Temporary phrenic nerve stimulated patients: What is the role of ultrasound examination?

BACKGROUND: Prolonged mechanical ventilation caused by ventilator-induced diaphragm dysfunction (VIDD) is a serious problem in critically ill patients. Identification of patients who will have difficulty weaning from ventilation along with attempts to reduce total time on mechanical ventilation is some of the aims of intensive care medicine. OBSERVATIONS: This article briefly summarizes current options for temporary phrenic nerve stimulation therapy in an effort to keep the diaphragm active as direct prevention and treatment of ventilator-associated diaphragmatic dysfunction in patients on mechanical ventilation. The results of feasibility studies using different approaches are promising but so far, the clinical relevance is low. One important question is which tool would reliably identify early signs of diaphragmatic dysfunction and also be useful in guiding therapy. The authors present a brief overview of the current options considering the advantages and disadvantages of the available examination modalities. Despite the fact that current data point out some limitations of ultrasound examination, we believe that it still has a unique position in the bedside examination of critically ill patients on mechanical ventilation. CONCLUSION: Temporary phrenic nerve stimulation, regardless of the specific approach used, has the potential to directly treat or reverse VIDD, and ultrasound examination plays an important role in the comprehensive care of critically ill patients.

The Role of Ultrasound Examination in the Differential Diagnosis of Cardiac Arrest in Prehospital Care: A Case Report.

The survival rate of patients with out-of-hospital cardiac arrest has improved in recent years; however, it remains low. One approach to improving outcomes in these cases is to implement point-of-care ultrasound as an integral part of advanced cardiac life support management. Due to its growing popularity among emergency physicians, several protocols for this examination have been developed; however, there are little data on its use in the prehospital setting. We present a case report on the role of ultrasound examination in cardiac arrest for both diagnostic and therapeutic management.

Where Did the Midline Catheter Disappear?

Intravascular catheter break off is a rare complication during insertion or nursing care. We report the intravascular break off of a midline catheter after wound dressing change and its migration into the pulmonary artery. The broken piece of catheter was removed percutaneously using a snare kit.

Phrenic nerve stimulation prevents diaphragm atrophy in patients with respiratory failure on mechanical ventilation.

BACKGROUND: Diaphragm atrophy and dysfunction is a major problem among critically ill patients on mechanical ventilation. Ventilator-induced diaphragmatic dysfunction is thought to play a major role, resulting in a failure of weaning. Stimulation of the phrenic nerves and resulting diaphragm contraction could potentially prevent or treat this atrophy. The subject of this study is to determine the effectiveness of diaphragm stimulation in preventing atrophy by measuring changes in its thickness. METHODS: A total of 12 patients in the intervention group and 10 patients in the control group were enrolled. Diaphragm thickness was measured by ultrasound in both groups at the beginning of study enrollment (hour 0), after 24 hours, and at study completion (hour 48). The obtained data were then statistically analyzed and both groups were compared. RESULTS: The results showed that the baseline diaphragm thickness in the interventional group was (1.98 ± 0.52) mm and after 48 hours of phrenic nerve stimulation increased to (2.20 ± 0.45) mm (p=0.001). The baseline diaphragm thickness of (2.00 ± 0.33) mm decreased in the control group after 48 hours of mechanical ventilation to (1.72 ± 0.20) mm (p<0.001). CONCLUSIONS: Our study demonstrates that induced contraction of the diaphragm by pacing the phrenic nerve not only reduces the rate of its atrophy during mechanical ventilation but also leads to an increase in its thickness - the main determinant of the muscle strength required for spontaneous ventilation and successful ventilator weaning. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov (18/06/2018, NCT03559933, https://clinicaltrials.gov/ct2/show/NCT03559933 ).

Initial Assessment of the Percutaneous Electrical Phrenic Nerve Stimulation System in Patients on Mechanical Ventilation.

OBJECTIVES: Maintaining diaphragm work using electrical stimulation during mechanical ventilation has been proposed to attenuate ventilator-induced diaphragm dysfunction. This study assessed the safety and feasibility of temporary percutaneous electrical phrenic nerve stimulation on user-specified inspiratory breaths while on mechanical ventilation. DESIGN: Two-center, nonblinded, nonrandomized study. SETTING: Hospital ICU. PATIENTS: Twelve patients mechanically ventilated from 48 hours to an expected 7 days. INTERVENTIONS: Leads were inserted to lie close to the phrenic nerve in the neck region using ultrasound guidance. Two initial patients had left-sided placement only with remaining patients undergoing bilateral lead placement. Percutaneous electrical phrenic nerve stimulation was used for six 2-hour sessions at 8-hour intervals over 48 hours. MEASUREMENTS AND MAIN RESULTS: Data collected included lead deployment success, nerve conduction, ventilation variables, work of breathing, electrical stimulation variables, stimulation breath synchrony, and diaphragm thickness measured by ultrasound at baseline, 24, and 48 hours. Primary endpoints included ability to capture the left and/or right phrenic nerves and maintenance of work of breathing within defined limits for 80% of stimulated breaths. Lead insertion was successful in 21 of 22 attempts (95.5%). Analysis of 36,059 stimulated breaths from 10 patients with attempted bilateral lead placement demonstrated a mean inspiratory lag for phrenic nerve stimulation of 23.7 ms (p < 0.001 vs null hypothesis of <88ms). Work of breathing was maintained between 0.2 and 2.0 joules/L 96.8% of the time, exceeding the 80% target. Mean diaphragm thickness increased from baseline by 7.8% at 24 hours (p = 0.022) and 15.0% at 48 hours (p = 0.0001) for patients receiving bilateral stimulation after excluding one patient with pleural effusion. No serious device/procedure-related adverse events were reported. CONCLUSIONS: The present study demonstrated the ability to safely and successfully place percutaneous electrical phrenic nerve stimulation leads in patients on mechanical ventilation and the feasibility of using this approach to synchronize electrical stimulation with inspiration while maintaining work of breathing within defined limits.

Comparison of five 2nd-generation supraglottic airway devices for airway management performed by novice military operators.

OBJECTIVES: Five different second-generation supraglottic airway devices, ProSeal LMA, Supreme LMA, i-gel, SLIPA, and Laryngeal Tube Suction-D, were studied. Operators were inexperienced users with a military background, combat lifesavers, nurses, and physicians. METHODS: This was a prospective, randomized, single-blinded study. Devices were inserted in the operating room in low light conditions after induction of general anesthesia. Primary outcome was successful insertion on the first attempt while secondary aims were insertion time, number of attempts, oropharyngeal seal pressure, ease of insertion, fibre optic position of device, efficacy of ventilation, and intraoperative trauma or regurgitation of gastric contents. RESULTS: In total, 505 patients were studied. First-attempt insertion success rate was higher in the Supreme LMA (96%), i-gel (87.9%), and ProSeal LMA (85.9%) groups than in the Laryngeal Tube Suction-D (80.6%) and SLIPA (69.4%) groups. Insertion time was shortest in the Supreme LMA (70.4 ± 32.5 s) and i-gel (74.4 ± 41.1 s) groups (p < 0.001). Oropharyngeal seal pressures were higher in the Laryngeal Tube Suction-D and ProSeal LMA groups than in other three devices. CONCLUSIONS: Most study parameters for the Supreme LMA and i-gel were found to be superior to the other three tested supraglottic airway devices when inserted by novice military operators.