For post graduates in anaesthesia

1. Post anaesthesia
discharge criteria and
complications
Moderator: DR SUKHYANTI KERAI
Presented by :DR RAVI PRAKASH

2. Post anaesthesia care unit(pacu)
• PACU : also referred as recovery room
• It is designed and staffed to monitor and care for patients who are
recovering from the immediate physiologic effect of anaesthesia and
surgery
• PACU care spans the transition from delivery of anaesthesia in operating
room to less acute monitoring on the hospital ward and in some cases at
home
• Must be equipped to monitor and resuscitate unstable pt. while providing a
comfortable calm tranquil environment for the recovery of stable pt.
• It should be in close proximity with operating room and with easy access of
post operative pt. by anesthesia provider and surgical caregivers

3. Standards of postanesthesia care
• ASA has given 5 standards which can be apply to post anesthesia care in all locations
• STANDARD 1
All pt. who have received GA,RA,or MAC shall receive appropriate
postanesthesia care
• STANDARD 2
✓ A pt.transported to the PACU shall be accompanied by a member of the
anesthesia team who is knowledgeable about the pt. condition
✓ continually evaluated and treated during transport with monitoring and
appropriate support needed
• STANDARD 3
upon arrival in PACU, Pt. shall be re evaluated and a verbal report provided to the responsible pacu
nurse
• STANDARD 4
✓ The patient’s condition shall be evaluated continually in the PACU by the methods appropriate to pt.
medical condition
✓ Particular attention should be given to monitor OXYGENATION, VENTILATION,CIRCULATION,level of
CONSIOUSNESS, and TEMPERATURE
• STANDARD 5
A physician is responsible for the discharge of the patient from the PACU

4. PHASES OF RECOVERY
• Phase 1:
• Immediate recovery phase requires intensive nursing care to detect early
signs of complications
• Receive a complete pt. record from operative room to plan postoperative care
• It is for pt. requiring close monitoring
• Phase 2:
• care of surgical pt. Who has been transferred from phase 1
• Less observation and less nursing care
• Step down or progressive care unit

5. PHASES OF RECOVERY
OT PACU Home
Phase 3
Phase 2
Phase 1

6. DISCHARGE SCORING SYSTEM
OT PACU Home
PADS score
Modified Aldrete score
White Score

7. Discharge criteria

8. FAST-TRACKING
OT PACU
Step-
down unit Home

9. Fast track recovery
• Increased use of short acting drugs
and technique
• Pt. already match the discharge
criteria at the time they reach PACU
• These pt. may bypass phase 1 unit
and go directly to phase 2

10. Physiological disorder manifested in
PACU
❑ Respiratory :
▪ Upper airway obstruction
⮚ Loss of pharyngeal muscle tone
⮚ Residual neuromuscular blockade
⮚ Laryngospasm
⮚ Edema and hematoma
⮚ Obstructive sleep apnea
▪ Arterial hypoxemia
⮚ Ventilation perfusion mismatch
⮚ Alveolar hypoventilation
⮚ Increase venous admixture
⮚ Decreased diffusion capacity
▪ Pulmonary edema
⮚ Post obstructive pulmonary edema
⮚ Transfusion related acute lung injury

11. Physiological disorder manifested in
PACU
❑ Cardiovascular
▪ Hemodynamic instability
⮚ Systemic hypertension
⮚ Systemic hypotension
▪ Myocardial ischemia
▪ Cardiac dysrhythmias
⮚ Tachycardia
⮚ Atrial dysrhythmias
⮚ Ventricular dysrhythmias
⮚ Bradydysrhythmias
⮚ Atrial fibrillation

12. Physiological disorder manifested in
PACU
❑ Renal
▪ Oliguria
▪ Contrast nephropathy
▪ Intraabdominal hypertension
▪ Rhabdomyolysis
❑ Others
▪ Bleeding
▪ Decreased body temperature
▪ Shivering
▪ Delerium
▪ Delayed awakening
▪ Nausea and vomiting
▪ pain

13. Clinical features:
Clinical features:
• Difficulty in breathing
• Desaturation
• Tachypnoea
• Tracheal tug
• Paradoxical breathing
pattern
• Reduced or absent
breath sounds
Upper airway obstruction…
1. Loss of pharyngeal muscle tone due to residual effects of drugs
Management:
• Head tilt, Jaw thrust
• CPAP with face mask
• Nasopharygeal airway
• Oxygen supplementation

14. Case 2
60year male, 60 kg
PAC: Diabetic controlled with oral hypoglycemics
Airway: WNL
Investigations; Hb 12 gm%,RBS: 122, Hb A1C: 8.2, B U; 52, s.cr..1.8, CXR & ECG ..WNL
For Umbilical hernia repair
GA with endotracheal tube and controlled ventilation
Induction: Propofol, fentanyl, rocuronium
Maintenance: O2 + N2O+ Isoflurane with boluses of rocuronium
Uneventful surgery….duration 75 minutes
Reversal: Glyco 0.6 mg + Neostigmine 3.0 mg….. extubated

15. • Saturation 90% on 100% oxygen given through face mask Bain circuit
• Making incomprehensible noises, looks jittery, eyes open, obeying commands
• RR 35/min
• Shallow breathing
• Chest clear on auscultation
• Pulse 125/min
• BP 190/106 mmHg

16. FURTHER EXAMINATION
• Not able to lift legs
• Able to hold head off the head ring for 3 seconds
• Bain circuit with 2 litre bag tidal volume 220 ml
DIAGNOSIS??

17. Residual neuromuscular blockade
DEFINITION
Defined using quantitative neuromuscular monitoring
Train of four ratio of < 0.9 according to recent opinions
As opposed to TOF ratio <0.7 previously
Small degree of residual paralysis at TOF ratio 0.7-0.9:
• Impaired pharyngeal function
• Increased risk of aspiration
• Weakness of upper airway muscles
• Airway obstruction
• Attenuation of hypoxic ventilator response
• Unpleasant symptoms of muscle weakness

19. Residual neuromuscular blockade….
Strategies For prevention
Intraoperative
• Limit dose of NMBD by using regional nerve blocks
/supraglottic airway devices if feasible
• Use intermediate /short acting NMBD
• Use neuromuscular monitoring
• Depth of NM blockade as per surgical requirement
• Use TIVA for maintainace of anaesthesia rather than
inhalational agents
• Use boluses of NMBDs rather than continuous infusion
Emergence from anaesthesia
▪ Attempt reversal only if some evidence of
spontaneous recovery is there
▪ Anticholinesterase should be administered on
average 15 to 30 minutes before clinician anticipate
removal of ETT
Preoperative
Caution in
▪ Elderly
▪ Liver or renal dysfunction
▪ Disease affecting neuromuscular junction
▪ Drugs affecting NM junction

21. NEOSTIGMINE…ADVERSE EFFECTS
• Paradoxical muscle weakness when given after neuromuscular
function completely recovered
• Nausea and vomiting
• Bradycardia, bradyarrhythmia,junctional rhythms,ventricular escape
beat,completeheart block
• Bronchoconstriction.

22. Reversal guidelines
Quantitative monitoring
e.g. acceleromyography
TOF count
0-1
Delay
reversal
TOF count
2-3
TOF ratio
>or=0.4
TOF ratio
0.4-0.7
TOF ratio
>0.7
Neostigmine
70 mcg/kg
Neostigmine
40-50mcg/kg
Neostigmine
20mcg/kg
Avoid
reversal
Qualitative monitoring
Peripheral nerve stimulator
TOF count
0-1
TOF Count
2-3
TOF count
4
With fade
TOF count
4
Without
fade
Delay
reversal
Neostigmin
70mcg/kg
Neostigmine
40-
50mcg/kg
Neostigmine
20mcg/kg
Extubate when TOF ratio >0.9
Allow 15-30 min before
tracheal extubation
Allow 10-15min before
Tracheal extubation

23. If NO neuromuscular monitoring used
• Anticholinesterase should be considered
• Anticholinesterase should be given until some evidence of recovery
of muscle strength
• Use or avoidance should not be on the basis of clinical tests for
muscle strength(5 sec head lift)
• Many pt. can perform these test even at TOF<0.5

24. Extubation using clinical sign
❑ TOF Ratio:
• 0.4 : unable to lift the head and arm
TV may be adequate
vital capacity and inspiratory force may be reduced
• 0.6 : head lift for 3 seconds
open eyes widely
VC and inspiratory forces reduced
• 0.7-0.75: able to cough sufficiently
head lift for 5sec
hand grip 60% control
• 0.8 or more: VC and inspiratory forces adequate
may have diplopia,generalized muscles weakness

25. Treatment of residual neuromuscular blockade
• Support ABC of patient
• Rule out other potential causes
• Is this really residual neuromuscular blockade?.......check nerve stimulator,
electrode, use different nerve muscle combination
• Have you given enough time for reversal agent to act?
• Treat potentiating factors†: hypothermia
Respiratory acidosis and metabolic alkalosis
Drugs administered in PACU; antibiotics, opioids
• Give small dose of neostigmine
• Use alternative agents(??)

26. Causes of prolonged neuromuscular blocakade
❑ Factors contributing to prolonged non depolarizing
NM blockade
• Drugs:
Inhaled anesthetic drugs
local anesthetics
cardiac antidysrhythmic
antibiotics; polymyxin aminoglycosides
lincosamine,metronidazole,tetracyclines
Corticosteroids
CCB
Dantrolene
Furosemide
• Metabolic and physiological states
Hypermagnesemia,hypocalcemia,hypothermia,
resp. acidosis,hepatic/renal failure,myasthenia syndromes
❑ Factors contributing to prolonged
depolarizing neuromuscular blockade
Excessive dose of succinylcholine
Reduced plasma cholinesterase activity
Decreased levels
Extreme of age
Disease states(hepatic,uremia,malnutrition,
plasmapheresis)
Harmonal changes
Pregnancy
Contraceptives
Glucocorticoids
Inhibited activity
Irreversible(echothiophate)
Reversible(edrophonium,neostigmine pyridostigmine)
Genetic variant(atypical plasma cholinesterase)

27. Case 1
4 year old boy
Preanaesthetic evaluation: unremarkable
For squint surgery
General anaesthesia with Proseal LMA with assisted spontaneous ventilation with O2+ N2O+Isoflurane
Intraoperative: Uneventful surgery lasted for 30 minutes
At conclusion of surgery, anaesthetic gases switched off
Surgical dressing done with head lifted
Suddenly SPO2 came down to 88% …………82%......70% DIAGNOSIS?
auscultation: diminished breath sounds

28. Upper airway obstruction
3. Laryngospasm
▪ Protective reflex glottic closure to prevent aspiration
▪ refers to sudden spasm of the vocal cord that completely occludes the
laryngeal opening
▪ Occurs in period when the pt. whose trachea has been extubated is
emerging from general anesthesia
▪ Although occurs in operating room but pt. who arrives in PACU after
G.A. are also at risk of laryngospasm when awakening

29. Upper airway obstruction
Laryngospasm….
• Trigger: Periglottic or distant visceral
stimulation
• Afferent arc: Sensory from laryngeal
receptor via internal branch of superior
laryngeal nerve (Vagus)
• Efferent arc: Motor to intrinsic
laryngeal muscles, lateral cricoarytenoids
and thyroarytenoids via recurrent
laryngeal nerve (vagus)
• Effect: Glottic closure by either true vocal
cord adduction alone or in combination
with adduction of false vocal cords

30. Incidence
• Rare but mostly seen during anesthesia emergence 48%,induction
28%,maintenance 24%
• Overall incidence 8.7/1000
• Incidence: infants >>children>>adults
• Adolescence : male > female ,male 12.1/1000 female 7.2/1000
• Children with URI or bronchial asthma : 98/1000

31. Laryngospasm….
Triggers
• Inadequate depth of anaesthesia
• Local stimulation of larynx: LMA
IPPV in inadequate depth
Secretions
Blood
Vocal cord trauma/surgery
• Distal stimulation Brewer-Luckhardt reflex

32. Risk factors
❑ Patient related:
• Young age
• Anxiety
• GERD
• URI or active br.asthma
• Chronic smoker,voice abuse
• Airway anomaly,sleep apnea syndrome
▪ Unsupervised pt. in recovery room
❑ Surgery related
• Throat and airway surgery,laryngeal surgery,tonsil surgery,thyroid surgery
• SLN injury
• Hypoparathyroidism due to hypocalcemia
• Reflex stimulation: anal surgery,cervical stimulation

33. Anesthesia related
• Insufficient depth of anesthesia during induction
• LMA > ETT
• IV anesthetic like thiopentone >propofol
• Barbiturate
• Ketamine
• Airway irritation
• Irritant volatile anesthetic:desfluran> isoflurane>>halothan/sevofluran
• Mucus and blood after extubation
• Airway handling
• Residual paralysis
• Vomiting and regurgitation

34. Diagnosis
• Harsh breathing inspiratory sound(stridor)
• Exclude other causes of obstruction like tounge drop,bronchospasm,
blood clot
• Fall in spo2 usually late
❑ Partial laryngospasm
• Signs of inspiratory airway obstruction:
• Suprasternal retraction
• Use of accessory muscles
• Paradoxical movement of chest and abdomen
• Auscultation : inspiratory obstruction

36. Date of download: 9/20/2019 Copyright © 2019 American Society of Anesthesiologists. All rights reserved.
Management of laryngospasm

37. Upper airway obstruction
❑ Airway Edema
Risk factors
▪ Prolonged procedures in prone or trendelenburg position
▪ Large amount of blood loss requiring aggressive intravascular fluid resuscitation
▪ Surgeries on tongue,pharynx,and,neck
Airway patency must precede removal of ETT
▪ Cuff Leak test
▪ Steroids
▪ Tracheal tube exchange catheter can be used for safe extubation
▪ Elective Mechanical ventilation to allow edema to settle

38. Cuff leak test
Spontaneously breathing
Cuff is deflated and for first 30 seconds monitored for cough
Only cough associated with gurgling is taken into account
ETT is then occluded at proximal end while the patient continues to breath
Ability to breath around tube is assessed by auscultation
On mechanical ventilation
Set TV to 10-12ml/kg
Measure expired TV
Deflate cuff of ETT
Remeasure expire TV(average of 4-6 breaths)
Difference in tidal volumes with cuff inflated and deflated is LEAK

39. Cuff leak test
Cuff leak test
Miller & Cole < 110 ml
< 130 ml
Jaber et al Leak
> 12-15% OK
< 12-15% Edema
De Bast et al <15.5%

40. UPPER AIRWAY OBSTRUTION
❑ Obstructive Sleep Apnea
▪ increased risk for post op desaturation,respiratory failure,postop. Cardiac event ,
and need for ICU
▪ STOP BANG questionnaire : screening tool for predicting OSA
▪ extubatION: fully awake and following commands
▪ Postop analgesia
-They are exquisitely sensitive to opiods,so minimize opiods consumption in PACU
-Regional anesthesia and multimodal anesthesia should be used for post op
analgesia
▪ Monitoring
-Provide CPAP in immediate postop period,should ask the pt. to bring there
machines if using at home
-Continous pulse oximetry monitoring

41. Arterial hypoxemia
Factors contributing to post operative arterial hypoxemia
• Alveolar hypoventilation
• Diffusion hypoxia
• Ventilation perfusion mismatch
• Increased venous admixture
• Decreased diffusion capacity

42. FIVE CAUSES OF HYPOXEMIA
1. Hypoventilation
• Residual effects of opioids, inhalational agents and other anaesthetic agents on CNS
• Generalized weakness due to residual effect of relaxants leading to decreased inspiratory efforts
• Postoperative abdominal binding
• Postoperative abdominal distention
• Pain leading to splinting
2. Low inspiratory oxygen pressure
Unrecognized disconnection of oxygen source, improper oxygen prescription, empty oxygen tank
3.Shunt
Blood going to alveoli-capillary interface not exposed to air/ventilation(wasted blood)
(Atelectasis,pulmonary edema,pulmonary emboli, pneumonia, aspiration )
Blunting of hypoxic pulmonary vasoconstriction in PACU by residual inhalational agents, vasodilator like NTG
4.Dead space ventilation: Air reaching alveoli-capillary interface not exposed to blood(wasted ventilation)
5. Diffusion limitation

44. • Case 3
• 65 years old male, weight 75 kg
• PAC: Unremarkable
• For laproscopic cholecystectomy
• GA with Proseal LMA with controlled ventilation
• Induction : fentanyl 150 mcg, thiopentone 200 mg, vecuromium 7 mg
• Maintenace : O2 + N2O + isoflurane; boluses of vec and fenta
• Duration of sx: 90 minutes
• Intraoperative ..Blood pressure raised after creation of pneumoperitoneum
• Controlled with Isoflurane increased upto 2%
• Extubated… Patient arousable, responding to verbal commands, maintaining vitals

45. • Shifted to recovery room
• 10 minutes later…Nursing staff called
• SPO2 is 90%..... ABG PH---7.42, PO2– 75, PCO2..48, HCO3..22
• Patient bit sleepy,arousable, opening eyes on commands, able to vocalize, pupils miotic
• Chest clear RR 10/minutes
• Oxygen supplementation through venturi mask FIO2 0.5, FLOW 12 l/min
• SPO2 97%
• 40 minutes later….cardiac arrest ?????
• ABG PH—7.01
• PO2- 120
• PCO- 103

46. Alveolar hypoventilation
• Hypoventilation alone may lead to arterial hypoxemia in a pt. breathing room air
• At sea level in a normocapnic pt. breathing room air
PAO2 is 100mmHg in health pt. without significant A-a gradien PaO2 is 100 mmHg
If PACO2 rises from 40 to 80 due to alveolar hypoventilation it decreases PaO2 to 50 mmhg
• Normally minute ventilation increases by approximately 2L/min for 1mmHg increase in paco2
• This normal response to paco2 is depressed in immediate post operative period by the residual
effect of inhaled anesthetics,opiods,sedative-hypnotics
• treatment:
• Supplimental O2
• External stimulation to wakefulness
• Pharmacological reversal
• Controlled ventilation

48. • Case# 5
A 84 years woman with COPD on MDI inhalers; h/o old pulmonary Kochs
Emergency surgery for Left leg bimalleolar fracture
O/E: PR=96/min, BP=112/74 mmHg, SPO2= 93-94% ORA
RR= 18/min, Chest= bilateral clear, CVS=WNL
Spinal anaesthesia with 2.0 ml of 0.5% hyperbaric bupivacaine
Maximum sensory block achieved T10
Intraop: Uneventful, duration 1 hour, Blood loss minimal
Post op: Patient conscious oriented
PR=80/min, BP= 128/86 mmHg, SPO2=91% ORA, Oxygen through face mask given, SPO2=98%
Chest & CVS= WNL

49. • After 1 hour
• Patient is somnolent ,minimally arousable
• PR=90/min, BP=118/78 mmHg, SPO2=98% on face mask at 4 L/min
• ABG=
PH 7.21
PCO2= 101
PO2=85
HCO3= 21
?????

50. • Recommended target SPO2 in COPD
• 88-92%
• Selected patients with a history of respiratory acidosis may require lower target range 85-90%
• OXYGEN ALERT CARD
• High doses of oxygen in COPD patients
V/Q mismatch
Absorption atelectasis
? Blunting of hypoxic drive

51. Ventilation perfusion mismatch
• Hypoxic pulmonary vasoconstriction refers to attempt of normal lung to
match ventilation and perfusion
• It constricts vessels in poorly ventilated areas in lung and directs blood to well
ventilated alveoli
• In PACU residual effect of inhaled anesthetics and vasodilators(to treat and
improve hemodynamics will blunt HPV and contribute to arterial hypoxemia
• Causes of postoperative pulm. Shunt:
• Atelectasis: mcc in immediate post op period
• Pulmonary edema
• Gastric aspiration
• Pulmonary emboli
• Pneumonia
• Treatment of atelectasis:
• Sitting position
• Incentive spirometry
• Positive airway pressure by face mask

52. Date of download: 9/16/2019 Copyright © 2019 American Society of Anesthesiologists. All rights reserved.

53. Post obstructive pulmonary edema
Promotion of transudation of fluid
Increased the hydrostatic pressure gradient across the pulmonary
vascular bed
Increased venous return + negative intrathoracic pressure
Exaggerated negative intrathoracic pressure
Inspiratory efforts against closed glosttis
It’s a transudative edema
The alveolocapillary unit. In health (left), the alveolus
remains fluid-free, because liquid filtered by Starling
transcapillary forces is cleared by interstitial lymphatics.
In negative-pressure pulmonary edema (right), negative
interstitial pressure results in an increased hydrostatic
gradient and alveolar flooding. The afterload-increasing
effect of the Müller maneuver increases this gradient
because of elevated left ventricular, left atrial, and thus
pulmonary capillary pressures. Pi ¼ interstitial pressure;
Pmv ¼ microvascular pressure.

55. Post obstructive pulmonary
edema
• Laryngospasm is m/c cause
• May occur by any cause that obstruct upper
airways
• Hypoxemia observed within 90 min
• Bilateral fluffy infiltrates on chest radiograph
Treatment:
▪ Supplemental O2
▪ Diuresis
▪ In severe cases positive pressure ventilation

56. Transfusion related acute lung injury(
TRALI)
• D/D of any pt. with pulm.edema who intraoperatively received blood
products
• 1-2 hrs after (upto 6hrs) of blood products transfusion
• Fever and hypotension
• Acute drop in WBC count ( sequestration of granulocytes within lung
and lung exudative fluid)
• Treatment :
• Supplemental O2,diuresis,and mechanical ventilation(if needed)
• Vasopressers may be required for refractory hypotension

57. TRALI

58. Post op hypertension
• Pt. with a h/o essential hypertension are at greater risk for systemic HTN
• Will require pharmacological blood pressure control
• Carotid endarterectomy and intra cranial procedures at greater risk

59. Case 4:
• 55 years old female weight 50 kg
• PAC : history of bronchial asthma on MDI inhales budecort and salbutamol x 3 years
• Chest clear
• For bipolar hemiarthroplasty of left hip joint
• Under combined spinal epidural anaesthesia with 2.5 ml of 0.5% hyperbaric bupivacaine
• Intraop…uneventful…. Vitals stable…..duration of surgery 90 minutes
• Blood loss… 800 ml
• IVF given …3 units RL
• After completion of surgery, patient shifted to PACU
• During shifting to transfer trolley…. BP 75/40 mm Hg, HR 106/min, patient complained of dizziness

60. Postop hypotension
1. HYPOVOLEMIC : decreased preload
2. DISTRIBUTIVE :decreased afterload
3. CARDIOGENIC : pump failure

61. Cardiac dysrhythmias
• Transient and multifactorial
• Reversible causes are :
• Hypoxemia
• Hypoventilation and hypercaphnea
• Endogeneous or exogeneous catecholamines
• Electrolyte abnormalities
• Acidemia
• Fluid overload
• Anemia
• Substance withdrawl

62. Cardiac dysrhythmias
• Atrial dysrhythmias
• 10% after non cardiothoracic surgry
• Incidence higher in cardio thoracic surgeries
• Risk increased by :
• Pre existing cardiac risk factors
• Positive fluid balance
• Dyselectrolytemia
• Oxygen desaturation
New onset dysrhythmias are ass. With increased mortality

63. Cardiac dysrhythmias
• Ventricular dysrhythmias
• Pvc and bigeminy common in PACU
• PVC: b/c of sympathetic stimulation( tracheal intubation,pain and high Pco2
• V tach: rare but indicative of cardiac problems
• Torsedes de pointes : consider Qt prolongation( drugs..)
• Bradyarythmias :
• Drugs: B- blockers,opiods ,anticholinesterase( for reversal),dexmedetomidine
• procedure: bowel distension,raised icp,iop,spinal anesthesia
• Atrial fibrillation :
• Control of rate immediate goal in new onset AF
• Hemodynamic instable: prompt cardioversion
• Mostly rx with b-blocker,ccb
• Amiodarone: consider QT prolongation,decr. HR,decr.BP

64. Myocardial ischemia: evaluation and t/t
• Pt. At low risk:
• ECG interpretation is influenced by pt. cardiac history and risk index
• Low risk pt.: <45 yr,no known cardiac dis ,only one risk factors
• ST segment changes in ECG,do not usually indicate myocardial ischemia
• Relative benin cause of ST changes:anxity esophagial reflux,hyperventilation
and hypokalemia
• RX: routine PACU observation unless sign and symptoms
• More aggressive evaluation if changes accompanied by rhythm disturbance
and hemodynamic instability

65. Myocardial ischemia
• In high risk pt.
• ST changes are significant in absence of sign and symptoms
• Post op myocardial ischemia rarely ass. With chest pain,confirmation depends
on sensitivity of cardiac monitoring
• Lead 2 and V5: detect 80% of ischemic events but visual interpretation is
often inaccurate
Any ST- T changes compatible with myocardial ischemia
Serum troponin
12 lead ECG
Cardiac monitoring
Cardiology follow up

66. Delayed recovery from GA
DRUG RELATED
• Anaesthetic drug overdose
• Wrong drug, wrong dose, wrong routes
• Susceptible patient- extremes of age, debilitated
• Delayed metabolism-hepatic disease
• Delayed excretion-renal disease
• Faulty technique- vaporizer not switched off
• Equipment malfunction-anaesthesia machine,
anesthesia circuits, vaporizers
• Drug interactions-MAOI,SSRI,oral contaceptives
• Atypical cholinesterases
• Central anticholinergic syndrome
Metabolic and endocrine causes
• Hyper/hypoglycaemia
• Electrolyte imbalaces;Hyponatremia
Hypocalcemia
• Uraemia
• Hypothermia
• Acidosis
• Hypothyroidism, Myxedema,thyroid storm
• Adrenal insufficiency
Neurological complications
Cerebral embolism
Cerebral haemorrhage
Cerebral ischemia-delibrate hypotension
, improper positioning
Hypoxic insults
Undiagnosed CNS lesions

69. Prevention of delirium after surgery
• Cognitive stimulation orientation(clock, calender)
• Improve sensory input glasses, hearing aids
• Mobilzation early mobilization and rehabilitation
• Avoidance of psychoactive medication lighys off, creating a relaxing
environment, minimizing nighttime interruptions, dedicated time for
sleep
• Fluid and nutrition
• Avoidance of

70. Anaesthetic specific intervention for
prevention of delirium
BEFORE SURGERY
• Correction of metabolic and electrolyte abnormalities
• Perioperative continuation of pharmacological therapy for neuropsychiatric disorders
DURING SURGERY
• Decrease exposure of drugs triggering delirium- opioids, benzodiazepams, antihistaminics,
dihydropyridines
• GA Vs RA- ↓ incidence by RA with light sedation
• Prevention of large intraoperative blood loss; Hct >30
AFTER SURGERY
• Postoperative pain management: Opioids- AVOID mepridine, opioid rotation
Preferable - Peripheral nerve blocks
-Multimodal regime featuring gabapentin

72. Shivering
• Incidence: G.A. 5-65%, Epidural: 33 %
• Risk factors :male gender and induction agent(propofol>>thiopent)
• Accurate core body temp: at tympanic membrane( rest all are less accurate )
• Immediate consequences
• ↑ O2 consumption,↑CO2 production,↑sympathetic tone( ↑CO,HR,BP,)
• Inhibit platelet function,cogulation factor activity,drug metabolism
• Post op bleeding,prolonged NM blocade,delayed awakening
• Long term effect:
• Myocardial ischemia
• Delayed wound healing
• ↑ peri op mortality
• RX:
• Forced air warmer
• Opiods in adults (meperidine is m/C used)
• Ondansetron
• Clonidine
• Ketamine: 0.5 mg/kg I.v. before G.A.and R.A

73. PONV
• Without prophylactic intervention: 1/3 pt. develop PONV with
inhalational
• Consequences:
▪ Delayed discharge from PACU
▪ Unanticipated hospital admission
▪ Pulmonary aspiration risk
▪ Post op discomfort to pt.
Prophylaxis for PONV:
▪ Anesthetic intervention:
▪ Propofol benefits over inhalational
▪ Nitrogen benefits over nitrous oxide
▪ Remifentanil benefits over fentanyl
▪ Pharmacological intervention :
▪ Droperidol 1.25 mg,ondansetron 4mg,dexamethasone 8mg

74. Pharmacological intervention in pacu

75. OLIGURIA:
• Urinary output < 0.5 ml/kg/hr
• Causes are:

76. Post op retention of urine

77. OXYGEN SUPPLEMENTATION IN PACU

78. ROUTINE ADMINISTRATION OF O2 IN PACU
Arguments against
1.Costly
2. Unnecessary as routinely SPO2 is
monitored in PACU
Arguments in favour
1.A significant number of pts develop hypoxia at
some point of stay in PACU
(positive correlation with age, ASA class, weight,
obesity, GA, IVF >1500ml)
2. Safe practice of PACU care with routine O2
care requires unrealistic ideal conditions

81. BRITISH THORACIC SOCIETY GUIDELINES FOR OXYGEN
USE IN ADULTS AND EMERGENCY SETTINGS(2017)

82. WHAT TO DO….?
• Oxygen supplementation in surgical patients has both benefits and risk
• Benefits of O2 supplementation- prevention of surgical site infection and PONV
• Hyperoxia has numerous harms
• As PACU frequently has inadequate resources( staff and monitors), it is acceptable to provide O2
routinely to surgical patients in early postoperative period(2-6 hours)
• The dose and duration of O2 should be individualized for each patient, e.g. an obese patient, patient
who received GA of long duration , O2 supplementation of relatively higher FIO2 and of longer duration
compared to a normal weight patient
• Oxygen to be PRESCRIBED according to target saturation range and should be monitored