Case | Sudden "failure" of heart function during operation at the age of 16

A few days ago, he was responsible for a scoliosis operation.
A 16-year-old male suffered severe hypotension during the operation.
Heart function monitoring showed that the stroke volume (SV) was as low as less than 20ml, various blood transfusions, vasoconstrictors, and cardiac infusions.
No effect of the drugs was seen.
The blood pressure was as low as 70/42mmHg at one time, but esmolol has been proved to have a better response many times.
When I was unable to do anything, a word from the superior doctor reminded me that it improved quickly after correction.

Can you guess what might have happened during the operation? Brief medical history: Male, 16 years old, 174cm/51kg, diagnosed with thoracolumbar scoliosis, planned to undergo posterior T2-L2 internal fixation scoliosis correction; two previous pectus excision operations; all preoperative examinations were performed It is normal, and the CObb angle of side bend is 54 degrees.

Routine induction: Propofol TCI 4ug/ml, Sufentanil 15ug, Rocuronium 30mg, Midazolam 1.
5mg, the tracheal tube is successfully inserted through the nose, and oral gauze packing and radial artery monitoring are performed at the same time.
Turning over to prone position after 15 minutes, the patient's vital signs were stable, blood pressure maintained at about 100/65mmHg, FloTrac cardiac function monitoring showed that SV 35ml, SVV 20, and the heart rate maintained at 80-90bpm did not change much.

Considering that the patient’s monitored stroke volume SV is only 35ml, check the patient’s preoperative heart ultrasonography again: SV 32ml, EF 64%, so I can rest assured that this is his normal heart function.

The first half of the operation is calm and bleeding is not much, and hemodynamic stability can be maintained by infusion; 2 hours after the start, the patient’s heart function showed that the SV dropped to about 23ml, the lowest was 18ml, and the SVV increased by 30-40%.
, Blood pressure also slowly dropped to 80/60mmHg, heart rate rose to about 110bpm; after reporting to the second-line doctor, began to try to correct: speed up the input of colloidal fluid 300ml, red blood cell 2u, plasma 200ml, SV, SVV did not improve; analysis SV is very low, It may be related to the weakened heart function.
The use of ephedrine 6mg iv and dopamine pump injection, but still did not improve; considering that the patient's heart rate is fast and needs to strengthen the heart, I decided to use cedilan 0.
2mg, but there is still no improvement; after using dopamine The heart rate increased, and esmolol 10mg was administered together.
A strange situation appeared.
The patient's blood pressure increased, the heart rate decreased, and the SV increased significantly to 40ml, but after a few minutes, it gradually recovered to the original state.
Repeated administration is still effective.

At this time, the operation is almost over.
The third-line doctor visited the room and reported the situation.
The instructions should be related to the patient's prone position and the heart being compressed.
It may be improved after turning over! In any case, the operation was ended quickly and turned over as soon as possible; a miracle occurred, and the patient's hemodynamic indicators were significantly improved.
After 10 minutes, the patient was awakened and extubated without serious complications.

After awakening, the chest and heart color Doppler ultrasound examination showed no special abnormalities, but the ribs were soft, and obvious heart beats were visible.

Intraoperative heart compression should be related to the patient’s lack of subcutaneous fat, and the ribs’ supporting effect on the heart is too weak.
Coupled with intraoperative pressure on the back, it is equivalent to cardiac tamponade and the diastolic function is significantly limited; in this case, cardiotonics are used.
Cannot increase cardiac output, and peripheral vasoconstrictor drugs can aggravate hypotension, so it should be disabled! Esmolol reduces heart rate, increases ventricular diastolic time and volume, and can improve heart function. Cardiac tamponade in the prone position is actually not uncommon.
The principle is also very simple.
The external compression of the heart causes diastolic restriction; however, I think about the principle incorrectly.
The heart is normally protected by ribs and sternum.
How can it be so simple that there is heart compression? Normally, many people like to sleep in the prone position; at the same time, our hospital has done many similar scoliosis operations, but there are very few cases of cardiac tamponade.
Is there anything special about this patient? Place? I thought that he had undergone pectus excavatum twice! Searching for "Pectus excavatum" in UpToDate found that there is a special cave.
The following briefly introduces related content: Pectus excavatum accounts for 90% of anterior chest wall deformities.
It is usually a sporadic disease, but may be related to connective tissue disease, neuromuscular disease and certain genetic diseases.
Related; among them, connective tissue diseases (especially Marfan syndrome, Ehlers-Danlos syndrome and osteogenesis imperfecta) and neuromuscular diseases (such as spinal muscular atrophy).

The prevalence of pectus excavatum in people with connective tissue disease is higher, which suggests that pectus excavatum may be caused by cartilage dysplasia; this deformity is caused by the abnormal cartilage remodeling caused by the imbalance between cartilage growth promoting genes and growth inhibitory genes.

Generally speaking, the pulmonary function test of patients with pectus excavatum shows that lung volume indicators such as forced vital capacity (FVC) are generally normal.

The electrocardiogram may show a rightward deviation of the electrocardiogram axis and ST-segment depression, which reflects the torsion and compression of the heart; some patients have conduction abnormalities, such as bundle branch block; the echocardiogram of patients with severe pectus excavatum may show slight right ventricular outflow Tract obstruction and reduced right ventricular systolic function.

The above cardiopulmonary function can be improved after the pectus excavatum is corrected.

This patient was highly suspected of Marfan syndrome based on his physical signs, but no obvious aortic and ocular lesions were found, and he was not diagnosed.

After pressing the anterior ribs of the heart, it was found that the rebound was excellent, and the dysplasia of the cartilage could not play a good role in supporting the heart.
During the operation, he was in a prone position.
At the same time, the operation of the back compressed the diastolic restriction of the heart, and finally the cardiac output decreased significantly.

Therefore, for patients with suspected Marfan syndrome or pectus excavatum, you should be aware of the cardiopulmonary function before surgery.
At the same time, the heart may be compressed in the prone position during the operation.
When placing the position, you should focus on the location of the surgical operation and avoid the heart as much as possible.
Directly under pressure.

A little thought, I hope you will gain.

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