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.

Cranial Electrode Belt Position Improves Diagnostic Possibilities of Electrical Impedance Tomography during Laparoscopic Surgery with Capnoperitoneum.

Laparoscopic surgery with capnoperitoneum brings many advantages to patients, but also emphasizes the negative impact of anesthesia and mechanical ventilation on the lungs. Even though many studies use electrical impedance tomography (EIT) for lung monitoring during these surgeries, it is not clear what the best position of the electrode belt on the patient's thorax is, considering the cranial shift of the diaphragm. We monitored 16 patients undergoing a laparoscopic surgery with capnoperitoneum using EIT with two independent electrode belts at different tomographic levels: in the standard position of the 4th-6th intercostal space, as recommended by the manufacturer, and in a more cranial position at the level of the axilla. Functional residual capacity (FRC) was measured, and a recruitment maneuver was performed at the end of the procedure by raising the positive end-expiratory pressure (PEEP) by 5 cmH2O. The results based on the spectral analysis of the EIT signal show that the ventilation-related impedance changes are not detectable by the belt in the standard position. In general, the cranial belt position might be more suitable for the lung monitoring during the capnoperitoneum since the ventilation signal remains dominant in the obtained impedance waveform. FRC was significantly decreased by the capnoperitoneum and remained lower also after desufflation.

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.

The use of cryopreserved platelets in the treatment of polytraumatic patients and patients with massive bleeding.

BACKGROUND: The short shelf-life of fresh platelets limits their efficient inventory management and availability during a massive transfusion protocol. Risk of insufficient availability can be mitigated by building an inventory of cryopreserved platelets (CPs). METHODS: A comparative study of fresh apheresis platelets (FAPs) and CPs was performed. Type-O CPs were processed with DMSO frozen at -80°C and reconstituted in thawed AB plasma. All patients enrolled in the study had the following parameters evaluated on admission: vital signs (body temperature, heart rate, mean arterial pressure), blood count, prothrombin time, activated partial thromboplastin time, fibrinogen level, and, in trauma patients, international severity score. Several outcomes were evaluated: 30-day survival, adverse events, quantity of administered blood products, fibrinogen concentrate and thromboxane (TXA), and laboratory parameters after transfusion (blood count, prothrombin time, activated partial thromboplastin time, fibrinogen level). RESULTS: Twenty-five (25) patients in the study group received transfusions totaling 81 units of CPs. Twenty-one (21) patients in the control group received a total of 67 units of FAPs. There were no significant differences in patient characteristics (p > 0.05) between groups. Both groups were comparable in clinical outcomes (30-day survival, administered blood products, fibrinogen concentrate, TXA, and adverse events). Among posttransfusion laboratory parameters, platelet count was higher in the group transfused with FAPs (97.0 ×109 /L) than in the group transfused with CPs (41.5 ×109 /L), p = 0.02025. Other parameters were comparable in both groups. CONCLUSION: The study suggests that CPs are tolerable and a feasible alternative to FAPs. However, larger randomized studies are needed to draw definitive conclusions.

[A Case of a patient with AIDS and pneumocystis pneumonia complicated by cytomegalovirus pneumonitis].

We report a case of a 39-year-old male admitted for respiratory failure. On admission, the patient was diagnosed with advanced HIV infection and Pneumocystis jirovecii pneumonia (PJP). The patient's condition improved following specific PJP therapy but then deteriorated. The patient was subsequently diagnosed with cytomegalovirus pneumonitis and treated with ganciclovir. The severe course of both opportunistic infections required long-term care at an intensive care unit. Despite complications, the patient was discharged after 108 inpatient days in a stable clinical condition. The case demonstrates a rare coincidence of PJP and cytomegalovirus pneumonitis while also emphasizing the importance of correct diagnosis, treatment and interdisciplinary care which, despite poor prognosis, may lead to successful cure of serious simultaneous opportunistic infections in AIDS.

Early Diagnosis of Cutaneous Mucormycosis Due to Lichtheimia corymbifera After a Traffic Accident.

A case report of cutaneous mucormycosis and obstacles to early diagnosis is presented. A 38-year-old male was involved in a car accident that led to amputation of both lower limbs. Subsequently, he developed fungal wound infection of the left lower limb stump. The infection was detected very early, although the diagnosis was difficult because only a small area was affected and histopathological examination was initially negative. The infection was proven by microscopy, culture and histopathology. The isolate was identified by sequencing of the rDNA ITS region gene (internal transcribed spacer region of ribosomal DNA) as Lichtheimia corymbifera. Liposomal amphotericin B and surgery were successful in management of the disease.

Effects of hypertonic saline and mannitol on cortical cerebral microcirculation in a rabbit craniotomy model.

BACKGROUND: Hyperosmolar solutions have been used in neurosurgery to modify brain bulk and prevent neurological deterioration. The aim of this animal study was to compare the short-term effects of equivolemic, equiosmolar solutions of mannitol and hypertonic saline (HTS) on cerebral cortical microcirculation in a rabbit craniotomy model. METHODS: Rabbits (weight, 2.0-3.0 kg) were anesthetized, ventilated mechanically, and subjected to a craniotomy. The animals were allocated randomly to receive a 3.75 ml/kg intravenous infusion of either 3.2% HTS (group HTS, n = 8) or 20% mannitol (group MTL, n = 8). Microcirculation in the cerebral cortex was evaluated using sidestream dark-field (SDF) imaging before and 20 min after the end of the 15-min HTS infusion. Global hemodynamic data were recorded, and blood samples for laboratory analysis were obtained at the time of SDF image recording. RESULTS: No differences in the microcirculatory parameters were observed between the groups before the use of osmotherapy. After osmotherapy, lower proportions of perfused small vessel density (P = 0.0474), perfused vessel density (P = 0.0457), and microvascular flow index (P = 0.0207) were observed in the MTL group compared with those in the HTS group. CONCLUSIONS: Our findings suggest that an equivolemic, equiosmolar HTS solution better preserves perfusion of cortical brain microcirculation compared to MTL in a rabbit craniotomy model.

Fractionated plasmatic separation and adsorption does not alter haemodynamic parameters in experimental acute liver failure.

OBJECTIVE: Acute liver failure (ALF) is a rare disease with a bad prognosis. Its start is accompanied by haemodynamic instability. The aim of our study was to evaluate the influence of fractionated plasmatic separation and adsorption (FPSA) on body haemodynamics using a large animal experimental model of ALF. METHODS: ALF was induced by the devascularisation of 21 laboratory pigs. FPSA was applied in 14 animals and seven animals formed a control group. Values of systemic vascular resistance index (SVRI), heart rate (HR), pulmonary artery wedge pressure (PAWP) and cardiac index (CI) at hours 3, 6, 9 and 12 of the experiment were compared. The values from laboratory tests conducted with FPSA-treated vs. untreated ALF animals were compared using Student's t-test, paired or unpaired, as required, and Mann-Whitney U-test using EXCEL and QUATRO spreadsheet applications. RESULTS: We found no significant differences in mean arterial pressure, SVRI, or plasma lactate (p>0.05) in the FPSA-treated group but there was a significant decrease(p<0.05) in intracranial pressure (ICP). Furthermore, we observed a significant decrease in HR at hour 3. A significant increase in CI at hour 9 and a significant decrease in pulmonary artery wedge pressure at hours 6 and 12 were also observed. CONCLUSION: Our study of FPSA application (Prometheus device) for treatment of experimental ALF in a large animal model did not confirm the earlier reported development of changes in body haemodynamics.

Survival and predictive factors of clinical outcome in patients with severe acquired brain injury.

BACKGROUND: Despite the many tools available to modern medicine, predicting the neurological and functional status of patients after severe brain injury remains difficult. AIM: This analysis evaluates the outcomes of patients with the most severe degree of cerebral function impairment. DESIGN: Retrospective cohort study. SETTING: Patients hospitalized in the long-term Intensive Care Unit (ICU) department in the Military University Hospital in Prague between 2015-2022. POPULATION: We analyzed patients with severe acquired brain damage from five distinct etiologies whose initial Glasgow Coma Scale (GCS) score was eight or less upon admission to ICU due to neurological damage. METHODS: Several parameters reflecting the patients' clinical status were evaluated. Overall survival after discharge from the ICU was calculated according to the Kaplan-Meier model with comparison between traumatic (TR) and non-traumatic (non-TR) etiologies. RESULTS: The analyzed cohort of 221 patients consisted of 116 patients of TR and 105 of non-TR etiology. There was no significant difference in overall survival between TR and non-TR groups. The length of hospitalization in the ICU was similar in both groups with a median of 94 days. The majority of patients had an improvement of GCS during the hospitalization with a median improvement of five points. GCS improvement occurred in the vast majority of patients regardless of TR or non-TR etiology. CONCLUSIONS: We did not observe a statistically significant difference in mortality or log-term neurological status between patients with severe brain injury of traumatic or non-traumatic etiology for the duration of our follow-up. The majority of patients had improved GCS, were successfully decannulated, but remained disabled with severe limitations of functional independence. CLINICAL REHABILITATION IMPACT: The return of the patient to normal life is a rehabilitation challenge, regardless of the etiology of brain injury, and is extremely influenced by the level of development of neurorehabilitation programs in individual institutions, the severity of brain injury, and the individual motivation of the patient.

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.

Evaluation of the insertion parameters and complications of the i-gel Plus airway device for maintaining patent airway during planned procedures under general anaesthesia: a protocol for a prospective multicentre cohort study.

INTRODUCTION: Supraglottic airway devices represent a less invasive method of airway management than tracheal intubation during general anaesthesia. Their continued development is focused mainly on improvements in the insertion success rate and minimalisation of perioperative and postoperative complications. The i-gel Plus is a novel, anatomically preshaped supraglottic airway device which achieves a perilaryngeal seal due to a non-inflatable cuff made of a soft thermoplastic elastomer. The purpose of this cohort study is to assess the success rate of the i-gel Plus use during elective procedures under general anaesthesia, its intraoperative performance, and the degree of postoperative complications. METHODS AND ANALYSIS: This is a multicentre, prospective, interventional cohort study. The enrolment will take place in seven centres in four European countries. We plan to enrol 2000 adult patients in total, who are scheduled for elective surgery under general anaesthesia, and with an indication for use of a supraglottic airway device for management of their airway. The study is projected to run over a period of 18 months. The primary outcome of the study is the total success rate of the i-gel Plus insertion in terms of successful ventilation and oxygenation through the device. Secondary outcomes include perioperative parameters, such as insertion time, seal/leak pressures, number of insertion attempts and postoperative adverse events and complications. Postoperative follow-up will be performed at 1 hour, 24 hours in all patients, and for selected patients at 3 and 6 months. ETHICS AND DISSEMINATION: The cohort study has received the following ethical approvals: General University Hospital Prague, University Hospital Olomouc, University Military Hospital Prague, University Hospital Barcelona, University Hospital Lodz, Antrim Area Hospital, Craigavon Area Hospital, Office for Research Ethics Committees Northern Ireland. The results will be published in peer-reviewed journals and presented at relevant anaesthesia conferences. TRIAL REGISTRATION NUMBER: ISRCTN86233693;Pre-results.

Effects of pleural effusion drainage in the mechanically ventilated patient as monitored by electrical impedance tomography and end-expiratory lung volume: A pilot study.

PURPOSE: In patients with pleural effusion (PLE) monitored by Electrical Impedance Tomography (EIT) an increase in end-expiratory lung impedance (EELI) is observed following evacuation of the PLE. We aimed at differentiating the effect of fluid removal from lung reaeration and describe the change in ventilation distribution. MATERIALS AND METHODS: Mechanically ventilated patients were monitored by EIT during PLE evacuation. End-expiratory lung volume (EELV) was measured concurrently. We included a calibration maneuver consisting of an increase in positive end-expiratory pressure (PEEP) by 5 cm H2O. The ratio ΔEELI/ΔEELV was used to compare changes of EELI and EELV in response to the calibration maneuver and PLE evacuation. At the same time we assessed distribution of ventilation using changes in tidal variation. RESULTS: PLE removal resulted in a 6-fold greater increase in ΔEELI/ΔEELV when compared to the calibration maneuver (r = 0.84, p < .05). We observed a relative increase in ventilation in the area of the effusion (mean 7.1%, p < .006) and an overall shift of ventilation to the dorsal fraction of the lungs (mean 8%, p < .0002). CONCLUSIONS: The increase in EELI in the EIT image after PLE removal was primarily due to the removal of the conductive effusion fluid.

Ultrasound detection of diaphragm position in the region for lung monitoring by electrical impedance tomography during laparoscopy.

BACKGROUND AND AIMS: During laparoscopic surgery, a capnoperitoneum is created to optimize the operating space for surgeons. One effect of this is abdominal pressure which alters the physiological thoraco-abdominal configuration and pushes the diaphragm and lungs cranially. Since the lung image acquired by electrical impedance tomography (EIT) depends on the conditions within the thorax and abdomen, it is crucial to know the diaphragm position to determine the effect of diaphragm shift on EIT thorax image. METHODS: The presence of diaphragm in the region of EIT measurement was determined by ultrasound in 20 patients undergoing laparoscopic surgery. Data were obtained in the supine position during spontaneous breathing in a mechanically ventilated patient under general anesthesia with muscle relaxation and in a mechanically ventilated patient under general anesthesia with muscle relaxation during capnoperitoneum. RESULTS: The diaphragm was shifted cranially during capnoperitoneum. The diaphragm detection rate rose by 10% during capnoperitoneum at the fifth intercostal space, from 55% to 65% and by 10% from 0% at mid-sternal level compared to mechanical ventilation without capnoperitoneum. CONCLUSION: The diaphragm was detected in the area contributing to the creation of the thoracic EIT image. Considering the cranial shift of diaphragm caused by excessive intra-abdominal pressure, the impedance changes in the abdomen and the principle of EIT, we assume there could be a significant impact on EIT image of the thorax acquired during capnoperitoneum. For this reason, for lung monitoring using EIT during capnoperitoneum, the manufacturer's recommendation for electrode belt position is not appropriate. The study was registered in ClinicalTrials.gov with an identifier NCT03038061.

Cardiovascular disease predictors and adipose tissue macrophage polarization: Is there a link?

Background The risk of cardiovascular disease is closely connected to adipose tissue inflammation. The links between cardiovascular risk predictors and pro and anti-inflammatory macrophages in human adipose tissue were analysed to gain an insight into the pathophysiology of cardiovascular disease. Design Subcutaneous and visceral adipose tissues were obtained from 79 subjects, 52 living kidney donors (during nephrectomy) and 27 patients with peripheral artery disease (during arterial tree reconstruction). Methods Macrophage subsets were isolated from adipose tissues and analysed by flow cytometry using CD14, CD16, CD36 and CD163 monoclonal antibodies. The mutually adjusted differences of phagocytic pro-inflammatory (CD14 + CD16 + CD36high), anti-inflammatory (CD14 + CD16-CD163+) and transitional subsets of macrophages were analysed in relation to cardiovascular predictors (sex, age, body mass index, smoking, hypercholesterolaemia, hypertension and statin treatment). Results Age, male sex and hypercholesterolaemia were closely positively associated with the phagocytic pro-inflammatory macrophage subset in visceral adipose tissues. Interestingly, the proportion of phagocytic pro-inflammatory macrophages was relevantly decreased by statin therapy. A strong positive association of body mass index to the phagocytic pro-inflammatory subset was found in subcutaneous adipose tissues only. A minor transitional subpopulation, CD14 + CD16 + CD36lowCD163+, increased with age in both adipose tissues. This transitional subpopulation was also negatively associated with obesity and hypercholesterolaemia in visceral adipose tissues. Conclusion An effect of cardiovascular risk predictors on adipose tissue macrophage subpopulations was revealed. Interestingly, while age, male sex and hypercholesterolaemia were connected with the pro-inflammatory macrophage subpopulation in visceral adipose tissues, body mass index had a prominent effect in subcutaneous adipose tissues only. A decreasing effect of statins on these pro-inflammatory macrophages was documented.

Induction of procalcitonin in liver transplant patients treated with anti-thymocyte globulin.

INTRODUCTION: The aim of this study was to compare the early postoperative kinetics of procalcitonin (PCT) and C-reactive protein (CRP) serum levels in patients undergoing orthotopic liver transplantation (OLTx) with different immunosuppressive regimens. METHODS: PCT and CRP serum concentrations were measured in a group of 28 OLTx recipients before induction of anesthesia, at 4 and 8 hours following graft reperfusion, and daily until postoperative day 4. The same parameters were determined in 12 patients undergoing liver resection without conjunctive immunosuppressive therapy. Summary data are expressed as medians and ranges. Two-tailed nonparametric tests were performed and considered significant at p values of less than 0.05. RESULTS: The highest serum levels of PCT (median 3.0 ng/mL, minimum 1.4 ng/mL, maximum 13.9 ng/mL) were found in patients after OLTx without ATG therapy, on postoperative day 1. In patients with ATG administration, PCT levels were highly increased on postoperative day 1 (median 53.0 ng/mL, minimum 7.9 ng/mL, maximum 249.1 ng/mL). Thereafter, PCT values continuously decreased independently of further ATG administration in both groups of patients. No evidence of infection was present in either group. In 12 patients undergoing liver resection, peak serum PCT levels did not exceed 3.6 ng/mL. CRP serum levels in a group of patients with and without ATG therapy increased significantly on postoperative day 1, followed by a decrease. The highest levels of CRP were found in patients after liver resection on postoperative day 2 and decreased thereafter. CONCLUSION: ATG administration to patients with OLTx is associated with an increase in serum PCT levels, with peak values on postoperative day 1, and this was in the absence of any evidence of infection. The results of this study indicate that ATG immunosuppressive therapy is a stimulus for the synthesis of PCT.

A Randomized Comparison of Bougie-Assisted and TracheoQuick Plus Cricothyrotomies on a Live Porcine Model.

OBJECTIVES: Cricothyrotomy is a rescue procedure in "cannot intubate, cannot oxygenate" scenarios where other methods of nonsurgical airway management have failed. We compared 2 cuffed cricothyrotomy sets, bougie-assisted cricothyrotomy (BACT) and novel percutaneous TracheoQuick Plus, on a live porcine model in a simulated periarrest situation. METHODS: Thirty-four anesthetized minipigs were randomly allocated into two groups: BACT technique (n = 17) and TracheoQuick Plus (n = 17). The primary outcome was duration of cricothyrotomy while secondary outcomes were total success rate, number of attempts, location of incision, changes in heart rate, oxygen saturation, and the incidence of complications. RESULTS: BACT was significantly faster than TracheoQuick Plus cricothyrotomy, with a median time of 69 sec (IQR 56-85) versus 178 sec (IQR 152-272). The total success rate was without difference. 94% of BACT was performed successfully on the first attempt, while in the TracheoQuick Plus group, it was only 18% (P < 0.001). Trauma to the posterior tracheal wall was observed once in the BACT group and 5 times in the TracheoQuick Plus group. Oxygen saturation was significantly higher in the BACT group both during and after the procedure. CONCLUSIONS: BACT is superior to TracheoQuick Plus cricothyrotomy on a live animal model.

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.