Post anesthesia care unit for Residents of Anesthesia

علما زدني آیه – سوره ( رب (۱۱۴طه

“ بيفزاى” دانشم بر پروردگارا

The Post Anesthesia Care Unit

Mansoor MasjediAss. Prof. of AnaesthesiaFellowship of critical care medicineAnesthesia grand round ,SUMS , Azar 1395

The post anesthesia care unitOVERVIEW

Admission to PACU Standards for Post anesth. care Early post-op physiologic changes Transport to the PACU

Upper airway obstructionPulmonary issues in the PACUCardiovas. issues in the PACURenal dysfunctionBody temp. & shiveringPONVDelirium , Emergence excitement & Delayed awakeningInfection control

• Discharge criteria• Future considerations• Summary

Practice Practice standards standards & Guidelines& Guidelines

The post anesthesia care unit

Emergence from general anesthesia and surgery may be accompanied by

a number of physiologic disturbances that affect

multiple organ systems

The post anesthesia care unit

• Recovery from anesthesia can range from uncomplicated toto life-threatening

• Must be managed by skilled nursing personnel

• Anesthesiologist plays a key role in optimizing safe recovery from anesthesia.

The post anesthesia care unitHistory

• Methods of anesthesia since160 yr ago • PACU has only been common for the past 50 yr • 1920’s and 30’s: several PACU’s opened in the US and abroad • After WW II , significant ↑PACU’s due to the shortage of nurses in US • In 1947 a study showed : over an 11 yr period, nearly half of the

deaths during 24 hrs post-op were preventable

1949: having a PACU → standard of care

The post anesthesia care unitStandards for postanesthesia care

Practice Standards delineate the required obligation of minimal care(can be exceeded by the clinical judgment )

I.All pts received GA , RA or MAC → PACU

II. Accompanied by a knowledgeable member of the anesth. care team , Continually evaluated & treated during transport with monitoring and support appropriate to the pt’s condition

III. Upon arrival , Reevaluated and a verbal report provided to the PACU nurse IV. Condition evaluated continually in the PACU (methods appropriate to the patient’s medical condition). Particular attention, monitoring

oxygenationventilationcirculationLOCTemp.

During recovery from all anesthetics : pulse oximetry in the initial phase of recovery.*

V. A physician is responsible for the discharge of the pt from PACU

The post anesthesia care unitStandards for postanesthesia care

• Unlike Practice Standards, Practice Guidelines are not requirements• recommendations to assist health care providers in clinical decision making

The ASA Practice Guidelines for Post anesthetic Care

Standards for PACU

Post Anesthesia Care Unit

1. All patients who have received general anesthesia, regional anesthesia, or monitored anesthesia care should receive postanesthesia management.

2. The patient should be transported to the PACU by a member of the anesthesia care team that is knowledgeable about the patient’s condition.

3. Upon arrival in the PACU, the patient should be re-evaluated and a verbal report should be provided to the nurse.

4. The patient shall be evaluated continually in the PACU. 5. A physician is responsible for discharge of the patient.

PACU – requirements/space

• Should be located close to the operating suite

• Should have 1.5 PACU beds per operating room used

• 120 square foot per patient

• Minimum 7 feet between beds


• Central nursing station

• 1 : 1 ratio good

• 1 : 3 ratio acceptable for busy OR’s


PACU – requirements/personnel


• Monitors:– ECG– Pulse oximeter– EtCO2– Non invasive BP – Invasive pressure monitor– Temperature

PACU – requirements/equipment


• Tray with labeled Emergency drugs

• Airway maintenance kit:– Laryngoscope (all size blades)– Endotracheal tubes (all sizes)– Face masks, Airways, Ambu Bag, Venturi masks

Also :– Cricothyroidotomy set– Tracheostomy set– Transport ventilator


• Immediate access to – clinical labs (ABG)– x-ray– blood bank

• Piped in – Oxygen– Air– Vacuum for suction

• Requires good ventilation (waste anesthetic gases)



PACU

Standards for PACU







Transportation from OR---to---PACU

• Stretcher/bed with side rails

• O2 tank

• Monitoring – SpO2, HR

• Anaesthesiologist + Surgeon

The post anesthesia care unitTransport to the PACU

Upper airway patency and respiratory efforts must be monitored from OR to PACU

Confirm adequate ventilation : rise and fall of the chest wall with inspiration listening for breath sounds feeling for exhaled breath with the palm of one’s hand over

the pt’s nose and mouth

The post anesthesia care unitThe post anesthesia care unitTransport to the PACUTransport to the PACU

Standards for PACU






The post anesthesia care unitAdmission to the PACU

• Specially trained nurses skilled in the prompt recognition of postop. complications make up the staff of the PACU

• Anesthesiologist , upon arrival to PACU:– Pt’s hx.– Medical condition– Anesthesia– Surgery

• Particular attention:– Oxygenation (pulse oximetry)– Ventilation (breathing frequency, airway patency, capnography)– Circulation (systemic blood pressure, heart rate, electrocardiogram [ECG])

• Vital signs at least q15 min.

205 / 554 errors due to nurse-physician communication errors

44,000 to 98,000 preventable deaths each year, with an associated cost of $17 to $29 billion.

Donchin 2003

CriCO (February 2016) – - 1744 patient deaths / 5 years- 1.7 billion in malpractice costs (30% of cases) CriCO 2016

On Admission to PACU

• Anaesthetist to PACU nurse hand over– Preop history– Intra-op factors:

Procedure Type of anesthesia EBL UOP

– Assessment and report of current status– Post-op instructions


Admission in PACU • Monitoring equipment attached

Cardiac monitor Blood pressure cuff (or IBP)Pulse oximetry

• Oxygen (nasal canula/mask) : 2-5 L/min• Surgical site examined • IV fluids/ IV line checked

• Vital signs oq 5 min. (for 30 min) o…..q 15 min. afterwards


Standards for PACU






EARLY POSTOPERATIVE PHYSIOLOGIC CHANGES

Most common : PONV, hypoxia, hypothermia , shivering , cardiovas. instability

The post anesthesia care unitComplications

Serious adverse outcomes correlate more closely with airway, respiratory & cardiovascular compromise

The post anesthesia care unitUpper airway obstructionLoss of pharyngeal muscle tone

The most freq. cause of airway obstruction in immediate postop period

1- Normal awake pt :Contraction of pharyngeal mus + negative insp. pressure by diaphragmfacilitating opening of the upper airway

2- ↓ LOC or Mus. Tone → A vicious cycle :Collapse of pharyngeal tissue during inspiration → ↑resp. effort & negative insp. pressure → further airway obstruction

Rx.Simply : jaw thrust oror CPAP or or both In selected patients: oral or nasal airway , LMA or ETT

The post anesthesia care unitupper airway obstructionResidual neuromuscular blockade

Residual NMB may not be evident on arrival because diaphragm recovers from NMB before pharyngeal mus. ETT in place + adequate ETCO2 & Vt ≠ ability to maintain upper airway & to clear secretions Stimulation of extubation + activity of pt transfer + mask support → keep airway open during transport to the PACU

Only after the pt is calmly resting in the PACU does upper airway obstruction become evident

Even with intermediate & short-acting NMBD , residual paralysis in the PACU may occur despite pharmacologic reversal

The post anesthesia care unitUpper airway obstructionResidual neuromuscular blockade

Anesthetized vs Awake pt. :o TOF ratio is often misleading;

o Values < 0.4 to 0.5 : not appreciated o Significant weakness persist to a ratio of 0.7o Nl pharyngeal function ˃ 0.9

o 5 sec of sustained tetanus to 100-Hz stimulation )the most reliable indicator of reversal ) : same errors as TOF ratio.

o In an awake pt, clinical assessment is preferred to painful TOF or tetanic stimulationo Clinical evaluation :

grip strength tongue protrusion lift the legs off the bed lift the head off the bed for 5 sec ( standard, reflecting both motor strength & maintenance and

protection of the airway) Oppose the incisors strongly against a tongue depressor is a more reliable indicator of pharyngeal

muscle tone ( TOF ratio of 0.85, as opposed to 0.60 for sustained head lift )

o If suspects persistence or return of neuromuscular weakness Common factors : Resp. acidosis and Hypothermia, alone or in combination

o Sugammadex vs Neostigmine,: might reduce residual NMB in the PACU ) return of TOF ratio to ˃ 0.9 within 5

min in 85% of pts )

The post anesthesia care unitUpper airway obstructionlaryngospasm

Sudden spasm of the vocal cords that completely occludes the laryngeal opening

o Typically when the extubated pt is emerging from GA o Most likely in OR @ tracheal extubationo In the PACU upon awakening

Rx.Jaw thrust maneuver with CPAP ) up to 40 cmH2O )

If failed

Immediate mus. relaxation → succinylcholine )0.1 to 1.0 mg/kg IV or 4 mg/kg IM)

Attempting to pass an ETT forcibly through a closed glottis because of laryngospasm

is not acceptable

The post anesthesia care unitUpper airway obstructionEdema or hematoma

Surgical complication in • prolonged procedures in the prone or Trendelenburg position general• large blood loss & aggressive fluid resuscitation • surgical procedures on the tongue, pharynx, and neck, including (thyroidectomy , carotid endarterectomy and cervical spine procedures) localized

Extubation in PACU

Cuff leak test

1. Ability to breathe around ETT when deflating tube cuff & occlusion of the proximal end 2. Measuring the intrathoracic pressure required to produce a leak around the endotracheal tube with the cuff deflated

(safe pressure threshold can be difficult to identify)3. Ventilating pts in the volume control mode measuring exhaled tidal volume before and after cuff deflation

) ˃ 15.5% is the advocated cutoff value for extubation )

The cuff leak test does not take the place of sound clinical judgment

I. Decompress the airway by releasing the clips or sutures on the wound and evacuating the hematomaII. If emergency tracheal intubation is required

Ready difficult airway equipment Surgical backup for emergency tracheostomy

III. If pt has spontaneous vent. → awake technique is preferred ) visualization of cords by direct laryngoscopy may not be possible

Evaluation of airway patency must precede removal of the endotracheal tube

Rx.

The post anesthesia care unitUpper airway obstructionObstructive sleep apnea

• OSA ; Often overlooked ,because most pts are not obese & the majority are undiagnosed

• Prone to airway obstruction and should not be extubated until fully awake & following commands

• Extubated pts : sensitive to opioids →→ Reg. anesth. for postop analgesia

• Preop. plan to provide CPAP in the immediate postop. period. – Bring their CPAP machines with them on the day of surgery to be set up before the pt’s arrival in the PACU. – If no CPAP at home or not have their machines with them → respiratory therapist )proper fit of the CPAP mask or

nasal airways and amount of positive pressure needed to prevent upper airway obstruction– In morbidly obese OSA pts : immediate CPAP post-extubation in OR rather than waiting for CPAP in PACU

Interestingly, benzodiazepines can have a greater effect on pharyngeal muscle tone than opioids

The post anesthesia care unitUpper airway obstructionManagement of upper airway obstruction

Immediate attention1. 1st : Jaw thrust with CPAP )5 to 15 cm H2O) 2. If not effective → Oral, nasal, or LMA

If Sedating effects of opioids and benzodiazepinesRx.

o Persistent stimulation o Small, titrated doses of naloxone )0.3 to 0.5 μg/kg IV) o Flumazenil )0.2 mg IV to maximum dose of 1 mg)

If Residual effects of NMBDRx.

o reversed pharmacologically oror o correcting contributing factors such as hypothermia

The post anesthesia care unitD.Dx. of arterial hypoxemia in the PACU

The most common causes of transient hypoxemia in immediate postop.→Atelectasis and alveolar hypoventilation

Hx., Operation course & clinical signs & symptoms will direct the workup to consider possible causes

D.DX. of arterial hypoxemia in the PACUAlveolar hypoventilation

At sea level, in a normocapnic pt breathing room air ; PAO2 is100 mm Hg → PaO2 ~ 100 mm Hg If Paco2 ↑ from 40 to 80 mmHg )alveolar hypoventilation)

results in a PAO2 of 50 mmHg

But in Immediate postop. period : Residual effects of inhaled anesth , opioids & sedative-hypnotics Residual NMB or underlying neuromus. dis. Restrictive pulmonary conditions:

preexisting chest wall deformity postop abdominal binding abdominal distention

Rx.Supplemental O2 External stimulationPharmacologic reversal Controlled mechanical ventilation

Hypoventilation alone is sufficient to cause arterial hypoxemia in a pt breathing room air

Minute ventilation ← ← ↑2 L/min ← ← 1-mm Hg ↑ in Paco2

D.Dx. of arterial hypoxemia in the PACUDecreased alveolar oxygen pressurediffusion hypoxia

Diffusion hypoxia:

Rapid diffusion of N2O into alveoli at the end of anesthesia

N2O dilutes the alveolar gas and produces a transient decrease in PAO2 & Paco2

↓ PAO2 → arterial hypoxemia ↓ Paco2 → depress resp. drive

If no suppl. O2 → persists for 5 to 10 min. →

arterial hypoxemia in the initial moments in the PACU

D.Dx. of arterial hypoxemia in the PACUVentilation-perfusion mismatch and shunt

Hypoxic pulmonary vasoconstriction

In Nl lungs ; constriction of vessels in poorly ventilated regions of the lung directs pulmonary blood flow to well ventilated alveoli

SO SO Residual effects of inhaled anesth. & vasodilators

blunt HPVarterial hypoxemia

Unlike V/Q mismatch, a true shunt will not respond to suppl. O2

Causes of postop. pulmonary shunt : atelectasis* pul edema gastric aspiration pul emboli

pneumonia sitting position incentive spirometrypositive airway pressure by facemask

Rx.

D.DX. of arterial hypoxemia in the PACUIncreased venous admixture

Increased venous admixture: typically refers to low cardiac output states, in which there is

mixing of desaturated venous blood + oxygenated arterial blood Normally, only 2% to 5% of CO is shunted through the lungs )minimal effect on PaO2)

In low CO states, blood returns to the heart severely desaturated

Shunt + Conditions that impede alveolar oxygenation )pul edema and atelectasis )

↓↓↓PaO2

D.Dx. of arterial hypoxemia in the PACUDecreased diffusion capacity

Presence of underlying lung disease & ↓diffusion capacity : Emphysema ILD Pul. fibrosis 1ry pul. hypertension

Finally,Disconnection of the O2 source or empty O2 tank

should be kept in mind

The post anesthesia care unitpulmonary edema

Less frequentlyoPostobstructive

osepsisoTRALI

Immediate postop. Pul. edema is often

cardiogenic , 2ndary to intravas. vol. overload or CHF

The post anesthesia care unitpulmonary edemaPostobstructive pulmonary edema

• Postobstructive pul. edema & resulting arterial hypoxemia are rare ) transudative edema)

• Muscular healthy pts are at increased risk• Laryngospasm is the most common cause • Arterial hypoxemia usually within 90 min of the upper airway obstruction and is

accompanied by bilateral fluffy infiltrates on the C-xray

Rx. • Supportive

– suppl. O2– diuresis– in severe cases, positive-pressure ventilation

The post anesthesia care unitpulmonary edemaTransfusion-related lung injury (TRALI)

• Any pt who intraop. received blood products

• Typically within 1 to 2 hrs )up to 6 hrs ) after transfusion of plasma-containing blood products

) PRBCs ,whole blood, FFP or Plt ) • Often ass. with fever & hypotension

• CBC : ? acute drop in the WBC count )sequestration of granulocytes within the lung and exudative fluid)

• Previously under diagnosed

Rx.• Supportive

– Supplemental O2– Drug-induced diuresis – Mechanical ventilation – Vasopressors

The post anesthesia care unitmonitoring and treatment of hypoxemiaOxygen supplementation

•Prophylactic O2 therapy to all pts after GA is controversial

•Even with O2 suppl. , a significant percentage of ptswill become hypoxic at some point during their PACU stay

Immediate desaturation correlates with age wt ASA class GA IVF ˃1500 mL duration of anesth. female gender

In the era of cost containment, the routine delivery of O2 to all pts recovering from GA is costly & unnecessary

The post anesthesia care unitoptimal perioperative oxygenationPostoperative nausea and vomiting ( PONV )

Can periop. supplemental oxygen reduce the incidence of PONV ?

Central effect , Elimination of nitrous oxide , Reduction of gastrointestinal ischemia

The post anesthesia care unitoptimal perioperative oxygenationWound infections

Supplemental oxygen appears to reduce the incidence of surgical wound infections

Grief and colleagues : higher O2 → ↓ surgical site infection from 11.2% to 5.2%

A multicenter RCT Spanish study : sup. O2 → 30% ↓ in surgical site infections

Another study ( against ): major intraabdominal surgeries , received 80% O2 had a significantly higher infection rate )25%) than those who received 35% O2 ) failure of randomization)

The role of nitrous oxide in the risk of wound infection remains controversial

Supplemental oxygen – O2 delivery sys.

Degree of hypoxemia , the surgical procedure and pt compliance determine

the O2 delivery system of choice in the PACU

Traditional nasal cannula with bubble humidifier : maximum 6 L/min to minimize discomfort and complications from inadequate humidification

Facemask )non-rebreather) or high-flow nebulizer )efficiency ?) Inadequate mask fit High-minute ventilation requirements

Newer high-flow nasal cannula Comfortable delivery of O2 at 40 L/min,37° C & 99.9% humidity FiO2 equal to traditional mask devices Deliver high-flow oxygen directly to the nasopharynx ) CPAP effect?)

As a general rule↑ 1 liter/min of O2 flow through nasal cannula → ↑FiO2 by 0.04

) 6 L/min → FiO2 ~ 0.44 )

oxygen delivery systemsContinuous positive airway pressure ( CPAP )

8% to 10% of post abdominal Sx. require intubation and mech. vent. in the PACU

CPAP : ↓ hypoxemia , ↑ FRC , improve pul compliance ,↓work of breath

CPAP in the PACU → ↓ incidence of intubation, pneumonia, infection, and sepsis

CPAP do not increase the risk of postop. anastomotic leaks

oxygen delivery systemsNoninvasive positive-pressure ventilation ( NIPPV )

If CPAP failed → NIPPV )its application in the PACU is limited )

In the past, NIPPV was avoided because of potential for gastric distention, aspiration, and wound dehiscence

Relative contraindications : hemodynamic instability life-threatening arrhythmias, altered mental status high risk of aspiration inability to use nasal or facial mask )head and neck procedures) refractory hypoxemia

Appropriate pt selection & careful instruction

NIPPV can be delivered by facemask using PSV or BIPAP

The post anesthesia care unitHemodynamic instability

Hemodynamic instability in the PACU has a negative impact on long-term outcome

Interestingly, Postop. hypertension and tachycardia

are ass. with ↑ ICU admission & higher mortality than hypotension and bradycardia

The post anesthesia care unithemodynamic instabilitySystemic hypertension

Rx. : A significant No. of pts, esp. known hx. of HTN , will require pharmacologic BP control in the PACU

Type of Sx. : Carotid endarterectomy and intracranial procedures

The post anesthesia care unithemodynamic instabilitySystemic hypotension

Postop. HOTN :)1) hypovolemic )decreased preload))2) Distributive )decreased afterload))3) cardiogenic )intrinsic pump failure)

The post anesthesia care unitHemodynamic instabilitySystemic hypotension Distributive (Decreased Afterload)

Iatrogenic sympathectomy, 2ndary to RA techniques ) high sympathetic block to T4) If not treated promptly→ ↓HR + severe HOTN → cardiac arrest ) even in young healthy pts ) Rx. : phenylephrine and ephedrine

Critically ill pts : rely on exaggerated symp. nerv. Sys. to maintain BP & HR Even minimal doses of inhaled anesthetics, opioids, sedative-hypnotics can ↓ SNS tone & sig. HOTN

Allergic )anaphylactic or anaphylactoid) reactions may be the cause of hypotension in the PACU Rx. : EPN is the drug of choice ↑serum tryptase confirms allergic reaction

does not differentiate anaphylactic from anaphylactoid reactionsmust be obtained within 30 to 120 min after the allergic reactionresults may not be available for several days

Neuromuscular blocking drugs are the most common cause of anaphylactic reactions in the surgical setting

Sepsis : take blood culture, and empirical antibiotic Rx Urinary tract manipulation and biliary tract procedures )sudden onset ) Rx. : Fluid resuscitation )most important & immediate ) & pressor support (Norepinephrine is the pressor of choice in septic patients. Vasopressin )vasodilation in septic shock) → low-dose )0.01 to 0.05 unit/min) → ↑ MAP,↓vasopressor req. , ? spare renal function

The post anesthesia care unitMyocardial ischemia: evaluation and treatmentPatients at low risk

Low risk pts — < 45 y/o, with no known cardiac dis. & only one risk factor—postop. ST-seg. changes on the ECG do not usually indicate myo. Isch.

Relatively benign causes of ST changes : anxiety, esophageal reflux, hypervent. & hypokal.

Rx. : Routine PACU observation unless signs and symptoms

More aggressive evaluation if changes are accompanied by cardiac rhythm disturbances or hemodynamic instability (or both)

ECG interpretation in the PACU is influenced by pt’s cardiac Hx. and risk index

The post anesthesia care unitmyocardial ischemia: evaluation and treatmentpatients at high risk

Any ST - T changes compatible with myo. isch → prompt further evaluation

Serum troponinA 12-lead ECG

Cardiac monitoringCardiology follow-up

In high risk pts, ST-T changes can be significant even in the absence of typical signs or symptoms

The post anesthesia care unitmyocardial ischemia: evaluation and treatmentcardiac monitoring

Postop myo isch. is rarely accomp by chest pain & confirmation depends on sensitivity of the cardiac monitoring

Leads II + V5 : reflect 80% of the ischemic events but visual interpretation of the cardiac monitor is often inaccurate

American College of Cardiology : computerized ST-seg. analysis in immediate postop period

A routine postop. 12-lead ECG is recommended only for pts with known or suspected CAD who have undergone high- or intermediate-risk Sx.

The post anesthesia care unitCardiac dysrhythmias

Periop. cardiac dysrhythmias are frequently transient & multifactorial

Reversible causes :1. hypoxemia 2. hypovent. & associated hypercapnia3. endogenous or exogenous catecholamines4. electrolyte abnormalities 5. acidemia 6. fluid overload7. anemia8. substance withdrawal

the post anesthesia care unitcardiac dysrhythmiastachycardia , atrial dysrhythmias

ATRIAL DYSRHYTHMIAS

Incidence : 10% after major non-cardiothoracic Sx.Higher after cardiac & thoracic procedures due to atrial irritation

Risk increased by Preexisting cardiac risk factors Positive fluid balance Electrolyte abnormalities Oxygen desaturation

New onset atrial dysrhythmias are not benign because

they are associated with a longer hospital stay & increased mortality

The post anesthesia care unitCardiac dysrhythmias

VENTRICULAR DYSRHYTHMIASPVCs & bigeminy → common in PACUPVCs : most often ↑sympath nervous sys. )tracheal intubation, pain & ↑ Pco2) V.tach : rare & indicative of a cardiac problemTorsades de pointes : consider QT prolong. ) intrinsic or drug related - amiodarone, procainamide, droperidol )

BRADYDYSRHYTHMIASOften iatrogenic ;

Drugs : beta-blocker , anticholinesterase reversal of NMBD , opioid & dexmedetomidine Procedure & pt-related : bowel distention, ↑ ICP or IOP , spinal anesth

ATRIAL FIBRILLATIONControl of ventricular rate : immediate goal in new-onset AFHemodynamically unstable may require prompt electrical cardioversionMost pts: IV ᵝ-blocker or calcium channel blocker ) Diltiazem is CCB of choice if ᵝ-blocker contraindicated )If hemodynamic instability is a concern, then the short-acting beta-blocker esmolol is an optionAmiodarone ; consider QT prolongation, ↓HR & BP

The post anesthesia care unitRenal dysfunction

Frequently, multifactorial, with an intraop. insult exacerbating a preexisting renal insufficiency

Focus on readily reversible causes ) urinary catheter obstruction or dislodgment ) Depending on surgical procedure )uro. / gyn.) → R/O anatomic obstruction or disruption of ureters, bladder, or urethra

The post anesthesia care unitrenal dysfunctionoliguriaIntravascular Volume Depletion

The most common cause of oliguria in immediate postop. period → a fluid challenge )500 - 1000 mL crystalloid) is usually effective

If surgical blood loss is suspected → check Hct.

Periop. events that alter renal perfusion: angiography ) renal vasocons. & direct renal tubular injury ) Periop. vol. dep. Surgical procedure ) ↓ renal vas. patency ) ↑ IAP

If a fluid challenge is contraindicated or oliguria persists, FENa CVP monitoring Echo

The post anesthesia care unitrenal dysfunctionoliguriaPostoperative Urinary Retention

Ultrasonography? Defined as : bladder vol. > 600 mL + inability to void within 30 min.incidence ~ 16%Predictive factors

age ˃ 50 y/o Intraop. Fluid ˃ 750 mLbladder vol. on entry to PACU ˃ 270 mL

Can cause bladder over distention and permanent detrusor damage

The post anesthesia care unitrenal dysfunctionContrast nephropathy

↑ed Angiography for carotid stenosis, aortic aneurysm & periph vas. dis.

contrast nephropathy more frequent in D.DX. Of postop. renal dysfunction

Periop management : Aggressive hydration with NS Alkalinization of the urine with sodium bicarbonate

The post anesthesia care unitrenal dysfunctionIntra-abdominal hypertension (IAH)

Any pt with oliguria and a tense abdomen after abdominal surgery

↓ renal perfusion → renal ischemia & dysfunction

Nl IAP in a non-obese pt is ~ 5 mmHg IAH is graded into four categories:

I: 12 to 15 mmHg II: 16 to 20 mmHgIII: 21 to 25 mmHgIV: ˃ 25 mmHg

Bladder pressure, an indirect measure of IAP :measured at end expiration in supine position without abdominal muscle contractionstransducer in the midaxillary line

Abdominal compartment synd.

The post anesthesia care unitrenal dysfunctionRhabdomyolysis

Postop of major crush or thermal injury & morbidly obese who undergo bariatric Sx. ) 22.7% )

Risk factors :o ↑ BMI o length of Sx.

Rx.o Early aggressive hydration to maintain U/O )mainstay of Rx.)o Loop diureticso Mannitol + bicarbonate ??o CRRT but not conventional hemodialysis

convection )i.e., the mechanism of solute removal in continuous hemofiltration) removes larger molecular weight solutes than

diffusion )i.e., the mechanism of solute removal in conventional hemodialysis)

If suspicious → measure CPK

The post anesthesia care unitBody temperature and shivering

Often after GA & epidural ) incidence 5% - 65% and 33% respectively ) risk factors : male gender & induction agent )pofol more shivering than pento.) postoperative shivering ; ↑O2 consumption, ↑CO2 production, ↑sympathetic tone ) ↑ CO , HR , BP & IOP ) Accurate core body temperature by tympanic membrane )Axillary, rectal, and nasopharyngeal are less accurate ) immediate consequences:

↓ platelet function, ↓coagulation factor activity ↓drug metabolism postop bleeding Prolongs NMB delay awakening

long-term deleterious effects myocardial ischemia & infarction delayed wound healing increased periop mortality

Rx. Forced air warmers Opioids in adults, meperidine is most commonly used Ondansetron Clonidine Ketamine )0.5 mg/kg IV)before general & reg. anesthesia : an effective prophylactic measure

The post anesthesia care unitpostoperative nausea and vomiting

Without prophylaxis , ~ 30% after inhalational anesth. )range, 10% to 80%)

Consequences of PONV delayed discharge unanticipated hospital admission pulmonary aspiration significant postop discomfort

Prophylactic measures: 1) Modification of anesth technique

a.propofol in lieu of a vol anesthb.nitrogen in lieu of nitrous oxidec.Remifentanil in lieu of fentanyl

2) pharmacologic intervention

.

The post anesthesia care unitDelirium

10% of pts ˃ 50 y/O within 5 days

Increases the length of hospital stay, pharmacy costs & mortality Risk factors:

1) age )˃70 y/o)2) preop cognitive imp.3) ↓ functional status4) Alcohol abuse5) Hx. of delirium6) Surgical blood loss 7) Hct < 30% 8) Number of intraop blood TQ9) Certain procedures )repair of hip fracture (>35%) , bilateral knee replacement ( 41%)

Intraop HOTNN2OAnesthetic technique (general vs regional)

Rx.: thorough evaluation hepatic and/or renal encephalopathy inadequate hydration periop medications hypoxemia & hypercapnia pain, sepsis, and electrolyte abnormalities

have not been shown to increase the risk of postop delirium or longer-term POCD

Pt > 60 y/o for minor surgery should be scheduled in an outpatient center

The post anesthesia care unitEmergence excitement

A transient confusional state upon emergence from GA Common in CHILDREN ( > 30% ) , usually within first 10 min. , peak age 2 and 4 yr , typically resolves quickly & followed by an uneventful recovery

Mostly ass. with rapid “wake up” from inhal. Anesth. most often : sevoflorane & desflorane Several studies : type of anesthetic agent itself

Predisposing factors : Anesthetic drug , postop. pain, Type of Sx. , age, preop. anxiety, underlying temperament, and adjunct

medications Simple preventive measures : ↓preop. Anxiety , Rx. postop. Pain , a stress-free environment for recovery

Medications for prevention & Rx. : midazolam?! , clonidine, dexmedetomidine, fentanyl , ketorolac, physostigmine

IN ADULTS ( incidence : 3% to 4.7%) risk factors:

preop. medication with midazolam (odds ratio : 1.9) breast surgery (OR : 5.190) abdominal surgery (OR : 3.206)length of surgery

cause

The post anesthesia care unitDelayed awakening

Even after prolonged Sx. & anesth. , a response to stimulation in 60 to 90 min should occur

When delayed awakening occurs :o vital signs (e.g., BP, Spo2 , ECG, body temp. )o neurologic exam&o Monitoring with pulse oximetryo ABG & pH o Electrolytes o Metabolic disturb. (e.g., blood glucose esp. in IDDM )

Residual sedation from drugs used during anesth is the most frequent cause of delayed awakening in the PACU

RX.Opioids → naloxone (20 to 40 μg increments in adults)Anticholinergics (especially scopolamine) → PhysostigmineBenzodiazepines → Flumazenil Hypothermia (esp. T < 33° C)Hypoglycemia↑ ICP → Computed tomography Residual neuromuscular block → peripheral nerve stimulation & administration of a reversal agent

The post anesthesia care unit Discharge criteria

The post anesthesia care unitdischarge criteriaPostanesthesia scoring systems

Original Aldrete score ( 1970 ) : 0, 1, or 2 to fie variables: activity, respiration, circulation, consciousness, and color. 9 out of 10 → discharge

Over the years, modified , In 1995,Pulse oximetry replaced visual assessment of oxygenation Additional assessments added for ambulatory surgery

The post anesthesia care unitInfection control

PACU has been described as the “weakest link” in the chain of care

Limitations in space (typically an open unit )staffing (Nurses and respiratory therapists )Time ( transient ; hrs rather than days)

An infection resulting from a lapse in infection control in the PACU might not be identified by routine monitoring until days later on the surgical unit

alcohol based hand rub @ entrance @ bedside @ other convenient locations & in individual pocket-sized containers

The PACUPACU is more than a post anesthesia observation unit

It is unique in its ability to support the care of pts ofall ages & in every stage of illness

Since its inception more than 50 years ago, the PACU has proved to be an exceptionally adaptable unit that is equipped to meet the demands of an

evolving health care system

Post anesthesia care unit for Residents of Anesthesia

Health & Medicine

Transcript of Post anesthesia care unit for Residents of Anesthesia