COMPLICATIONS COMPLICATIONS OF GENERAL OF GENERALANESTHESIAANESTHESIA

COMPLICATIONS COMPLICATIONS OF GENERAL OF GENERAL ANESTHESIAANESTHESIA

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Shaymaa AfifShaymaa Afif

What it is Genaral anasthesia??

• is a state of unconsciousness and loss of protective reflexes resulting from the administration of one or more general anaesthetic agents. A variety of medications may be administered, with the overall aim of ensuring hypnosis, amnesia, analgesia, relaxation of skeletal muscles, and loss of control of reflexes of the autonomic nervous system

Complications of anesthesia

• Complications of anesthesia are inevitable even with most experienced Doctors.

• These complications range from minor to catastrophic.

• When anesthetic complications occur, appropriate evaluation, management, and documentation to minimize the negative outcomes.

• Incidence • Perioperative mortality rate due to anesthetic

cause account is less than 1:20,000.

Classification..1. Respiratory complications2. Cardiovascular complications3. Neurological complications4. PONV5. Temperature changes 6. Adverse drug effect and

hypersensitivity7. Complications of positioning8. Miscellaneous

A) Respiratory complications

I. Complications of laryngoscopy and intubation

II. Respiratory obstructionIII. HypoxemiaIV. Hypercapnia and hypocapniaV. Hypoventilation VI. Aspiration pneumonia

I- Complications of laryngoscopy and intubationI- Complications of laryngoscopy and intubation

1. Errors of ETT positioning:1. Errors of ETT positioning:a. Esophageal intubationb. Endobronchial intubationc. Position of the cuff in the larynx

2. Airway trauma:2. Airway trauma:a. Tooth damage.b. Dislocated mandible.c. Sore throat. d. Pressure injury on trachea.e. Edema of glottis or trachea.f. Post intubation granuloma of vocal cords.

3. Physiologic responses to airway instrumentation:3. Physiologic responses to airway instrumentation:a. Sympathetic stimulationb. Laryngospasmc. Bronchospasm

4. ETT malfunction:4. ETT malfunction:a. Risk of ignitionb. ETT obstructionc. Cuff perforation

II- Respiratory obstructionII- Respiratory obstruction::SignsSigns::

11 . .Inadequate tidal volumeInadequate tidal volume..22 . .Retraction of the chest wall and of the Retraction of the chest wall and of the

supraclavicular,infraclavicular and supraclavicular,infraclavicular and suprasternal spacessuprasternal spaces..

33 . .Excessive abdominal movementExcessive abdominal movement..44 . .Use of accessory muscles of respirationUse of accessory muscles of respiration..

55 . .Noisy breathing (unless obstruction is Noisy breathing (unless obstruction is absolute and complete)absolute and complete)..

66 . .CyanosisCyanosis..

Sites of obstructionSites of obstruction:: At the lips. By the tongue Above the glottis At the glottis: laryngeal spasm,

Bronchospasm Faults of apparatus: Kink or obstruction of

ETT

III- HypoxemiaIII- Hypoxemia:: PaO2 less 60 mmHg or SaO2 less 90%PaO2 less 60 mmHg or SaO2 less 90%

CausesCauses::11 . .Decreased FiO2Decreased FiO222 . .HypoventilationHypoventilation

33 . .V/Q mismatchV/Q mismatch44 . .Increased O2 utilization by tissuesIncreased O2 utilization by tissues

55 . .Tissue hypoxiaTissue hypoxia

Clinical signs of hypoxiaClinical signs of hypoxia( ( sweating, tachycardia, cardiac arrhythmias, hypertension, and sweating, tachycardia, cardiac arrhythmias, hypertension, and

hypotensionhypotension ) )are nonspecific; bradycardia, hypotension, and cardiac are nonspecific; bradycardia, hypotension, and cardiac arrest are late signsarrest are late signs . .

Increased intrapulmonary shunting relative to closing capacity Increased intrapulmonary shunting relative to closing capacity is the most common cause of hypoxemia following general is the most common cause of hypoxemia following general anesthesiaanesthesia . .

TreatmentTreatment:: oxygen therapy with or without positive airway pressure. oxygen therapy with or without positive airway pressure.

Additionally, treatment of the causeAdditionally, treatment of the cause . .

IV) HypercapniaIV) HypercapniaPaCO2 or ETCO2 > 40 mmHgPaCO2 or ETCO2 > 40 mmHg..

CausesCauses::Increased FiCO2Hypoventilation

Increased dead spaceIncreased CO2 production by tissues

Treatment:Treatment: of the cause of the cause

V) HypoventilationV) Hypoventilation A. CausesA. Causes : :

11 - -Respiratory obstructionRespiratory obstruction22 - -Factors affecting the ventilatory driveFactors affecting the ventilatory drive

a. Respiratory depressant drugsa. Respiratory depressant drugs b. Hypothermiab. Hypothermia

c. CV strokec. CV stroke33 - -Peripheral factorsPeripheral factors a. Muscle weaknessa. Muscle weakness

b. Painb. Pain c. Decreased diaphragmatic movementc. Decreased diaphragmatic movement..

d. Pneumo or hemothoraxd. Pneumo or hemothorax.. e. Decreased chest wall compliance e.g. kyphoscoliosise. Decreased chest wall compliance e.g. kyphoscoliosis..

C. C. TreatmentTreatment:: should be directed at the underlying cause. Marked should be directed at the underlying cause. Marked

hypoventilation may require controlled ventilation until hypoventilation may require controlled ventilation until contributory factors are identified and correctedcontributory factors are identified and corrected..

VI- Pulmonary aspirationVI- Pulmonary aspiration

Incidence and severity increase in emergency cases, especially Incidence and severity increase in emergency cases, especially patients with delayed gastric emptying such as patients with delayed gastric emptying such as CSCS, , intestinal intestinal obstructionobstruction..

- Aspiration of material with a pH less than 2.5 causes extensive Aspiration of material with a pH less than 2.5 causes extensive

lung damage.lung damage.

ManifestationsManifestations::

They vary depending on the degree of aspiration. The patient may They vary depending on the degree of aspiration. The patient may become hypoxic, tachycardic and tachypnoeic. Bronchospasm often become hypoxic, tachycardic and tachypnoeic. Bronchospasm often occurs and auscultation of the chest may reveal wheeze and occurs and auscultation of the chest may reveal wheeze and

crepitations.crepitations.

B) Hemodynamic B) Hemodynamic ComplicationsComplications

I. Hypotension I. Hypotension

A.Causes A.Causes : : hypoxemia, hypovolemia, decreased myocardial hypoxemia, hypovolemia, decreased myocardial

contractility (myocardial ischemia, pulmonary edema), contractility (myocardial ischemia, pulmonary edema), decreased systemic vascular resistance, cardiac decreased systemic vascular resistance, cardiac

dysrhythmias, pulmonary embolus, pneumothorax, cardiac dysrhythmias, pulmonary embolus, pneumothorax, cardiac tamponade. tamponade.

B.TreatmentB.Treatment: : fluid challenge; pharmacologic treatment includes fluid challenge; pharmacologic treatment includes

inotropic agents (dopamine, dobutamine, epinephrine) and inotropic agents (dopamine, dobutamine, epinephrine) and alpha receptor agonists (phenylephrine). CVP and PA alpha receptor agonists (phenylephrine). CVP and PA catheter monitoring may be needed to guide therapycatheter monitoring may be needed to guide therapy

II. Hypertension II. Hypertension A.A. CausesCauses: : enhanced SNS activity (pain, bladder distension), enhanced SNS activity (pain, bladder distension),

preoperative hypertension, hypervolemia, preoperative hypertension, hypervolemia, hypoxemia, increased intracranial pressure, and hypoxemia, increased intracranial pressure, and vasopressors. vasopressors.

B.TreatmentB.Treatment:: correction of the initiating cause; various correction of the initiating cause; various

medications can be used to treat hypertension medications can be used to treat hypertension including beta blockers, calcium channel blockers, including beta blockers, calcium channel blockers, nitroprusside or nitroglycerin.nitroprusside or nitroglycerin.

III. Cardiac dysrhythmias III. Cardiac dysrhythmias A. CausesA. Causes: hypoxemia, hypercarbia, hypovolemia, pain, : hypoxemia, hypercarbia, hypovolemia, pain,

electrolyte and acid-base imbalance, myocardial electrolyte and acid-base imbalance, myocardial ischemia, increased ICP, digitalis toxicity, ischemia, increased ICP, digitalis toxicity, hypothermia, anticholinesterases and malignant hypothermia, anticholinesterases and malignant hyperthermia. hyperthermia.

B.TreatmentB.Treatment: of the cause.: of the cause.

C) Neurological complicationsC) Neurological complications

I- Awareness:I- Awareness:

Incidence: 0.2% Increased in obstetric, Incidence: 0.2% Increased in obstetric, cardiac anesthesia and hypovolemic cardiac anesthesia and hypovolemic patients. patients.

II- Delayed recovery:II- Delayed recovery:

A.A. Metabolic and electrolyte causesMetabolic and electrolyte causes

B.B. Cerebral hypoperfusionCerebral hypoperfusion

C.C. Cerebral depression by drugsCerebral depression by drugs

III- Perioperative Neuropathy:III- Perioperative Neuropathy:

D) Complications of positioning

ComplicationPositionPrevention

Air embolismSitting, prone, reverse Trendelenburg

Maintain venous pressure above 0 at the wound.

BackacheAnyLumbar support, padding, and slight hip flexion.

Compartment syndromeEspecially lithotomyMaintain perfusion pressure and avoid external compression.

Corneal abrasionEspecially proneTaping and/or lubricating eye.

Nerve palsies  

  Brachial plexusAnyAvoid stretching or direct compression at neck or axilla.

  Common peronealLithotomy, lateral decubitusPad lateral aspect of upper fibula.

  RadialAnyAvoid compression of lateral humerus.

  UlnarAnyPadding at elbow, forearm supination.

Retinal ischemiaProne, sittingAvoid pressure on globe.

Skin necrosisAnyPadding over bony prominences.

E) Postoperative Nausea and VomitingE) Postoperative Nausea and Vomiting Risk factors Risk factors A.A. Patient risk factors: short fasting status, anxiety, young age, Patient risk factors: short fasting status, anxiety, young age,

female, female, obesity, gastroparesis, pain, history of postoperative obesity, gastroparesis, pain, history of postoperative

nausea/vomiting or motion sickness. nausea/vomiting or motion sickness. B. Surgery-related factors: gynecological, abdominal, ENT, B. Surgery-related factors: gynecological, abdominal, ENT,

ophthalmic, and plastic surgery; endocrine effects of surgery; ophthalmic, and plastic surgery; endocrine effects of surgery; duration of surgery. duration of surgery.

C. Anesthesia-related factors: premedicants (morphine and other C. Anesthesia-related factors: premedicants (morphine and other opioids), anesthetics agents (nitrous oxide, inhalational agents, opioids), anesthetics agents (nitrous oxide, inhalational agents, etomidate, methohexital, ketamine), anticholinesterase reversal etomidate, methohexital, ketamine), anticholinesterase reversal agents, gastric distention, longer duration of anesthesia, mask agents, gastric distention, longer duration of anesthesia, mask ventilation, intraoperative pain medications, regional ventilation, intraoperative pain medications, regional anesthesia. anesthesia.

D. Postoperative factors: pain, dizziness, movement after surgery, D. Postoperative factors: pain, dizziness, movement after surgery, premature oral intake, opioid administration. premature oral intake, opioid administration.

Treatment of Postoperative Nausea and Vomiting (PONV) Treatment of Postoperative Nausea and Vomiting (PONV) Droperidol, Metoclopramide, Ondansetron, Dolasetron, Droperidol, Metoclopramide, Ondansetron, Dolasetron,

Granisetron Propofol 10-20 mg IV, Dexamethasone, Granisetron Propofol 10-20 mg IV, Dexamethasone, Promethazine. Combination therapy is the most effective. Promethazine. Combination therapy is the most effective.

F) Allergic Drug Reactions• 1. Anaphylaxis • 2. Anaphylactoid reactions

A. Initial therapy 1. Discontinue drug administration and all anesthetic agents. 2. Administer 100% oxygen. 3. Intravenous fluids (1-5 liters of LR). 4. Epinephrine (10-100 mcg IV bolus for hypotension; 0.1-0.5

mg IV for cardiovascular collapse).

B. Secondary treatment Antihistaminic medications IV. Epinephrine 2-4 mcg/min, norepinephrine 2-4 mcg/min. Aminophylline 5-6 mg/kg IV over 20 minutes. 1-2 grams methylprednisolone or 0.25-1 gm

hydrocortisone. Sodium bicarbonate 0.5-1 mEq/kg. Airway evaluation (prior to extubation).

G) G) Temperature changesTemperature changesI) Hypothermia:I) Hypothermia:It is unintentional decrease of core body temperature to < 35 C during anesthesiaIt is unintentional decrease of core body temperature to < 35 C during anesthesiaCauses:Causes:I.I. Drop in core temperature.Drop in core temperature.II.II. Central inhibition of thermoregulation. Central inhibition of thermoregulation.

Contributing factorsContributing factors::Extremes of age, prolonged surgery, cold infusion or irrigation fluids, Extremes of age, prolonged surgery, cold infusion or irrigation fluids,

muscle relaxantsmuscle relaxants..

PreventionPrevention::A.A. increase ambient temp and humidityincrease ambient temp and humidityB.B. warm solutionswarm solutionsC.C. enclose exposed visceraenclose exposed visceraD.D. humidify the inspired gaseshumidify the inspired gasesE.E. warm mattress and blanketwarm mattress and blanketF.F. use low flow anesthesia.use low flow anesthesia.

II) Malignant Hyperthermia

• It is a fulminant skeletal muscle hypermetabolic syndrome occurring in genetically susceptible patients after exposure to an anesthetic triggering agent. Triggering anesthetics include halothane, enflurane, isoflurane, desflurane, sevoflurane, and succinylcholine.

• Early signs: tachycardia, tachypnea, unstable blood pressure, arrhythmias, cyanosis, mottling, sweating, rapid temperature increase, and cola-colored urine.

• Late (6-24 hours) signs: pyrexia, skeletal muscle swelling, left heart failure, renal failure, DIC, hepatic failure.

Cont……..• Incidence and mortality • A. Children: approx 1:15,000 general

anesthetics. • B. Adults: approx 1:40,000 general

anesthetics when succinylcholine is used; approx 1:220,000 general anesthetics when agents other than succinylcholine are used.

• C. Familial autosomal dominant transmission.

• D. Mortality: 10% overall; up to 70% without dantrolene therapy. Early therapy reduces mortality for less than 5%.

H) MISCELLANEOUS

• Renal dysfunction: Oliguria (urine output less then 0.5 mL/kg/hour) most likely reflects decreased renal blood flow due to hypovolemia or decreased cardiac output.