Anesthetics Nursing Considerations & Management

Anesthetics are drugs used to cause complete or partial loss of sensation. These drugs are subdivided based on site of action and can either be general or local. General anesthetics can cause central nervous system (CNS) depression to produce loss of pain sensation and consciousness. On the other hand, local anesthetics cause the same sensation and feeling in a certain area of the body without producing the systemic effects related to severe CNS depression.

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Table of Common Drugs and Generic Names

Here is a table of commonly encountered anesthetic agents, their generic names, and brand names:

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General and Local Anesthesia

General Anesthesia

General anesthesia involves the administration of combined different general anesthetic agents with the fewest adverse effects to achieve analgesia (loss of pain perception), unconsciousness (loss of awareness of one’s own surroundings), and amnesia (inability to recall what took place).

It also blocks the autonomic reflexes governing involuntary reflex response of the body to injury which can compromise cardiac, respiratory, gastrointestinal, and immune status.

Muscle reflexes are also blocked to prevent jerking movements that might interfere with surgical procedures.

Risk Factors Associated with General Anesthesia

Widespread CNS depression can occur in individuals with the following risk factors:

• CNS Factors: neurological diseases that may produce an abnormal reaction to the CNS-depressing and muscle-relaxing effects of general anesthetic agents like epilepsy, stroke, and myasthenia gravis.
• Cardiovascular (CV) Factors: underlying CV diseases which can can be worsened by severe reactions to anesthesia (shock, hypotension, dysrhythmia, and ischemia) like coronary artery disease (CAD).
• Respiratory Factors: obstructive pulmonary diseases that can complicate delivery of gas anesthetics, intubation, and mechanical ventilation like asthma, chronic obstructive pulmonary disease (COPD), and bronchitis.
• Renal and hepatic function: conditions that interfere with metabolism and excretion of anesthetics that could lead to prolonged anesthesia like acute renal failure and hepatitis.

Administration of General Anesthesia

Patient undergo predictable stages during administration of anesthesia. These steps are referred to as the depth of anesthesia:

• Stage 1 – Analgesia Stage: Characterized by loss of pain sensation and with the patient still conscious and able to communicate.
• Stage 2 – Excitement Stage: Period of excitement and often combative behavior with many signs of sympathetic stimulation.
• Stage 3 – Surgical Anesthesia: Involves muscle relaxation, regular respirations, progressive loss of eye reflexes and pupil dilation. It is the stage in which surgery can be safely performed.
• Stage 4 – Medullary Paralysis: Very deep CNS depression with loss of respiratory and vasomotor center stimuli, in which death can occur rapidly. It is considered a critical period because anesthesia has become too intense.

Administration of general anesthesia is divided into three phases:

• Induction: from beginning of anesthesia to stage 3. The most dangerous period of induction is stage 2 because of the systemic stimulations that occur.
• Maintenance: from stage 3 to completion of surgical procedure.
• Recovery: from discontinuation of anesthetic to regained consciousness, movement, and ability to communicate of the patient. 

Local Anesthesia

Refers to a loss of sensation in limited areas of the body. Can be achieved by different methods:

• Topical administration: involves the application of cream, lotion, ointment, or drop of local anesthetic to traumatized skin to relieve pain. It can also involve application of these forms to the mucous membranes in the eyes, nose, throat, mouth, urethra, anus, or rectum.
• Infiltration: involves injecting the anesthetic directly into the tissues to be treated. It brings the anesthetic into contact with the nerve endings in the area and prevents them from transmitting nerve impulses to the brain.
• Field Block: involves injecting the anesthetic all around the area that will be affected by the surgery. Anesthesia comes in contact with all of the nerve endings surrounding the area. It is often used for tooth extraction.
• Nerve Block: involves injecting the anesthetic at some point along the nerve(s) that run to and from the region in which the loss of pain sensation or muscle paralysis is desired. Several types of nerve blocks include: peripheral nerve block, central nerve block, epidural anesthesia, caudal block, and spinal anesthesia.

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General Anesthetic Agents

General anesthetic agents can be classified into: barbiturate anesthetics, nonbarbiturate general anesthetics, anesthetic gases, and volatile liquids.

Barbiturate Anesthetics

Description

• Barbiturate anesthetics are intravenous drugs used to induce rapid anesthesia, which is then maintained with an inhaled drug.

Therapeutic Action

The desired and beneficial actions of barbiturate anesthetics are as follows:

• Barbiturate anesthetics depress the CNS to produce hypnosis and anesthesia without analgesia.

Indications

Barbiturate anesthetics are indicated for the following medical conditions:

• Thiopental is the most widely used intravenous anesthetics.
• Both thiopental and methohexital do not have analgesic properties so patients would require analgesics post-operation.
• These drugs are indicated for induction and maintenance of anesthesia as well as for induction of hypnosis.

Here are some important aspects to remember for indication of barbiturate anesthetics in different age groups:

Children

• At greater risk for complications after anesthesia (e.g. laryngospasm, bronchospasm, aspiration, etc.)
• Nursing care should include support and reassurance; assessment of child for any skin breakdown related to immobility, and safety precautions.

Adults

• They should receive education about what will happen during administration of anesthesia. Expected body reactions should also be explained.
• Continuously reassure adult patients during the time that they are aware of their surroundings but they are unable to speak.
• Most general anesthetics are not recommended during pregnancy because of potential adverse effects to the fetus.
• A period of 4-6 hours after receiving anesthetic is required for lactating women before they can start nursing.

Older adults

• They are more susceptible to adverse effects (e.g. CNS, CV, and dermatological effects).
• At risk for developing toxicity because of possible hepatic and renal impairment.
• Safety measures should be instituted (e.g. side rails, call light, ambulation assistance, and skin care).
• Longer monitoring and regular orienting and reassuring is essential.
• After general anesthesia, it is important for nurses to promote vigorous pulmonary toilet to decrease the risk of pneumonia.

Pharmacokinetics

Here are the characteristic interactions of barbiturate anesthetics and the body in terms of absorption, distribution, metabolism, and excretion:

Contraindications and Cautions

The following are contraindications and cautions for the use of barbiturate anesthetics:

• Silicon (e.g. Rubber stoppers, disposable syringes). Methohexital will cause an immediate breakdown of the silicone.
• Pregnancy, lactation. CNS depressive effects to baby and fetus.
• Neither drug should be used until the anesthesiologist nor are staff ready and equipped for intubation and respiratory support. The rapid onset of action of these drugs can cause respiratory depression and apnea.

Adverse Effects

Use of barbiturate anesthetics may result to these adverse effects:

• CNS: CNS suppression
• CV: bradycardia, hypotension
• Respiratory: respiratory depression
• GI: decreased GI activity
• Nausea and vomiting are common after recovery.

Interactions

The following are drug-drug interactions involved in the use of barbiturate anesthetics:

• Theophylline, oral anticoagulants, beta-blockers, corticosteroids, hormonal contraceptives, phenylbutazones, metronidazole, quinidine, carbamazepine: decreased effectiveness of these drugs with barbiturates
• Narcotics: increased risk for apnea

Nonbarbiturate Anesthetics

Description

• Nonbarbiturate anesthetics are the other parenteral drugs used for intravenous administration in anesthesia.

Therapeutic Action

The desired and beneficial actions of nonbarbiturate anesthetics are as follows:

• Nonbarbiturate anesthetics are very potent amnesiacs that are thought to be acting in the reticular activating system and limbic system to potentiate the effects of GABA.
• It has little effect on cortical function.

Indications

Nonbarbiturate anesthetics are indicated for the following medical conditions:

• Midazolam, the prototype nonbarbituare anesthetic, is widely used to produce amnesia or sedation for many diagnostic, therapeutic, and endoscopic procedures. It can also be used to induce anesthesia and to provide continuous sedation for intubated and mechanically ventilated patients.
• Droperidol produces marked sedation and produces a state of mental detachment. It also has antiemetic effect which reduces the incidence of nausea and vomiting in surgical and diagnostic procedures.
• Ketamine is useful in situations when cardiac depression is dangerous because it causes sympathetic stimulation with increase in blood pressure and heart rate.
• Propofol is used for short procedures because it has a very rapid clearance and produces much less of a hangover effect and allows for quick recovery.

Here are some important aspects to remember for indication of nonbarbiturate anesthetics in different age groups:

Children

• At greater risk for complications after anesthesia (e.g. laryngospasm, bronchospasm, aspiration, etc.)
• Nursing care should include support and reassurance; assessment of child for any skin breakdown related to immobility; and safety precautions.
• Propofol is widely used for diagnostic tests and short procedures in children older than 3 years of age because of its rapid onset and metabolism.
• Etomidate is not recommended for use in children younger than 10 years of age.

Adults

• They should receive education about what will happen during administration of anesthesia. Expected body reactions should also be explained.
• Continuously reassure adult patients during the time that they are aware of their surroundings but they are unable to speak.
• Most general anesthetics are not recommended during pregnancy because of potential adverse effects to the fetus.
• A period of 4-6 hours after receiving anesthetic is required for lactating women before they can start nursing.

Older adults

• They are more susceptible to adverse effects (e.g. CNS, CV, and dermatological effects).
• At risk for developing toxicity because of possible hepatic and renal impairment.
• Safety measures should be instituted (e.g. side rails, call light, ambulation assistance, and skin care).
• Longer monitoring and regular orienting and reassuring is essential.
• After general anesthesia, it is important for nurses to promote vigorous pulmonary toilet to decrease the risk of pneumonia.

Pharmacokinetics

Here are the characteristic interactions of nonbarbiturate anesthetics and the body in terms of absorption, distribution, metabolism, and excretion:

Contraindications and Cautions

The following are contraindications and cautions for the use of nonbarbiturate anesthetics:

• Conditions that can be compromised by vomiting. Midazolam is more likely to cause nausea and vomiting than other anesthetics.
• Renal or hepatic failure, prolonged QT intervals. Contraindicated with use of droperidol.
• Respiratory depression and arrest is associated with use of nonbarbiturate anesthetics so life support equipment should be readily available always.

Adverse Effects

Use of nonbarbiturate anesthetics may result to these adverse effects:

• Midazolam: CNS suppression, respiratory depression
• Droperidol: chiils, hypotension, hallucinations, drowsiness, QT prolongation
• Etomidate: myoclonic and tonic movements
• Ketamine: hallucinations, dreams, psychotic episodes (can cross blood-brain barrier)
• Propofol: local burning on injection sites, bradycardia, hypotension, pulmonary edema
• Fospropofol: sensation of perianal burning, stinging, tingling, rash (do not usually require intervention and will usually pass)

Interactions

The following are drug-drug interactions involved in the use of nonbarbiturate anesthetics:

• Ketamine and halothane can cause severe cardiac depression with hypotension and bradycardia.
• NMJ Blockers. Potentiated muscular blocking of NMJ if paired with ketamine
• Inhaled anesthetics, other CNS depressants, narcotics, propofol, thiopental. Increased toxicity and length of recovery with use of midazolam.

Anesthetic Gases

Description

• Anesthetic gases enter the bronchi and alveoli, pass the capillary system and is transported to the heart to be pumped throughout the boyd. It has high affinity for fatty tissue (including the lipid membrane of the nerves in the CNS), and is lipophilic.
• Passes quickly to the brain and causes CNS depression.
• Very flammable and associated with toxic adverse effects.

Therapeutic Action

The desired and beneficial actions of anesthetic gases are as follows:

• Moves quickly in and out of the body that it can accumulate in closed body compartments (e.g. sinuses) and cause pressure there.
• Very potent analgesic.
• Do not cause muscle relaxation.

Indications

Anesthetic gases are indicated for the following medical conditions:

• Nitrous oxide is usually used for dental surgery. It is also combined with other agents for anesthetic use.
• Only one anesthetic gas, nitrous oxide (blue cylinder), is still used.

Here are some important aspects to remember for indication of anesthetic gases in different age groups:

Children

• At greater risk for complications after anesthesia (e.g. Laryngospasm, bronchospasm, aspiration, etc.)
• Nursing care should include support and reassurance; assessment of child for any skin breakdown related to immobility; and safety precautions.
• Children need to be cautioned not to bite themselves when receiving dental anesthesia.

Adults

• They should receive education about what will happen during administration of anesthesia. Expected body reactions should also be explained.
• Continuously reassure adult patients during the time that they are aware of their surroundings but they are unable to speak.
• Most general anesthetics are not recommended during pregnancy because of potential adverse effects to the fetus.
• A period of 4-6 hours after receiving anesthetic is required for lactating women before they can start nursing.

Older adults

• They are more susceptible to adverse effects (e.g. CNS, CV, and dermatological effects).
• At risk for developing toxicity because of possible hepatic and renal impairment.
• Safety measures should be instituted (e.g. side rails, call light, ambulation assistance, and skin care).
• Longer monitoring and regular orienting and reassuring is essential.
• After general anesthesia, it is important for nurses to promote vigorous pulmonary toilet to decrease the risk of pneumonia.

Pharmacokinetics

Here are the characteristic interactions of anesthetic gases and the body in terms of absorption, distribution, metabolism, and excretion:

Contraindications and Cautions

The following are contraindications and cautions for the use of anesthetic gases:

• Conditions which are at risk for hypoxia. Oxygen is always given with nitrous oxide because the drug can block the reuptake of oxygen after surgery. Susceptible patients should be monitored for signs of hypoxia, chest pain, and stroke.
• Pregnancy. Potential adverse effects to the fetus.
• Lactation. Should wait 4 hours after administration of nitrous oxide before nursing a baby.

Adverse Effects

Use of anesthetic gases may result to these adverse effects:

• Respiratory: pneumothorax
• GI: bowel obstruction
• EENT: acute sinus pain, middle ear pain
• Inactivates Vitamin B₁₂.

Interactions

The following are drug-drug interactions involved in the use of anesthetic gases:

• Ketamine and halothane can cause severe cardiac depression with hypotension and bradycardia.

Volatile Liquids

Description

• Volatile liquids are also inhaled anesthetics because they are unstable at room temperature and release gases.
• Most volatile liquids are halogenated hydrocarbons.

Therapeutic Action

The desired and beneficial actions of volatile liquids are as follows:

• Depresses the CNS, causing anesthesia. It also relaxes muscles.
• It sensitizes the myocardium to the effects of norepinephrine and epinephrine.

Indications

Volatile liquids are indicated for the following medical conditions:

• Halothane, the prototype drug, is used for maintenance of anesthesia and can be effective as an induction agent.
• Desflurane is widely used to in outpatient surgery because of its rapid onset and quick recovery time.
• Isoflurane is widely used to maintain anesthesia after inductions. It can cause muscle relaxation.

Here are some important aspects to remember for indication of volatile liquids in different age groups:

Children

• At greater risk for complications after anesthesia (e.g. Laryngospasm, bronchospasm, aspiration, etc.)
• Nursing care should include support and reassurance; assessment of child for any skin breakdown related to immobility, and safety precautions.
• Halothane is widely used for children, especially those with respiratory dysfunction because it tends to produce bronchial dilation. However, it is contraindicated for those with increased intracranial pressure (ICP).

Adults

• They should receive education about what will happen during administration of anesthesia. Expected body reactions should also be explained.
• Continuously reassure adult patients during the time that they are aware of their surroundings but they are unable to speak.
• Most general anesthetics are not recommended during pregnancy because of potential adverse effects to the fetus.
• A period of 4-6 hours after receiving anesthetic is required for lactating women before they can start breastfeeding.

Older adults

• They are more susceptible to adverse effects (e.g. CNS, CV, and dermatological effects).
• At risk for developing toxicity because of possible hepatic and renal impairment.
• Safety measures should be instituted (e.g. side rails, call light, ambulation assistance, and skin care).
• Longer monitoring and regular orienting and reassuring is essential.
• After general anesthesia, it is important for nurses to promote vigorous pulmonary toilet to decrease the risk of pneumonia.

Pharmacokinetics

Here are the characteristic interactions of volatile liquids and the body in terms of absorption, distribution, metabolism, and excretion:

 

Route	Onset	Peak	Duration
Inhaled	Rapid	Rapid	End of inhalation
T1/2: Unknown Metabolism: liver Excretion: kidney (urine)

Contraindications and Cautions

The following are contraindications and cautions for the use of volatile liquids:

• Hepatic impairment. Can contribute to hepatic toxicity.
• Cardiovascular disease. Associated with bradycardia and hypotension
• Respiratory depression and increased sensitivity. Has tendency to cause respiratory depression and it is an irritant to the airways.
• Pregnancy, lactation. Potential adverse effects to the fetus and the baby.
• All of these drugs have the potential to trigger malignant hyperthermia. In such cases, dantrolene is the preferred treatment and should be readiily available.

Adverse Effects

Use of volatile liquids may result to these adverse effects:

• Halothane’s recovery syndrome: fever, anorexia, nausea, vomiting, hepatitis (can progress to fatal hepatic necrosis). It is not used for more than 3 weeks to reduce the patient risk.
• Desflurane is associated with a collection of respiratory reactions: cough, increased secretions, laryngospasm.

Interactions

The following are drug-drug interactions involved in the use of volatile liquids:

• Caution should be used when any of these drugs is combined with other CNS suppressants.

Nursing Considerations

Here are important nursing considerations when administering this drug:

Nursing Assessment

These are the important things the nurse should include in conducting assessment, history taking, and examination:

• Assess for the mentioned cautions and contraindications (e.g. drug allergies, hepatic and renal impairment, etc.) to prevent any untoward complications.
• Perform a thorough physical assessment (e.g. weight, neurological status, vital signs, heart sounds, skin color and lesions, bowel sounds, etc.) to establish baseline data before drug therapy begins, to determine effectiveness of therapy, and to evaluate for occurrence of any adverse effects associated with drug therapy.
• Monitor laboratory test results (e.g. liver and renal function tests) to determine possible need for a reduction in dose and evaluate for toxicity.

Nursing Diagnoses

Here are some of the nursing diagnoses that can be formulated in the use of this drug for therapy:

• Impaired gas exchange related to respiratory depression
• Impaired skin integrity related to immobility secondary to effects of positioning during anesthesia and immobility
• Risk for injury related to CNS depressive drug effects

Implementation with Rationale

These are vital nursing interventions done in patients who are taking general anesthetics:

• Prepare emergency equipment to maintain airway and provide mechanical ventilation when patient is not able to maintain respiration because of CNS depression.
• Monitor temperature for prompt detection and treatment of malignant hyperthermia. Maintain dantrolene on standby.
• Monitor vital signs and ECG readings to assess systemic response to CNS depression and provide appropriate support as needed.
• Provide safety measures (e.g. adequate lighting, raised side rails, etc.) to prevent injuries.
• Educate client on drug therapy to promote understanding and compliance.
• Provide comfort measures (e.g. pain relief, skin care, etc.) to help patient tolerate drug effects.

Evaluation

Here are aspects of care that should be evaluated to determine effectiveness of drug therapy:

• Monitor patient response to therapy (analgesia, loss of consciousness).
• Monitor for adverse effects (e.g. respiratory depression, hypotension, bronchospasm, skin breakdown, etc).
• Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
• Monitor patient compliance to drug therapy.

Local Anesthetic Agents

Description

• Local anesthetic agents are used primarily to prevent the patient from feeling pain for varying periods of time after the agents have been administered in the peripheral nervous system.
• They can cause loss of the following sensations in this sequence: temperature, touch, proprioception, and skeletal muscle tone.
• They are very powerful nerve blockers and should not be absorbed systemically. Systemic absorption can lead to toxic effects on the nervous system and the heart.
• Local anesthetics can either be esters or amides. Pramoxine is a local anesthetic agent that does not fit into either of these classes.

Therapeutic Action

The desired and beneficial actions of local anesthetics are as follows:

• Local anesthetics work by causing a temporary interruption in the production and conduction of nerve impulses. They affect the permeability of nerve membranes to sodium ions. By preventing the sodium ions from entering the nerve, they stop the nerve from depolarizing.
• Reduce the height and rate of rise of the action potential and increase the excitation threshold. Conduction velocity is slowed too.
• Ester local anesthetics are broken down immediately in the plasma by enzymes calledplasma esterses.

Indications

Local anesthetics are indicated for the following:

• Infiltration anesthesia, peripheral and sympathetic nerve blocks, central nerve blocks, spinal and caudal anesthesia, topical anesthetic for skin or mucous membrane disorders.

Here are some important aspects to remember for indication of local anesthetics in different age groups:

Children

• Nursing care should include support and reassurance; assessment of child for any skin breakdown related to immobility; and safety precautions.
• Local anesthetics are used in children in much the same way as they are used in adults.
• Infants are at particular risk for systemic absorption and toxicity from topically-applied local anesthetics. Tight diapers and occlusive dressings can increase systemic absorption.

Adults

• They should receive education about what will happen during administration of anesthesia. Expected body reactions should also be explained.
• Regional or local anesthetics are preferred if surgery is needed during pregnancy.

Older adults

• They are more susceptible to adverse effects (e.g. CNS, CV, and dermatological effects).
• At risk for developing toxicity because of possible hepatic and renal impairment.
• Safety measures should be instituted (e.g. side rails, call light, ambulation assistance, and skin care).
• Longer monitoring and regular orienting and reassuring is essential.

Pharmacokinetics

Here are the characteristic interactions of local anesthetics and the body in terms of absorption, distribution, metabolism, and excretion:

Contraindications and Cautions

The following are contraindications and cautions for the use of local anesthetics:

• Allergy to anesthetics and parabens. To avoid hypersensitivity reactions.
• Heart block. Could be exacerbated with systemic absorption
• Shock. Can alter the local delivery and absorption of these drugs
• Decreased plasma esterase. Can result in toxic levels of ester-type local anesthetics
• Pregnancy, lactation. Potential adverse effects to fetus and baby.

Adverse Effects

Use of local anesthetics may result to these adverse effects:

• CNS: headache (especially with epidural and spinal anesthesia), restlessness, anxiety, dizziness, tremors, blurred vision, backache
• CV: peripheral vasodilation, myocardial depression, arrhythmias, blood pressurechanges
• Respiratory: respiratory arrest
• GI: nausea, vomiting
• Loss of skin integrity, especially in patients who are unable to move.

Interactions

The following are drug-drug interactions involved in the use of local anesthetics:

• Succinylcholine: increased and prolonged neuromuscular blockade
• Epinephrine: less risk of systemic absorption and increased local effects of local anesthetics

Nursing Considerations

Here are important nursing considerations when administering this drug:

Nursing Assessment

These are the important things the nurse should include in conducting assessment, history taking, and examination:

• Assess for the mentioned cautions and contraindications (e.g. drug allergies, hepatic and renal impairment, etc.) to prevent any untoward complications.
• Perform a thorough physical assessment (e.g. weight, neurological status, vital signs, heart sounds, skin color and lesions, bowel sounds, etc.) to establish baseline data before drug therapy begins, to determine effectiveness of therapy, and to evaluate for occurrence of any adverse effects associated with drug therapy.
• Inspect site for local anesthetic application to ensure integrity of the skin and to prevent inadvertent systemic absorption of the drug.
• Monitor laboratory test results (e.g. liver and renal function tests, plasma esterases) to determine possible need for a reduction in dose and evaluate for toxicity.

Nursing Diagnoses

Here are some of the nursing diagnoses that can be formulated in the use of this drug for therapy:

• Disturbed sensory perception related to local anesthetic effect
• Impaired skin integrity related to immobility caused by action of drugs
• Risk for injury related to loss of sensation and mobility

Implementation with Rationale

These are vital nursing interventions done in patients who are taking local anesthetics:

• Prepare emergency equipment to maintain airway and provide mechanical ventilation if needed.
• Ensure that patients receiving spinal anesthesia or epidural anesthesia are well hydrated and remain lying down for up to 12 hours after the anesthesia to minimize headache.
• Provide skin care to site of administration to reduce risk of skin breakdown.
• Provide comfort measures to help patient tolerate drug effects.
• Provide safety measures (e.g. adequate lighting, raised side rails, etc.) to prevent injuries.
• Educate client on drug therapy to promote understanding and compliance.

Evaluation

Here are aspects of care that should be evaluated to determine effectiveness of drug therapy:

• Monitor patient response to therapy (loss of feeling in designated area).
• Monitor for adverse effects (e.g. respiratory depression, blood pressure changes, arrhythmias, GI upset, skin breakdown, injury, CNS alterations, etc).
• Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
• Monitor patient compliance to drug therapy.

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