A 23-year-old male patient (height: 175 cm, weight: 52 kg), American Society of Anesthesiologists II, presented to the hospital owing to acute left-sided chest pain and tightness and shortness of breath for 6 h. Chest CT performed on admission showed an 80%–90% left-sided spontaneous pneumothorax (
Preoperative chest radiograph and computed tomography scan showing an 80%–90% left-sided pneumothorax (red arrow).
On the day of the operation, the patient fasted for 8 h and did not receive any premedication. After entering the operating room, the venous channel of the right upper limb was opened, standard monitoring was established, and vital signs were within the normal range. Additionally, right radial artery catheterization was performed to monitor arterial blood pressure (ABP) and blood samples were collected. Vitals were recorded as follows: ABP 121/65 mmHg, HR 66 bpm, SpO2 98%, and BIS 98. Arterial blood samples were obtained for blood gas analysis just before the operation, 15 min after artificial pneumothorax, at the end of the operation, and 15 min after awakening; the results are shown in
Perioperative arterial blood gas analysis data.
| Pre-operation | Fifteen min after artificial pneumothorax | End of operation | Fifteen min after awakening | |
|---|---|---|---|---|
| pH | 7.42 | 7.36 | 7.33 | 7.38 |
| PaCO2 (mmHg) | 38.3 | 44.2 | 48.7 | 39.5 |
| PaO2 (mmHg) | 133.3 | 134.8 | 151.8 | 154.5 |
| BE (mEq/L) | 2.4 | 1.6 | 0.9 | 1.3 |
Oxygen supplementation was administered using a mask at 2 L/min. The loading dose of dexmedetomidine (0.5 μg/kg) was infused intravenously within 10 min, Ramsay score was 3, and BIS value was 75–80 in the quiet state after dexmedetomidine administration. After the sterile technique, the left TPVB was performed under ultrasound guidance. A low-frequency convex array probe was placed in the 6th intercostal space and rotated to locate it in the 6th paravertebral space. A 22G 80-mm short beveled needle was advanced under ultrasound guidance using an in-plane technique to the 6th paravertebral space. After frequent aspiration to avoid intravascular injection, 30 ml of 0.375% ropivacaine was injected into the paravertebral space, and a high bright arc and dark drug area were visible on ultrasonography. The vital signs were stable, no complications were observed, and the cold sensation on the operative side was lost from 3rd to 8th thoracic nerve level approximately 20 min after the operation.
Anesthesia was induced until the cold sensation in the surgical area disappeared. General anesthesia was induced using midazolam 4 mg, penehyclidine hydrochloride 0.5 mg, esketamine 30 mg, and propofol 30 mg. After 5 min, the BIS value was 50–60, oxygen supplementation was administered by mask at 5 L/min, and the patient breathed smoothly and spontaneously. Subsequently, anesthesia was maintained using propofol 4–8 mg/kg/h and esketamine 0.5 mg/kg/h. BIS was maintained at 50–60, spontaneous respiratory rate was 15–18 breaths/min, and vital signs were stable.
Surgery commenced after the patient was positioned in the right lateral recumbency, and the thoracic surgeon placed a 2 cm incision in the 4th–5th intercostal space of the left anterior axillary line. After starting the artificial pneumothorax, the collapse of the left lung was satisfactory and operative field was ensured. Arterial blood gases were within normal ranges, and vital signs were stable. The surgical procedure was uneventful, without complications, such as respiratory depression, coughing, or body movement. The surgery lasted 40 min, with a bleeding volume of 5 ml, urine volume of 300 ml, crystallite infusion of 500 ml, and colloid infusion of 500 ml. After resecting the bullae, the lungs were slowly expanded using noninvasive positive pressure ventilation with a mask for 20 s. The infusion of esketamine and propofol was discontinued 15 min before the end of surgery. The patient regained consciousness immediately at the end of surgery and flumazenil (30 mg) was injected intravenously. He was instructed to nod his head 2 min after flumazenil administration, and the vitals were recorded as follows: ABP 112/63 mmHg, HR 59 bpm, SpO2 96%, and BIS 96.
The patient was transferred to the PACU for monitoring, and the vital signs were stable. After 30 min of observation in the PACU, the patient was transferred to the ward. During the postoperative follow-up, the patient had a visual analog scale (VAS) score of 1 within 24 h after surgery, ≤2 at rest, and 3–4 during cough at 24–48 h after surgery. Postoperative chest CT showed that the left lung was inflated well, with no abnormalities. The patient was discharged from the hospital 2 days postoperatively and developed no nausea, vomiting, or any other complications.