ICU + ANAESTHESTICS
ICU principle Indications for ICU ICU Additions ICU complications ® solutions
• Respiratory Cannot be managed by ward !! Analgesia support: Acute
support
• Threatened airway or hard to • Ventilator assoc. lung injury (barotrauma, volutrauma) ®
• Cardiovascular
support
intubate short-term APO, hypoxia
Nutritional support:
• Post-CPR ® long-term: fibrosis, recurrent infection, cor-pulmonale
• Renal support
• Severe Sepsis • Mouth • Ventilator assoc. pneumonia (25% complication)
• Nutritional • Major trauma (closely monitor • NGT ® position semi-fowler and head elevation
support vitals + neuro obs) • (PEG) – percutaneous • Catheter related blood infections (e.g. from CVC) – 25%
• Neurological • Post-op major surgery (e.g. AAA endoscopic mortality ®Rx with ABx or Ag impregnated catheters
support repair) gastrostomy (tube from • Delirium ® AT4 assessment (to identify delirium)
• Dermatological • Any Organ failure ®Ventilatory/ surface of abdomen to ® Dexmedetomidine (sedate agitated pts) + Rx cause
support circulatory/renal support ® stomach)
• TPN via CVC® Chronic
dialysis? Ionotropes?
• Liver support
thrombophlebitis risk
• Bleeding/massive transfusion • Catheter assoc. UTI
• High analgesia/sedation req. – so given via central line • Stress related mucosal ulcers (e.g. erosion of upper GIT)
risk of resp. depression (NOT peripheral ® Rx: PPI and H2 antagonist
• Complex co-morbidity w/ high cannula) • VTE ® calf compression +SC clexane
likelihood of early post-op • Critical illness myopathy (due to corticosteroids or muscle
complication (e.g. poorly relaxants) ® difficult to wean off mech. Ventilation
controlled OSA, PPH patient) • Critical illness neuropathy ® optimize BSL control
• Transfusion related reactions (TRALI, sepsis, overload,
coagulopathy)
Why is it difficult to mobilise after being ventilated?
• Patient may have decompensated from the initial event and thus, organs and muscles need to take time to adapt to the new conditions
• Critical illness will also cause both myopathy and neuropathy particularly after paralysing agents have been used
• The long-term immobility = muscle atrophy as deconditioned when ill è MOBILISE Early w/ PT è reactivate muscles to restore power and endurance.
• If patient has a tracheostomy tube still in place, the reduced air intake means there is reduced ventilation due to reduced tidal volume. This will cause a low
V/Q mismatch, thus causing organ hypoperfusion.
What is the prognosis of patients who have gone through ICU?
• POOR despite successful resuscitation and rehabilitation. Often there is some damage to organs during the entire process.
• +++ morbidity and mortality è longer rehabilitation period è lose their independence earlier relative to healthy age-matched controls.
• +++ f/u with different specialists and allied health professional to manage their condition and progress è costs, logistics, time
• +++ new meds, which can lead to further financial burden and increase the risk of drug-drug interactions, non-compliance due to polypharmacy.
Why is it important to ask about antibiotic usage during a sepsis crisis?
• Antibiotics may confound the blood culture results, particularly if there is bacterial infective source
• Antibiotics may actually be asking the severity of the condition patient is in (false sense of security when managing patient)
• Be aware of possible anaphylactic allergic reactions to certain antibiotics
What can be done when locating the source?
• Strip patient from head to toe
• 2ND survey to determine key ports of entry (e.g. IDC, wound site, central lines, cannula sites) as well as areas of excoriations, lacerations, puncture wound
ICU MORTALITY RISK CALCULATORS (APACHE-II and MPM)
What are the 2 main factors consider during admission?
1) the potential to reverse the acute condition
2) the baseline physiological reserve (their baseline health).
e.g. patients with a 90% probability of dying w/ underlying terminal condition should be given palliative care approach rather than have invasive
interventions
, FLUID Management; FLUID + ELECTROLYTES
Assessing volume levels: Examination Bedside Investigations: Mx (conservative):
Hypervolaemic 1. Aids = finished meal? Cups of water? Ø Wt, BMI Overload (WET) Dry
Ø XS fluid intake IDC/drain output? Ø BLADDER SCAN ® ?IDC
Dehydration signs:: Non- 1L fluid restrict Hydrate
Ø XS salt intake Ø Urine - ↑SG, urine osmolarity pharm Na restricted diet
Ø IVF 1. VITALS = hypoTN, Tachycardia, CRT >2s, Ø ECG – arrythmias?
tachypnoea Pharm 20mg IV furosemide IVF resus – crystalloid
2. Dry MM – stick tongue out (0.9% NS or Hartman’s)
Euvolaemic Blood Investigations:
3. Sunken eyeballs Ø FBC (↓Hb – anaemia)
Hypovolaemic 4. Cold peripheries Ø EUC / CMP Practice note:
(Dehydrated) 5. Low urine output Ø Serum osmolarity What is the best fluid? -amount/type always depends on
Ø Vomit / diarrhoea 6. Low weight patient’s weight
Ø LFT – check albumin
Ø Internal bleeding Fluid overload signs: Ø BNP - HF What is 3rd spacing? Low level of fluid in intravascular space
Ø Burns 1. Elevated JVP but XS fluid in interstitial space ® appear hypovolemic or fluid
Ø DI 2. Displaced apex beat (most sensitive for HF) Imaging Investigations overloaded at same time
3. Pulm. Oedema (bibasal crackles, low sats) Ø ECHO
When to refer?
4. Peripheral oedema, ascites Ø CXR
Ø Cannot maintain adequate fluid balance
5. Weight gain
Ø Cannot maintain electrolytes
Colloid Crystalloid
Vol.
Vol for vol 3x vol needed
needed
• Molecules too large to cross capillary walls – fluid • Molecules small enough to cross capillary walls ® less fluid in intravascular space
MoA remain in intravascular space • Short half life (30-60 mins)
• Long half-life (hrs-days)
Hypotonic Isotonic Hypertonic
• 5% dextrose and • Normal saline (0.9%) • 3% NaCl
• Greater increased effect on intravascular vol. (1.5:1) 0.18% NS • Lactated ringer’s soln (aka • 5% NaCl
Example
• Hypotonic saline Hartmann’s)
o For sepsis (NOT for TBI)
• plasmolyte
ECF Increased Increased Increased
Natural Synthetic
ICF Increased none Decreased
Example • Whole blood • Geleatins
• Dextrans • Correct hyperNa • Fluid resus hypoNa (severe)
• FFP
• Maintenance fluid • Maintenance fluid cerebral oedema
• pRBC • Hydroxyethyl starch
Ind. • IV drug solvent • Hypovolaemic hypoNa
• Albumin
Use • Children • IV drug solvent
ECF Increased (esp. intravascular vol.)
• Hypoglyceamia or
ICF NONE with insulin IV
Use • Cirrhosis • Fluid resus FLUID OVERLOAD – cerebral, peripheral, pulmonary oedema
• Critically ill – ARDS, • Maintenance fluid • hypoNa, hypoK • 0.9% NS = Osmotic
burns, sepsis • Hypovolaemic hypoNa • hyperglyceamia HYPERchloraemia demyelination
• Bleed ® blood • IV drug solvent • cerebral oedema acidosis syndrome ®
A/E • Fluid overload ® cardiac failure A/E • Ringer’s/ Hartman = cerebral oedema
• Allergic ++ lactate in liver failure,
NO dextrose in: hyper K
• Expensive + may not be vegan
• brain haemorrhage • Plasmalyte ® high HCO3
• re-feeding
syndrome
Resus Maintenance Replacement fluids
Fluid 0.9% NS Crystalloids (NS, dextrose) or colloids Crystalloids ® selected with similar electrolyte content to fluids that are lost
Sepsis, hypoTN PERI-OP & POST-OP
Scenario POST-OP + VOMITING + DIARRHOEA
NBM due to bowel obstruction
Rapid fluid bolus (within 10-30mins) Replace lost body fluids and electrolytes
• Adults NS or LR 500-1000mL IV NBM patients but do not have volume Hypovol. shock • Hartmann’s BEST as less Cl- to
bolus depletion, hypotension, or ongoing losses
(N + D, burns, sepsis, minimise risk of hyperchloremic acid
• Children: NS or LR 10-20mL/kg IV • Adults ® 1-2mL/kg/hr fistula) (check lactate)
bolus • Children (> 28 days) ® 4:2:1 rule
• Dextrose-saline (normal maintenance
Method o 4mL/kg/hr (1st 10 kg) Dehydration
fluid)
o +2mL/kg/hr (2nd 10 kg) (poor intake)
• If hypoTN ® bolus Hartman/saline
o +1mL/kg/hr (remaining)
• Colloid Transfusion (4x pRBC + 2x FFP)
*Maintenance fluid requirement per kg of wt
higher in children due to increased SA Haemorrhage • FFP/ platelets (stop bleed)
• BUT need to find source
• vasopressors (e.g. metaraminol) ®
maintain BP and reduce peripheral • Pre-existing fluid loss (STAT bolus – 500mL 0.9% saline/Hartmann’s
• Patient’s weight
fluid loss soln)
• Check EUC before prescribing
Consider • Ionotropes (e.g. dobutamine, • Measure Ongoing losses (replace future losses – measure vomits,
levoseminardin) • Give oral/NG-tube fluids whenever diarrhoea vs intake)
possible ® minimizes fluid overload
• Blood products (FFP, packed RBC • DO NOT Give K at a rate > 10mM/hr or use maintenance protocols
– group + X-match)
Special cases:
Post-op Cell lysis during surgery ® elevated K, AKI No K
Low protein diet (0.6g/kg/day) = ↓hyperfiltration
Sepsis Hartman or 0.9% saline ® vasopressors + monitor? CKD Avoid fluid overload ® monitor K ® ?ECG
HF Nb: may normally be hypotensive ® low Na diet, Alcoholic Pabrinex BEFORE dextrose (avoid Korsakoff)
furosemide, fluid restriction and record daily weights Ø Replaced B1 (100mg thiamine)
Liver failure 5% dextrose – excess Na causes ascites Brain Saline (dextrose destroys brain)
haemorrhage
, 60% TOTAL BODY WT = TOTAL WATER
Calculating fluids:
• 60% of total body weight is water
• 4:2:1 rule in children
• CHECK HcT (for haemodilution) due
to XS fluid resuscitation
0.9% NS GLUCOSE
COLLOID PARKLAND FORMULA for burns
(ALBUMIN The volume required over 24 hours will be:
) • 4 ml x % burn SA x body weight in kg
• half this volume is given in the first 8 hours
• Resus w/ NS or Hartmann’s but consider
colloids (albumin) if deep burns
DOES NOT ENTER ICF
Daily Requirements: (for 70kg man)
• Water = 25-30 mL/kg/day (2L)
• Glucose » 50/100g.day (50-100g)
• Na, K and Cl = 1mM/kg/day
(70mM)
Input vs Output:
• Daily weighing
• UO » 0.5mL/kg/hr
• Oral intake / IVF / NGT
• Drains/ stoma / IDC
High risk patients (need senior input)
• Elderly or frail patients
• Significant oedema
• Sodium imbalance (low or high Na)
• Heart failure
Base Excess 0 to -2 -2 to -6 -6 to -10 < -10 • Renal failure
• Liver failure
