Background: Traumatic hemothorax is a common complication of blunt chest trauma and remains associated with significant morbidity and mortality. Although contrast-enhanced computed tomography (CT) is central to diagnosis, the optimal criteria for selecting patients who require invasive management versus conservative treatment remain unclear. This study aimed to evaluate the management strategies and clinical outcomes of traumatic hemothorax and to identify predictors of surgical intervention and postoperative complications. Methods: We conducted a retrospective, single-center cohort study including adult patients admitted to a Level II Emergency Department with hemothorax following blunt chest trauma between January 2019 and December 2024. Primary outcomes were the need for urgent chest drainage or surgery. Secondary outcomes included postoperative complications, length of hospital stay, and intensive care unit admission. Univariable and multivariable regression analyses were performed to identify factors associated with surgical intervention and complications. Results: Seventy-two patients were included (mean age 60.0 ± 20.5 years; 80.6% male). Rib fractures were the most common cause of hemothorax (61.1%). Chest tube placement was required in 70.8% of cases, and 31.9% underwent urgent surgical intervention. Active bleeding on contrast-enhanced CT was identified in 16.7% of patients and was the only independent predictor of urgent surgery (OR 3.85, 95% CI 1.07-13.88; p = 0.039). The initial volume of blood drained after chest tube insertion did not differ between surgically and non-surgically managed patients. Conservative management was successful in 19.4% of cases. Postoperative complications occurred in five patients and were associated with a higher comorbidity burden. Overall mortality was 5.6%. Conclusions: In traumatic hemothorax following blunt chest trauma, active bleeding on contrast-enhanced CT seems to be the strongest predictor of urgent surgical intervention, whereas initial pleural drainage volume alone is not. Conservative management is safe in selected patients, while comorbidities influence postoperative outcomes. Multidisciplinary management and accurate radiological assessment are essential to guide timely and appropriate treatment.

Background: In patients aged 65 years and older who experience severe trauma, their underlying health status significantly influences overall mortality. This study aimed to determine whether computed tomography (CT) evaluation of skeletal muscle quality could serve as an effective risk stratification tool in the emergency department (ED) for this population. Methods: Retrospective observational study conducted between January 2018 and September 2021, including consecutive patients ≥65 years admitted to the ED for a major trauma (defined as having an Injury Severity Score > 15). Muscle quality analysis was made by specific software (Slice-O-Matic v5.0, Tomovision®, Montreal, QC, Canada) on a CT-scan slice at the level of the third lumbar vertebra (L3). Results: A total of 263 patients were included (72.2% males, median age 76 (71–82)), of whom 88 (33.5%) died during hospitalization. The deceased patients had a significantly lower skeletal muscle area density (SMAd) compared with survivors. The multivariate Cox regression analysis confirmed that SMAd <38 at the ED admission was an independent risk for death (adjusted HR 1.68 [1.1–2.7]). The analysis also revealed that, among the survivors after the first week of hospitalization, the patients with low SMAd had an increased risk of death (adjusted HR 3.12 [1.2–7.9]). Conclusions: Skeletal muscle density assessed by a CT scan at ED admission may represent a valuable prognostic marker for risk stratification patients ≥65 years with major trauma. In patients with SMAd <38 HU the in-hospital mortality risk could be particularly increased after the first week of hospitalization.

Background: In patients over 65 years who experience severe trauma the underlying health status has a significant impact on overall mortality. This study aims to assess if CT evaluation of skeletal muscle quality could be a risk stratification tool in the ED for these patients. Methods: Retrospective observational study between January 2018 and September 2021, including consecutive patients ≥ 65 years admitted to the ED for a major trauma (defined as Injury Severity Score > 15). Muscle quality analysis was made by specific software (Slice-O-Matic v5.0, Tomovision®, Montreal, QC, Canada) on a CT-Scan slice at the level of the third lumbar vertebra. Results: 263 patients were included (72.2% males, median age 76 [71-82]), and 88 (33.5%) deceased. The deceased patients had a significantly lower skeletal muscle area density (SMAd) compared to survivors. The multivariate Cox regression analysis confirmed that SMAd < 38 at the ED admission was an independent risk for death (adjusted HR 1.68 [1.1 – 2.7]). The analysis also revealed that, among the survivors after the first week of hospitalization, the patients with low SMAd had an increased risk of death (adjusted HR 3.12 [1.2 – 7.9]). Conclusions: The skeletal muscle density evaluated by a CT scan at ED admission could be a valuable risk stratification tool for patients ≥ 65 years with major trauma. In patients with SMAd <38 HU the in-hospital mortality risk could be particularly increased after the first week of hospitalization.

BACKGROUND:Positive end-expiratory pressure (PEEP) can potentially modulate inspiratory effort (ΔPes), which is the major determinant of self-inflicted lung injury. RESEARCH QUESTION:Does high PEEP reduce ΔPes in patients with moderate-to-severe ARDS on assisted ventilation? STUDY DESIGN AND METHODS:Sixteen patients with Pao2/Fio2 ≤ 200 mm Hg and ΔPes ≥ 10 cm H2O underwent a randomized sequence of four ventilator settings: PEEP = 5 cm H2O or PEEP = 15 cm H2O + synchronous (pressure support ventilation [PSV]) or asynchronous (pressure-controlled intermittent mandatory ventilation [PC-IMV]) inspiratory assistance. ΔPes and respiratory system, lung, and chest wall mechanics were assessed with esophageal manometry and occlusions. PEEP-induced alveolar recruitment and overinflation, lung dynamic strain, and tidal volume distribution were assessed with electrical impedance tomography. RESULTS:ΔPes was not systematically different at high vs low PEEP (pressure support ventilation: median, 20 cm H2O; interquartile range (IQR), 15-24 cm H2O vs median, 15 cm H2O; IQR, 13-23 cm H2O; P = .24; pressure-controlled intermittent mandatory ventilation: median, 20; IQR, 18-23 vs median, 19; IQR, 17-25; P = .67, respectively). Similarly, respiratory system and transpulmonary driving pressures, tidal volume, lung/chest wall mechanics, and pendelluft extent were not different between study phases. High PEEP resulted in lower or higher ΔPes, respiratory system driving pressure, and transpulmonary driving pressure according to whether this increased or decreased respiratory system compliance (r = -0.85, P < .001; r = -0.75, P < .001; r = -0.80, P < .001, respectively). PEEP-induced changes in respiratory system compliance were driven by its lung component and were dependent on the extent of PEEP-induced alveolar overinflation (r = -0.66, P = .006). High PEEP caused variable recruitment and systematic redistribution of tidal volume toward dorsal lung regions, thereby reducing dynamic strain in ventral areas (pressure support ventilation: median, 0.49; IQR, 0.37-0.83 vs median, 0.96; IQR, 0.62-1.56; P = .003; pressure-controlled intermittent mandatory ventilation: median, 0.65; IQR, 0.42-1.31 vs median, 1.14; IQR, 0.79-1.52; P = .002). All results were consistent during synchronous and asynchronous inspiratory assistance. INTERPRETATION:The impact of high PEEP on ΔPes and lung stress is interindividually variable according to different effects on the respiratory system and lung compliance resulting from alveolar overinflation. High PEEP may help mitigate the risk of self-inflicted lung injury solely if it increases lung/respiratory system compliance. TRIAL REGISTRATION:ClinicalTrials.gov; No.: NCT04241874; URL: www. CLINICALTRIALS:gov.

PURPOSE:To assess the accuracy of differential time to positivity (DTP) method for the diagnosis of catheter-related bloodstream infections (CRBSI) in the routine practice of our intensive care unit (ICU). MATERIALS AND METHODS:Over a five-year study period, ICU patients with a central venous catheter in place for ≥48 h and undergoing DTP test with catheter tip culture were analyzed. We investigated: the accuracy of DTP test with the usual threshold of 120 min in confirming the clinical suspicion of CRBSI; the most accurate threshold value of DTP to detect CRBSI; the diagnostic accuracy of the ratio (rather than the difference) between times to positivity. RESULTS:Among 278 episodes of paired blood cultures, 13% were CRBSIs. DTP value ≥120 min used for the diagnosis of CRBSI yielded 41% sensitivity and 74% specificity. Performance of DTP values in predicting CRBSI was low (AUC = 0.60 [95%CI: 0.48-0.72]). Cutoff value of the ratio between times to positivity was 0.80, with 46% sensitivity and 79% specificity. CONCLUSIONS:The routine use of the DTP method at any cutoff point has inadequate accuracy in detecting CRBSI in the real every day clinical practice. Not even the ratio between times to positivity seems to be clinically useful.

OBJECTIVE:To assess epidemiological, clinical and neuroimaging features of acute confusional state in the Headache and Neurological Deficits with cerebrospinal fluid Lymphocytosis (HaNDL) syndrome.BACKGROUND:HaNDL is an increasingly recognized syndrome in which migraine-like headache episodes accompanied by hemiparaesthesia and/or hemiparesis and/or dysphasia are associated to CSF lymphocytic pleocytosis. The International Classification of Headache Disorders (ICHD-3) includes HaNDL syndrome in group 7 "headache attributed to non-vascular intracranial disorder" code 7.3.5, and lists the HaNDL-associated signs/symptoms that may be found less frequently. Confusional state is not mentioned in the 7.3.5-ICHD-3 "notes" or "comments" section as part of the HaNDL neurological spectrum. Moreover, the acute confusional state pathogenesis in HaNDL syndrome remains still uncertain and debated.METHODS:Here, we report a 32-year-old male who complained episodes of migraine-like headache and left hemiparaesthesia complicated by confusional state which led to discovering CSF lymphocytosis. Since other workup to determine the cause of his symptoms was otherwise negative, he was diagnosed as having HaNDL syndrome. We also ascertained and reviewed all available reports of HaNDL to assess the significance of confusional state in this syndrome.RESULTS:The search yielded 159 HaNDL cases among single reports and small/large series. Out of 159 patients who fulfilled the inclusion criteria for HaNDL according to the current ICHD at the time of diagnosis, 41 (25.7%) presented with acute confusional state. Among 41 HaNDL patients with confusional state, 16 (66.6%) out of 24 who underwent spinal tap had increased opening pressure.CONCLUSION:We propose that a mention of acute confusional state may be included in the "comments" section of "7.3.5-syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL)," when ICHD-3 diagnostic criteria will be updated. Moreover, we speculate that intracranial hypertension may play a role in the pathogenesis of the acute confusional state associated to HaNDL syndrome. Larger case series are needed to evaluate this hypothesis.

Aim: To compare the ability of the most used Early Warning Scores (EWS) to identify adult patients at risk of poor outcomes in the emergency department (ED).Methods: Single-center, retrospective observational study. We evaluated the digital records of consecutive ED admissions in patients > 18 years from 2010 to 2019 and calculated NEWS, NEWS2, MEWS, RAPS, REMS, and SEWS based on parameters measured on ED arrival. We assessed the discrimination and calibration performance of each EWS in predicting death/ICU admission within 24 hours using ROC analysis and visual calibration. We also measured the relative weight of clinical and physiological derangements that identified patients missed by EWS risk stratification using neural network analysis.Results: Among 225,369 patients assessed in the ED during the study period, 1941 (0.9%) were admitted to ICU or died within 24 hours. NEWS was the most accurate predictor (area under the receiver operating characteristic [AUROC] curve 0.904 [95% CI 0.805-0.913]), followed by NEWS2 (AUROC 0.901). NEWS was also well calibrated. In patients judged at low risk (NEWS < 2), 359 events occurred (18.5% of the total). Neural network analysis revealed that age, systolic BP, and temperature had the highest relative weight for these NEWS-unpredicted events.Conclusions: NEWS is the most accurate EWS for predicting the risk of death/ICU admission within 24 h from ED arrival. The score also had a fair calibration with few events occurring in patients classified at low risk. Neural network analysis suggests the need for further improvements by focusing on the prompt diagnosis of sepsis and the development of practical tools for the measurement of the respiratory rate.

Background: Descending necrotizing mediastinitis (DNM) is a severe, life-threatening complication of oropharyngeal infections with cervical necrotizing fasciitis. In this study, we aimed to identify any possible factors that correlate with favorable outcomes. Methods: We retrospectively analyzed our series of 18 patients who underwent surgical treatment for DNM from a cervical abscess. Gender, age, symptoms, etiopathogenesis, comorbidities, time to surgery from diagnosis, degree of diffusion, identified microorganisms, surgical procedure, days in the intensive care unit, need for tracheostomy, complications, and surgical outcomes were reviewed. Results: The main type of surgery was thoracotomy + cervicotomy in eight cases (50.0%), followed by cervicotomy +VATS in four (22.2%). Seven patients (38.9%) had two or more surgeries; a bilateral operation was necessary for four patients. Evaluating the risk factors associated with post-operative complications, age ≥ 60 years (p:0.031), cervicotomy alone as surgical approach (p = 0.040), and the bilateral approach (p = 0.048) resulted in significance in terms of the univariate analysis; age ≥ 60 years (p = 0.04) and cervical approach (p = 0.05) maintained their significance in terms of the multivariate analysis. Conclusions: The low mortality of our series emphasizes the importance of an extensive and immediate surgical drainage of both the neck and the mediastinum. Mediastinal drainage from cervicotomy seems to be a risk factor for post-operative complications. Minimally invasive surgery on the chest cavity, such as with Uniportal-VATS, could be a good approach above all in elderly patients and all those cases where bilateral access is required.

We report a case of primary malposition of a PICC inserted by guidewire replacement in the emergency room. Intraprocedural tip location by intracavitary electrocardiography was not feasible because the patient had atrial fibrillation; intraprocedural tip location by ultrasound (using the so-called "bubble test") showed that the tip was not in the superior vena cava or in the right atrium. A post-procedural chest X-ray confirmed the malposition but could not precise the location of the tip. A CT scan (scheduled for other purposes) finally visualized the tip in a very unusual location, the left pericardiophrenic vein.

BACKGROUND: The efficacy of noninvasive oxygenation strategies (NIOS) in treating COVID-19 disease is unknown. We conducted a prospective observational study to assess the rate of NIOS failure in subjects treated in the ICU for hypoxemic respiratory failure due to COVID-19. METHODS: Patients receiving first-line treatment NIOS for hypoxemic respiratory failure due to COVID-19 in the ICU of a university hospital were included in this study; laboratory data were collected upon arrival, and 28-d outcome was recorded. After propensity score matching based on Simplified Acute Physiology (SAPS) II score, age, PaO2/FIO2 and PaCO2 at arrival, the NIOS failure rate in subjects with COVID-19 was compared to a previously published cohort who received NIOS during hypoxemic respiratory failure due to other causes. RESULTS: A total of 85 subjects received first-line treatment with NIOS. The most frequently used methods were helmet noninvasive ventilation and high-flow nasal cannula; of these, 52 subjects (61%) required endotracheal intubation. Independent factors associated with NIOS failure were SAPS II score (P = .009) and serum lactate dehydrogenase at enrollment (P = .02); the combination of SAPS II score ≥ 33 with serum lactate dehydrogenase ≥ 405 units/L at ICU admission had 91% specificity in predicting the need for endotracheal intubation. In the propensity-matched cohorts (54 pairs), subjects with COVID-19 showed higher risk of NIOS failure than those with other causes of hypoxemic respiratory failure (59% vs 35%, P = .02), with an adjusted hazard ratio of 2 (95% CI 1.1–3.6, P = .01). CONCLUSIONS: As compared to hypoxemic respiratory failure due to other etiologies, subjects with COVID-19 who were treated with NIOS in the ICU were burdened by a 2-fold higher risk of failure. Subjects with a SAPS II score ≥ 33 and serum lactate dehydrogenase ≥ 405 units/L represent the population with the greatest risk.

Non-invasive ventilation (NIV) is increasingly being used to treat episodes of acute respiratory failure not only in critical care and respiratory wards, but also in emergency departments.Aim of this review is to summarize the current indications for the management of NIV for respiratory failure.Current literature about the topic was reviewed and critically reported to describe the rationale and physiologic advantages of NIV in various situations of respiratory failure.Early NIV use is commonly associated with the significant decrease in endotracheal intubation rate, the incidence of infective complications (especially ventilatory associated pneumonia), Intensive Care Units and the length of hospital stay and, in selected conditions, also in mortality rates. Severe acute exacerbation of chronic obstructive pulmonary disease (pH<7.35 and relative hypercarbia) and acute cardiogenic pulmonary oedema are the most common NIV indications; in these conditions NIV advantages are clearly documented. Not so evident are the NIV benefits in hypoxaemic respiratory failure occurring without prior chronic respiratory disease (De novo respiratory failure). One recent randomized control trial reported in hypoxaemic respiratory failure a survival benefit of high-flow nasal cannulae over standard oxygen therapy and bilevel NIV. Evidence suggests the advantages of NIV also in respiratory failure in immunocompromised patients or chest trauma patients. Use during a pandemic event has been assessed in several observational studies but remains controversial; there also is not sufficient evidence to support the use of NIV treatment in acute asthma exacerbation.NIV eliminates morbidity related to the endotracheal tube (loss of airway defense mechanism with increased risk of pneumonia) and in selected conditions (COPD exacerbation, acute cardiogenic pulmonary edema, immunosuppressed patients with pulmonary infiltrates and hypoxia) is clearly associated with a better outcome in comparison to conventional invasive ventilation. However, NIV is associated with complications, especially minor complications related to interface. Major complications like aspiration pneumonia, barotrauma and hypotension are infrequent.

BACKGROUND: The aim of this study is to determine relationships between lung aeration assessed by lung ultrasound (WS) with non-invasive ventilation (NIMV) outcome, intensive care unit (ICU) admission and mechanical ventilation (MV) needs in COVID-19 respiratory failure. METHODS: A cohort of adult patients with COVID-19 respiratory failure underwent LUS during initial assessment. A simplified LUS protocol consisting in scanning six areas, three for each side. was adopted. A score from 0 to 3 was assigned to each area. Comprehensive LUS score (LUSsc) was calculated as the sum of the score in all areas. LUSsc, the amount of involved sonographic lung areas (LUSq), the number of lung quadrants radiographically infiltrated and the degree of oxygenation impairment at admission (SpO(2)/FiO(2) ratio) were compared to NIMV Outcome, MV needs and ICU admission. RESULTS: Among 85 patients prospectively included in the analysis, 49 of 61 needed MV. LUSsc and LUSq were higher in patients who required MV (median 12 [IQR 8-14] and median 6 [IQR 4-6], respectively) than in those who did not (6 [IQR 2-9] and 3 [IQR 1-5], respectively), both P<0.001. NIMV trial failed in 26 patients out 36. LUSsc and LUSq were significantly higher in patients who failed NIMV than in those who did not. From ROC analysis, LUSsc >= 12 and LUSq >= 5 gave the best cut-off values for NIMV failure prediction (AUC=0.95, 95% CI 0.83-0.99 and AUC=0.81, 95% CI 0.65-0.91, respectively). CONCLUSIONS: Our data suggest LUS as a possible tool for identifying patients who are likely to require MV and ICU admission or to fail a NIMV trial.

PURPOSE:Whether subglottic secretions (SS) culture during invasive mechanical ventilation may aid microbiological surveillance is unknown. We conducted a prospective study to assess SS cultures predictivity of endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) isolates.MATERIALS AND METHODS:109 patients receiving mechanical ventilation for ≥48 hours underwent SS and ETA surveillance cultures twice weekly; blind BAL was performed in case of clinically suspected pneumonia.RESULTS:SS and ETA cultures were fully concordant in 170 (81%-overall accuracy) of 211 sample pairs. As compared to ETA, SS culture global sensitivity and specificity were 84% [95%CI: 77 to 91] and 74% [95%CI: 66 to 82]; negative and positive predictive values were 82% and 77%. Forty-four episodes of clinically suspected pneumonia were observed. Compared to BAL, SS culture global sensitivity and specificity were 68% [95%CI: 45 to 81] and 63% [95%CI: 44 to 82]; negative and positive predictive values were both 65%. SS sensitivity, specificity, positive and negative predictive values in anticipating BAL isolates were comparable to ETA (all p > 0.20).CONCLUSIONS:SS cultures show worthy accuracy in identifying ETA isolates, with excellent sensitivity and good negative predictivity. SS cultures may be not inferior to ETA in predicting BAL results in case of ventilator-associated pneumonia.TRIAL REGISTRATION:ClinicalTrials.gov, NCT03153241. Registered on 15 May 2017, https://clinicaltrials.gov/ct2/show/NCT03153241.

Background: Non-invasive ventilation (NIV) is increasingly being used to treat episodes of acute respiratory failure not only in critical care and respiratory wards, but also in emergency departments.Aim: Aim of this review is to summarize the current indications for the management of NIV for respiratory failure.Methods: Current literature about the topic was reviewed and critically reported to describe the rationale and physiologic advantages of NIV in various situations of respiratory failure. Results: Early NIV use is commonly associated with the significant decrease in endotracheal intubation rate, the incidence of infective complications (especially ventilatory associated pneumonia), Intensive Care Units and the length of hospital stay and, in selected conditions, also in mortality rates.Severe acute exacerbation of chronic obstructive pulmonary disease (pH<7.35 and relative hypercarbia) and acute cardiogenic pulmonary oedema are the most common NIV indications; in these conditions NIV advantages are clearly documented. Not so evident are the NIV benefits in hypoxaemic respiratory failure occurring without prior chronic respiratory disease (De novo respiratory failure). One recent randomized control trial reported in hypoxaemic respiratory failure a survival benefit of high-flow nasal cannulae over standard oxygen therapy and bilevel NIV. Evidence suggests the advantages of NIV also in respiratory failure in immunocompromised patients or chest trauma patients.Use during a pandemic event has been assessed in several observational studies but remains controversial; there also is not sufficient evidence to support the use of NIV treatment in acute asthma exacerbation.Conclusion: NIV eliminates morbidity related to the endotracheal tube (loss of airway defense mechanism with increased risk of pneumonia) and in selected conditions (COPD exacerbation, acute cardiogenic pulmonary edema, immunosuppressed patients with pulmonary infiltrates and hypoxia) is clearly associated with a better outcome in comparison to conventional invasive ventilation. However, NIV is associated with complications, especially minor complications related to interface. Major complications like aspiration pneumonia, barotrauma and hypotension are infrequent.

Background: In symptomatic patients, admitted in emergency department for acute chest pain and dyspnea, who require an urgent treatment, a rapid diagnosis and prompt management of massive pleural effusion or hemothorax can be lifesaving. Aim: The aim of this review was to summarize the current diagnostic and therapeutic approaches for the management of the main types of pleural effusions that physicians can have in an emergency department setting. Methods: Current literature about the topic was reviewed and critically reported, adding the experience of the authors in the management of pleural effusions in emergency settings. Results: The paper analyzed the main types of pleural effusions that physicians can have to treat. It illustrated the diagnostic steps by the principal radiological instruments, with a particular emphasis to the role of ultrasonography, in facilitating diagnosis and guiding invasive procedures. Then, the principal procedures, like thoracentesis and insertion of small and large bore chest drains, are indicated and illustrated according to the characteristics and the amount of the effusion and patient clinical conditions. Conclusion: The emergency physician must have a systematic approach that allows rapid recognition, clinical cause identification and definitive management of potential urgent pleural effusions.

Necrotizing fasciitis (NF) is a rare infection that spreads rapidly along the subcutaneous soft tissue planes. NF rarely involves the periorbital region due to the excellent blood supply of this region. We report a case of periorbital necrotising fasciitis following herpes zoster (HZ) in an immunocompromised 70-year-old patient with a dramatically rapid evolution into septic shock. In our patient, the surprisingly rapid spread of the bacterial superinfection led the periorbital cellulitis to turn into frank NF within 2 hours, with an overwhelming evolution. Despite the prompt start of a systemic antibiotic therapy and the immediate surgical intervention, the patient had a septic shock; she was treated in ITU for 31 days and then discharged to a medical ward and eventually died for a mix of complications of the medical treatment and comorbidities. This case is unique because any documented cases of periorbital NF triggered by HZ had never led to a septic shock and death. Ophthalmologists should be aware that even common skin lesions caused by shingles can determine a dramatic clinical picture, in presence of predisposing factors.

BACKGROUND: Several respiratory abnormalities can be present in primary hypothyroidism and can be reversed with adequate hormone treatment. However, the role of thyroid hormone replacement therapy on the respiratory system in patients with nonthyroidal illness syndrome is still unclear. This physiologic study evaluated the effect of thyroid hormone treatment on respiratory muscle function in subjects with nonthyroidal illness syndrome and while on mechanical ventilation. The primary end point was neuromechanical efficiency, which provides an estimate of the efficiency of diaphragmatic contraction. Secondary end points were the transdiaphragmatic pressure-time product and the swing of the electrical activity of the diaphragm, which reflect the work of breathing and inspiratory effort, respectively. METHODS: Fifteen subjects on mechanical ventilation for >= 48 h and with a diagnosis of nonthyroidal illness syndrome who had a failed spontaneous breathing trial, received intravenous triiodothyronine. The hormone was administered as an intravenous bolus of 0.4 mu g/kg triiodothyronine, followed by continuous perfusion at 0.6 mu g/kg for 24 h. Neuromechanical efficiency was calculated as the ratio between the drop in airway pressure during an expiratory occlusion and the corresponding electrical activity of the diaphragm peak. Recordings were taken at baseline and after 3, 6, and 24 h. RESULTS: After study completion, free triiodothyronine serum concentrations increased in all the subjects (mean +/- SD increase, 0.84 +/- 0.34 pg/mL). Neuromechanical efficiency showed no significant changes throughout the study (mean +/- SD baseline, 1.40 +/- 0.87 cm H2O/mu V; 3 h, 1.28 +/- 0.64 cm H2O/mu V; 6 h, 1.33 +/- 0.87 cm H2O/mu V; 24 h, 1.41 +/- 0.96 cm H2O/mu V). Similarly, no variations in transdiaphragmatic pressure-time product per min (mean +/- SD baseline, 238.1 +/- 124 cm H2O x s/min; 3 h, 242.5 +/- 140.3 cm H2O x s /min; 6 h, 247.5 +/- 161.7 cm H2O x s/min; 24 h, 281.2 +/- 201.2 cm H2O x s/min) or swing of electrical activity of the diaphragm (mean baseline, 20.9 +/- 13.1 mu V; 3 h, 17.2 +/- 8.3 mu V; 6 h, 17.4 +/- 11.3 mu V; 24 h, 20.3 +/- 13.7 mu V) were observed during hormone administration. CONCLUSIONS: In the subjects on mechanical ventilation who were admitted to the ICU with nonthyroidal illness syndrome, thyroid hormone replacement treatment did not yield any benefit on respiratory muscle function when assessed by neuromechanical efficiency, which indicated that, in these subjects restoring normal levels of serum thyroid hormones is debatable.