IPg2 Study: Left-sided Lung Isolation
IPg2 Study: Left-sided Lung Isolation
Lung isolation is primordial in thoracic surgery. To achieve it, two techniques are used: the
 double lumen tube (DLT) and the bronchial blocker (BB). Left-sided DLT (L-DLT) is use by the
 majority of anesthesiologists for both left and right thoracic surgeries. Standard
 right-sided DLT (Rs-DLT) is rarely use since it is dif¬ficult to properly position it and
 that there is a risk of misalignment between the lateral orifice of the tube and the origin
 of the right upper lobe (RUL) bron¬chus. In 2007, the investigators have published results
 suggesting enlarging the Rs-DLT's lateral orifice. The modified R-DLT (Rm-DLT) was more
 frequently in an adequate position: 77% vs 37% of patients (p = 0.0121), and easier to
 reposition: 97% vs 74% of patients (p= 0.0109) in comparison to the standard R-DLT group. The
 data suggest the superiority of the Rm-DLT compared to Rs-DLT for optimal positioning to
 facilitate one-lung ventilation (OLV) during thoracic surgery. It is believed that DLT tend
 to provide quicker and better quality of lung collapse than BB. In 2013, investigators have
 demonstrated an equivalent quality of lung collapse (LC) between L-DLT and BB used with two
 apnea periods when initiating OLV. Complementary analysis showed a significative difference
 to obtain complete LC (CLC) between L-DLT for left thoracoscopy and L-DLT for right
 thoracoscopy and BB in right or left surgery. The investigator hypothesis is that, when using
 L-DLT for left video-assisted thoracoscopic surgery (VATS), LC of the isolated lung will be
 slower and of poorer quality compare to the use of the Rm-DLT. The primary objective is to
 compare the delay between pleural opening (PO) and CLC in left VATS when using three lung
 isolation devices: 1) L-DLT and 2) Rm-DLT. Secondary objectives are: 1) to evaluate quality
 of LC, 2) to evaluate the level of obstruction of the lumen of the left bronchus, 3) to
 evaluate the quality of OLV (PaO2) 4) To collect blind surgeon's opinion about de device used
 and 5) to measure the delay between OLV and PO for evaluating the role of absorption
 atelectasis in obtaining CLC. After obtaining IRB approval, the investigators propose a study
 of 40 patients undergoing an elective left VATS at IUCPQ involving one lung ventilation. They
 will have to be 21 years or more, to read, understand and sign an informed consent at their
 pre-operative evaluation. This study will be prospective, randomized, and blind to thoracic
 surgeons.
Background:

 Lung isolation is frequently used in thoracic surgery. The quality of the isolation is
 crucial, especially for video-assisted thoracoscopic surgery (VATS). Two techniques are
 principally used to obtain lung isolation: the double lumen tube (DLT) and the bronchial
 blocker (BB).

 The left-sided DLT (L-DLT) is used by the majority of anesthesiologists, as much for left as
 for right thoracic surgeries. The standard right-sided DLT (Rs-DLT) is rarely used since
 positioning its lateral orifice with the origin of the right upper lobe (RUL) can be
 difficult.(1-4) In 2007, the investigators have published their results suggesting an
 enlargement of the lateral orifice of the Rs-DLT.(5) They have demonstrated that the modified
 right-sided double lumen tube (Rm-DLT) remained more frequently in optimal position than the
 Rs-DLT (77% vs. 37%, p=0.0121) and that it was also easier to reposition the tube after
 turning the patient in lateral decubitus (97% vs. 74%, p=0.0109).

 More recently, investigators have demonstrated, with three dimensional reconstruction of
 computed tomography of 106 patients, that angulation between the RUL and the horizontal
 posterior plane varies from -26 to +58°, justifying the modification of the Rs-DLT proposed
 in 2007. (Unpublished data)

 The use of BB for lung isolation is believed to provide a slower and a poorer quality of lung
 collapse (LC) than DLT. Over the years, the investigators have demonstrated an equivalent
 quality of lung collapse between the L-DLT and BB when two apnea periods are used at the
 beginning of one-lung ventilation (OLV). (Unpublished data) Further to complementary
 analysis, investigators have noted a significant difference in time to get complete lung
 collapse between left and right thoracic surgery when using the L-DLT. Time to obtain
 complete lung collapse (CLC) was not different when comparing BB and L-DLT in left thoracic
 surgery.

 The hypothesis to explain these observations is that when the bronchial extremity of the
 L-DLT is inserted into the left main stem bronchus (LMSB), the LMSB and its relative superior
 position, associated to a progressive collapse of the left lung, could induce a dynamic
 obstruction of the distal extremity of the L-DLT lumen, and consequently slowing the lung
 collapse. Investigators have also regularly observed this type of obstruction during
 bronchoscopic examination when positioning the L-DLT.

 In past studies comparing L-DLT to BB, time to get CLC was measured from the beginning of
 OLV. Nevertheless, the interval between this time point and the pleural opening (PO) is
 sometime difficult to control. Technical incidents can prolong this period and induce a bias.
 Furthermore, in the last investigator's protocol, the second period of apnea is done at
 pleural opening. For these reasons, the authors consider that the time to get CLC should be
 measured from the pleural opening since it is the crucial moment for the surgical team.
 Investigators are proposing to evaluate the PO-CLC interval as a primary objective.(6)

 Hypothesis:

 The hypothesis of the proposed study is that the use of the L-DLT will allow for a slower and
 a poorer quality of CLC compared to the ones obtained with the Rm-DLT in left VATS.
Inclusion Criteria:

 -  signed informed consent

 -  elective left video-assisted thoracoscopy

 -  one lung ventilation

 Exclusion Criteria:

 -  Anticipated difficult mask ventilation or intubation

 -  tracheal or high bronchial origin of the right upper lobe main bronchus

 -  severe COPD or asthma

 -  pleural disease

 -  previous left thoracic surgery

 -  chest radiotherapy

 -  chimiotherapy

 -  significant systemic co-morbidity

 -  active or chronic pulmonary infection

 -  fibrosis, other interstitial diseases

 -  endobronchial mass

 -  tracheostomy

 -  severe desaturation in the peroperative period

 -  any clinical situation precluding the use of an isolation device