Post-operative complications

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Contents

Introduction

The management of post-operative complications can be approached in a number of ways. Perhaps the most practical way is to consider the frequency in which various complications may occur (Common and important post-operative problems). Another strategy is to consider the problems that relate directly to the procedure and those that are more general and patient-related (Categorisation of potential post-operative complications).

This chapter will take the former approach, but obviously it is sensible that in managing any patient with a post-operative problem, the doctor considers:

  • the procedure
  • the general state of health of the patient before the illness/operation
  • progress since the procedure.

Thus, the questions to be asked should include:

  • what procedure was done, when was it done and why was it done
  • is there any coexisting illness (i.e. is there a past medical history of note [e.g. chronic respiratory disease])
  • is the patient on any medication
  • what has now happened to the patient to demand your attention
  • what investigations have been done (both pre- and post-procedure)?

These will then be followed by:

  • is the cause of the problem clear-cut
  • if yes, how should I proceed with management
  • if no, what will I need to do to make a clear diagnosis?

This chapter contains a number of examples of postoperative complications. A model answer is provided for each scenario. As a learning exercise, cover each model answer (in italics) and provide your own answer. Put yourself in the position of the intern.

Confusion

A 67-year-old man becomes confused 2 days after a laparotomy for a perforated peptic ulcer. The operation was uneventful and 2 litres of gastric contents were evacuated from the peritoneal cavity. Lavage was performed and the perforation closed. What critical piece of information would help you determine the cause of the confusion? How would you approach the problem?

Hypoxia is the most important and common cause of confusion. If this patient has a chest infection, you may have the quick explanation for his confusion.

To approach the problem, gain all the information you can about the patient's pre-operative state of health, the details of the procedure and progress since the operation. From the case notes you will hopefully glean information on the patient's past medical history, medications, examination findings and general fitness. From the past history, look for evidence of chronic respiratory disease and sustained alcohol consumption. Various investigations may have been undertaken (e.g. blood biochemistry) that may give clues as to the current problem. Any problems associated with the operation (the procedure itself or the anaesthetic) should be noted. The case records and the nursing observations since the procedure may help determine the cause of the current problem. Note any investigations that have been performed since the procedure.

Take a history from the patient, if his state of confusion allows. Examine the patient, looking particularly for evidence of hypoxia. A chest infection may explain the confusion. There may be other causes of hypoxia to consider (e.g. opiate toxicity, cardiac failure). If the patient is not obviously hypoxic, he may be septic, have a fluid and electrolyte disturbance, be suffering a drug complication or be in alcohol withdrawal.

To test some of these hypotheses, several investigations may be required. These may include arterial blood gas analysis, serum biochemistry, blood culture, an electrocardiogram (ECG) and a chest X-ray.

Before you start the investigations, some simple measures can be adopted. Ensure that the patient is given supplemental oxygen through a face mask and that intravenous fluids are being given. If sepsis is likely, you may want to start the patient on a broad-spectrum antibiotic. Ideally, you would like pulse oximetry performed and may even want to consider further management on a high-dependency unit.

You have excluded hypoxia as a cause for the confusion and the patient does not appear to be septic. There is no apparent electrolyte disturbance and you are reasonably confident that the patient is suffering alcohol withdrawal symptoms (delerium tremens). Describe your plan of management.

Move the patient to a quiet, well-lit room. Arrange continuous nursing care, preferably with a nurse familiar to the patient. Institute an alcohol withdrawal program. The protocol for this program will stipulate regular observations of the patient's symptoms, allocating a score to various symptom grouping and correlating the amount of sedation (if any) that needs to be given according to the score. Symptoms to be scored include nausea, anxiety, visual disturbances and agitation. The preferred sedative is oral diazepam.

Pulmonary embolism

Five days after a bilateral salpingo-oophorectomy and total abdominal hysterectomy, your 62-year-old patient complains of breathlessness and right-sided chest pain. You suspect she might have suffered a pulmonary embolism. Describe your initial plan of management.

If she has had a major pulmonary embolism, the patient may have circulatory collapse and require resuscitation. Your priority will be an assessment of her cardiovascular system. Provided the patient is stable, you can proceed with your investigations. These will include an ECG, arterial blood gas analysis, a chest X-ray and either a CT pulmonary angiogram (CTPA) or a ventilation-perfusion (V/Q) isotope scan performed The CTPA will allow accurate definition of the major pulmonary vasculature and can detect filling defects and obstruction. The scans are undertaken after rapid bolus administration of 100–140mLof non-ionic contrast. This technique can be used to detect 3–4-mm clots in the second-, third- and fourth-order branches of the pulmonary vasculature. The V/Q scan (looking for mismatch defects) is better in the definition of peripheral lung lesions.

Once the diagnosis of pulmonary embolism has been confirmed, the patient should be given intravenous heparin.

Clinical examination of a patient with suspected deep venous thrombosis (DVT) or pulmonary embolism is relatively inaccurate and should not be relied on to determine diagnosis or treatment.

Fever

Six days after an open appendicectomy and removal of a perforated appendix, your 45-year-old patient develops a fever. He has a temperature of 38.5.C and a tachycardia of 100 beats per minute. Describe your actions at the bedside.

The temperature is almost certainly the result of sepsis, and the timing of the fever in relation to the date of the procedure suggests that the infection probably originates at the site of the operation (rather than the chest).

First, make an overall assessment of the general state of health of the patient. Is he relatively well, or is he about to slip into septic shock? Establish the progress since the operation. Inquire if there is anything that may predispose the patient to infection; for example, he might be a diabetic. Look at the nursing observation chart and observe the pattern of the fever and pulse rate. This may give a clue as to the likely cause. A spiking fever over several days could be due to an intra-abdominal abscess.

Although a chest infection may not be the cause of the fever, the chest must be examined carefully. After that, the abdomen should be inspected and the wound examined. Cannula and drain sites should also be examined for evidence of infection. Occasionally, a DVT will be accompanied by a low-grade fever, and the legs should be examined.

The patient has only recently spiked the fever and prior to this had been making an uneventful recovery from his operation. He was otherwise in good health before developing appendicitis. The only abnormal finding is a 2-cm tender and red swelling in the middle of the wound, with a narrow margin of surrounding erythema. What would you do?

This problem may be solved relatively easily by an incision into the abscess. It is possible to do this at the bedside. Explain to the patient the problem and what you propose to do. Provided the incision is kept within the previous incision, it should be relatively pain-free. A small nick with a scalpel could be all that is required to relieve the problem. Otherwise, the patient could be provided with some analgesia and then the abscess drained more formally under local anaesthetic. This would enable the wound to be probed and opened somewhat more than might have been achieved with a scalpel blade alone.

There is no need for investigation or antibiotics; the problem is one of localised superficial infection.

Initial assessment of a patient with suspected sepsis must include an appreciation of the type of procedure undertaken and the risk of infection from that procedure. Also to be considered are the consequences, should infection in that particular patient occur, for example, reduced resistance to infection in an immunocompromised individual. The type of procedure and the pattern of fever will give important clues as to the site of sepsis and the causative organism. Investigations to be considered include those to:

  • identify the site of infection
  • diagnose the type of infection.

Oliguria

You have received a telephone call from the nurse who is looking after your 68-year-old patient. He informs you that the patient has only voided 50 mL of urine in the 6 hours since he returned from the operating suite after a sigmoid colectomy for perforated diverticular disease. The nurse wants to give a bolus of frusemide to increase the urine output. What do you do?

While it is possible that this man's problem may be fluid retention and pump failure, it is more likely that he has received inadequate fluid replacement, either during or immediately after the operation and you are dealing with an under-filled patient.

There are many causes of oliguria in the postoperative period and a diuretic may be the worse way of managing the patient if appropriate assessment has not been made. You must go and see the patient. Given the scenario, this patient may have lost a considerable amount of fluid as a result of the peritonitis and may still be losing fluid into the peritoneal cavity. Remember that not all fluid lost by a patient may be readily evident. Patients with paralytic ileus and/or peritonitis can accumulate many litres of fluid within the peritoneal cavity - so-called ‘third space’ loses.

At the bedside you will look at the charts, note the details of the surgical procedure, calculate how much fluid was lost during the operation and how much was given. The amount of fluid given since the time of the operation should be noted. Any discharge from drains or a nasogastric tube should be measured.

The pre-operative state of health must be noted. A history of cardiac disease and heart failure will alert you to the possibility of pump failure.

In most instances it will be relatively safe to manage the problem at the bedside. Run in 500 mL of isotonic saline rapidly and observe the effect on urine output over the next few hours. Further boluses of fluid may be required and a diuretic should only be given once you are confident that the patient has had adequate fluid replacement. In more complex cases, the resources of an intensive care unit may be required to help determine the nature of the underlying problem.

In summary, the oliguria may be due to:

  • inadequate filling
  • inadequate output (pump failure)
  • renal tract obstruction.

In other words, all the alternative explanations for oliguria must be considered; the problem may be something as simple as a blocked urinary catheter.

Wound discharge

Five days after undergoing a laparotomy for ischaemic small bowel (and bowel resection), your 73-year-old patient develops a pinkish discharge from the wound. What action do you take and why?

While there are a number of causes of discharge, the most urgent to consider is the possibility that this discharge is the harbinger of disruption of the deep layers of the wound, with the consequent risk of complete wound failure. Alert the nursing staff to provide some sterile dressings to cover the wound, should it suddenly burst.

Look to see if the patient has any risk factors for wound failure. What was his pre-operative nutritional status and have his serum proteins been measured? Find out what has happened to the patient since the operation. Has there been any process that could have led to an untoward increase in intra-abdominal pressure, such as a chest infection or paralytic ileus.

Explain to the patient what you fear and that he may need to be taken back to the operating theatre (for the wound to be resutured). The wound must be inspected. A non-inflamed wound with seepage of pink fluid is highly suggestive of acute failure of the wound. Extensive bruising around the wound might suggest discharge of a seroma, while a red, angry wound might make you think of infection.

If there is any doubt as to the nature of the problem, the wound should be gently probed (with sterile instruments). If you see the intestine, go no further. Be prepared to cover a dehisced wound with a sterile drape and call for help.

If the patient has suffered a deep wound dehiscence, why might it have happened?

The reasons for acute wound failure may be classified as follows:

  • local factors: poor suturing techniques; poor tissue healing (infection, necrosis, malignancy, foreign bodies); increased intra-abdominal pressure
  • general factors: malnutrition, diabetes mellitus. In most instances, acute wound failure is due to a local factor.

Bleeding

You have been asked to review a 27-year-old man who has recently undergone a splenectomy for trauma. The nursing staff report fresh blood in the drain. How would you approach this problem?

You need further information. The bleeding may be localised or generalised. It may be reactionary, primary or secondary. How long ago was the operation and how much blood is in the drain? A small amount of fresh blood a few hours after the operation may be of little consequence. Is the bleeding confined to the drain or is there evidence of bleeding at other sites (wound, intravenous cannula)? If the former, the problem may be haemorrhage from the operative site, and if the latter, the patient may have a disorder of coagulation.

Your initial assessment must include a review of the charts. In what circumstances was the operation performed? If the patient had a massive and rapid transfusion to maintain his circulatory state, then the problem may be one of a coagulation defect. What has happened since the operation? A rising pulse and falling blood pressure would suggest that the patient is still bleeding, and what is seen in the drain may only be the tip of the iceberg. In other words, there could be a considerable volume of blood collecting at the operative site, with only a little escaping into the drain. Remember that when a drain drains, positive information may be gleaned; however, an empty drain means little.

Examine the patient and look for evidence of circulatory insufficiency. The material in the drain tube and drainage bag may be fresh and not clotted, or it may be serosanguinous. A normotensive patient with old clot in the drain is probably a stable patient.

It is more important to pay attention to the general state of the patient, rather than the contents of the drainage bag.

In summary, your clinical assessment of this case should include:

  • the severity of the bleed
  • the site of the bleed
  • the cause of the bleed
  • the need for further action (e.g. coagulation studies, cross-matching blood, contacting senior staff).

Shock

You are on your way to the ward to review a 66-yearold man who collapsed 3 hours after a transurethral prostatectomy. He is hypotensive and confused. What are your thoughts?

Your priority will be on resuscitation. However, to do this effectively you must have a clear idea of the probable cause of his collapse. The important causes of shock to consider in these circumstances are:

  • pump failure (cardiogenic)
  • haemorrhage (hypovolaemia)
  • sepsis (septicaemia)
  • anaphylaxis (drug reaction).

What will you do at the patient's bedside?

Make a rapid assessment of the state of the patient. How profound is the hypotension? If he is connected to a monitor, see if you can determine any changes in the ECG that would suggest an acute myocardial problem.

Ensure that the patient has an oxygen mask in place and run oxygen at 6 L/min. Attach a pulse oximeter. On the assumption that the cause of the problem is not cardiac failure, run in 500 mL of isotonic saline rapidly. While this is happening, take blood samples for assay of cardiac enzymes (creatine kinase), myocardial breakdown proteins (troponin), haematological and biochemical screen, blood cross-match and culture. Arterial blood gas analysis should be considered.

Once these things have been done, stand back and review the situation. Look at the charts. Is there a history of ischaemic heart disease or other cardiac problems? Did the patient come in with urinary retention and could he have infected urine. How major was the procedure that was performed and how much fluid was used during the procedure, both intravenous administration and as irrigation? What is in the urine drainage bag? A large volume of fresh blood would suggest hypovolaemia as the cause of the collapse. Were there any complications during the procedure?Howhas been the patient's progress since the operation? It is important to know if this has been a sudden collapse or a steady deterioration since the procedure.

There is nothing of significance from the past medical history and the operation was uneventful and associated with minimal blood loss. The fluid in the bladder irrigation system is tinged with blood and there are no blood clots. The patient's vital signs were within normal limits until about 15 minutes before you were alerted to the problem. The ECG monitor does not show any acute changes. How are you going to further the management of this case?

The cause of the problem appears not to be hypovolaemia. It is either septicaemia or a cardiac event. A normal ECG does not exclude an acute myocardial problem and you must await the enzyme assays and troponin levels.

Work on the assumption that the patient is in septic shock. In addition to the oxygen by face mask and fluid loading, antibiotics should be given. The choice of antibiotics will depend on the likely organisms. Gramnegative aerobes are an important and common cause of urinary infection, and working on the assumption that the presumed sepsis has originated from the urinary tract, concentrate on these organisms. The trio of an aminoglycoside (gentamicin), metronidazole and amoxycillin remains perhaps the most effective antibiotic combination in the management of patients with Gram-negative septic shock.

Leg swelling

Five days after major surgery, your patient complains of pain and swelling in the right leg. Discuss your initial assessment of the problem.

Of prime concern is whether this patient has a DVT. Before you examine the patient, determine if there is a past history of venous thromboembolic disorders and establish the risk factors for DVT. See exactly what type of surgery was performed and what, if any, prophylactic measures were taken to minimise the risk of clot formation. Remembering Virchow's triad, consider the changes that may bring about DVT:

  • change in flow
  • change in the vessel wall
  • change in the constituents of the blood.

Apart from DVT, other conditions to consider include congestive cardiac failure, dependent oedema and cellulitis. Remember that clinical assessment for the presence of DVT is, at best, unreliable. A tender, swollen calf suggests that the patient may have a DVT.

The patient is 63 years old and had an unremarkable past history. In particular, he had no history of thromboembolic problems or cardiac disease. He was not overweight and had been mobile before the operation. The patient had been classified as having a low risk for DVT and immediately before the operation had been given a dose of an unfractionated heparin preparation. A calf vein compression device had been used during the procedure. He had undergone an anterior resection of the rectum for carcinoma. The procedure had been uncomplicated.

From your assessment you suspect the patient may have a DVT. What do you do next?

An ultrasonographic examination of the deep veins of the thigh and leg should confirm or refute the diagnosis. If the patient has a DVT, it will be important to document the extent of the clot and the degree of luminal occlusion. Extension of the clot into the femoral vein increases the risk of detachment and pulmonary embolism.

If clot is present and extends into the popliteal vein or beyond, heparin should be started and graded compression stockings applied. If conventional heparin is to be used, a typical regimen is a loading dose of 5000 IU followed by 1000 IU per hour. The patient will require monitoring with serial activated partial thromboplastin time (APTT) measurements. Alternatively, a lowmolecular- weight heparin can be given. This does not require APTT estimations and can therefore be used on an outpatient basis.

The patient will probably be anticoagulated with warfarin for 3–6 months.
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