Postoperative Complications
CASE 99: SuDDen ShortneSS oF breath
history
As the doctor on call, you are asked to see a 66-year-old woman on the orthopaedic ward who has become acutely short of breath. She is 7 days post hemiarthroplasty for a fractured femur and her recovery has been slow. When you arrive, the patient has an oxygen mask on and is feeling more comfortable. She is still complaining of pain on deep inspiration and finds it difficult to talk in full sentences. She has no known cardiovascular disease but is overweight. She is an ex-smoker.
examination
The patient is tachypnoeic with a respiratory rate of 35/min and oxygen saturations of 92 per cent on 35 per cent oxygen. She is afebrile and has a blood pressure of 100/80 mmHg and a pulse rate of 120/min. There is good air entry throughout on both sides of the chest. Abdominal examination is unremarkable.
INVESTIGATIONS
|
|
|
Normal |
haemoglobin |
|
13.0 g/dl |
11.5–16.0 g/dl |
mean cell volume |
|
84 fl |
76–96 fl |
WCC |
|
11.2 × 109/l |
4.0–11.0 × 109/l |
platelets |
|
235 × 109/l |
150–400 × 109/l |
Sodium |
|
135 mmol/l |
135–145 mmol/l |
potassium |
|
4.0 mmol/l |
3.5–5.0 mmol/l |
urea |
|
6.0 mmol/l |
2.5–6.7 mmol/l |
Creatinine |
|
55 μmol/l |
44–80 μmol/l |
ph |
|
7.38 |
7.36–7.44 |
partial pressure of Co2 |
(pCo2) |
3.8 kpa |
4.7–5.9 kpa |
partial pressure of o2 (po2) |
6.6 kpa |
11–13 kpa |
|
base excess |
|
–1.1 |
+/−2 |
lactate |
|
1.0 |
<2 mmol/l |
Figure 99.1 shows an electrocardiogram (eCg).
I |
aVR |
v1 |
v4 |
II |
aVL |
v2 |
v5 |
III |
aVF |
v3 |
v6 |
II |
|
|
|
Figure 99.1 electrocardiogram.
Questions
• |
What is the likely diagnosis? |
|
• |
What are the risk factors? |
|
• |
How would you treat the patient? |
|
• |
Which investigations would confirm your diagnosis? |
225 |
100 Cases in Surgery
ANSWER 99
The patient has had a pulmonary embolism (PE). The sudden shortness of breath, pleuritic chest pain, recent lower-limb surgery and drop in po2 support this diagnosis. The ECG shows an S1 Q3 T3 anomaly, which is consistent with right heart strain caused by a large obstructing embolus. These ECG changes are not always seen, the commonest findings being either a normal ECG or a sinus tachycardia.
!Risk factors for pulmonary embolism
•Surgery and trauma
•hypercoagulable states
•pregnancy
•oral contraceptives and oestrogen replacement
•malignancy
•Stroke
•indwelling venous catheters
•previous history/family history of venous thromboembolism
•Congestive heart failure
•obesity
The risk of pulmonary embolism increases with prolonged bed rest or immobilization. Pulmonary emboli usually arise from thrombi originating in the deep venous system of the lower extremities, but may originate in the pelvic, renal, or upper extremity veins and the right heart chambers. The patient should be placed on high-flow oxygen and arterial blood gases should be taken. A chest x-ray is required to exclude other pathology. If clinical suspicion is high, the patient should be anticoagulated with low-molecular-weight heparin until the diagnosis. . is confirmed with either a computerized tomography (CT) pulmonary angiogram or a V/Q(ventilation–perfusion) scan. A duplex scan of the lower limbs may confirm a deep vein thrombosis, which would account for the origin of the embolus. The patient should then be started on long-term warfarin provided there are no contraindications.
KEY POINTS
•all surgical patients require prophylactic heparin to prevent deep vein thrombosis.
•if a pe is suspected, anticoagulation should be started prior to confirmation of the diagnosis.
226
Postoperative Complications
CASE 100: poStoperative SepSiS
history
You are asked to review a 67-year-old man on the orthopaedic ward who underwent a total knee replacement 4 days ago. The nursing staff report that he has developed a temperature over the past 24 h. He was making a good postoperative recovery and had his urinary catheter removed 48 h ago. He reports no chest symptoms. He is eating and drinking and has opened his bowels normally. He passed urine 2 h ago. His past medical history includes hypertension and depression. He takes ramipril 5 mg od, simvastatin 40 mg and sertraline 50 mg od. Up until 3 years ago he smoked 20 cigarettes a day. He does not drink alcohol. He is married and is a retired accountant.
examination
He has a temperature of 37.8°C with a pulse rate of 92/min and a blood pressure of 114/82 mmHg. The oxygen saturations are 96 per cent on room air. He is comfortable in bed but looks flushed. He is orientated in time, place and person. His cardiorespiratory and abdominal examinations are unremarkable. He has no calf swelling or tenderness. The wound looks dry and the knee has a typical postoperative appearance.
INVESTIGATIONS
|
|
Normal |
haemoglobin |
11.8 g/dl |
11.5–16.0 g/dl |
mean cell volume |
86 fl |
76–96 fl |
WCC |
15.6 × 109/l |
4.0–11.0 × 109/l |
platelets |
289 × 109/l |
150–400 × 109/l |
erythrocyte sedimentation rate (eSr) |
34 mm/h |
10–20 mm/h |
Sodium |
135 mmol/l |
135–145 mmol/l |
potassium |
3.9 mmol/l |
3.5–5.0 mmol/l |
urea |
5.1 mmol/l |
2.5–6.7 mmol/l |
Creatinine |
78 μmol/l |
44–80 μmol/l |
C-reactive protein (Crp) |
88 mg/l |
<5 mg/l |
D-dimer: positive |
|
|
Urinalysis |
|
|
WCC: +++ |
|
|
protein: ++ |
|
|
nitrite: positive |
|
|
blood: + |
|
|
eCg: normal |
|
|
Questions
•What tests form the basis of a ‘septic screen’?
•What is the likely diagnosis?
•How should he be managed?
227
100 Cases in Surgery
ANSWER 100
It is very common to be called to see a postoperative patient with a raised temperature. In the first 24 h after the operation, a temperature rise may occur as a result of the release of inflammatory mediators from traumatized tissues. Temperatures occurring after 24 h are commonly due to pneumonia, urinary tract infection, wound infection, deep vein thrombosis, pulmonary embolism, bowel obstruction or ileus. With this in mind, after completing a full history and examination, a ‘septic screen’ should be performed.
!Septic screen
•urine dipstick and urine sent for microscopy, culture and sensitivity
•blood cultures
•Sputum cultures
•Wound swab – if appropriate
•Chest x-ray
Other useful tests that should also be performed are:
•Full blood count/urea and electrolytes/C-reactive protein
•ECG: useful to identify cardiac complications of sepsis (i.e. atrial fibrillation)
•Arterial blood gases: if septic or hypoxic
In this case, the patient has developed a urinary tract infection; the clues in the scenario are the history of previous catheterization and the urine dipstick positive for both nitrites and leucocytes. The D-dimer test should be interpreted with caution as it invariably goes up after surgery. Similarly, because of their lack of specificity, CRP and ESR are of limited value. Empirical antibiotic treatment should be commenced after the urine is sent for culture and sensitivity. The presence of a bacteraemia could lead to a potentially devastating infection of the knee prosthesis, so in this patient there is an argument for giving the initial doses of antibiotics intravenously to ensure that high tissue levels are reached quickly.
KEY POINT
• a septic screen should be done to investigate the cause of a postoperative pyrexia.
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