Page 571 - ACCCN's Critical Care Nursing

548 P R I N C I P L E S A N D P R A C T I C E O F C R I T I C A L C A R E

and may contribute to worsening of the cardiac output, ● implementing measures to reduce patient anxiety,
in particular when cardiogenic shock is due to con- including communication, explanation and analgesic
tractile dysfunction. and sedative medications (avoiding those that are
● An increase in cardiac workload to overcome the rise cardio-depressive) where appropriate
in systemic afterload increases myocardial oxygen ● ensuring that visiting practices are appropriate for
demand, but cannot be met due to coronary artery the patient (which may require facilitating lengthy
occlusion. visits by a loved one, limiting visiting time, or being
● Developing pulmonary congestion is no longer con- selective with the visitors who remain with the
tained within the pulmonary capillary and moves into patient).
the alveolar capillary space, creating pulmonary
oedema, further impeding oxygen delivery to the Collaborative Management
circulation. Typical treatment regimens require preload reduction,
augmentation of contractility with intravenous inotropes
NURSING PRACTICE and afterload manipulation. These aspects are under-
Treatment of cardiogenic shock includes haemodynamic taken concurrently due to the potential severity of cardio-
genic shock. Endotracheal intubation with mechanical
management, respiratory and cardiovascular support, ventilation is implemented if necessary (the need for
biochemical stabilisation and reversal or correction of the mechanical ventilation is associated with an increase in
underlying cause. This complex presentation requires a mortality) (see Chapter 15).
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coordinated approach to the multiple aspects of care of
a patient with cardiogenic shock. Preload management
Preload reduction relieves pulmonary congestion, reduces
Independent Practice myocardial workload and improves contractility, which is
A rapid response to impending deterioration associated in part impaired by overstretched ventricles. Careful
with cardiogenic shock includes repeated assessment and assessment of patient fluid status is necessary prior to
measures to optimise oxygen supply and demand. either the administration of small aliquots of fluid to
enhance deteriorating myocardial function or enhanced
Assessment diuresis to reduce circulating blood volume. Any fluid
offloading is balanced against the risk of excessive blood
Frequent, thorough assessment of the patient’s status is volume depletion and depression of cardiac output and
essential, focusing on: blood pressure. Desired endpoints of therapy are a
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1. identification of patients at risk of clinical reduction in right atrial, pulmonary artery, and pulmo-
deterioration; nary artery wedge pressures, or in intrathoracic blood
2. assessment of the severity of shock and identifica- volume, global end-diastolic volume and extravascular
tion of organ or system dysfunction; lung water, depending on available monitoring equip-
3. assessment of the impact of treatment; and ment. Measures to reduce preload include:
4. identification of complications of treatment. ● sitting a patient up with their legs either hanging over
Assessment follows a systematic approach and is con- the side of the bed or in a dependent position
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ducted as often as indicated by the patient’s condition, ● IV diuretics (frusemide) given usually as intermittent
centring on the cardiovascular system, as well as related boluses or if necessary as a continuous infusion
systems that cardiac function influences, including respi- ● venodilation (glyceryl trinitrate infusions at 10–
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ratory, renal, neurological and integumentary. 200 µg/min titrated to blood pressure)
● continuous haemofiltration (might be considered to
rapidly reduce circulating volume)
Optimising oxygen supply and demand ● continuous positive airway pressure (indicated for
As cardiogenic shock is associated with an imbalance of pulmonary relief, with the additional benefit of reduc-
oxygen supply and demand throughout the body, mea- ing venous return).
sures to optimise this balance by increasing oxygen Additional measures to reduce pulmonary hypertension
supply and decreasing demand are essential. Strategies to may be employed. Morphine is useful to lessen the
increase oxygen supply include: anxiety and oxygen demands during cardiogenic shock,

● positioning the patient upright to promote optimum and may offer additional benefits by reducing pulmonary
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ventilation by reducing venous return and lessening artery pressure and pulmonary oedema. Other treat-
pulmonary oedema (but may contribute to worsening ment options include correction of hypercapnoea if
hypotension) present, and nitric oxide by inhalation.
● administering oxygen, continuous positive airway
pressure (CPAP) and bi-level positive airway pressure Inotropic therapy
(BiPAP) support as required. 66 Intravenous positive inotropes promote myocardial con-
tractility to improve cardiac output and blood pressure.
Strategies to reduce oxygen demand include:
Currently available inotropes are not uniform in their
● limiting physical activity beneficial effect on cardiac output and blood pressure