Facilitation of alternative one-lung and two-lung ventilation by use of an endotracheal tube exchanger for pediatric empyema during video-assisted thoracoscopy
- First Online:
- Cite this article as:
- Ho, A.C.Y., Chung, H., Lu, P. et al. Surg Endosc (2004) 18: 1752. doi:10.1007/s00464-003-9128-3
- 73 Views
Video-assisted thoracoscopic surgery (VATS) has emerged as an innovative and popular procedure for the management of postpneumonic empyema in children refractory to medical response. Alternative uses of two- and one-lung ventilations have been required during VATS. This study evaluated the efficacy of alternating one- and two-lung ventilation through intraoperatively through the same single-lumen endobronchial tube using a tube exchanger during a thoracoscopic procedure for pediatric empyema.
Between May 1995 and August 2001, 62 consecutive pediatric patients undergoing VATS for evacuation of the loculated empyema cavity were studied. The same single-lumen endobronchial tube was used, with an indwelling endotracheal tube exchanger in place for readjustment of the tube position to provide alternation of one- and two-lung ventilations in a thoracosopic procedure. Duration of operation, heart rate, mean arterial pressure, peak airway pressure, an partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2) changes during one- and two-lung ventilations were recorded. The quality of lung deflation and inflation was rated by the surgeon using direct visualization as excellent, fair or poor.
The mean operating time was 90 min (range, 50–120 min). No differences were found in heart rate, mean arterial pressure, or PaO2 during one- and two-lung ventilations. Peak airway pressure and PaCO2 during two-lung ventilation were significantly higher than during one-lung ventilation. The quality of lung deflation and inflation was judged excellent for all the patients.
The VATS procedure can be performed safely and effectively in children using proper anesthetic technique. Retention of a tube exchanger within a single-lumen endobronchial tube an easily provide alternative one- and two-lung ventilations without inducing any significant airway flow obstruction during the operation.
KeywordsPediatric empyemaVideo-assisted thoracoscopyVATSIntubation deviceSingle-lumen endobronchial tubeTube exchanger
For a significant number of children, thoracic empyema results in morbidity, mortality, and consumption of hospital resources if it is not recognized or treated appropriately. Surgical treatment of postpneumonic empyema is essential for children with an unsatisfactory medical response. Video-assisted thoracoscopic surgery (VATS) has emerged as an innovative and popular procedure for the evacuation and drainage of postpneumonic empyema in pediatric patients [9, 17]. Alternative uses of two- and one-lung ventilations are needed during this surgery. Several methods are used to achieve this.
For adults, one-lung ventilation is achieved most commonly with a double-lumen tube [1, 2] or a Univent tube [7, 8]. These tubes offer easy and reliable switching from two-lung ventilation to one-lung ventilation and vice versa. However, because double-lumen tubes and Univent tabes for small children are unavailable, a bronchial blocker and single-lumen endobronchial tube are used currently for lung separation in the pediatric population. Cuffed endobronchial tubes were inserted and inflated for most children to allow selective ventilation of the unaffected lung, and to prevent the transbronchial spread of purulent secretions into the trachea and the dependent lung . However, for smaller children, an uncuffed endobronchial tube of the largest size accordingly to the patient’s age was selected to achieve one-lung ventilation and minimize transbronchial contamination.
Although a single-lumen tube for endobronchial intubation enables one-lung ventilation, the anesthesiologist faces a challenge when alternate uses of bilateral lung ventilation and one-lung ventilation are required during surgery. This study was designed to evaluate the efficacy of intraoperative alternation of one- and two-lung ventilations, through the same single-lumen endobronchial tube using an indwelling endotracheal tube exchanger during a thoracoscopic procedure for pediatric empyema and pleura decortication.
Materials and methods
After ethics approval and informed consent, 62 children (36 boys and 26 girls) with post pneumonic empyema undergoing VATS adhesiolysis, pleura debridement, and irrigation between May 1995 and August 2001 were studied. These patients ranged in age from 2 months to 15 years (mean age, 5 years). Empyema was considered for all the parapneumonic effusion patients, mainly through chest radiography and chest computed tomography. Empyema was diagnosed for cases in which a positive Gram stain or frank pus was aspirated from the pleural cavity. All the patients in these cases received antibiotics and closed chest tube drainage as their primary therapy after their initial diagnostic thoracocentesis. All the children referred for surgery had unsatisfactory medical responses, with persistent bronchopleural fistula, unremitting fever, tachypnea, chest pain, sepsis, localized empyema, and persistent lung collapse despite chest tube drainage.
All the patients were taken to the operation room without premedication. Noninvasive arterial blood pressure, electrocardiography, pulse oximeter, capnography, and body temperature were routinely monitored. After preoxygenation, anesthesia was induced with intravenous administration of fentanyl (5 μg/kg), and midazolam (0.1 mg/kg). Vecuronium bromide (0.1 mg/kg) was administered to facilitate endotracheal intubation. The vocal cords were exposed by direct laryngoscopy, and orotracheal intubation was performed with an endotracheal tube sized according to the age of the child. The tube then was pushed blindly into the right or left main bronchus of the healthy lung. If thoracoscopic examination of right empyema was performed, it required total collapse of the right affected lung. Orotracheal intubation of the left main bronchus was performed for one-lung ventilation. The position of the tube was checked clinically by auscultation of the chest on both sides. A flexible bronchocopy is needed to ensure a good position for the tip of the tube. A total of 38 patients underwent right thoracoscopy, and 24 patients had the procedure performed on the left side. Anesthesia was maintained with fentanyl (5 μg/kg/h), isoflurane (0.5–1.5%) in oxygen, and vecuronium (0.1 mg/kg/h).
A radial arterial line was inserted for continuous blood pressure monitoring and arterial blood gas analysis. Volume-controlled ventilation was performed with the fraction of inspired oxygen (FIO2) at 1, an inspiratory-to-expiratory ratio of 1:2, and a 10-ml/kg tidal volume at a ventilatory rate of 12 to 18 beats per minute during two-lung ventilation. Ventilatory settings were set according to the age during the study.
After initiation of one-lung ventilation, alveolar recruitment of the dependent lung was performed by increasing peak inspiratory pressure to 40 cm H2O, together with a peak end-expiratory pressure (PEEP) of 10 cm H2O, for 10 respiratoty cycles. Then 5 min later, arterial blood gas analysis was performed for all the patients, and peak inspiratory airway pressures were recorded at the same time.
All the patients were placed in the lateral decubitus position. Trocar placement was dictated by the location of the loculated empyema cavity. Thoracoscopic examination was carried out accordingly, and total collapse of the affected lung was confirmed by direct vision. A 5- or 10-mm 0° telescope was placed around the eighth intercostal space in the midaxillary line. The second incision (2–4 cm) was made in the fifth intercostal space to allow the placement of conventional instruments directly the thoracic cavity. All purulent tissue and fibrin peel in the pleural cavity and lung parenchyma were evacuated thoracoscopically, and the infected necrotic lung tissue was excised and removed.
We gently advanced the exchanger blindly and distally to the tip of the endobronchial tube, stopping if there was any resistance. After that, we pulled the tip back about 0.5 to 1 cm from the bronchi to prevent damage to the bronchi. Positive pressure ventilation with 10 cm H2O PEEP was applied to reexpand the affected lung. Peak inspiratory pressures were recorded after the establishment of two-lung ventilation with the retaining tube exchanger in the dependent main bronchus. If peak airway pressure exceeded basal values by 30% during two-lung ventilation, tidal volume was reduced to 8 ml/kg, the inspiratory pause was zeroed, and the inspiratory-to-expiratory ratio was increased to 1:1. A suction catheter was placed in the tube together with the exchanger in larger children to prevent overflow from the one main bronchus into the other when the tube was pulled back. For smaller children, a suction catheter could not be placed because the diameter of the tube used was limited. Therefore, machine ventilation was changed to hand ventilation for small tidal volume to prevent overflow from the one main bronchus into the other when the tube was pulled back.
Affected lung expansion was witnessed by the surgeon through direct vision. If the lung was coated in fibrin peel and did not expand, the surgeon requested one-lung ventilation again by sliding back the endobronchial tube to the dependent main bronchus guided by the endotracheal tube exchanger to create a plane between the lung parenchyma and the pleural peel using a peanut. The procedure was repeated several times during surgery. Thoracoscopic decortication was subsequently performed.
When the surgery was completed and the tube exchanger was no longer needed, it was removed. After normal saline irrigation and meticulous hemostasis, a single chest tube was inserted through the trocar incision. After surgery, the patients were sent to the intensive care unit with the endotracheal tube in place for postoperative care. The endotracheal tube was removed on the second to fourth postoperative days. The chest tube was removed when air leakage stopped and chest radiography showed full lung expansion. Patients were discharged after removal of the chest tube.
Selective bronchial intubation was achieved successfully for all the patients. The right bronchus was easily intubated in all the patients, whereas intubation of the left bronchus required two to three attempts in seven patients and was facilitated by a malleable stylet used to guide the distal end of the tube to the left main bronchus.
Effect of one-lung and two-lung ventilations on PaO2, PaCO2, peak airway pressure, heart rate, and mean arterial pressure
Two-lung ventilation (with tube exchanger)
192.8 ± 18.5
190 6 ± 12.7
46.1 ± 2.3
47.7 ± 2.6
Peak airway pressure (cm H2O)a
29.1 ± 2.4
31.6 ± 2.7
Heart rate (beats/min)
117 ± 10
116 ± 6
Mean arterial pressure (mmHg)
62.0 ± 4.3
62.2 ± 3.8
Thoracoscopic debridement and irrigation were completed successfully in all the patients. None of the patients required conversion to open thoracotomy, and there was no procedure-related morbidity or mortality. Most of the patients (n = 58) were extubated on the second postoperative day. The remaining four patients were extubated 4 days after the operation. Postoperative fiberoptic bronchoscopy follow-up evaluation showed no abnormality in the dependent main bronchus. The mean postoperative hospital stay was 13.7 days (range, 9–23 days).
Pediatric empyema encompasses a spectrum of inflammatory manifestations ranging from thin parapneumonic pleural effusion to the formation of a thick constricting rind. The treatment of choice for this suppurative process continues to be early evacuation of loculated pus. Pediatric patients with empyema who manifest an unsatisfactory medical response often are considered for surgical intervention as early as possible to avoid subsequent potentially fatal complications.
Various reports have proposed VATS as a treatment for empyema in children to avoid the morbidity of open surgical drainage, to allow prompt clinical resolution of symptoms, and to prevent sequelae associated with delayed management [9, 17]. Because of recent advances in the VATS technique, patients with pleural and thoracic disorders currently can be managed less invasively [13, 16]. The VATS procedure requires one-lung ventilation with a properly collapsed lung. If the operation is performed without selective blocking of the bronchus of the affected lung, the trachea and the dependent lung may be contaminated or flooded with the contents of the abscess cavity during manipulation of the diseased lung . Flooding of the trachea and the dependent lung may acutely impair ventilation and lead to inflammation and abscess formation in the dependent lung. One-lung ventilation is indicated when isolation of one lung is necessary to prevent contamination by secretion or blood in the other lung or to provide adequate ventilation to the healthy lung. For adults, there are several options for isolation the two lungs: double-lumen tube [1, 2]; Univent tube [7, 8]; bronchial blockade with a Fogarty arterial embolectomy catheter , pulmonary catheter  or urinary catheter ; and even a single-lumen endobronchial tube. However, Univent tubes and double-lumen endobronchial tubes are too large for use with most small children. Thus, for the infant or child, one-lung anesthesia is achieved commonly by using a single-lumen endobronchial tube or a bronchial blocker .
Blockade of the diseased bronchus with the balloon of the Fogarty catheter [5, 6] achieves the objectives usually provided by a double-lumen tube in adults. The diameter of the Fogarty catheter and the size of the balloon make them ideal for blocking the small bronchus of a pediatric patient. The catheter can be passed easily through the vocal cords using direct laryngoscopy, and correct position can be verified by subsequent fiberoptic bronchoscopy. Bronchial blockers prevent both gas leakage from ruptured bronchioles and reflux of blood and pus. They provide selective intubation and the additional benefit of bilateral pulmonary ventilation. Although use of a flexible bronchoscope allowed precise placement of a balloon-tipped catheter, intraoperative dislodgement of the blocker still is a common problem in small children. Moreover, repositioning of the blocker requires more time.
In the pediatric population, placement of a single-lumen endobronchial tube is an alternative for lung separation. It is easier to insert and position a single-lumen endobronchial tube than to insert and position a bronchial blocker. Also, an endobronchial tube can avoid the risk of intraoperative dislodgment of a blocker.
Single-lumen endobronchial intubation may be performed blindly or under direct vision. It has been reported that using the retaining stylet during the entire intubation procedure allows more accurate placement of the endobronchial tube without increasing the incidence of tracheobronchial mucosa injury . A single-lumen endotracheal tube usually tends to enter the right main bronchus. Many factors can influence the rate of success for the left or right endobronchial intubation: size of the endotracheal tube, position of the tracheobronchial tube tip to the left of the midline, smaller angle of deviation from the midline for the right bronchus than for the left bronchus, and curvature of an ordinary endotracheal tube toward the right of the trachea midline. These anatomic features are responsible for the easiest blind intubation of the right bronchus. The single-lumen tube reportedly enters the left main-stem bronchus with a success rate of 92% when the concavity of the single-lumen tube is facing posteriorly . The disadvantages of single-lumen endobronchial intubation alone include incapability of providing suctioning and inflation of the contralateral lung during one-lung ventilation.
Video-assisted thoracoscopic debridement has emerged as an innovative and popular procedure for children with empyema, and alternative uses of two- and one-lung ventilations are needed during this surgery. Our surgical department has used VATS for advanced-stage empyema of pleura debridement in the pediatric population since 1995 . Evacuation of necrotic lung debris and peels has been performed without significantly increasing morbidity.
In this study, we sought a quick and reliable technique for blind endotracheal intubation using an ordinary single-lumen endobronchial tube without a bronchial blocker because use of a bronchial blocker is more time-consuming. We successfully used the same single-lumen endobronchial tube, with a tube exchanger in place to readjust the tube position for alternation of one- and two-lung ventilations in a thoracosopic procedure.
The purposeful retention of a tube exchanger in the bronchus can provide two-lung ventilation by withdrawal of the endobronchial tube to the trachea, and one-lung ventilation by pushing of the endobronchial tube to the dependent bronchus. Because the exchanger occupied some space of the tube lumen, peak airway pressure and PaCO2 significantly increased in our study. This may be attributable to flow obstruction to some extent in the single-lumen tube. The lumen within the tube exchanger may provide additional space for the ventilation. Both the airway pressure and PaCO2 values during the retention of the tube exchanger were within acceptable ranges, and thus did not cause any ventilatory problem. There was not much increase in PaCO2 during one- and two-lung ventilations when the total minute volume ventilation was maintained without change. There was no significant difference in oxygenation between one- and two-lung ventilations. The alveolar recruitment strategy that we applied to the dependent lung augmented PaO2 values during one-lung ventilation. Recruiting atelectatic zones of the dependent lung and applying sufficient levels of PEEP may attenuate the decrease in PaO2 during one-lung ventilation. Continued perfusion of the nonventilated lung results in a gross shunt effect associated with hypoxemia , and the hypoxemia may be decreased by active hypoxic pulmonary vasoconstriction, which results in a gradual redistribution of pulmonary blood flow away from the hypoxic collapsed lung into the ventilated lung . In our study, we used a high concentration of inspired oxygen (FIO2, 1.0) and intermittent two-lung ventilations. One-lung ventilation during VATS is likely to minimize arterial hypoxemia.
In summary, we describe a technique of facilitating alternative one- and two-lung ventilations by using an indwelling endotracheal tube exchanger during VATS for the treatment of lung empyema in children. Because the retention of a tube exchanger did not induce ventilatory problem, but did provide an easier approach to endobronchial reintubation for resuming one-lung ventilation, this method seemed to be more versatile than a bronchial blocker. It is safe, practical, and less time-consuming.