Anatomy
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Thorax
A 21 year old patient presents to ED complaining of a progressive weakness in his right arm on abduction, particularly while lifting and pushing. He has recently been discharged from hospital following emergency thoracotomy and admission for penetrating chest trauma. Which of the following nerves is most likely injured:
Answer:
Serratus anterior along with pectoralis minor, draws the scapula forwards and is the chief muscle concerned with all reaching and pushing movements. The long thoracic nerve (C5,6,7) innervates the serratus anterior segmentally. It lies behind the mid-axillary line on the surface of the muscle, deep to the fascia and segmentally innervates the serratus anterior. Damage to the long thoracic nerve results in serratus anterior weakness, which gives the scapula a peculiar winged appearance. The patient is unable to raise the arm fully or to carry out pushing movements, and attempts to do so are followed by further projection of the lower end of the scapula.Resuscitative Thoracotomy
Anatomy / Thorax / Thoracic Wall
Last Updated: 3rd July 2020
The patient should be positioned in the supine position if not already so.
Time should not be wasted on full asepsis but a rapid application of skin preparation is appropriate.
Using a scalpel and blunt forceps, bilateral 4 cm thoracostomies should be made in the 5th intercostal space in the mid-axillary line, breaching the intercostal muscles and parietal pleura.
The thoracostomies should be connected with a deep skin incision following the 5th intercostal space.
Two fingers should be inserted into a thoracostomy to hold the lung out of the way while cutting through all layers of the intercostal muscles and pleura towards the sternum using heavy scissors. This should be performed on the left and right sides leaving only a sternal bridge between the two anterolateral thoracotomies.
The sternum or xiphoid should be divided using the heavy scissors. If unable to cut through bone with scissors, a Gigli saw (serrated wire) may be used.
The “clam shell” should be opened using one or two large self retaining retractors/rib spreaders from the full thoracotomy set. If this is not available, the incision can be held open manually by one or two gloved assistants. The retractor should be opened to its full extent to provide adequate exposure of the chest cavity with access to all areas. If exposure is inadequate the incisions need to be extended posteriorly.
Once the chest is opened steps include:
- Damage control maneuvers are used to manage hemorrhage that will impede performance of pericardiotomy or aortic cross-clamping
- The pericardial sac is opened, and temporising measures are used to control any cardiac injuries, if present. Air embolism is managed if identified
- The aorta is cross-clamped to allow filling of the heart and facilitate ongoing fluid resuscitation.
- Open cardiac massage is initiated once the heart has filled sufficiently
- The thoracic structures are systematically explored, looking for any additional bleeding or hematoma formation that might suggest underlying injury
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- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
