15- Post operative Explains Flashcards
What is the definition of postoperative cognitive dysfunction (POCD)?
Deterioration in performance in a battery of neuropsychological tests that would be expected in less than 3.5% of controls, or long-term, possibly permanent disabling deterioration in cognitive function following surgery.
What factors are associated with late POCD?
Increasing age, emboli, and biochemical disturbances.
What factors are associated with early POCD?
Increasing age, general anesthesia rather than regional anesthesia, longer duration of anesthesia, reoperation, and postoperative infection.
How are patients identified as malnourished according to NICE guidelines?
Patients with a BMI < 18.5 kg/m² or unintentional weight loss of > 10% over 3-6 months, or patients with a BMI < 20 kg/m² and unintentional weight loss of > 5% over 3-6 months.
Who is considered at risk of malnutrition according to NICE guidelines?
Patients who have eaten nothing or very little for more than 5 days and are likely to continue eating little for another 5 days, or patients with poor absorptive capacity, high nutrient losses, or high metabolism.
When should parenteral nutrition be considered according to NICE guidelines?
Parenteral nutrition should be considered in patients with unsafe or inadequate oral intake, or in patients with a non-functional gastrointestinal tract, perforation, or inaccessibility.
What is the recommended approach for feeding patients for less than 14 days?
Feeding via a peripheral venous catheter is recommended for patients needing parenteral nutrition for less than 14 days.
What is the recommended approach for feeding patients for more than 30 days?
A tunneled subclavian line is recommended for patients needing parenteral nutrition for more than 30 days.
In what situations is continuous administration of parenteral nutrition recommended?
Continuous administration is recommended for severely unwell patients.
When should a change from continuous to cyclical feeding be considered?
If parenteral nutrition is needed for more than 2 weeks, a change from continuous to cyclical feeding should be considered.
What is the recommended approach for unwell patients in the first 24-48 hours of parenteral nutrition?
Do not give more than 50% of the daily regimen to unwell patients in the first 24-48 hours.
What is the recommendation for perioperative parenteral feeding in surgical patients?
In malnourished surgical patients with an unsafe swallow or a non-functional gastrointestinal tract, perforation, or inaccessibility, perioperative parenteral feeding should be considered.
What is circulatory support in the context of critically ill patients?
Circulatory support is provided to patients who have impaired tissue oxygenation, often as a result of circulatory shock.
What are some methods of haemodynamic monitoring for patients requiring circulatory support?
Methods of haemodynamic monitoring include regular urine output measurements, blood pressure monitoring, ECG monitoring for cardiac arrhythmias, and pulse oximeter measurements for estimating hemoglobin oxygen saturation.
How is invasive arterial blood pressure monitoring performed?
Invasive arterial blood pressure monitoring is done using an indwelling arterial line, most commonly placed in the radial artery. Care should be taken not to cannulate end arteries.
What is central venous pressure (CVP) and how is it measured?
Central venous pressure represents right atrial filling pressure and volume status. It is measured using a CVP line typically placed in the superior vena cava via the internal jugular route. A fluid challenge can be used to assess response, with a prolonged rise in CVP indicating adequate intravascular volume.
What is the purpose of a Swan-Ganz catheter in circulatory support?
A Swan-Ganz catheter, traditionally inserted to monitor cardiac output, provides information on left ventricular preload, pulmonary artery occlusion pressure, left atrial pressure, stroke volume, systemic vascular resistance, pulmonary artery resistance, and oxygen delivery and consumption.
When would vasoactive drugs be considered in circulatory support?
Vasoactive drugs may be considered in patients with ongoing circulatory compromise despite adequate circulating volume. These drugs are typically administered via the central venous route.
What are some commonly used inotropes in circulatory support and their effects?
Commonly used inotropes include noradrenaline (α agonist with vasopressor action), adrenaline (α and β receptor agonist that increases cardiac output and peripheral vascular resistance), dopamine (β1 agonist that increases contractility and heart rate), dobutamine (β1 and β2 agonist that increases cardiac output and decreases systemic vascular resistance), and milrinone (phosphodiesterase inhibitor that improves muscular contractility and acts as a vasodilator).
What does the pulmonary artery occlusion pressure (PAOP) measure?
The pulmonary artery occlusion pressure is an indirect measure of the left atrial pressure and the filling pressure of the left heart.
How is the most accurate trace of the pulmonary artery occlusion pressure obtained?
The most accurate trace is obtained by inflating the balloon at the tip of the catheter and occluding the vessel.
What is the significance of the pulmonary artery end diastolic pressure measurement?
If it is not possible to occlude the vessel, the measurement obtained will be the pulmonary artery end diastolic pressure.
How is the pulmonary artery occlusion pressure interpreted?
A normal pulmonary artery occlusion pressure is 8-12 mmHg. A low pressure (<5 mmHg) indicates hypovolemia, while a low pressure with pulmonary edema indicates ARDS. A high pressure (>18 mmHg) suggests overload.
What additional measurements can help accurately classify patients when combined with the pulmonary artery occlusion pressure?
When combined with measurements of systemic vascular resistance and cardiac output, it is possible to accurately classify patients.
How is systemic vascular resistance (SVR) derived?
Systemic vascular resistance is derived from the mean aortic pressure, mean right atrial pressure, and cardiac output using the formula: SVR = 80(mean aortic pressure - mean right atrial pressure) / cardiac output.
What is total parenteral nutrition (TPN) commonly used for?
TPN is commonly used in nutritionally compromised surgical patients.
What components are found in TPN bags?
TPN bags contain combinations of glucose, lipids, and essential electrolytes.
How is the exact composition of TPN determined?
The exact composition of TPN is determined based on the patient’s nutritional requirements.
What are the potential complications associated with peripheral infusion of TPN?
Peripheral infusion of TPN may result in thrombophlebitis.
Where should longer-term infusions of TPN be administered?
Longer-term infusions of TPN should be administered into a central vein, preferably via a PICC line.
What are some complications associated with TPN?
Complications related to TPN include sepsis, re-feeding syndromes, and hepatic dysfunction.
What are the indications for IV fluids in paediatric patients?
Indications for IV fluids include resuscitation and circulatory support, replacing ongoing fluid losses, maintenance fluids for children who cannot consume oral fluids, and correction of electrolyte disturbances.
Which fluids should be avoided in children outside the neonatal period?
In children outside the neonatal period, saline/glucose solutions should not be given, especially saline 0.18/glucose 4% solutions. The report suggests that 0.45% saline/5% glucose may be used, but preference should be given to isotonic solutions.
What type of fluid should neonates receive during surgery?
Neonates should receive glucose 10% during surgery.
What are the recommended daily water and electrolyte requirements for maintenance fluids based on body weight?
For the first 10kg of body weight, the water requirement is 100ml/kg/day, sodium requirement is 2-4 mmol/kg/day, and potassium requirement is 1.5-2.5 mmol/kg/day. For the second 10kg of body weight, the water requirement is 50ml/kg/day, sodium requirement is 1-2 mmol/kg/day, and potassium requirement is 0.5-1.5 mmol/kg/day. For subsequent kilograms of body weight, the water requirement is 20ml/kg/day, sodium requirement is 0.5-1.0 mmol/kg/day, and potassium requirement is 0.2-0.7 mmol/kg/day.
Which fluids are recommended for use in paediatric patients?
Recommended fluids include 0.9% saline, 5% glucose (only with saline for maintenance and not to replace losses), and Hartmann’s solution.
When should potassium be added to maintenance fluids, and how should it be monitored?
Potassium should be added to maintenance fluids based on the patient’s plasma potassium levels, which should be monitored.
What type of fluid should other children receive during surgery?
Other children should receive isotonic crystalloid during surgery.
How much glucose is typically given to neonates for maintenance?
Neonates typically receive 10% glucose at a rate of 60ml/kg/day.
What are acute transfusion reactions?
Acute transfusion reactions are adverse signs or symptoms that occur during or within 24 hours of a blood transfusion.
What are the most frequent reactions in acute transfusion reactions?
The most frequent reactions in acute transfusion reactions are fever, chills, pruritus, or urticaria. These symptoms typically resolve promptly without specific treatment or complications.
What signs may indicate a potentially fatal reaction during a blood transfusion?
Severe dyspnea, pyrexia, or loss of consciousness occurring in temporal relationship with a blood transfusion may be the first indication of a more severe potentially fatal reaction.
What are the proposed mechanisms underlying transfusion-related lung injury?
There are two proposed mechanisms for transfusion-related lung injury. One involves the sequestration of primed neutrophils within the recipient pulmonary capillary bed. The other mechanism suggests that HLA mismatches between donor neutrophils and recipient lung tissue are to blame.
What are the causes of adverse transfusion reactions?
The causes of adverse transfusion reactions are multi-factorial. Immune-mediated reactions can occur due to component mismatch, often caused by clerical error. Non-immune mediated complications may occur due to product contamination, which can be bacterial or viral.
What are some examples of immune-mediated transfusion reactions?
Immune-mediated transfusion reactions include alloimmunization, thrombocytopenia, transfusion-associated lung injury, graft vs host disease, acute or delayed hemolysis, ABO incompatibility, and Rhesus incompatibility.
What are some examples of non-immune mediated transfusion reactions?
Non-immune mediated transfusion reactions include hypocalcemia, congestive heart failure (CCF), infections, and hyperkalemia.
What are the characteristics of an oropharyngeal airway?
Oropharyngeal airways are easy to insert and use, do not require paralysis, are ideal for very short procedures, and are often used as a bridge to a more definitive airway.
What are the characteristics of a tracheostomy?
A tracheostomy reduces the work of breathing and dead space. It may be useful in slow weaning. Percutaneous tracheostomy is widely used in the intensive care unit (ITU). Tracheostomy tends to dry secretions, so humidified air is usually required.
What are the characteristics of a laryngeal mask?
Laryngeal masks are widely used, very easy to insert, sit in the pharynx and align to cover the airway, but provide poor control against reflux of gastric contents. Paralysis is not usually required. They are commonly used for a wide range of anaesthetic uses, especially in day surgery, but are not suitable for high-pressure ventilation.
What is the main advantage of an oropharyngeal airway?
The main advantage of an oropharyngeal airway is that it is easy to insert and use.
What are the characteristics of an endotracheal tube?
An endotracheal tube provides optimal control of the airway once the cuff is inflated. It can be used for long or short-term ventilation. Errors in insertion can result in esophageal intubation, so end-tidal CO measurement is usually performed. Paralysis is often required, and higher ventilation pressures can be used.
What is a disadvantage of a laryngeal mask?
A disadvantage of a laryngeal mask is that it provides poor control against reflux of gastric contents.
When is a tracheostomy commonly used?
A tracheostomy is commonly used in the intensive care unit (ITU) and may be useful in slow weaning.
What is an important consideration when using an endotracheal tube?
When using an endotracheal tube, it is important to measure end-tidal CO to detect any potential esophageal intubation.
Why is paralysis often required with an endotracheal tube?
Paralysis is often required with an endotracheal tube to provide optimal control of the airway.
What is a limitation of a laryngeal mask?
A limitation of a laryngeal mask is that it is not suitable for high-pressure ventilation, although a small amount of PEEP (positive end-expiratory pressure) may be possible.
What is the definition of sepsis?
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection.
What is the purpose of the Sequential (Sepsis-Related) Organ Failure Assessment Score (SOFA)?
The SOFA score helps identify and categorize patients with sepsis by grading abnormality by organ system and accounting for clinical interventions.
What are the criteria used in the SOFA score?
The SOFA score includes criteria such as PaO2/FIO2 ratio, platelet count, bilirubin level, mean arterial pressure (MAP), Glasgow Coma Scale (GCS), creatinine level, and urine output.
What does a SOFA score of 2 or more indicate?
A SOFA score of 2 or more reflects an overall mortality risk of approximately 10% in a general hospital population with suspected infection.
What is the purpose of the qSOFA score?
The qSOFA score is a bedside prompt that helps identify patients with suspected infection who are at greater risk for a poor outcome outside the intensive care unit (ICU).
What are the criteria used in the qSOFA score?
The qSOFA score includes criteria such as respiratory rate (>22 breaths per minute), altered mentation (Glasgow Coma Scale <15), and systolic blood pressure (<100 mmHg).
How can septic shock be identified?
Septic shock can be identified by a clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) of 65 mmHg and having a serum lactate level >2 mmol/L (18mg/dL) despite adequate volume resuscitation.
What are the resuscitation goals for patients with septic shock?
The resuscitation goals for patients with septic shock include a central venous pressure (CVP) of 8-12 mmHg, a MAP >65 mmHg, urine output >0.5 ml/kg per hour, and a superior vena cava oxygen saturation >70%.
What is considered a normal lactate level?
A normal lactate level is considered to be within the normal range. 0.5 to 2.2 mmol/L.
What is the parameter and corresponding scores for PaO2/FIO2 ratio?
PaO2/FIO2 ratio: >400 (score 0), <400 (score 1), <300 (score 2), <200 (score 3), <100 (score 4).
What is the parameter and corresponding scores for platelet count?
Platelets x10 microliters: >150 (score 0), <150 (score 1), <100 (score 2), <50 (score 3), <20 (score 4).
What is the parameter and corresponding scores for bilirubin level?
Bilirubin micro Mol/L: 20 (score 0), 20-32 (score 1), 33-101 (score 2), 102-204 (score 3), >204 (score 4).
What is the parameter and corresponding scores for cardiovascular (MAP)?
Cardiovascular (MAP): >70 mmHg (score 0), MAP 70 mmHg (score 1), Dopamine <5 or dobutamine (any dose) (score 2), Dopamine 5.1-15 or epinephrine 0.1 or norepinephrine 0.1 (score 3), Dopamine >15 or epinephrine >0.1 or norepinephrine >0.1 (score 4).
What is the parameter and corresponding scores for Glasgow Coma Scale (GCS)?
GCS: 15 (score 0), 13-14 (score 1), 10-12 (score 2), 6-9 (score 3), <6 (score 4).
What is the parameter and corresponding scores for creatinine level?
Creatinine micro mol/L: <110 (score 0), 110-170 (score 1), 171-299 (score 2), 300-440 (score 3), >440 (score 4).
What is the parameter and corresponding scores for urine output?
Urine output ml/day: >500 (score 0), >500 (score 1), >500 (score 2), <500 (score 3), <200 (score 4).
What is the mechanism of action of Suxamethonium?
It inhibits the action of acetylcholine at the neuromuscular junction.
How is Suxamethonium degraded in the body?
It is degraded by plasma cholinesterase and acetylcholinesterase.
How does Suxamethonium compare to other muscle relaxants in terms of onset and duration of action?
It has the fastest onset and shortest duration of action among all muscle relaxants.
What is the effect of Suxamethonium prior to paralysis?
It produces generalized muscular contraction.
