Therapeutic Strategies PO2 ??? Rebreathing Electrolytes/ECG monitoring RESP ALKALOSIS Sedation

Therapeutic Strategies PO2 PO2 Rebreathing PCO2 RESP ALKALOSIS RESP ACIDOSIS permissive Electrolytes pH Sedation NIV/MV

….Hypoxia kills…..Hypercarbia does not…. Hickling ICM 1989

Hypercapnia: clinical relevance and mechanisms of action …but consider pH….& Target Organs Curr Op Crit Care. 2015;21(1):7-12

Permissivity NOT allowed “mixed” pH 7.08 PCO2 70 HCO3 20

Permissivity NOT allowed

CPAP vs BIPAP vs MV ….There is always PEEP !!!!!!!!!!!!

Alveolar recruitment and PaO2 THE BEST PEEP VD Alveolar recruitment and PaO2 DO2 low moderate high PEEP

H-L INTERACTIONS …….if when the PEEP goes up, the BP goes down… The HEART is preload dependent…give fluids !!!!!!!!!!

NIV vs ETI in respiratory acidosis TOO EARLY TOO LATE 2 hours Trial plus LACTATE CLEARANCE

Therapeutic Strategies PO2 PO2 PCO2 RESP ALKALOSIS rebreathing RESP ACIDOSIS permissive pH sedation NIV/MV fluids Electrolytes ( K, Mg, Ca) MET ALKALOSIS acetazolamide surgery

Total body water MEN WOMEN young 60% b.w. elderly 50% young 50% 40%

70 Kg MAN ICF = 28 L ECF = 14 L 1/3 intravascular 2/3 interstitial 70% veins 18% arteries 3% arterioles

Persistance of fluids in blood Circulating volume after 60 minutes 5% dextrose = 5% ? = Cristalloids = 16% Colloids = 30-50% 5% dextrose =5% NS=16% Colloids=30-50% Albumin=50-80% Albumin = 75-100% FIRST………….TEST !!!!

Therapeutic Strategies PO2 PO2 PCO2 RESP ALKALOSIS rebreathing RESP ACIDOSIS permissive pH sedation NIV/MV fluids electrolytes MET ALKALOSIS MET ACIDOSIS perfusion acetazolamide N surgery

IF (VENOUS) pH IS RAISED BY NaHCO3, IS THERE ANY SALUTARY EFFECT ? IS A LOW pH BAD ? CAN ALKALI RAISE pHi ? IF (VENOUS) pH IS RAISED BY NaHCO3, IS THERE ANY SALUTARY EFFECT ? DOES NaHCO3 HAVE NEGATIVE SIDE EFFECTS? CHEST (2000) 117: 260-67

The CO2 lung presentation & low flow V O2 demand DO2 PCO2 VO2 ATP AMP + H+ Lact- + H+ H+ + HCO3-

H+ vs Ca++ & troponins

BICARBONATE YES NO LOSSES RENAL FAILURE HYPERKALEMIA INTOXICATIONS RABDOMIOLYSIS DKA ? DYE ? ………….. HYPOPERFUSION CARDIAC ARREST HYPERCAPNIA HYPOK, HYPOMg, HYPOCa …

Four steps in hypoperfusion best filling best vascular tone inotropes ↓ VO2 + MV Advanced options(ACP,VAD…)

Key points In Respiratory disorders : first O2, then pH/PCO2, permissivity? In Metabolic Alkalosis: (US-guided) filling & electrolytes Colloids / Cristalloids / Both……?( think of deresuscitation) In Metabolic Acidosis …look at perfusion