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Give me a 10marks answer about ventilator strategies during one lung ventilation from millers, barasch, Morgan for AIIMS md anaesthesia exams

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Ventilator Strategies During One-Lung Ventilation (OLV)

[Miller's Anesthesia 10e | Barash's Clinical Anesthesia 9e | Morgan & Mikhail's Clinical Anesthesiology 7e]

Introduction

One-lung ventilation (OLV) presents the anesthesiologist with a unique conflict: maximizing atelectasis in the non-ventilated (operative/nondependent) lung for surgical access, while preventing atelectasis and injury in the ventilated (dependent) lung to optimize gas exchange. The ventilatory goal during OLV is to maintain the dependent lung near functional residual capacity (FRC) while facilitating collapse of the nondependent lung to maximize its pulmonary vascular resistance (PVR) and promote hypoxic pulmonary vasoconstriction (HPV).
  • Miller's Anesthesia, p. 7192 (vol. 2)

1. Pre-OLV Preparation: Denitrogenation

Before allowing the operative lung to collapse, thorough denitrogenation with 100% FiO2 is essential. Nitrogen (present in air-oxygen mixtures) has low blood-gas solubility and significantly delays collapse of the nondependent lung, impairing surgical visualization - especially during VATS. Nitrous oxide speeds collapse even faster than oxygen but is avoided in thoracic surgery due to the risk of expanding blebs or bullae.
  • Miller's Anesthesia, p. 7189
Recruitment maneuver before OLV: Because atelectasis develops in the dependent lung during the two-lung phase in lateral decubitus, a recruitment maneuver (sustained inflation at 20 cmH2O for 15-20 seconds) should be applied immediately after initiating OLV to reduce pre-existing atelectasis.
  • Miller's Anesthesia, p. 7190

2. Inspired Oxygen Fraction (FiO2)

An FiO2 of 1.0 is generally recommended during OLV. A high oxygen concentration provides a safety margin against hypoxemia and promotes denitrogenation-atelectasis of the nondependent lung, aiding its collapse. However, FiO2 1.0 carries the risk of absorption atelectasis in the dependent lung and evidence for oxygen toxicity has accumulated both experimentally and clinically.
  • Barash, p. 3201-3202; Morgan & Mikhail, p. 1046
Some clinicians use FiO2 50-80% (Morgan & Mikhail recommends lower FiO2 of 50-80% as part of protective lung ventilation), with lower ventilatory pressures as part of a lung-protective strategy. Barash notes an O2 80% / N2O 20% mixture may be used as long as SpO2 remains adequate.

3. Tidal Volume (VT)

The historical recommendation of 10-12 mL/kg used during two-lung ventilation is now abandoned for OLV. Protective lung ventilation with lower VT is the modern standard.
ParameterRecommended Value
Tidal Volume6-8 mL/kg IBW
Peak airway pressure< 35-40 cmH2O
Plateau pressure< 25 cmH2O
  • Morgan & Mikhail, p. 1046: "Lower tidal volumes (<6 mL/kg), lower FiO2 (50-80%) and lower ventilatory pressures (plateau pressure <25 cmH2O; peak airway pressure <35 cmH2O)"
  • Barash, p. 3203: "Protective lung ventilation strategies which include the use of low VT, PEEP, and recruitment maneuvers"
Caution: VT < 3 mL/kg per lung may cause derecruitment, atelectasis, and hypoxemia in the dependent lung. Barash cites a large retrospective analysis (>30,000 patients) showing lower 30-day mortality with VT of 8-9 mL/kg intraoperatively - emphasizing that ARDS data may not directly translate to the short-duration OLV setting.

4. Ventilation Mode: Pressure-Controlled vs. Volume-Controlled

Both modes are acceptable. Pressure-controlled ventilation (PCV) is increasingly preferred because it:
  • Limits peak and plateau airway pressures, reducing barotrauma risk
  • Produces a decelerating flow pattern - more homogeneous VT distribution and reduced dead space ventilation
  • Allows lungs to be ventilated at lower mean airway pressures
  • Morgan & Mikhail, p. 1046-1047: "Pressure-controlled ventilation may diminish the risk of barotrauma by limiting peak and plateau airway pressures, and the flow pattern results in a more homogenous distribution of the tidal volume and reduced dead space ventilation"
  • Barash, p. 3213: "PV should be used with a low VT and the lowest peak airway pressure (e.g., with an I:E ratio of 1:1), with a high respiratory rate or using pressure control ventilation"
In PCV, the respiratory rate is adjusted upward (typically 12-16 breaths/min) to maintain adequate minute ventilation.

5. Positive End-Expiratory Pressure (PEEP) - Dependent Lung

PEEP applied to the dependent (ventilated) lung maintains alveolar patency, prevents atelectasis, and keeps lung volume near FRC - the point of lowest PVR.
  • Recommended PEEP: 5 cmH2O as a starting point (Barash: VT 6-8 mL/kg with PEEP 5 cmH2O)
  • If hypoxemia occurs: increase PEEP to 5-10 cmH2O (Morgan & Mikhail Step 4: "Ensure sufficient PEEP to the dependent, nonoperative lung to eliminate atelectasis")
Caution with PEEP in COPD: In emphysematous patients, external PEEP may compound intrinsic auto-PEEP from air-trapping, causing dynamic hyperinflation, elevated PVR, and worsening oxygenation. Barash specifically warns: "Patients with COPD are of particular concern because the application of PEEP may cause dynamic hyperinflation secondary to the increase in respiratory rate to maintain PaCO2."
  • Barash, p. 3213; Miller's Box 49.12, p. 7212

6. Driving Pressure (DP) - Emerging Concept

Driving pressure = Plateau pressure - PEEP = VT / Respiratory System Compliance
Barash dedicates a section to DP as the single variable most strongly associated with outcome in ARDS ventilation (Amato et al., 3,562 ARDS patients). In OLV:
  • Park et al. (RCT, 292 thoracic surgery patients): DP-guided ventilation (VT 6 mL/kg + titrated PEEP to minimize DP) vs. conventional protective ventilation reduced postoperative pneumonia and ARDS
  • Ventilating at the lowest DP reflects the patient's "functional lung size" and avoids both underdistension (atelectasis) and overdistension (barotrauma/volutrauma)
  • Target: DP < 14-15 cmH2O
  • Barash, p. 3208-3209

7. CPAP to the Nondependent (Operative) Lung

The single most effective maneuver to increase PaO2 during OLV is applying CPAP (5-10 cmH2O) to the nondependent (collapsed, operative) lung.
Mechanism: CPAP maintains patency of nondependent alveoli, allowing some oxygen uptake in the otherwise collapsed lung. It also slightly increases PVR in the nondependent lung, diverting blood flow back to the ventilated lung. CPAP must be applied after first delivering an insufflation breath to the nondependent lung.
  • Barash, p. 3201-3202; Morgan & Mikhail Step 5; Miller's Box 49.12
VATS Limitation: During video-assisted thoracoscopic surgery (VATS), CPAP to the operative lung is generally not acceptable because it prevents complete lung collapse needed for surgical visualization and stapler placement. It should be used cautiously, if at all, during VATS.
  • Barash, p. 3201 (explicitly states this limitation)

8. Recruitment Maneuvers (RM)

RMs open atelectatic zones in the dependent lung and are a key pillar of protective ventilation.
Technique:
  • Sustained airway pressure of 35-40 cmH2O for 30-40 seconds, OR
  • Stepwise PEEP increments of 5 cmH2O (5 breaths each) up to PEEP 20 cmH2O / plateau 40 cmH2O
Concerns with RM during OLV:
  • Transient worsening of hypoxemia during RM (blood shifts away from ventilated lung during positive pressure hold)
  • Hemodynamic compromise from impaired venous return
  • Risk of overpressure leaks past the bronchial cuff, stressing bronchial stumps
  • Controversy exists - stepwise approaches are better tolerated than sustained inflation
  • Barash, p. 3207-3208: RMs are "the most controversial part of protective ventilation" with conflicting literature
  • Miller's Box 49.12; Morgan & Mikhail, p. 1046-1047

9. Mechanical Power

Barash introduces mechanical power as the energy per unit time transferred from the ventilator to the lung (product of tidal volume, driving pressure, and respiratory rate). It integrates all potentially harmful ventilatory parameters into a single variable. Higher mechanical power is associated with VILI. During OLV, minimizing mechanical power by reducing VT, DP, and respiratory rate while maintaining adequate ventilation is the contemporary goal.
  • Barash, p. 3209-3210

10. Permissive Hypercapnia

When adequate oxygenation is maintained but CO2 remains elevated despite reasonable minute ventilation and low VT strategy, permissive hypercapnia (allowing PaCO2 to rise) is acceptable.
  • Morgan & Mikhail, p. 1046: "Permissive hypercapnia is reasonable for those rare patients with elevated CO2 tensions despite adequate oxygen saturation and a reasonable minute ventilation"
  • End-tidal CO2 is an unreliable guide during OLV due to increased dead space and unpredictable arterial-to-end-tidal CO2 gradient; periodic ABG analysis is recommended

11. Management of Hypoxemia During OLV

Hypoxemia (SpO2 <90%, PaO2 <60 mmHg) requires a stepwise approach. The nadir is reached 20-30 minutes after initiating OLV.
Step-by-step management (Miller's Box 49.12 + Morgan & Mikhail):
  1. Severe/precipitous desaturation - Resume two-lung ventilation immediately
  2. Increase FiO2 to 1.0
  3. Recheck DLT/blocker position with fiberoptic bronchoscopy (surgical manipulation commonly dislodges tube)
  4. Optimize cardiac output - Surgeon may be inadvertently compressing the IVC; stop vasodilators; decrease volatile agent to ≤1 MAC
  5. Recruitment maneuver of the ventilated (dependent) lung (20 cmH2O for 15-20s; accept transient further desaturation)
  6. Increase PEEP to the ventilated lung (5-10 cmH2O) - avoid in emphysema
  7. Apneic oxygen insufflation to the nondependent lung (oxygen blow-by)
  8. CPAP 1-2 cmH2O to nondependent lung (preceded by recruitment breath) - avoid during VATS
  9. Partial ventilation techniques of the nondependent lung: intermittent IPPV, small VT ventilation, selective lobar collapse with bronchial blocker
  10. Pharmacologic manipulation of HPV (avoid vasodilators that inhibit HPV)
  11. Resume two-lung ventilation if all else fails
  12. Venovenous ECMO - last resort
  • Miller's, p. 7212-7213; Morgan & Mikhail, p. 1047; Barash, p. 3213-3214

12. Anesthetic Agents and HPV

Volatile anesthetic agents (≥1 MAC) inhibit HPV, which is the body's most important mechanism to redirect blood flow away from the non-ventilated lung. TIVA (propofol-based) preserves HPV better than inhalational agents. However, at ≤1 MAC, modern volatile agents have minimal clinically significant HPV inhibition.
  • Barash, p. 3213: "TIVA may be preferable to inhalation anesthetics"
  • Morgan & Mikhail: "Hypoxemia has become less frequent...due to better...anesthetic agents with less detrimental effects on hypoxic pulmonary vasoconstriction"

13. Fluid Management

Restrict fluid administration during OLV and lung resection to prevent fluid overload, which increases pulmonary capillary permeability and the risk of ALI. The risk increases proportionally with the amount of lung parenchyma resected.
  • Barash, p. 3213: "Fluid administration during the procedure must be limited to avoid fluid overload that could increase pulmonary capillary permeability"

14. Lung Reinflation at End of OLV

The operative lung is reinflated gradually to a peak inspiratory pressure <30 cmH2O to prevent disruption of the staple line. Clamping the lumen serving the dependent lung during reinflation limits overdistension.
  • Morgan & Mikhail, p. 1046

Summary Table: Recommended Ventilator Settings During OLV

ParameterRecommendation
FiO21.0 (or 0.5-0.8 for lung protection)
Tidal Volume6-8 mL/kg IBW
ModePressure-controlled (preferred) or volume-controlled
PEEP (dependent lung)5 cmH2O; titrate up to 10 if hypoxic
Plateau pressure< 25 cmH2O
Peak airway pressure< 35-40 cmH2O
Driving pressureMinimize; target < 14-15 cmH2O
Respiratory rateIncrease to maintain normocarbia / permissive hypercapnia
CPAP (nondependent lung)5-10 cmH2O (avoid during VATS)
Recruitment maneuversApply at start of OLV and when hypoxic
Anesthetic agentTIVA preferred; volatile ≤1 MAC acceptable

Key Takeaway for AIIMS

The modern approach to OLV has shifted from a pure oxygenation-first strategy to a lung-protection-first strategy balancing low VT (6-8 mL/kg), individualized PEEP (titrated to minimize driving pressure), recruitment maneuvers, pressure-controlled ventilation, and targeted management of HPV. The incidence of intraoperative hypoxemia has fallen from ~25% in the 1970s to <5% today, largely due to routine fiberoptic bronchoscopy, protective ventilation, and better HPV-preserving agents. However, the focus has now shifted to preventing ventilator-induced lung injury (VILI) and acute lung injury (ALI) - which carries a 40% mortality/major morbidity rate when it occurs after pneumonectomy (incidence ~7.9%).
  • Morgan & Mikhail, p. 1045-1046; Miller's, p. 7190-7213; Barash, p. 3201-3213

Simplify the about matter

Ventilator Strategies During One-Lung Ventilation (OLV)

What is the Core Problem?

During OLV, one lung is collapsed for surgery. This creates two competing goals:
  • Collapse the operative lung (for surgical access)
  • Protect the ventilated lung (to maintain gas exchange and prevent injury)
The main risks are hypoxemia and ventilator-induced lung injury (VALI).

1. Before Starting OLV - Denitrogenation

  • Ventilate with 100% O2 before collapsing the operative lung
  • This flushes out nitrogen, which delays lung collapse (nitrogen is poorly soluble)
  • Perform a recruitment maneuver (20 cmH2O for 15-20 sec) to the dependent lung just after starting OLV, to clear pre-existing atelectasis

2. FiO2

  • Use FiO2 1.0 as default - gives a safety margin against hypoxemia
  • Downside: causes absorption atelectasis in the ventilated lung
  • Modern protective strategy: FiO2 0.5-0.8 is acceptable if SpO2 is maintained

3. Tidal Volume (VT)

  • Old practice: 10-12 mL/kg (same as two-lung) - now abandoned
  • Current standard: 6-8 mL/kg IBW
  • < 3 mL/kg causes atelectasis and hypoxemia
  • Goal: avoid both overdistension (barotrauma) and under-ventilation (atelectasis)

4. Ventilation Mode

Pressure-Controlled Ventilation (PCV) is preferred over volume-controlled because:
  • Limits peak airway pressures - less barotrauma
  • Decelerating flow pattern - more even VT distribution
  • Lower mean airway pressure
Increase respiratory rate (12-16/min) to compensate for low VT.

5. PEEP (to the Ventilated/Dependent Lung)

SituationPEEP
Routine OLV5 cmH2O
HypoxemiaIncrease to 5-10 cmH2O
COPD patientUse cautiously - risk of air trapping and auto-PEEP
PEEP keeps the dependent lung at FRC (the point of lowest pulmonary vascular resistance).

6. Airway Pressure Limits

ParameterTarget
Plateau pressure< 25 cmH2O
Peak airway pressure< 35-40 cmH2O
Driving pressure (Pplat - PEEP)Minimize; aim < 14-15 cmH2O
Driving pressure is now considered the most important parameter - it reflects the stress on the functional lung and correlates best with outcome.

7. CPAP to the Operative (Nondependent) Lung

  • Most effective single maneuver to treat hypoxemia during OLV
  • Apply CPAP 5-10 cmH2O to the collapsed lung
  • Keeps some alveoli open - allows oxygen uptake in the operative lung
  • NOT used during VATS - the lung must be fully collapsed for the surgeon to see and use the stapler

8. Recruitment Maneuvers (RM)

  • Purpose: open atelectatic areas in the dependent lung
  • Technique: 35-40 cmH2O for 30-40 seconds, or stepwise PEEP increases
  • Warning: causes transient worsening of hypoxemia and hypotension during the maneuver
  • Controversial - stepwise RM preferred over sudden sustained inflation

9. Permissive Hypercapnia

  • If low VT causes CO2 to rise, allow it (acceptable if SpO2 is maintained)
  • Do NOT increase VT just to normalize CO2 - this risks lung injury
  • Monitor with arterial blood gas (end-tidal CO2 is unreliable during OLV due to increased dead space)

10. Managing Hypoxemia - Step-by-Step

When SpO2 drops below 90%, act in this order:
  1. Severe/sudden drop - Resume two-lung ventilation immediately
  2. Increase FiO2 to 1.0
  3. Check DLT/blocker position with fiberoptic bronchoscope
  4. Optimize cardiac output - check for IVC compression by surgeon; reduce volatile agent to ≤1 MAC
  5. Apply recruitment maneuver to the ventilated lung
  6. Increase PEEP (5-10 cmH2O) on the ventilated lung
  7. Apply oxygen insufflation/CPAP (1-2 cmH2O) to the collapsed lung
  8. Consider partial ventilation of the operative lung (small VT, intermittent IPPV)
  9. Last resort - V-V ECMO

11. Choice of Anesthetic Agent

  • Volatile agents at > 1 MAC inhibit HPV (hypoxic pulmonary vasoconstriction), which is the body's main mechanism to divert blood away from the collapsed lung
  • TIVA (propofol) preserves HPV better
  • At ≤ 1 MAC, volatile agents are clinically acceptable

12. Fluid Management

  • Restrict fluids - excess fluid increases pulmonary capillary permeability
  • Risk of acute lung injury (ALI) is proportional to how much lung is resected
  • ALI after pneumonectomy: 7.9% incidence, ~40% mortality/major morbidity

Quick Summary Box

ParameterSetting
FiO21.0 (or 0.5-0.8 protective)
Tidal Volume6-8 mL/kg IBW
ModePressure-controlled (preferred)
PEEP5 cmH2O, titrate up if hypoxic
Plateau pressure< 25 cmH2O
Peak pressure< 35-40 cmH2O
Driving pressureMinimize (< 14-15 cmH2O)
CPAP (operative lung)5-10 cmH2O (not in VATS)
AnestheticTIVA preferred; volatile ≤ 1 MAC
FluidsRestrict

One-Line Concept for Exams

OLV strategy = Low VT (6-8 mL/kg) + PCV + PEEP 5 cmH2O + Recruitment maneuvers + CPAP to operative lung (if not VATS) + TIVA + Fluid restriction = Protect the ventilated lung while collapsing the operative lung.

Just from millers

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I now have all the Miller's content needed. Here is the simplified, Miller's-only answer:

Ventilator Strategies During One-Lung Ventilation

Miller's Anesthesia 10e, Chapter 49

Core Concept (Miller's)

The anesthesiologist's goal during OLV is to maximize PVR in the nonventilated lung while minimizing PVR in the ventilated lung - by keeping the ventilated lung as close as possible to its FRC.
(Miller's p. 7192)

1. Pre-OLV: Denitrogenation

  • Ventilate with 100% O2 before collapsing the operative lung
  • Nitrogen (poorly soluble) delays lung collapse - problematic for VATS and emphysema patients
  • N2O collapses lung faster than O2 but is not used due to risk of expanding blebs/bullae
  • Immediately after starting OLV, perform a recruitment maneuver on the dependent lung: hold at 20 cmH2O for 15-20 seconds (like a Valsalva)
  • This clears atelectasis that forms during the two-lung lateral decubitus phase
(Miller's p. 7189-7190)

2. Acceptable Oxygen Saturation Limits

  • Target: SpO2 ≥ 90% (PaO2 > 60 mmHg)
  • High 80s briefly acceptable in patients with no significant comorbidities
  • Higher SpO2 target needed in: coronary/cerebrovascular disease, anemia, reduced cardiopulmonary reserve
  • COPD patients desaturate faster during OLV with isovolemic hemodilution
(Miller's p. 7191)

3. Hypoxic Pulmonary Vasoconstriction (HPV) - the Body's Defense

  • HPV diverts blood flow away from the hypoxic (collapsed) lung - can reduce its flow by up to 50%
  • Stimulus: alveolar O2 tension (PAO2) - causes precapillary vasoconstriction via NO/COX pathways
  • Biphasic temporal response:
    • Phase 1: starts immediately, peaks at 20-30 min
    • Phase 2: starts at 40 min, peaks at 2 hours
  • So PaO2 typically hits its nadir at 20-30 min then stabilizes or improves
  • HPV is inhibited by vasodilators (nitroglycerin, nitroprusside) - these worsen PaO2 during OLV
  • Thoracic epidural: no direct HPV effect, but causes hypotension/reduced CO which indirectly worsens oxygenation
(Miller's p. 7196-7197)

4. Intraoperative Position

  • Lateral decubitus position gives significantly better PaO2 than supine during OLV
  • True for both normal lung function and COPD patients
  • Gravity directs more blood flow to the dependent (ventilated) lung
(Miller's p. 7193)

5. PEEP to the Ventilated (Dependent) Lung

Key principle from Miller's: PVR is lowest at FRC. PEEP keeps the lung at FRC, improving oxygenation. But the effect of PEEP is unpredictable in individuals and depends on baseline auto-PEEP.
Auto-PEEP in OLV:
  • Many patients cannot fully exhale a large VT through one lumen of a DLT - they develop dynamic hyperinflation and auto-PEEP
  • Auto-PEEP averages 4-6 cmH2O in lung cancer patients with COPD
  • Applying external PEEP in a patient with high auto-PEEP pushes the lung above FRC, worsening oxygenation
Miller's rule:
  • Patients with normal lung mechanics or restrictive disease - benefit from PEEP (FRC is low, PEEP brings them up to FRC)
  • Patients with COPD/emphysema - may worsen with external PEEP if auto-PEEP is already present
  • Titrate PEEP to minimize driving pressure (Pplateau - PEEP) as the optimal individual strategy
(Miller's p. 7204-7205)

6. Tidal Volume

  • Start with: 5-6 mL/kg IBW + PEEP 5 cmH2O (except COPD patients)
  • Manage VT so that:
    • Peak airway pressure < 35 cmH2O
    • Plateau pressure ≈ 25 cmH2O
    • Peak pressure > 40 cmH2O = hyperinflation injury risk to the ventilated lung
  • Optimal VT is individual - results of VT changes are unpredictable due to interaction with auto-PEEP
  • Lateral position increases dead space - requires ~20% increase in minute ventilation to maintain same PaCO2
(Miller's p. 7206)

7. End-Tidal CO2 Monitoring

  • Turning to lateral position increases arterial-to-end-tidal CO2 gradient (Pa-ETCO2)
  • During OLV, PETCO2 is unreliable for tracking PaCO2 - individual variations are large
  • Use arterial blood gas for accurate CO2 monitoring during OLV
(Miller's p. 7208)

8. Volatile Anesthetics and HPV

  • All volatile agents inhibit HPV in a dose-dependent manner
  • At ≤1 MAC, the inhibition is modest and clinically acceptable in most patients
  • Vasodilators (nitroglycerin, nitroprusside, calcium channel blockers) inhibit HPV and worsen oxygenation - reduce or avoid during OLV
(Miller's p. 7196-7198)

9. Cardiac Output

  • Good cardiac output is essential - low CO worsens hypoxemia during OLV
  • Thoracic epidural causing hypotension, surgeon compressing the IVC, or high volatile agent concentrations can all drop CO and worsen SpO2
  • Optimize: vasopressors/inotropes as needed, keep MAC ≤1
(Miller's p. 7197)

10. Treatment of Hypoxemia During OLV

(Miller's Box 49.12, p. 7212-7213)
Severe/sudden desaturation:
  • Resume two-lung ventilation immediately
Gradual desaturation - stepwise:
StepAction
1FiO2 → 1.0
2Fiberoptic check of DLT/blocker position
3Optimize cardiac output; reduce volatile to ≤1 MAC; stop vasodilators
4Recruitment maneuver to ventilated lung (20 cmH2O, 15-20 sec)
5Increase PEEP to ventilated lung (avoid in COPD)
6Apneic O2 insufflation to the collapsed lung
7CPAP 1-2 cmH2O to the collapsed lung (recruit it first)
8Partial ventilation of the operative lung (intermittent IPPV, small VT, selective lobar collapse)
9Pharmacologic manipulation of HPV
10Venovenous ECMO (last resort)
Note on CPAP during VATS: Uncontrolled inflation of the operative lung interferes with surgical visualization - apply cautiously and only when necessary
(Miller's p. 7212-7213)

Miller's Simplified Strategy Table (Table 49.9 equivalent)

ParameterMiller's Recommendation
FiO21.0
Tidal Volume5-6 mL/kg IBW
PEEP5 cmH2O (except COPD)
Peak airway pressure< 35 cmH2O
Plateau pressure≈ 25 cmH2O
Minute ventilationIncrease ~20% from two-lung setting
PEEP optimizationTitrate to lowest driving pressure
CO2 monitoringABG preferred over ETCO2
Volatile agent≤ 1 MAC
VasodilatorsAvoid (inhibit HPV)

One-Line Summary (Miller's)

OLV = 5-6 mL/kg IBW + PEEP 5 cmH2O + Peak pressure <35 cmH2O + Keep lung at FRC + Optimize HPV + Stepwise treatment of hypoxemia
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