physiology (version 1.2.1)

deadspace_total: Estimate ventilation dead-space

Description

Estimate ventilation dead-space

Usage

deadspace_total(ideal_weight_kg, age_y = NULL, elbow_ml = 10,
  humidifier_ml = 7, ett_diameter_mm = NULL)
deadspace_anatomic(ideal_weight_kg, age_y = NULL)
deadspace_anatomic_adult(ideal_weight_kg = NULL)
deadspace_anatomic_child(ideal_weight_kg, age_y = NULL)
deadspace_intrathoracic_ml(ideal_weight_kg)

Arguments

ideal_weight_kg

Ideal weight in kilograms. May be calculated using ideal_weight_adult or ideal_weight_child

age_y

Age in years, optional for estimating ETT and HME sizes automatically

elbow_ml

Numeric volume of elbow of breathing circuit in ml

humidifier_ml

Numeric volume of humidifier of breathing circuit in ml

ett_diameter_mm

Numeric internal diameter of endotracheal tube. Default is NULL which would estimate this from the age of patient

Value

estimate of anatomic dead-space in ml

Functions

• deadspace_anatomic: Estimate anatomic dead-space

• deadspace_anatomic_adult: Estimate anatomic dead-space in an adult

• deadspace_anatomic_child: Estimate anatomic dead-space in an infant or child

• deadspace_intrathoracic_ml: intrathoracic component of dead-space is age independent

Details

'Mean intrathoracic anatomic dead space was 1.03 ml/kg and was not related to age.' Numa, 1985

References

http://www.atsjournals.org/doi/abs/10.1164/arrd.1971.104.2.215 http://rc.rcjournal.com/content/53/7/885.short https://www.ncbi.nlm.nih.gov/pubmed/8727530

See Also

Other respiratory: alveolar_PAO2_mmHg

Other airway equipment: deadspace_things_ml, ett_size_by_age, ett_vol_ml

Examples

# NOT RUN {
  height <- seq(1, 2, 0.05)
  male <- rep(FALSE, length(height))
  iw <- ideal_weight_adult(height_m = height, male = male)
  
# }
# NOT RUN {
  plot(iw, deadspace_anatomic_adult(ideal_weight_kg = height))
  
# }
# NOT RUN {
  # discontinuity at age 6 is driven by ideal weight more than the
  # lograithmic calculation
  iw <- c(seq(12, 18, 0.2), seq(18.5, 24, 0.5))
  youngest = 3
  oldest = 9
  ages <- seq(youngest, oldest, (oldest - youngest) / (length(iw) - 1))
  
# }
# NOT RUN {
  plot(iw, deadspace_anatomic_child(ideal_weight_kg = iw, age_y = ages),
       type = "l")
  
# }