Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02942953 |
| Other study ID # |
2015209 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
July 13, 2016 |
| Last updated |
October 21, 2016 |
| Start date |
June 2015 |
| Est. completion date |
October 2015 |
Study information
| Verified date |
October 2016 |
| Source |
Institut Guttmann |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Spain: Comité Ético de Investigación Clínica |
| Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
The diaphragmatic pacemaker (DP) has proven its utility in replacing mechanical ventilation
(MV) in patients with chronic spinal cord injury (SCI) and Amyotrophic Lateral Sclerosis
(ALS), by improving the patients quality of life and reducing morbi-mortality and the
associated health care costs. The anesthetic management of these patients and the
particularities of the surgical procedure represent an anesthetic challenge. The objective
of our study is to analyze the management and the intraoperative complications in the
patients with DP in our institution.
Description:
Patients included are part of a program developed by the Spinal Cord Injury Unit of the
Institut Guttmann of placement and strengthening of the diaphragm with NeuRx® Diaphragm
Pacing Stimulation (DPS) System (Synapse Biomedical, Oberlin, OH, USA) device for patients
suffering from neuromuscular disorders or upper spinal cord injuries dependent on MV. All of
them were preselected by a multidisciplinary expert committee after the assessment of their
clinical history and the evaluation of the phrenic nerve function using two complementary
techniques like phrenic nerve stimulation and fluoroscopic evaluation of diaphragm movement.
Pediatric patients were the exception, since they underwent surgery in order to obtain a
definitive diagnosis on the phrenic nerve functionality. Patients were admitted in the
center 24 hours prior to the intervention.
The surgical procedure of DP implantation consists in placing four intramuscular electrodes,
two in each hemidiaphragm, using a conventional abdominal laparoscopy with carbon dioxide
insufflation at 10 L/minute speed and pressure up to 15 mmHg. Four ports are inserted: one
for the optical equipment, two for the mapping electrode and electrode insertion instruments
and a smaller sized port as an exit site for the wires of the electrodes. Reverse
Trendelenburg position is required for the procedure. It consists in locating the optimum
point for electrode insertion. The process involves mapping between 30 and 50 different
points in each hemidiaphragm by applying an electric stimulus of 2-24 mA at 100 µsec pulse
widths11. It results in both qualitative and quantitative assessment of diaphragmatic
movement: qualitative through laparoscopy and quantitative using the external assessment of
the intraabdominal pressure during stimulation with temporal mapping electrode. Site of main
electrode is identified as the location of each hemidiaphragm's change of maximum pressure
and site of secondary electrode as replica of main site. Once the sites are identified in
each hemidiaphragm, intramuscular electrode placement phase is initiated. Response to
desired stimulation is checked subsequently. Finally the electrodes are tunneled out to the
corresponding percutaneous exit site and an electrocardiogram strip is recorded with all
electrodes active in order to confirm there is no capture of cardiac rhythm. In the case of
pediatric age patients equipment and incisions were adapted to patient's weight and size.
However the surgical procedure was the same.
Upon arrival to the operating room, heart rate (HR), non-invasive arterial pressure (NIAP),
pulse oximetry oxygen saturation (SaO2) and capnography (Carescape Monitor B850, GE
Healthcare, Finland) were standardly monitored. In patients with previous history of
ischemic cardiopathology and/or difficult to manage autonomic dysreflexia crisis, invasive
arterial pressure was monitored through radial artery catheterization using the Seldinger
technique (Leathercath Arterial; Vygon Ecoven, France). In most cases no premedication was
provided. In pediatric patients prophylactic atropine was required for induction, it was
given in doses of 0.01 mg/kg. Induction was carried out either intravenously with propofol
in doses raging 1.5-2 mg/kg in adult patients and 3 mg/kg in pediatric patients or by
inhalation with sevoflurane in pediatric patients. After a prior priming of the circuit, a
series of three forced inspirations were carried out using reservoir bag at concentrations
of 6% of the anesthetic until reaching a minimal alveolar concentration (MAC) of 2.0-3.5%.
Anesthetic maintenance was carried out following anesthetist's criterion, with sevoflurane
of 2-2.5% MAC or continuous intravenous infusion with propofol for Total Intravenous
Anesthesia (TIVA) maintaining the infusion at 10 mg/kg/h for 30 minutes, followed by 8
mg/kg/h for another 30 minutes and 6 mg/kg/h until the end of the intervention, maintaining
bispectral index (BIS) value of 40-60. Patients were disconnected from their usual
ventilation system and transferred to the GE Datex-Ohmeda Aespire 3000 (GE Healthcare,
Finland) system on volume control mode, with tidal volume of 6 mL/kg, respiratory rate
between 10 and 15 breaths per minute and PEEP +7 cmH₂O with a mixture of O2/air at 50% in
order to reach oxygen saturation superior to 95% before initiating the surgical procedure.
Given the type of procedure, it was attempted to minimize the use of muscle relaxants, since
these are not required in patients with tracheostomy. Rocuronium at 0.4 mg/kg at the
anesthetist's criterion was used for managing the airway in patients who needed orotracheal
intubation (OTI). In these cases, neuromuscular relaxation was monitored (NMT Neuromuscular
Transmission MechanoSensor GE Healthcare, Finland) and a Train of Four (TOF) measurement of
100% was obtained prior to administering muscle relaxants. OTI was performed when TOF answer
was 0 and diaphragmatic mapping phase initiated solely if TOF answer was 4 and with a
percentage superior to 90%. When these levels of response were not achieved, sugammadex 2
mg/kg was used to reverse the blocking in case of induction with rocuronium or neostigmine
0.04-0.07 mg/kg.
Intraoperative analgesia was carried out using continuous infusion of remifentanil (0.5-1
µg/kg/min) until the end of the intervention. Surgeons infiltrated laparoscopic ports with
bupivacaine 0.5% with vasoconstrictor before incision. Patients requiring OTI received a
fentanyl bolus (3 µg/kg) in the induction and in all cases at the end of the surgery a
fentanyl bolus (1.5 µg/kg) was administered in order to avoid postoperative hyperalgesia
associated to remifentanil.
Isolated boluses of propofol (0.5-1 mg/kg) or fentanyl (1-1.5 µg/kg) were administered when
patients required anesthetic deepening for a correct tolerance of the laparoscopic technique
without using muscle relaxants. Patients received bolus of 5 mg ephedrine repeatedly until
normal values were reached if intraoperative arterial hypotension appeared, defined as a 20%
decrease of baseline or mean arterial pressure (MAP) inferior to 60 mmHg.
Patients with dysreflexive events manifesting as hypertensive crisis with pressure 20%
higher than baseline associated to bradycardia were treated using anesthetic deepening
and/or hypotensive drugs (bolus of urapidil 25 mg every 10 minutes) until reaching a correct
pressure control.
At the end of the intervention all patients were connected to their usual MV, either
invasive or not, with supplemental oxygen. They also received intravenous analgesic
treatment in the ward with paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs)
dexketoprofen or metamizole magnesium and tramadol as rescue medication during 24-48 hours.
In the immediate postoperative period, following protocols a control X-ray was carried out
in order to rule out pneumothorax. If present, it was drained percutaneously. Patients
remained in post-anesthesia care unit (PACU) for at least two hours. They were transferred
to ward while maintaining continuous monitoring of ECG, NIAP and SaO₂ during 24 h once they
were aware and oriented in the three spheres and the following criteria were met: analgesia
is optimized visual analogue scale (VAS) inferior to 2), dysreflexive events and
postoperative spasms ruled out, arterial pressure is normalized, heart rate to baseline
values and oxygen saturation higher than 95%. Stimulation of diaphragm was initiated in the
ward during the first 3-4 days following surgery in SCI and after one week in ALS depending
on the medical team in charge of the stimulation process. Correct conditioning of the
diaphragm and weaning from MV required repeated sessions. Surgical team carried out a 15
days post-intervention follow-up and given that it was a neuroprosthesis, they also did
follow-ups one month and one year after the surgery. Once patients were released, the team
in charge of neurostimulation carried out postoperative follow-ups at three, six and twelve
months. Subsequently they conducted annual controls.
The information compiled included demographic data, ASA classification, diagnostic that led
to device placement, chronically used MV type and tracheostomy use.
Type of anesthesia administered was also indicated, including specific accessory monitoring,
drugs used, airway management, surgery duration and placement or not of permanent
electrodes.
All incidents or complications occurred during the procedure were also recorded, whether
they were related to anesthetic or surgical technique. During intraoperative period there
were recorded any arrhythmias related to electric stimulation during mapping phase,
disadaptation to MV or poor tolerance to the pneumoperitoneum (peak pressure > 35 cmH2O and
plateau pressure > 30 cmH2O, desaturation < 90%) and presence of autonomic dysreflexia
crisis related to painful stimulus (blood pressure > 20% of baseline or systolic blood
pressure > 155 mmHg and diastolic blood pressure DBP > 100 mmHg). As for surgical
complications in the immediate postoperative period, pneumothorax appearance was given
special attention.
