough tissue.

Induced pain may persist after anesthesia

effect disappear.

- Other causes of after pain or discomfort include:

infection, trismus& hematoma.

3-haematoma formation : - penetration of blood vessel: I.D.N., post. super.dental, or

I.O.N.block. - Bleeding from the pteryg.v.plexus: rapid swelling of the cheek - discoloration of the skin,1-2 days due to breakdown

of blood pigments. - Bleeding from I.O.venous plexus: black eye. What to tell the patient? Like a bruise, blood will stop

spontaneously& swelling will disperse but there is discomfort due to irritant effect of blood. - bleeding in pterygo-mandibular space:

trismus, hematoma, infection (you give AB).

4 - Intra-vascular injection.: detected by aspiration.

What to do ? - Intra vascular bleeding increased by using non-

aspirating syringe, can be reduced by touching the bone, then withdraw the needle.

- Toxic effect by anesthesia agent or vasoconstrictor or both.If the patient starts to faint: stop injection & start management of fainting. 5 - Blanching: 1 - at the site of injection: Tense tissue& vasoconstrictor. 2 - at a site remote from injection: Intravascular injection or interference with autonomic nerve supply of the blood vessels. Ischemia: 30 minutes. How to reduce? Aspiration or

withdrawal. what to tell patient? Assurance.

6-Trismus : injury to medialpteryg.m., hematoma, infection. Onset: later & if due to infection there is temperature,

pain& unwell. If there is pus you have to drain+AB+ hot saline mouth wash

N.B.: inflammation adjacent to muscle causes spasm & blood within tissue spaces is irritant & cause spasm.

7-facial paralysis: facial nerve is motor: paralysis partial or complete. If needle reaches posterior border of ascending ramus, fluid deposited in parotid gland which has a fascia sheath & so, IDNB fails.

S. & s. : lips, eyelids affected: Assurance.

8 - Prolonged impairment of sensation: - nerve damage: trauma by needle or neurotoxic fluid (alcohol). Use of cartridge eliminated the risk. - Hemorrhage & infection near the nerve impair sensation. Surgery related to lower third molar & premolars effect lip sensation. N.B.: Test for anesthesia& paraesthesia by pin-prick & cotton-wool over the skin (closed eyes). Area recorded & follow up at intervals(3-6-18 months).

9-Broken needles: stainless steel disposable and pre-sterile needles reduced the incidence of breakage.

If not available: Standard needle sterilized & not in chemical disinfectant.

To avoid breakage : needle straight, do not force in tissue, do not change direction while part of it is in tissue (withdraw). By doing this, needle is not bended. Do not straighten: It will become weak & easy to break.

It breaks at the hub. So, do not insert all needle(5mm out).

If broken: Hold the tissue under pressure & use artery forceps to grasp it.

If broken inside the tissue: inform the patient & explain. Do not try to remove at this stage, radiographs to confirm presence & position. Refer to consultant for opinion& management. Broken part of needle is kept for metallurgy investigations.

10 - Infection: rare complication. Sometimes, pterygo- mandibylar space infection.11- Lip trauma: children: not to bite lip. Swelling or sore ulcer which heal with minimal scar. Adults: I.D.N. block: smoking, hot drinks. 12 - Visual disturbances: rare, unilateral or bilateral. Squint, diplopia or even transient blindness reported. Difficult to explain ! !, vascular spasm, intra-arterial injection most likely. Reassure Maxillary injection: solution infiltrate to the orbit may reach & anesthetize the motor nerve to muscles of the eye.

General reactions1- Fainting: vasovagal shock (syncope) with or without loss of

consciousness.

- Dizzy, weak, nausea, skin: pale, cold, clammy.

- Do not leave patient alone.

What to do? Supine position, loosen tight clothes, cold swab, smelling salts. Duration 30-60 seconds. If more than that, then it is NOT VASOVAGAL SCHOCK, So:

Maintain air-way, give O2, seek medical aid. If still conscious you give glucose.

- Pregnant women? Asthmatic pt.?

- Vital signs records: pulse rate, respiratory rate, blopressure.

History of repeated fainting: supine position, premedication, breakfast. If still faint: GA.

2-DRUG INTERACTION : some drugs may interact with LA. Ask patient & if necessary his physician (e.g.) monoamine oxidase inhibitors(MAOI)& tricyclic drugs. These could potentiate the action of adrenaline& nor-adrenaline -----dangerous rise in bl. Pr. & cardiac arrythmia(.Tricyclic> MAOI).

N.B.: Use a non-amine vasoconstrictor(citanest with octapressin). Profound hypertention---transient---intracranial haemorrhage or

acute heart failure. What to do? Refer immed .to hospital with monitoring equipment.

Under GA : Do not use adrenaline or nor-adrenaline Without permission from anesthetist. What to use ? ( halothane, cyclopropane, ethyle chloride )

Pt. Allergic to sulpha: no LA containing Para-amino-benzoic acid ring.

3- serum hepatitis: Hbv,Hcv-----infective hepatitis.

The antigen retained in bl., although pt. has no signs& symptoms, so, it can be transmitted to another patient (infection incubation period up to 6 months).Cross infection is eliminated by the use of sterilized needles & syringes.(hypodermic needles should never be used for more than one pt.)

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4- Sensitivity reaction: swelling,urticaria at the site of injection or anaphylactic shock. Pathological response of the tissues sensitized to allergens. Any LA agent may evoke such response

Pts. With allergic disease are liable to be hypersensitive& occasionally normal patient.

Local reaction > systematic.

Give antihistamine: piriton 4mg/ t.d.s./ 3/7 days.

Anaphylactic shock :

severe hypotension, loss of consciousness,

respiratory depression, facial& laryngial oedema& urticaria. If not treated properly, it is fatal.

Hydrocortisone 100mg(2ml) I.V. or & adrenaline 0.5ml

of 1/1000 concentration I.M. or S.C. very slowly. Store

adrenaline in a dark place.

So, always ask about allergy to LA.& if so, use different LA agent.

5- Occupational dermatitis :

procaine (novacaine dermatitis ): painful cracking & skin fissuring( around nails& between fingers).

Lignocaine: rare dermatitis.

Topical anesthesia containing Para-amino-benzoic acid derivative (benzocaine) : allergy there ,but rare.

5- Cardio-pulmonary ER :

Respiratory failure 0r Cardiac arrest ,as result of LA is very remote.

Respiratory arrest : rate & depth of breathing are depressed (watch excursion of chest).

If only depression is recognized( respiration is still present) : pure O2 by face mask will affect recovery.

If not : flat on the floor--clear the airway--neck extended by pulling the mandible upwards& forwards, ventilation of lung, start by manual pulmonary resuscitation or mouth to mouth breathing (normal rate of breathing 12-18/minutes), for 20 minutes. If not successful: rush to hospital.

Cardiac arrest : signs of cardiovascular failure are variable: pale skin, sweating. Patient laid flat, legs raised to encourage blood flow to the heart to improve cardiac output, give O2 which may lead to recovery.

If not ,and condition progress to cardiac arrest, then, the time limit is 3 minutes (cerebral anoxia). Signs & symptoms: No carotid artery pulse, Eye-pupils dilated with no response to light: Then, Do cardiac massage( CPR. ).

Precautionary measures

-The exercise of care & skill : Do not wait to be stimulated by an ER. Fainting: occurs with high temperature & humidity. what to do?. Cool& ventilation of the clinic.

- Good history, records, history of fainting, observe, any signs appear: supine position.

- Efficient suction apparatus available - O2 cylinder or modern anesthetic machine or manual

resuscitator near at hand. - Hold regular practices & checks on your ER equipments. -Telephone of hospital or skillful doctor must be available. - Imagine an ER happens & you save the life of the

patient, because of preparing your precautionary measures. What a good feeling !!.