Pacing catheter insertion
· prepare and insert PAC introducer as previously described, monitor ECG and arterial blood pressure
· confirm with medical officer method of insertion (insert in B4 using a blind technique or transfer to CCU and insert with aid of fluoroscopy)
· assist medical officer to insert pacing swan
· prepare, check and connect pacing box to patient
· set and document pacing threshold and parameters
Pacing swans are inserted infrequently and therefore the expiry date frequently expires prior to its use. Therefore please borrow pacing swan catheters from the general intensive care unit and fill out the appropriate reimbursement forms.
Removal of pacing catheter
Equipment Gauze swabs, tegaderm occlusive dressing, persist plus swab stick, stitch cutter, bung.
· explain procedure to patient
· position supine (increase CVP, thereby decreasing risk of venous air emboli)
· transfer or disconnect IV solutions if applicable and occlude with bungs
· continuously monitor PA distal lumen while withdrawing the pacing catheter
Clinical applications
Although pre-morbid states and intra-operative events play a primary role in predicting outcomes, patient care in the immediate post operative period is crucial to outcome. Diligent informed and proactive nursing management is required to prevent complications and promote recovery.
The admission of a patient to the cardiothoracic intensive care setting is a systematic process. Please refer to chapter 1. A complete verbal report from the anaesthetist and surgical consultant or registrar in his absence will alert the bedside nurse to any relevant intraoperative events (dysrhythmias, hypotension, difficult intubation, vasoactive medications and so on).
When the admission procedure has been completed (Airway Breathing Circulation) attention is turned to the systematic gathering of data to evaluate the adequacy of performance of the cardiovascular, pulmonary, renal, neurologic, gastrointestinal, haemotoligic and metabolic systems. Thorough patient assessment together with a complete verbal report from the attending anaesthetist and surgical consultant serves as a basis for formulating an individualised nursing plan.
Cardiac assessment
Several pre and intraoperative factors influence the cardiovascular status. An immediate ECG is obtained.
· intraoperative events (complete/incomplete revascularisation, residual valvular disease)
· impaired myocardial contractility (CPB sequalae)
· hypovoelaemia (vasodilatation, rewarming, blood loss)
· left ventricular afterload (vasoconstriction)
· dysrhythmias (acidosis, electrolyte imbalance, hypoperfusion, myocardial stunning or injury)
Blood pressure
Mean, systolic and diastolic pressures alert the bedside nurse to possible decrease in cardiac output. Generally a MAP 65-75 mm Hg is indicative of adequate cardiac output. A MAP of 75-85 mm Hg may be required to maintain flow through IMA grafts. A MAP of 60 mm Hg is essential for vital organ perfusion.
Right heart pressure
Right heart pressure (CVP) indicates the filling pressures (preload) and should be maintained 10-12 mm Hg.
Cardiac rate and rhythm
Cardiac rate and rhythm must be stable for adequate cardiac output. Blood balance is worked out on volume of drainage and total of transfused blood products.
Skin perfusion is a cardinal sign of poor cardiac output. The body shuts down circulation to cutaneous tissues to maintain perfusion to vital organs. Cold clammy skin is indicative of inadequate cardiac output and should always be investigated, even in the presence of normal systemic pressure, central venous pressure and temperature. Investigate poorly perfused skin in relation to nursing therapeutics and medical interventions (commencement of weaning and so on)
Respiratory assessment
All patients who have undergone cardiac and thoracic surgery must have a meticulous respiratory assessment. This involves
· assessment of pre-existing respiratory disease (asthma, COAD, smoking)
· duration of CPB (haemodilution, destruction of red cells, pulmonary microemboli)
· destruction of surfactant (hypothermia, 100 % oxygen administration, inadequate humidity, inappropriate TV)
· atelectasis
· haemo/pneumotherax
· initial ventilation settings see Chapter 4
· weaning/extubation criteria see chapter 4
· early mobilisation (day 1), optimising analgesia, 2 hrly deep breathing and coughing and bronchodilator therapy prn.
Renal assessment
Urinary output is a good indicator of renal function and should be at least 20 ml per hour per square metre body surface area (H x W)
Renal function is impaired by
· low cardiac output MAP <>
· lengthy CPB (hypoperfusion, microemboli)
· nephrotoxic medications (Vancomycin)
Se Cr should be between .06 & .12
Neurological assessment
Diffuse and localised neurological deficits can occur and their presence must be established as early as possible and thoroughly investigated in origin. It is unit policy to carry out 4 hourly neurological observations on all patients recovering from cardiac surgery while in the critical care setting.
Gastrointestinal assessment
Abdominal distension, type and amount of gastric loss may indicate problems. It is usually related to decreased cardiac output, microemboli, and anaesthetic and analgesic agents, and antibiotic therapy, aspirin and warfarin therapy. All cardiac surgical patients must have an orogastric tube on free drainage during the period of postoperative ventilation. It may be necessary to insert a naso gastric tube in patients requiring CPAP to prevent regurgitation. All tracheotomised patients require a naso enteric tube, which should be aspirated 4hrly according to protocol, see chapter 5.
Haematological assessment
Chest tube drainage is continuously monitored. Expect some degree of drainage. If bleeding > 200mls/hr, ensure patient remains sedated, MAP 65-70 mmHg and patient is repositioned on the side to facilitate drainage. The low pressure suction system is checked for integrity and function hourly (3 kpa). If bleeding continues clotting studies are necessary (see chapter 2). Communication with the nursing team leader (by the bedside nurse) and the surgical team and the on call registrar (by the team leader) is essential to keep all relevant parties informed in case of return to theatre being necessary.
Metabolic assessment
Metabolic acidosis with base excess > 2 mEq/l is related to reperfusion of previously poorly perfused microcirculation on CPB. Body temperature should return to normal 2-4 hrs post operatively. Therapeutic hypothermia is established during bypass to reduce metabolism and provide myocardial protection. Rewarming occurs centrally with patient remaining on bypass until a central (core) temperature of > 37 C° is reached. The patient is separated from bypass and central body temperature starts to fall due to the ambient temperature of the operating theatre. Frequently patients arrive in the cardiothoracic intensive care setting 32-36°C and require warming. See chapter 5. Avoid shivering as it increases oxygen requirement and therefore has potentially detrimental myocardial sequalae.
Fluid and electrolyte management
In the first 24 hrs there is an increase in extracellular fluid, total exchangeable sodium and a decrease in exchangeable potassium. Blood products are transfused in accordance with blood loss to a formula of blood balance = loss + 100mls.
Hydration:
Dextrose/Saline & 30 mmol KCL at 1ml/kg/hr
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