The clinical specificities of the catabolic phase in the postoperative period

Nervous system.

• As a result of the residual action of the narcotic and sedative substances during the first few days postoperatively, the patient is most likely to be somnolent and indifferent to his/her surroundings.

• From the second day the effect of most anaesthetics begins to cease and pain reactions evolve into unstable psychotic states that can manifest as disorderly behaviour, anxiety or, alternatively, depression. These are mostly due to postoperative complications (e.g. progressive hypoxia and fluid and electrolyte disorders).

Cardiovascular system.

The common cardiologic complications are as follows:

• skin pallor;

• 20 to 30% increase in the pulse rate;

• moderate increase in blood pressure;

• muffled heart sounds.

Respiratory system.

• Fast shallow breathing with a reduction in vital capacity by 30-50%.

Shallow breathing can result from the pain at the site of operation, an elevation of the diaphragm or limitations in its movement after abdominal surgery or development of paresis of the gastrointestinal tract.

Liver and kidneys.

• Progressive dysproteinaemia;

• decrease in the synthesis of enzymes;

• decrease in urinary output as a result of a fall in renal perfusion and a rise in blood aldoster-one and antidiuretic hormone (ADH) levels.

The resolution phase

The resolution phase commonly lasts 4 to 6 days and is a gradual transition from the catabolic phase to anabolic one. This period is characterised by the reduction in the overactivity of the sympathetic nervous system and adrenals, and slowing down catabolism which becomes evident as a decrease in nitrogen urinary excretion to as low as 5-8 g/24 hours (as compared with 15-20 g/24 hours in the catabolic phase). The positive nitrogen balance (the amount of nitrogen excreted is less than the amount given) suggests improvement in protein metabolism. In this period, potassium urinary excretion decreases as the electrolyte starts accumulating to take part in the synthesis of protein and glycogen. The fluid and electrolyte balance is restoring. As far as the autonomous nervous and endocrine systems are concerned, the parasympathetic activity predominates and blood growth hormone (GH) level is rising, as are those of insulin and androgen.

During the resolution phase, the increased waste of energy and plastic materials (protein, fat, carbohydrates) is still, though at a somewhat reduced rate, under way. When this eventually fades away, the active synthesis of protein and glycogen starts with subsequent production of fat, which rises as the intensity of catabolism falls. The persistent predominance of anabolism over catabolism is a sign of the transfer of the postoperative period to the anabolic phase.

The resolution phase occurs 3 to 7 days after the surgery if the postoperative period is uneventful (i.e. without complications). The signs suggestive of the beginning of the resolution stage are generally as follows:

• absence of pain;

• normalisation of body temperature;

• resumption of appetite.

In addition, patients become active, and their body functions restore (the skin colour returns to normal; breathing becomes deep and its rate reduces; the heart rate returns to the preoperative one; peristaltic bowel sounds and flatus passage resume).

The anabolic phase

The anabolic phase is characterised by an increase in the synthesis of protein, glycogen, and fat, which have been depleted during the operation and the postoperative catabolic period. Furthermore, the parasympathetic nervous system tends to be overactive. Similarly, the secretion of anabolic hormones (GH and androgens) increases to allow for the protein synthesis. GH, for instance, is responsible for the transport of amino acids from the intercellular space to the cells, while androgens promote the synthesis of proteins in the liver, kidneys, and myocardium directly. The specific hormonal responses increase the amounts of protein in the blood, organs as well as in the wound site, which accounts for the reparative processes and proliferation and maturation of the connective tissue. During the postoperative anabolic phase the replenishment of the hepatic and muscular glycogen stores occurs, which is mediated by the counter-insulin action of GH.

Clinically, the anabolic phase is, in fact, the period of recovery, restoration of the impaired functions of the cardiac, respiratory, excretory, digestive and nervous systems. In this phase, the patient's general condition improves, appetite increases, the heart beat and rate return to normal as do the blood pressure levels, the digestive functions (food passage, intestinal absorption and spontaneous bowel movements) are restored.

The anabolic phase usually lasts 2-5 weeks, which is dependent on the extent of the surgery, the patient's state preoperatively as well as the severity and duration of the catabolic phase.

This phase of the postoperative period ends with an increase in weight, which occurs after 3-4 weeks and continues till full recovery, which sometimes can take several months. The restoration of the body weight depends on a number of factors like the extent of weight loss preoperatively (depending on the nature of the condition), the extent of the surgery, postoperative complications, the course and duration of the postoperative catabolic phase. It usually takes 3 to 6 months for the reparative process (i.e. maturation of the connective tissue and formation of the scar) to complete.

Immediately after the operation the patient is transferred either to the ward or intensive care unit which are arranged to monitor the patients and, if needed, to provide them with emergency and intensive care. These units are equipped with gadgets and appliances that constantly record the pulse rate and rhythm, ECG, EEG. The emergency laboratory ensures a prompt monitoring of blood haemoglobin, haematocrit, electrolyte and protein levels, as well as circulating blood volume and acid-base balance. The intensive care unit is also equipped with all that is necessary to provide the emergency aid: medications and transfusion fluids, a mechanical ventilation apparatus, sterile sets for venous injections or infusions and tracheostomy, defibrillator, sterile catheters, tubes, a set for change of dressing.

In the postoperative period, the patient is to be examined thoroughly using the general physical methods (inspection, palpation, percussion, auscultation) and, whenever necessary, laboratory investigations (e.g. ECG, X-ray, EEG). Each patient should be constantly monitored both for psychotic signs (consciousness, behaviour changes such as excitement, depression, delirium, hallucination) and skin condition (pallor, cyanosis, jaundice, dryness and perspiration).

Examining the cardiovascular system, the physician will pay attention to the pulse rate, character and rhythm, as well as blood pressure levels and, if pertinent, those of the central venous pressure; the character of the heart sounds and the presence or absence of murmurs.

The respiratory system is assessed by way of percussion and auscultation: the rate, depth and rhythm of breathing are taken into consideration.

The evaluation of the gastrointestinal tract involves inspection of the tongue (dryness, fur), inspection and palpation of the abdomen (distension, involvement in breathing, signs of peritoneal irritation like the symptom of defence of the abdominal wall muscles or rebound tenderness, the presence of bowel sounds), the liver is palpated for its enlargement and tenderness. The patient is to be asked of the passage of flatus and stools as well.

The examination of the urinary system includes the determination of diurnal urine volume and urine output through the permanent catheter.

The clinical and laboratory findings (haemoglobin level, haematocrit, metabolic indicators, circulating blood volume, blood electrolytes, etc.) should be meticulously scrutinised as this helps determine the type and amount of transfusion fluid as well as prescribe the appropriate drugs.

The patient should be examined on a regular basis as this enables the physician to reveal the early signs of deterioration and therefore duly adjust the current therapy.

All the clinical and laboratory findings are liable to be recorded in a special chart of observation at the intensive care unit, and also in the patient's case history.

When monitoring the patient, the physician uses specific criteria to determine the cause of the vital organs' deterioration:

1. The cardiovascular system:

• pulse rate above 120 beats per minute;

• fall (J80 mm Hg) and rise (i200 mm Hg) in systolic blood pressure;

• cardiac arrhythmia;

• reduction (< 50 mm of H₂O) and elevation (> 110 mm H₂O) in the central venous pressure.

2. The respiratory system:

• respiratory rate above 28 per minute;

• extremely dull percussion notes, all over the lung;

• the absence of breath sounds over the dull areas.

3. The skin and visible mucous membranes:

• extreme pallor;

• acrocyanosis;

• cold sticky sweat.

4. The urinary system:

• decrease in urine production (< 10 ml per hour);

• anuria.

5. The gastrointestinal tract:

• defencive rigidity of muscles of the anterior abdominal wall;

• black stools, occult blood in the stools;

• vivid rebound tenderness;

• abdominal distention;

• absence of flatus and bowel sounds for more than 3 days.

6. The central nervous system:

• loss of consciousness, delirium, hallucinations;

• excessive talking, speech and motion excitement;

• depression.

7. The state of the operation wound:

• profuse blood staining of the wound dressing;

• gapping of the wound edges;

• evisceration (eventration) of the abdominal organs into the wound;

• profuse soaking of the dressing with pus or intestinal contents.

The treatment consists in compensation of metabolic disorders, restoration of the body functions, normalisation of the redox reactions in the tissues - oxygen transfer, elimination of the products of incomplete metabolism and carbon dioxide and replenishment of the increased energy waste. Parenteral and, whenever possible, enteral nutritional support is a very important method to improve and maintain of the protein and electrolyte balance. It is advisable to give fluids and nutrients by the natural way and try to implement this as early as possible.

The following are important hints on intensive therapy of the postoperative patient:

1. Relief of pain with analgesics, electro-analgesia, peridural anaesthesia, etc.

2. Restoration of the cardiovascular functions, correction of the deficient microcirculation (cardiovascular drugs and rheopolyglucan).

3. Prevention and treatment of respiratory insufficiency (oxygen therapy, breathing gymnastics, controlled breathing).

4. Detoxication therapy (see Chapter VI).

5. Correction of the metabolic imbalance (fluid, electrolyte balance, acid-base balance, protein synthesis; see " Blood components" ).

6. Balanced parenteral nutritional support (see " Blood components" ).

7. Restoration of the urinary system functions.

8. Restoration of the body functions affected by the surgery (intestinal paresis in abdominal interventions, pulmonary hypoventilation or atelectasis in respiratory operations, etc.).

Complications may develop in the early postoperative period (before the patient has been discharged from the surgical unit).

During the first two days postoperatively the following complications can be encountered:

• bleeding (internal or external);

• acute circulatory failure (shock);

• cardiac arrest;

• asphyxia, respiratory failure;

• complications of anaesthesia;

• fluid and electrolyte disorders;

• failure of the urinary system (oliguria, anuria);

• gastric or intestinal paresis.

On the subsequent days (days 3-8) there is a high risk of congestive heart failure, pneumonia, thrombophlebitis, thromboembolism, acute liver failure and wound infection.

After the patient has been discharged from the hospital (late postoperative period) complications can arise from the organs which have been operated on (e. g. as a result of gastric resection, postcholecystectomy, abdominal adhesions). Some other complications are not infrequent: ligature fistula (stitch abscess), postoperative hernia, keloid cicatrix.

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