The Therapeutic Potential of Intraoperative Hypercapnia During Video-Assisted Thoracoscopy in Pediatric Patients

The effect of intraoperative transnasal humidified rapid-insufflation ventilatory exchange on emergence from general anesthesia in patients undergoing microlaryngeal surgery: a randomized controlled trial

BACKGROUND

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has received extensive attention for its utility in tubeless anesthesia. Still, the effects of its carbon dioxide accumulation on emergence from anesthesia have not been reported. This randomized controlled trial aimed at exploring the impact of THRIVE combined with laryngeal mask (LM) on the quality of emergence in patients undergoing microlaryngeal surgery.

METHODS

After research ethics board approval, 40 eligible patients receiving elective microlaryngeal vocal cord polypectomy were randomly allocated 1:1 to two groups, THRIVE + LM group: intraoperative apneic oxygenation using THRIVE followed by mechanical ventilation through a laryngeal mask in the post-anesthesia care unit (PACU), or MV + ETT group: mechanically ventilated through an endotracheal tube for both intraoperative and post-anesthesia periods. The primary outcome was duration of PACU stay. Other parameters reflecting quality of emergence and carbon dioxide accumulation were also recorded.

RESULTS

Duration of PACU stay (22.4 ± 6.4 vs. 28.9 ± 8.8 min, p = 0.011) was shorter in the THRIVE + LM group. The incidence of cough (2/20, 10% vs. 19/20, 95%, P < 0.001) was significantly lower in the THRIVE + LM group. Peripheral arterial oxygen saturation and mean arterial pressure during intraoperative and PACU stay, Quality of Recovery Item 40 total score at one day after surgery and Voice Handicap Index-10 score at seven days after surgery were of no difference between two groups.

CONCLUSIONS

The THRIVE + LM strategy could accelerate emergence from anesthesia and reduce the incidence of cough without compromising oxygenation. However, these benefits did not convert to the QoR-40 and VHI-10 scores improvement.

TRIAL REGISTRATION

ChiCTR2000038652.

Moderate hypercapnia may not contribute to postoperative delirium in patients undergoing bronchoscopic intervention

This study aimed to investigate the risk factors and whether acute hypercapnia contributes to postoperative delirium (POD) during bronchoscopic intervention under general anesthesia or deep sedation.A prospective study was conducted with 119 consecutive patients who had undergone bronchoscopic intervention between February 2016 and December 2016 at the Emergency General Hospital.Twenty-eight patients (23.8%) were diagnosed with POD. The patients were divided into 2 groups: the POD (n = 28) and the control group (n = 91). The mean age of the POD group was higher than that of the control group (P < .01). All the blood gas values, PaCO2 (P < .01), PaO2 (P < .01), and PH (P < .01), were significantly different. Multivariate analyses revealed that age (P < .01), operation duration (P = .01), and PO2 (P = .01) were independent predictive factors of POD, while hypercapnia (P = .54) was established as not being a predictive factor of POD.Age, operation duration, and PO2 were determined as independent predictive factors of POD, whereas moderate hypercapnia is not likely to contribute to POD in patients undergoing bronchoscopic intervention. Clinical Trial Registration Identifier: ChiCTR-POC-15007483.

Optimal PEEP during one-lung ventilation with capnothorax: An experimental study

BACKGROUND

One-lung ventilation (OLV) with induced capnothorax carries the risk of severely impaired ventilation and circulation. Optimal PEEP may mitigate the physiological perturbations during these conditions.

METHODS

Right-sided OLV with capnothorax (16 cm H₂ O) on the left side was initiated in eight anesthetized, muscle-relaxed piglets. A recruitment maneuver and a decremental PEEP titration from PEEP 20 cm H₂ O to zero end-expiratory pressure (ZEEP) was performed. Regional ventilation and perfusion were studied with electrical impedance tomography and computer tomography of the chest was used. End-expiratory lung volume and hemodynamics were recorded and.

RESULTS

PaO₂ peaked at PEEP 12 cm H₂ O (49 ± 14 kPa) and decreased to 11 ± 5 kPa at ZEEP (P < 0.001). PaCO₂ was 9.5 ± 1.3 kPa at 20 cm H₂ O PEEP and did not change when PEEP step-wise was reduced to 12 cm H₂ O PaCO_2. At lower PEEP, PaCO₂ increased markedly. The ventilatory driving pressure was lowest at PEEP 14 cm H₂ O (19.6 ± 5.8 cm H₂ O) and increased to 38.3 ± 6.1 cm H₂ O at ZEEP (P < 0.001). When reducing PEEP below 12-14 cm H₂ O ventilation shifted from the dependent to the nondependent regions of the ventilated lung (P = 0.003), and perfusion shifted from the ventilated to the nonventilated lung (P = 0.02).

CONCLUSION

Optimal PEEP was 12-18 cm H₂ O and probably relates to capnothorax insufflation pressure. With suboptimal PEEP, ventilation/perfusion mismatch in the ventilated lung and redistribution of blood flow to the nonventilated lung occurred.

Cardiorespiratory effects of variable pressure thoracic insufflation in cats undergoing video-assisted thoracic surgery

OBJECTIVE

To evaluate the effects of intrathoracic insufflation on cardiorespiratory variables and working space in cats undergoing video-assisted thoracic surgery.

STUDY DESIGN

Prospective randomized study.

ANIMALS

Six healthy cats.

METHODS

Cats were anesthetized using a standardized protocol. A Swan-Ganz catheter was positioned in the pulmonary artery under fluoroscopic guidance for measurement of cardiac output. Intrathoracic pressures (ITP) of 0 (baseline), 3, and 5 mm Hg were induced with CO₂ and maintained for 30 minutes. Statistical comparison of cardiorespiratory variables was performed. After the procedures, all cats were recovered from anesthesia. Videos of thoracic working space at each ITP level were scored in a blinded fashion by 3 board-certified surgeons using a numerical scale from 0-10.

RESULTS

All cats tolerated insufflation with 3 and 5 mm Hg for 30 minutes without oxygen desaturation, although ventilatory levels had to be increased substantially to maintain eucapnia and oxygenation. Cardiac index was not significantly different from baseline after 30 minutes at 3 mm Hg but was significantly lower after 30 minutes at 5 mm Hg compared with 3 mm Hg. Oxygen delivery was unaffected by 3 or 5 mm Hg compared with baseline. Scores for working space increased between baseline and 3 and 5 mm Hg but were not different between 3 and 5 mm Hg.

CONCLUSION

CO₂ insufflation to 5 mm Hg seems well tolerated in healthy cats, provided ventilatory settings are substantially increased as ITP increases.

CLINICAL SIGNIFICANCE

Thoracic CO₂ insufflation of 3 mm Hg in cats during video-assisted thoracic surgery is associated with less hemodynamic perturbation than 5 mm Hg insufflation and may provide the benefit of improved working space compared with baseline.

Anesthetic management of thoracoscopic resection of lung lesions in small children

BACKGROUND

Video-assisted thoracoscopic surgery has dramatically increased over the last decade because of both medical and cosmetic benefits. Anesthesia for video-assisted thoracoscopic surgery in small children is more challenging compared to adults due to the considerable problems posed by small airway dimensions and ventilation. The optimal technique for one-lung ventilation has yet to be established and the use of remifentanil infusion in this setting is not well described.

AIMS

This study investigated the use of extraluminal bronchial blocker placement for one-lung ventilation and the effect of infusion of remifentanil in infants and small children undergoing video-assisted thoracoscopic surgery.

METHODS

We retrospectively reviewed the technique of one-lung ventilation and the hemodynamic effects of remifentanil infusion in 31 small children during elective video-assisted thoracoscopic surgery for congenital lung lesions under anesthesia with sevoflurane or isoflurane, oxygen, and air. Patients' heart rate, blood pressure, and endtidal carbon dioxide at baseline (after induction of anesthesia), immediately after one-lung ventilation, during carbon dioxide insufflation, and at the end of one-lung ventilation were extracted from the database and analyzed. The use of vasopressors or dexmedetomidine was also recorded and analyzed.

RESULTS

Extraluminal placement of a bronchial blocker alongside the tracheal tube was successfully performed in 90.3% of cases (28 patients) without any serious complications or arterial oxygen desaturation. There was no significant rise in blood pressure or heart rate even with the rise of endtidal carbon dioxide concentration during video-assisted thoracoscopic surgery. In 58% of patients (18 patients), phenylephrine was administered to maintain the blood pressure within 20% of the baseline value. There was no significant change in the heart rate of all patients at each time point.

CONCLUSION

One-lung ventilation with an extraluminal parallel blocker was used effectively in this series of young children undergoing thoracoscopic excision of congenital pulmonary lesions. Remifentanil infusion attenuated surgical stress effectively in infants and small children undergoing video-assisted thoracoscopic surgery.

Brain Oxygenation During Thoracoscopic Repair of Long Gap Esophageal Atresia

BACKGROUND

Elongation and repair of long gap esophageal atresia (LGEA) can be performed thoracoscopically, even directly after birth. The effect of thoracoscopic CO₂-insufflation on cerebral oxygenation (rScO₂) during the consecutive thoracoscopic procedures in repair of LGEA was evaluated.

METHODS

Prospective case series of five infants, with in total 16 repetitive thoracoscopic procedures. A CO₂-pneumothorax was installed with a pressure of maximum 5 mmHg and flow of 1 L/min. Parameters influencing rScO₂ were monitored. For analysis 10 time periods of 10' during surgery and in the perioperative period were selected.

RESULTS

Median gestational age was 35+3 [range 33+4 to 39+6] weeks; postnatal age at time of first procedure 4 [2-53] days and time of insufflation 127[22-425] min. Median rScO₂ varied between 55 and 90%. Transient outliers in cerebral oxygenation were observed in three patients. In Patient 2 oxygenation values below 55% occurred during a low MABP and Hb < 6 mmol/L. The rScO₂ increased after erythrocytes transfusion. Patient 5 also showed a rScO₂ of 50% with a Hb <6 mmol/L during all procedures, except for a substantial increase during a high paCO₂ of 60 mmHg. Patient 4 had a rScO₂ > 85% during the first procedure with a concomitant high FiO₂ > 45%. All parameters recovered during the surgical course.

CONCLUSIONS

This prospective case series of NIRS during consecutive thoracoscopic repair of LGEA showed that cerebral oxygenation remained stable. Transient outliers in rScO₂ occurred during changes in hemodynamic or respiratory parameters and normalized after interventions of the anesthesiologist. This study underlines the importance of perioperative neuromonitoring and the close collaboration between pediatric surgeon, anesthesiologist and neonatologist.

Clinical outcomes of CO2-less single-port video-assisted thoracoscopic thymectomy versus open thymectomy: comparative study

BACKGROUND

Although video-assisted thoracoscopic surgery (VATS) for thymic disorders has been introduced, its oncological outcome and benefits over others open approaches remains unclear. Single-port VATS thymectomy using a flexible port and CO₂ has been described. However, VATS thymectomy is possible by a single incision of 3 cm without CO₂ insufflation or special port device avoiding objections related to CO₂ insufflation and allowing instruments to move more freely making procedure easier and cheaper. Our institutional experience in open and CO₂-less VATS single-port thymectomy was retrospectively reviewed to evaluate compared to sternotomy, the clinical and oncological outcomes with this novel approach.

METHODS

A retrospective review consisting of 84 patients who underwent thymectomy because different thymic disorders especially thymoma was performed. Eighteen patients underwent CO₂-less VATS single port thymectomy, while 66 underwent thymectomy through open sternotomy. Many clinical factors associated with the surgical and clinical outcomes, including tumor recurrence and clinical remission, were recorded.

RESULTS

Non major postoperative complications were observed in any group. The median operative time and postoperative hospital stay of CO₂-less VATS single port thymectomy were 95 min and 1 day, respectively and 120 min and 7 days for open sternotomy. The thymoma was the most common thymic disorder with 7 patients (38%) in VATS group and 28 patients (42.4%) for the open approach. The median lesion size was 2.6 cm in the VATS group and 3.2 cm in the open approach. No thymoma recurrence in patients undergoing VATS was observed during the follow-up time, while in the open surgery group 14.28% recurrence was observed, distributed as follows: loco-regional 75% and 25% at distance; free disease period of these patients was 8.3 months. Thymectomy associated with myasthenia gravis (MG) was observed in 6 (33%) patients in the VATS group and 32 (48%) patients for sternotomy; our results regarding thymectomy for the treatment of MG were established by the MG post-intervention status [complete stable remission (CSR), pharmacologic remission, minimal manifestations, improved, unchanged and worse exacerbation, and died of MG] and reflected similar results in both approaches.

CONCLUSIONS

CO₂-less VATS single-port thymectomy is a feasible and safe procedure. Oncologic outcomes are similar to open approaches. Complications, surgical time and hospital stay are shorter compared with sternotomy. This is an initial experience, further work is required to evaluate long-term results.

Neonatal brain oxygenation during thoracoscopic correction of esophageal atresia

Background

Little is known about the effects of carbon dioxide (CO₂) insufflation on cerebral oxygenation during thoracoscopy in neonates. Near-infrared spectroscopy can measure perioperative brain oxygenation [regional cerebral oxygen saturation (rScO₂)].

Aims

To evaluate the effects of CO₂ insufflation on rScO₂ during thoracoscopic esophageal atresia (EA) repair.

Methods

This is an observational study during thoracoscopic EA repair with 5 mmHg CO₂ insufflation pressure. Mean arterial blood pressure (MABP), arterial oxygen saturation (SaO₂), partial pressure of arterial carbon dioxide (paCO₂), pH, and rScO₂ were monitored in 15 neonates at seven time points: baseline (T0), after anesthesia induction (T1), after CO₂-insufflation (T2), before CO₂-exsufflation (T3), and postoperatively at 6 (T4), 12 (T5), and 24 h (T6).

Results

MABP remained stable. SaO₂ decreased from T0 to T2 [97 ± 3–90 ± 6 % (p < 0.01)]. PaCO₂ increased from T0 to T2 [41 ± 6–54 ± 15 mmHg (p < 0.01)]. pH decreased from T0 to T2 [7.33 ± 0.04–7.25 ± 0.11 (p < 0.05)]. All parameters recovered during the surgical course. Mean rScO₂ was significantly higher at T1 compared to T2 [77 ± 10–73 ± 7 % (p < 0.05)]. Mean rScO₂ levels never dropped below a safety threshold of 55 %.

Conclusion

The impact of neonatal thoracoscopic repair of EA with insufflation of CO₂ at 5 mmHg was studied. Intrathoracic CO₂ insufflation caused a reversible decrease in SaO₂ and pH and an increase in paCO₂. The rScO₂ was higher at anesthesia induction but remained stable and within normal limits during and after the CO₂ pneumothorax, which suggest no hampering of cerebral oxygenation by the thoracoscopic intervention. Future studies will focus on the long-term effects of this surgery on the developing brain.

Effect of Acute Hypercapnia on Outcomes and Predictive Risk Factors for Complications among Patients Receiving Bronchoscopic Interventions under General Anesthesia

Background

The aim of this study is to investigate the effect of acute hypercapnia on surgery outcomes among patients receiving bronchoscopic interventions under general anesthesia. Furthermore, independent predictive factors for surgery complications were analyzed.

Method

A total of 323 patients with airway stenosis were enrolled in this retrospective study. Each patient underwent interventional rigid bronchoscopy under general anesthesia. Arterial blood gas (ABG) was measured intraoperatively. In light of PaCO₂ levels in ABG, patients were divided into three groups: Group C (control) (PaCO₂:≤ 60 mmHg), Group M (moderate) (PaCO₂:61–100 mmHg), and Group S (severe) (PaCO₂: >100 mmHg). Parameters, including PaO₂ levels and recovery delays, were compared across three groups. Complications among patients receiving bronchoscopic interventions were evaluated as well. Independent predictive factors for surgery related complications were analyzed by multivariable regression method.

Results

Significant differences in weight (p=0.04), ASA IV (p=0.008), dyspnea index (p=0.003),COPD (p=0.02), dynamic airway collapse (p=0.002), severe stenosis severity (p=0.02), and stenosis locations among three groups were observed. Mild (PaCO₂:~60 mmHg) to moderate (PaCO₂:60–100 mmHg) hypercapnia was not associated with delayed recovery, whereas severe hypercapnia (PaCO₂:>100 mmHg) was associated with delayed recovery, as well as declined PaO₂ (p=0.00) and elevated blood glucose levels (p=0.00). The complications of bronchoscopic interventions included postoperative congestive heart failure (14 cases, 4.3%), tracheorrhagia (8 cases, 2.5%), delayed recovery (19 cases, 5.9%), and transfers to ICU after surgery (10 cases, 3.1%). The multivariable regression analysis showed that procedure duration (p=0.003), lobectomy (p=0.007), dynamic airway collapse (p=0.01), severe bronchial stenosis (p=0.01) and hypercapnia (p=0.02) were independent predictive factors for surgery related complications.

Conclusions

Acute hypercapnia lower than 100 mmHg was not associated with detrimental consequences, whereas severe hypercapnia (PaCO₂: >100 mmHg) was associated with lower levels of PaO₂. Hypercapnia was an independent predictive factor for bronchoscopic intervention complication, which may help physicians to optimize the therapeutic choices.

Real-time ventilation and perfusion distributions by electrical impedance tomography during one-lung ventilation with capnothorax

BACKGROUND

Carbon dioxide insufflation into the pleural cavity, capnothorax, with one-lung ventilation (OLV) may entail respiratory and hemodynamic impairments. We investigated the online physiological effects of OLV/capnothorax by electrical impedance tomography (EIT) in a porcine model mimicking the clinical setting.

METHODS

Five anesthetized, muscle-relaxed piglets were subjected to first right and then left capnothorax with an intra-pleural pressure of 19 cm H2 O. The contra-lateral lung was mechanically ventilated with a double-lumen tube at positive end-expiratory pressure 5 and subsequently 10 cm H2 O. Regional lung perfusion and ventilation were assessed by EIT. Hemodynamics, cerebral tissue oxygenation and lung gas exchange were also measured.

RESULTS

During right-sided capnothorax, mixed venous oxygen saturation (P = 0.018), as well as a tissue oxygenation index (P = 0.038) decreased. There was also an increase in central venous pressure (P = 0.006), and a decrease in mean arterial pressure (P = 0.045) and cardiac output (P = 0.017). During the left-sided capnothorax, the hemodynamic impairment was less than during the right side. EIT revealed that during the first period of OLV/capnothorax, no or very minor ventilation on the right side could be seen (3 ± 3% vs. 97 ± 3%, right vs. left, P = 0.007), perfusion decreased in the non-ventilated and increased in the ventilated lung (18 ± 2% vs. 82 ± 2%, right vs. left, P = 0.03). During the second OLV/capnothorax period, a similar distribution of perfusion was seen in the animals with successful separation (84 ± 4% vs. 16 ± 4%, right vs. left).

CONCLUSION

EIT detected in real-time dynamic changes in pulmonary ventilation and perfusion distributions. OLV to the left lung with right-sided capnothorax caused a decrease in cardiac output, arterial oxygenation and mixed venous saturation.

Intraoperative Bronchopleural Fistula During Thoracoscopic Lobectomy: The Role of End-Tidal CO2 Monitoring

Video-assisted thoracoscopic surgery has become a common procedure in pediatric surgery. We present a case of accidental intraoperative bronchopleural fistula during a video-assisted thoracoscopic surgery procedure, which was first identified by the anesthesia team. We discuss differential diagnoses including the role of end-tidal carbon dioxide monitoring as an aid to prompt diagnosis.

Thoracoscopic enucleation of esophageal leiomyoma in prone position and single lumen endotracheal intubation

INTRODUCTION

Esophageal leiomyomas are the most common benign tumors of the esophagus. Surgical enucleation is warranted for symptomatic patients. Thoracoscopic enucleation is the preferable approach for being less invasive by avoiding the discomfort and complications associated to larger thoracic incisions. The purpose of this study was to review our experience with enucleation of esophageal leiomyoma using a prone-position thoracoscopy technique.

METHODS

Between January 2009 and July 2012, ten patients underwent resection of esophageal leiomyoma by thoracoscopy approach in prone position. Indications for surgical treatment were symptomatic tumors (dysphagia). All patients were followed postoperatively for at least 3 months with contrast x-ray of the esophagus. After single-lumen endotracheal intubation (nonselective intubation) in supine, patients were placed in prone position. Pneumothorax was kept at 6 to 8 mmHg using CO2 insufflation. A myotomy was performed over the tumor using hook cautery carefully protecting the mucosa from injuries. The myotomy was closed with continuous sutures.

RESULTS

The procedures were completed in the prone position in all cases, without any conversion. Mean operative time was 89.2 ± 28.7 minutes. Bleeding was negligible, and there were no intraoperative or postoperative complications. No intensive care unit support was needed for any patient. Chest x-ray in the first postoperative day showed no significant changes in any patient. The mean hospital stay was 3.2 days. Contrast x-ray of the esophagus was normal in all patients at 3 months postoperatively.

CONCLUSIONS

Thoracoscopic enucleation of esophageal leiomyoma is a feasible, simple, and safe procedure. Thoracoscopy in the prone position with CO2 insufflation allows the use of usual technique of intubation and also provides optimal operative field. The advantages of the thoracoscopic approach are less postoperative discomfort and lower risk of complications from open thoracotomy (especially pulmonary).

Anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients: the issue of safety in infant and younger children

Background

The purpose of this study was to assess the safety issues concerning anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients.

Methods

The medical records of 52 pediatric patients undergoing VATS using general anesthesia and one-lung ventilation (OLV) were reviewed. OLV was achieved with a Fogarty catheter (n = 23) or endobronchial intubation (n = 7) in patients < 10 years of age (group Y, n = 30), and using a double-lumen tube (n = 19) or a univent (n = 3) in children aged between 10 and 16 years of age (group O, n = 22). Hypoxemia, hypercarbia, the difference between E_TCO₂ and PaCO₂, and the effect of CO₂ insufflation were assessed.

Results

A decrease in SpO₂ less than 90% was observed in 40% of the group Y, compared to none of the group O (P < 0.05). A hypercarbia (E_TCO₂ > 50 mmHg) was observed more frequently in group Y (40%) than in group O (0%; P < 0.05). The difference between the E_TCO₂ and PaCO₂ was 10.4 ± 8.9 mmHg in group Y and 4.6 ± 3.9 mmHg in group O (P < 0.05). Hypercarbia and acidosis occurred more frequently in patients with CO₂ insufflation than those without insufflation in group Y.

Conclusions

Although the anesthesia for VATS in pediatric patients was successfully accomplished, the infants and younger children presented with more intra-operative problems when compared with older children. The anesthetic management for VATS in infants and younger children requires careful and vigilant monitoring.

Thoracoscopic repair of congenital diaphragmatic hernia: intraoperative ventilation and recurrence

INTRODUCTION

Thoracoscopic repair of congenital diaphragmatic hernia (CDH) has been described, but its efficacy and safety have not been validated. The aim was to compare our experience of thoracoscopy with laparotomy repair.

METHODS

After ethics approval, we reviewed the notes of neonates with CDH operated in our institution between 2003 and 2008. Two historical groups were compared: infants who underwent laparotomy (2003-2008) or thoracoscopy (2007-2008). Data were compared by t test or Mann-Whitney tests.

RESULTS

Thirty-five children had open repair of CDH, and 13 had thoracoscopic repair. Groups were homogeneous for age and weight. Five (38%) neonates who had thoracoscopy were converted to open for surgical difficulties (n = 4) and O(2) desaturation (n = 1). Patch repair was used in 12 (34%) open and 6 (46%) thoracoscopic repairs. End-tidal CO(2) was significantly elevated during thoracoscopy, but this was not reflected in arterial CO(2) or pH. There were 3 (8%) recurrences after open repair and 2 (25%) after thoracoscopy (P = .19).

CONCLUSION

Thoracoscopic repair of CDH is feasible. Arterial blood gases should be closely monitored. Despite higher EtCO(2), conversion to open was mainly because of difficult repair. A randomized trial is necessary to assess the effect of thoracoscopy on ventilation and recurrences.