Measure of Respiration Rate and Physiological regulation

Respiration

Human survival depends on the ability of oxygen to reach body cells and for CO₂ to be removed from the cells. Respiration is the mechanism the body uses to exchange gases between the atmosphere and the blood and the blood and the cells. Respiration involves :

a.     Ventilation

b.     Diffusion and

c.      Perfusion

Definition

Respiration is the act of breathing. It is made up of one inspiration, one expiration and one pause.

Ventilation the movement of gases in and out of the lungs. The rate, depth and rhythm of ventilatory movements indicate the quality and efficiency of ventilation.

Diffusion is the movement of oxygen and CO₂ between the alveoli and the red blood cells.

Perfusion is the distribution of red blood cells to and from the pulmonary capillaries.

Physiological regulation

Breathing is generally a passive process. The respiratory center in the brain stem regulates the involuntary control of respiration.

The most important factor in the control of ventilation is the level of CO₂ in the blood. An elevation of CO₂ in arterial blood causes the respiratory control system in the brain to increase the rate and depth of breathing.

The increased ventilatory effort removes excess CO₂ during exhalation.

Eupnea : Condition where there is normal rate and depth of Ventilation.

Respiratory rate : Adults normally breath smoothly 12 to 20 times a minute.

Characters of respiration

 respiratory rate : the nurse observe a full inspiration and expiration when counting ventilation or respiration rate.

Table : Normal average respiratory rate:

Age   Rate

New born    35 - 40

Upto 1 year          30 - 50

1-2    25 - 32

3- 12 20 - 30

13 - 19       16 - 19

Adults         12 - 20

Ventilatory depth is the degree of excursion or movement in the chest wall. Ventilatory movements may be deep, normal or shallow.

  Deep  respiration  involves a  full  expansion of the lungs with full exhalation.

Shallow respiration: is present when only a small quantity of air passes through the lungs and ventilatory movement is difficult to see.

Ventilatory rhythm:

With normal breathing, a regular interval occurs after each respiratory cycle. Respiration is regular or irregular in rhythm.

Factors which regulate respiration :

Respiratory center in the medulla

Nerve fibres of the autonomic nervous system.

Chemical composition of blood.

What to Note when taking respiration:

Rate and depth

Movement and expansion of chest and abdomen.

Rhythm.

Whether quiet or noisy. Comfort of the patient, whether breathing is done unconsciously or with effort.

Procedure :

Keep the patient in a relaxed and comfortable position.

Try to count the respirations without the patient knowing that you are watching him or he may change the rate of respiration.

Keep the fingers on the patient' s wrist, as if for counting pulse and watch the rise and fall of the chest and abdomen or if the patient is sitting watch the movements of the shoulders.

Chart the rate and record any abnormalities.

Frequency of Monitoring Respiration:

Twice a day for all patients.

Every four hours for postoperative patients.

Every 30 minutes for immediate postoperative patients.

Every 15 minutes for critically ill patients.

Alteration in (abnormal) breathing patterns

Brady pnea: the respiratory is abnormally slow (less than 12 breaths per minute) Occurs in coma due to cerebral haemmorrhage or large doses of sedatives, 

Tachy pnea : the respiratory rate is abnormally rapid (greater than 20 breaths per    minute)

Apnea : Respirations cease for several seconds.

Respiratory arrest: Persistant cessation of respiration. 

Hyper Ventilation : Rate and depth of respirations increase.

Hypoventilation : Rate is abnormally low and depth is shallow. Shallow respiration occurs in diseases of the lung such as pneumonia and pleurisy. 

Sighing  or  air  hunger:  Indicates  a  need  for  more

oxygen.  Occurs  in  severe  haemorrhage   diabetic coma or due to stimulation of respiratory center by excess of acid.

Wheezing: Sound made during expiration may be due to obstruction in the lower respiratory tract as in the case of asthma.

Stertorous breathing: Noisy snoring inspiration occurs in unconscious patients which may be due to the tongue slipping back. Peculiar hissing respiraton occurs in uraemic coma.

Stridor:  It is noisy inspiration due to the obstruction of upper respiratory tract. This noise may be harsh, grating or whistling sound.

Orthopnea: Inability to breath easily unless in an upright position.     

Dyspnoea:Difficult  breathing.If  it  is  during inspiration it is due to laryngeal     obstruction; if it is during expiration it is due to Asthma.          

Cheyne stokes  or  periodic breathing  : Alternative periods        of hyperponea,  occuring  in a        rhythmical cycle. It is important to note this phenomenon as this is a serious sign.

Asphyxia: Occurs due to lack of oxygen supplied to the cells. This is found in drowning patients of persons who have inhaled poisonous gases (coal gas).