VD/VT

In medicine, the ratio of physiologic dead space over tidal volume (V_D/V_T) is a routine measurement, expressing the ratio of dead-space ventilation (V_D) to tidal ventilation (V_T), as in physiologic research or the care of patients with respiratory disease.^[1]

Equation

\frac{V_D}{V_T} = \frac{P_a CO_2 - P_E CO_2}{P_a CO_2}

References

↑ Raymond LW (1978). "The alveolar air equation abbreviated.". Chest 74 (6): 675–6. doi:10.1378/chest.74.6.675. PMID 738126.

Mechanical ventilation

Fundamentals

Modes of mechanical ventilation
Mechanical ventilation in emergencies
Mechanical ventilation in neonates
Nomenclature of mechanical ventilation

Modes

SIMV
CMV
AC
SPON
BPAP
APRV
MMV
HFV

Related illness

Pressure

P_EEP
FiO₂
Δ_P
P_IP
P_S
P_AW
P_plat

Volumes

Other

C_dyn
C_static
P_AO₂
V_D/V_T
OI
A-a gradient

Index of the respiratory system

Description	Anatomy nose larynx lower thorax Physiology Development

Disease	Congenital Neoplasms and cancer Chest trauma Infection common cold pneumonia tuberculosis Other Symptoms and signs eponymous

Treatment	Procedures mechanical ventilation Drugs nasal throat obstructive airway diseases cough and cold histaminergics pulmonary arterial hypertension other Surgery