Automatic Tube Compensation (ATC) for Weaning Patients With Severe Neurotoxic Snake Envenoming

This study has been completed.
Sponsor:
Information provided by:
Postgraduate Institute of Medical Education and Research
ClinicalTrials.gov Identifier:
NCT00804011
First received: December 5, 2008
Last updated: NA
Last verified: December 2008
History: No changes posted
  Purpose

In the mechanically ventilated patient, the single greatest cause of imposed work of breathing is the resistance caused by the endotracheal tube. Commonly used maneuvers to overcome this resistance include the use of continuous positive airway pressure or pressure support.However, a new mode of ventilatory support called automatic tube compensation (ATC) delivers exactly the amount of pressure necessary to overcome the resistive load imposed by the endotracheal tube for the flow measured at the time (so called variable pressure support).

The aim of this study is to evaluate whether a combination of pressure support with automatic tube compensation is superior to PS alone in weaning patients with severe neurotoxic snake envenoming.


Condition Intervention
Snake Bite
Weaning
Mechanical Ventilation
Other: ATC
Other: PSV

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Supportive Care
Official Title: Automatic Tube Compensation Versus Pressure Support in Weaning Patients With Severe Neurotoxic Snake Envenoming

Further study details as provided by Postgraduate Institute of Medical Education and Research:

Primary Outcome Measures:
  • Duration of weaning [ Time Frame: 6 month ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • ICU stay [ Time Frame: 6 month ] [ Designated as safety issue: No ]

Enrollment: 41
Study Start Date: July 2004
Study Completion Date: April 2008
Primary Completion Date: December 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Automatic tube compensation plus pressure support
Other: ATC
Automatic tube compensation
Other Name: Automatic tube compensation
Active Comparator: 2
Pressure support alone
Other: PSV
Pressure support ventilation
Other Name: Pressure support ventilation

Detailed Description:

Snake envenoming is a common medical emergency encountered in the tropical countries, and an estimated 35,000 to 50,000 people die of snake bite every year in India. The bites of Elapid snakes cause predominantly neurotoxicity, which manifests as paralysis of the muscles of the eyes, tongue, throat and respiration, leading to respiratory failure, and if untreated death. The management of these patients includes ventilatory support and administration of snake anti-venom (SAV). Respiratory failure, requiring mechanical ventilatory support, is a frequent cause for admission to the intensive care unit (ICU).

Mechanical ventilation is a life-saving intervention and once there is improvement of the underlying indication for mechanical ventilation, it can be withdrawn abruptly in the majority. However, approximately 20-30% of patients still require gradual discontinuation i.e. weaning. This process is not only difficult in patients with chronic respiratory diseases and neuromuscular disorders like neurotoxic snake bite, but is also associated with significant complications like pneumonia, prolonged ICU stay and even mortality, especially in those with persistent weaning failure.

In the mechanically ventilated patient, it has long been recognized that the single greatest cause of imposed work of breathing (WOB) is the resistance caused by the endotracheal tube (ETT). Commonly used maneuvers to overcome the ETT resistance include the use of continuous positive airway pressure (CPAP) or pressure support (PS). However, a new mode of ventilatory support called automatic tube compensation (ATC) delivers exactly the amount of pressure necessary to overcome the resistive load imposed by the endotracheal tube for the flow measured at the time (so called variable pressure support). This mode theoretically can decrease weaning duration and increase the probability of successful extubation by decreasing the WOB.

Recently, we have reported our ICU data of 55 patients of severe neurotoxic snake envenoming in which we evaluated if usage of a higher dosage of SAV offered any significant clinical advantage over a lower dose, and found no difference between the high-dose and low-dose groups. The aim of this study is to evaluate whether a combination of PS with ATC is superior to PS alone in weaning patients with severe neurotoxic snake envenoming.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Patients with severe neurotoxic snake envenoming (defined as requirement of mechanical ventilation for ventilatory failure) will be included in the study. - Snake envenoming will be diagnosed on the history of snakebite, presence of fang marks, presence of local manifestations such as swelling, cellulitis, blister formation; or if the dead snake is brought for identification.
  • Significant improvement in the neuroparalysis with improvement in grade of power to at least MRC 3
  • Normal sensorium
  • Minimal suction requirements (less than thrice in the eight hours preceding the assessment
  • No requirement for any vasoactive drugs
  • No sedation (vi) core temperature less than 38.0°C
  • Hemoglobin more than 9 gm/dL (viii) systolic blood pressure more than 90 mm Hg
  • Overall physician assessment whether the patient is fit for weaning.

Exclusion Criteria:

  • If they do not meet the inclusion criteria
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00804011

Locations
India
Department of Pulmonary Medicine
Chandigarh, UT, India, 160012
Sponsors and Collaborators
Postgraduate Institute of Medical Education and Research
Investigators
Principal Investigator: Ritesh Agarwal, MD, DM, FCCP PGIMER, INDIA
Study Chair: Ashutosh N Aggarwal, MD, DM, FCCP PGIMER, INDIA
  More Information

No publications provided

Responsible Party: Dr Ritesh Agarwal, PGIMER, India
ClinicalTrials.gov Identifier: NCT00804011     History of Changes
Other Study ID Numbers: MS/486/Res/507
Study First Received: December 5, 2008
Last Updated: December 5, 2008
Health Authority: India: IEC, PGIMER, Chandigarh

Keywords provided by Postgraduate Institute of Medical Education and Research:
Snakebite
Weaning
Mechanical ventilation

Additional relevant MeSH terms:
Snake Bites
Bites and Stings
Poisoning
Substance-Related Disorders

ClinicalTrials.gov processed this record on July 23, 2014