|
Hazards and Complications of IPPB |   |
Virtually every therapeutic intervention in health care includes some type of potential risks, and respiratory therapy is certainly no exception. Since IPPB therapy artificially hyperventilates the patient, and by definition hyperventilation exceeds normal metabolic need, there is a potential for both hazards and complications.
RCPs administering IPPB therapy need to be watchful for signs of dangerous
hyperventilation, including: dizziness, tingling of the fingers, agitation,
confusion and alkalosis or increased pH. Allowed to persist unheeded,
these can lead to life-threatening a acid-base imbalance or even cardiac
arrest.
| Since so much of the efficacy of IPPB depends on the RCP, the potential risks and problems should be addressed in the initial stages of planning for IPPB. Hazards and complications must also be considered throughout the course of therapy as part of the process of assessing the patient for unwanted side effects. The major hazards and complications associated with IPPB include: |  |
- Increased intracranial pressure
- Impeded venous return
- Increased airway resistance
- Pulmonary barotrauma
- Nosocomial infection
- Hemoptysis
- Hypocapnia and respiratory alkalosis
- Hypoventilation, hyperoxia, and respiratory acidosis
- Gastric distention
- Air trapping, auto-PEEP, overdistention
- Psychological dependence
Increased intracranial pressure. IPPB therapy creates airway pressure
that in turn can cause an increase in the mean intrathoracic pressure.
Venous drainage from the head can be impeded, and this may result in venous
congestion within the cranial cavity, compromising the capillary blood
flow to brain tissue. Unless the patient has a pre-existing CNS disease,
this hazard can be avoided by properly administering the IPPB therapy.
However, if at all possible IPPB should be administered to these patients
in a sitting position, and they should be allowed long periods of expiration
and periods of spontaneous breathing between positive pressure breaths.
Impeded venous return. IPPB therapy, especially if improperly applied,
can cause a significant decrease in venous return, which can lead to a
decrease in cardiac output, tachycardia, and dyspnea. Positive intrathoracic
pressure can impede venous return, causing a drop in cardiac output. Normal
individuals can compensate for this effect by increasing venomotor tone.
If the patient is already hypotensive or if compensation is not possible,
the administration of IPPB therapy can drastically lower cardiac output.
As a result, RCPs considering administering IPPB need to first conduct
a preliminary bedside assessment of the patient's cardiovascular status,
and subsequently monitor any high risk patients during their therapy,
looking for any signs or symptoms of compromised cardiovascular function.
Increased airway resistance. An increase in airway resistance
can occur during IPPB therapy, especially in patients with hyperreactive
airways. Asthmatic patients and those with chronic lung disease, should
always be given bronchodilators along witb IPPB treatments. Administration
of bland aerosols alone is not recommended since they can cause bronchospasms
in some patients.
Pulmonary barotrauma. Lung injury due to excessively high pressure
(baratrauma) is most likely to occure in COPD patients whose pulmonary
system is already compromised by the presence of bunae or blebs. The administration
of positive-pressure can cause their lungs to rupture causing pneumothorax,
pneumomediastinum, pneumopericardium or subcutaneous emphysema. RCPs can
prevent barotrauma by: preassessment, monitoring, and vigilance for symptoms
such as sharp chest pain, tachycardia and tachypnea. IPPB treatment should
be immediately terminated if any of these symptoms present. By using the
lowest possible IPPB pressure levels that improve patient ventilation,
RCPs can minimize the potential for barotrauma or pneumothorax.
Nosocomial infection. It is well documented that respiratory care
equipment can be a source of hospital-acquired infections. The IPPB apparatus
is clearly a potential source of hospital-acquired infection. RCPs responsible
for IPPB therapy should implement the CDC's Universal precautions, when
appropriate, follow the guidelines for prevention of tuberculosis transmission.
Because IPPB directly applies gases to the patient's tracheobronchial
tree, the potential for infection of the patient is increased. In addition,
patients receiving IPPB have substantially lowered resistance to common
infections. IPPB machines should be cleaned/sterilized regularly to prevent
cross-contamination of patients. Patients' individual circuits should
be sealed in polyethylene bags between treatments, as airborne bacteria
or viruses can settle on them, and circuits should be changed every 24-48
hours.