Page 348 - ACCCN's Critical Care Nursing

Respiratory Assessment

and Monitoring 13

Amanda Corley
Mona Ringdal

assess critically ill patients and monitor for responses to
Learning objectives treatment or early signs of deterioration.
This chapter provides a comprehensive description of the
After reading this chapter, you should be able to: principles and practice of respiratory assessment, moni-
● demonstrate an understanding of respiratory anatomy and toring, and diagnostics. This knowledge is important in
normal physiology providing timely and effective interventions for critically
● describe the mechanisms that contribute to altered ill patients with respiratory dysfunction. The following
respiratory function two chapters then discuss the management of respiratory
● examine the key principles underpinning assessment and alterations (Chapter 14) and oxygenation and ventilation
monitoring of respiratory function interventions (Chapter 15).
● discuss nursing assessment and monitoring activities for
critically ill patients with respiratory dysfunction RELATED ANATOMY AND
● explain the importance of patient assessment skills, and the PHYSIOLOGY
contribution of diagnostic and laboratory findings to
ongoing clinical management The thorax cavity contains the trachea and bronchial tree,
● justify the physiological bases for different types of the two lungs, pleura and diaphragm. The mediastinum,
monitoring located between the lungs, houses and protects the heart,
● discuss some common forms of diagnostic procedures used great vessels and the oesophagus. Twelve pairs of ribs
in critical care cover the lungs, ten of which are connected to the spine
posteriorly, and to the sternum or to the cartilage of the
rib above anteriorly (ribs 8–10). The 11th and 12th ribs
have no anterior attachment (see Figure 13.1). 1
Key words The respiratory system is divided into upper and lower
respiratory tracts: the upper airways consist of the nose,
work of breathing nasal conchae, sinus and pharynx; the lower respiratory
2
gas exchange tract includes the larynx, trachea, bronchi and lungs.
Larger airways are lined with stratified epithelial tissue,
oxygen delivery which have a relatively high cellular turnover rate; these
hypoxaemia cells protect and clear these large airways. There are also
pulse oximetry additional specialised features of this tissue including an
capnography extensive distribution of mucus/goblet cells and cilia,
arterial blood gases which facilitate the mucociliary clearance system and aid
diagnostic imaging airway clearance.

UPPER RESPIRATORY TRACT
INTRODUCTION The nasal cavities contain an extremely vascular and
mucoid environment for warming and humidifying
The respiratory system ensures adequate tissue and cel- inhaled gases. To maximise exposure to this surface area,
lular oxygenation for the body. It is responsible for gas the nasal conchae create turbulent gas flow. Cilia at the
exchange through the uptake of oxygen and excretion of top of the epithelial cells and mucus provide filtration
carbon dioxide; assists in optimal organ function; con- and cleaning of the inhaled air. Mucus is moved by the
tributes to acid–base balance; and therefore plays a large cilia lining the conducting airways towards the pharynx
role in maintaining homeostasis. A thorough under- at a rate of 1–2 cm per minute. One litre of mucus is
standing of the anatomy, physiology and pathophysio- produced every day with only a small part not reabsorbed
logy of this complex body system is required to accurately by the body. 3,4 325