Predictive Hypoxemic Threshold for Tolerating the Apnea Test While Assessing Death by Neurological Criteria.

BACKGROUND: The apnea test (AT) plays a vital role in diagnosing brain death by evaluating the absence of spontaneous respiratory activity. It entails disconnecting the patient from mechanical ventilation to raise the CO2 partial pressure and lower the pH. Occasionally, the AT is aborted because of safety concerns, such as hypoxemia and hemodynamic instability, to prevent worsening conditions. However, the exact oxygen partial pressure level needed before commencing AT, indicating an inability to tolerate the test, is still uncertain. This study seeks to determine pre-AT oxygen levels linked with a heightened risk of test failure. METHODS: We conducted a retrospective cohort study involving patients suspected of having brain death at the Tel Aviv Medical Center from 2010 to 2022. The primary outcome was defined as an arterial partial O2 pressure (PaO2) level of 60 mmHg or lower at the conclusion of the AT. This threshold is significant because it marks the point at which the saturation curve deflects, potentially leading to rapid deterioration in the patient's oxygen saturation. RESULTS: Among the 70 patients who underwent AT, 7 patients met the primary diagnostic criteria. Patients with a PaO2 ≤ 60 mmHg at the conclusion of the AT exhibited a significantly lower initial median PaO2 of 243.7 mmHg compared with those with higher pre-AT PaO2 levels of 374.8 mmHg (interquartile range 104.65-307.00 and interquartile range 267.8-444.9 respectively, P value = 0.0041). Pre-AT PaO2 levels demonstrated good discriminatory ability for low PaO2 levels according to the receiver operating characteristic (ROC) curve, with an area under the curve of 0.76 (95% confidence interval 0.52-0.99). CONCLUSIONS: PaO2 values at the conclusion of the AT are closely associated with PaO2 values at the beginning of the test. Establishing a cutoff value of approximately 300 mmHg PaO2 at the onset of AT may assist in avoiding saturation drops below 90%.

Outcome and survival following tracheostomy in patients ≥ 85 years old.

PURPOSE: To evaluate percutaneous dilatational tracheostomy in patients ≥ 85 years old: its complication rate and possible risk factors. In addition, to assess prognostic factors for short, intermediate and long term survival following the procedure. METHODS: A retrospective case-control study of 72 patients ≥ 85 years who received percutaneous dilatation tracheotomy (PTD), compared to a control group of younger patients (n = 182). Demographics, clinical and laboratory data were collected. Survival and risk for complications were analyzed. RESULTS: The study group's mean age was 89 ± 4. Twelve patients had complications, three (4.2%) were major. No significant difference was found in overall complication rates between the groups. Cerebrovascular disease with neurologic deficits and pre-procedure albumin levels were significantly associated with complications. Survival rates did not differ in 1 week and 1 month following procedure between study and control group. There was a significant difference in the 1-year survival rates between the patients ≥ 85 years and the control groups (18.1% vs. 34.4%, p = 0.01, respectively). Congestive heart failure, a frailty score > 0.27 and failure to wean from a cannula were associated with reduced 1-year survival. CONCLUSION: PTD is safe for patients ≥ 85 years. Complication risk factors and reduced survival should be discussed with patients and families before conducting tracheostomies. LEVEL OF EVIDENCE: 3b.

Cortisol Levels During First Admission Day Are Associated With Clinical Outcomes in Surgical Critically Ill Patients.

IMPORTANCE: To explore the correlation between cortisol levels during first admission day and clinical outcomes. OBJECTIVES: Although most patients exhibit a surge in cortisol levels in response to stress, some suffer from critical illness-related corticosteroid insufficiency (CIRCI). Literature remains inconclusive as to which of these patients are at greater risk of poor outcomes. DESIGN: A retrospective study. SETTING: A surgical ICU (SICU) in a tertiary medical center. PARTICIPANTS: Critically ill patients admitted to the SICU who were not treated with steroids. MAIN OUTCOMES AND MEASURES: Levels of cortisol taken within 24 hours of admission (day 1 [D1] cortisol) in 1412 eligible patients were collected and analyzed. Results were categorized into four groups: low (0-10 µg/dL), normal (10-25 µg/dL), high (25-50 µg/dL), and very high (above 50 µg/dL) cortisol levels. Primary endpoint was 90-day mortality. Secondary endpoints were the need for organ support (use of vasopressors and mechanical ventilation [MV]), ICU length of stay (LOS), and duration of MV. RESULTS: The majority of patients (63%) had high or very high D1 cortisol levels, whereas 7.6% had low levels and thus could be diagnosed with CIRCI. There were statistically significant differences in 90-day mortality between the four groups and very high levels were found to be an independent risk factor for mortality, primarily in patients with Sequential Organ Failure Assessment (SOFA) less than or equal to 3 or SOFA greater than or equal to 7. Higher cortisol levels were associated with all secondary endpoints. CIRCI was associated with favorable outcomes. CONCLUSIONS AND RELEVANCE: In critically ill surgical patients D1 cortisol levels above 50 mcg/dL were associated with mortality, need for organ support, longer ICU LOS, and duration of MV, whereas low levels correlated with good clinical outcomes even though untreated. D1 cortisol level greater than 50 mcg/dL can help discriminate nonsurvivors from survivors when SOFA less than or equal to 3 or SOFA greater than or equal to 7.

Kinetics of C-reactive protein during extracorporeal membrane oxygenation.

BACKGROUND: The exposure of blood to the artificial circuit during extracorporeal membrane oxygenation (ECMO) can induce an inflammatory response. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation. METHODS: In this retrospective observational study, we analyzed results of daily plasma CRP measurements in 110 critically ill patients, treated with ECMO. We compared CRP levels during the first 5 days of ECMO operation, between different groups of patients according to ECMO configurations, Coronavirus disease 2019 (COVID-19) status, and mechanical ventilation parameters. RESULTS: There was a statistically significant decrease in CRP levels during the first 5 days of veno-venous (VV) ECMO (173 ± 111 mg/L, 154 ± 107 mg/L, 127 ± 97 mg/L, 114 ± 100 mg/L and 118 ± 90 mg/L for days 1-5 respectively, p < 0.001). Simultaneously, there was a significant reduction in ventilatory parameters, as represented by the mechanical power (MP) calculation, from 24.02 ± 14.53 J/min to 6.18 ± 4.22 J/min within 3 h of VV ECMO initiation (p < 0.001). There was non-significant trend of increase in CRP level during the first 5 days of veno arterial (VA) ECMO (123 ± 80 mg/L, 179 ± 91 mg/L, 203 ± 90 mg/L, 179 ± 95 mg/L and 198 ± 93 for days 1-5 respectively, p = 0.126) and no significant change in calculated MP (from 14.28 ± 8.56 J/min to 10.81 ± 8.09 J/min within 3 h if ECMO initiation, p = 0.071). CONCLUSIONS: We observed a significant decrease in CRP levels during the first 5 days of VV ECMO support, and suggest that the concomitant reduction in ventilatory MP may have mitigated the degree of alveolar stress and strain that could have contributed to a decrease in the systemic inflammatory process.

Linear Correlation Between Mean Arterial Pressure and Urine Output in Critically Ill Patients.

OBJECTIVE: Mean arterial pressure (MAP) plays a significant role in regulating tissue perfusion and urine output (UO). The optimal MAP target in critically ill patients remains a subject of debate. We aimed to explore the relationship between MAP and UO. DESIGN: A retrospective observational study. SETTING: A general ICU in a tertiary medical center. PATIENTS: All critically ill patients admitted to the ICU for more than 10 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: MAP values and hourly UO were collected in 5,207 patients. MAP levels were categorized into 10 groups of 5 mm Hg (from MAP < 60 mm Hg to MAP > 100 mg Hg), and 656,423 coupled hourly mean MAP and UO measurements were analyzed. Additionally, we compared the UO of individual patients in each MAP group with or without norepinephrine (NE) support or diuretics, as well as in patients with acute kidney injury (AKI).Hourly UO rose incrementally between MAP values of 65-100 mm Hg. Among 2,226 patients treated with NE infusion, mean UO was significantly lower in the MAP less than 60 mm Hg group (53.4 mL/hr; 95% CI, 49.3-57.5) compared with all other groups (p < 0.001), but no differences were found between groups of 75 less than or equal to MAP. Among 2500 patients with AKI, there was a linear increase in average UO from the MAP less than 60 mm Hg group (57.1 mL/hr; 95% CI, 54.2-60.0) to the group with MAP greater than or equal to 100 mm Hg (89.4 mL/hr; 95% CI, 85.7-93.1). When MAP was greater than or equal to 65 mm Hg, we observed a statistically significant trend of increased UO in periods without NE infusion. CONCLUSIONS: Our analysis revealed a linear correlation between MAP and UO within the range of 65-100 mm Hg, also observed in the subgroup of patients treated with NE or diuretics and in those with AKI. These findings highlight the importance of tissue perfusion to the maintenance of diuresis and achieving adequate fluid balance in critically ill patients.

Two-hour indirect calorimetry measurement as a predictor of 24-hour energy expenditure in critically ill surgical patients: A longitudinal study.

BACKGROUND: Measuring energy expenditure (EE) by indirect calorimetry (IC) has become the gold standard tool for critically ill patients to define energy targets and tailor nutrition. Debate remains as to the optimal duration of measurements or the optimal time of day in which to perform IC. METHODS: In this retrospective longitudinal study, we analyzed results of daily continuous IC in 270 mechanically ventilated, critically ill patients admitted to the surgical intensive care unit in a tertiary medical center and compared measurements performed at different hours of the day. RESULTS: A total of 51,448 IC hours was recorded, with an average 24-h EE of 1523 ± 443 kcal/day. Night shift (00:00-8:00) was found to have significantly lower EE measurements (mean, 1499 ± 439 kcal/day) than afternoon (16:00-00:00; mean, 1526 ± 435 kcal/day) and morning (8:00-16:00; mean, 1539 ± 462 kcal/day) measurements (P < 0.001 for all). The bi-hourly time frame that most closely resembled the daily mean was 18:00-19:59, with a mean of 1521 ± 433 kcal/day. Daily EE measurements of the continuous IC at days 3-7 of admission showed a trend toward a daily increase in 24-h EE, but the difference was not statistically significant (P = 0.081). CONCLUSIONS: Periodic measurements of EE can differ slightly when performed at various hours of the day, but the error range is small and may not necessarily have a clinical impact. When continuous IC is not available, a 2-h EE measurement between 18:00 and 19:59 can serve as a reasonable alternative.

Central catheter tip migration in critically ill patients.

OBJECTIVES: Chest X-ray (CXR) is routinely required for assessing Central Venous Catheter (CVC) tip position after insertion, but there is limited data as to the movement of the tip location during hospitalization. We aimed to assess the migration of Central Venous Catheter (CVC) position, as a significant movement of catheter tip location may challenge some of the daily practice after insertion. DESIGN AND SETTINGS: Retrospective, single-center study, conducted in the Intensive Care and Cardiovascular Intensive Care Units in Tel Aviv Sourasky Medical Center 'Ichilov', Israel, between January and June 2019. PATIENTS: We identified 101 patients with a CVC in the Right Internal Jugular (RIJ) with at least two CXRs during hospitalization. MEASUREMENTS AND RESULTS: For each patient, we measured the CVC tip position below the carina level in the first and all consecutive CXRs. The average initial tip position was 1.52 (±1.9) cm (mean±SD) below the carina. The maximal migration distance from the initial insertion position was 1.9 (±1) cm (mean±SD). During follow-up of 2 to 5 days, 92% of all subject's CVCs remained within the range of the Superior Vena Cava to the top of the right atrium, regardless of the initial positioning. CONCLUSIONS: CVC tip position can migrate significantly during a patient's early hospitalization period regardless of primary location, although for most patients it will remain within a wide range of the top of the right atrium and the middle of the Superior Vena Cava (SVC), if accepted as well-positioned.

Separation from mechanical ventilation and survival after spinal cord injury: a systematic review and meta-analysis.

BACKGROUND: Prolonged need for mechanical ventilation greatly impacts life expectancy of patients after spinal cord injury (SCI). Weaning outcomes have never been systematically assessed. In this systematic review and meta-analysis, we aimed to investigate the probability of weaning success, duration of mechanical ventilation, mortality, and their predictors in mechanically ventilated patients with SCI. METHODS: We searched six databases from inception until August 2021 for randomized-controlled trials and observational studies enrolling adult patients (≥ 16 years) with SCI from any cause requiring mechanical ventilation. Titles and abstracts were screened independently by two reviewers. Full texts of the identified articles were then assessed for eligibility. Data were extracted independently and in duplicate by pairs of authors, using a standardized data collection form. Synthetic results are reported as meta-analytic means and proportions, based on random effects models. RESULTS: Thirty-nine studies (14,637 patients, mean age 43) were selected. Cervical lesions were predominant (12,717 patients had cervical lesions only, 1843 in association with other levels' lesions). Twenty-five studies were conducted in intensive care units (ICUs), 14 in rehabilitative settings. In ICU, the mean time from injury to hospitalization was 8 h [95% CI 7-9], mean duration of mechanical ventilation 27 days [20-34], probability of weaning success 63% [45-78] and mortality 8% [5-11]. Patients hospitalized in rehabilitation centres had a greater number of high-level lesions (C3 or above), were at 40 days [29-51] from injury and were ventilated for a mean of 97 days [65-128]; 82% [70-90] of them were successfully weaned, while mortality was 1% [0-19]. CONCLUSIONS: Although our study highlights the lack of uniform definition of weaning success, of clear factors associated with weaning outcomes, and of high-level evidence to guide optimal weaning in patients with SCI, it shows that around two-thirds of mechanically ventilated patients can be weaned in ICU after SCI. A substantial gain in weaning success can be obtained during rehabilitation, with additional duration of stay but minimal increase in mortality. The study is registered with PROSPERO (CRD42020156788).

Outcomes of prolonged mechanical ventilation in patients who underwent bedside percutaneous dilatation tracheostomy in intermediate care units - A single center study.

BACKGROUND: The number of chronic critical illness (CCI) patients requiring prolonged mechanical ventilation (PMV) is increasing worldwide, mandating health professionals to discuss interventions while considering disease trajectory. The aim of this study was to analyze the survival of CCI patients who underwent percutaneous dilatational tracheostomy (PDT) within intermediate care units. METHODS: We carried out a retrospective study of all patients who underwent PDT in our intermediate care units from 2009 to 2015. Based on their survival statuses at different time points, patients were categorized into groups of survival at one week, one month, and one year following the procedure. RESULTS: This study included 254 patients. The mean age was 77.7 (±11.8) years. Out of the 254 patients included, 213 patients (84.2%) were defined as nursing care dependent. In-hospital mortality was 38.2% (97 patients). Seven patients (2.7%) were discharged to their homes. Overall survival rates at one week, one month, and one year following PDT were 88.6%, 66.1%, and 29.5%, respectively. Upon multivariate analyses, higher creatinine levels and resuscitation prior to the procedure were associated with increased mortality rates at one week and one month following tracheostomy. Higher creatinine and low albumin levels were associated with increased mortality at one year following tracheostomy. CONCLUSION: The prognosis of CCI patients in intermediate care units is generally poor. Identified risk factors for complications and survival should be presented to patients and their surrogates when discussing courses of action and future treatments.

Bedside percutaneous dilatational tracheostomy in patients outside the ICU: a single-center experience.

PURPOSE: To assess the safety of medical-ward bedside percutaneous dilatational tracheostomy (GWB-PDT). MATERIALS AND METHODS: A retrospective study of all patients who underwent elective GWB-PDT between 2009 and 2015. A joint otolaryngology-ICU team performed all GWB-PDTs. The patients were followed until decannulation, discharge or death. Complications were divided into early (within 24 h) and late, and into minor and major. RESULTS: Two hundred and fifty six patients were included in the study. The mean age was 77.7 ±â€¯11.8 Medical history included cardiac comorbidities (42.6%) and cerebrovascular accidents (34.4%). Overall, 48 patients (18.9%) had 60 complications, of which 70% (42/60) were minor (13 early; 29 late complications). Fifteen patients (5.9%) had major complications. Eight patients had early major complications (loss of airway - two patients [0.8%], pneumothorax - two patients [0.8%], resuscitation - one patient [0.4%], and a single patient (0.4%) died within 24 h following PDT). Two additional patients (0.8%) underwent conversion to an open tracheostomy. Seven patients had late complications (airway complications in six patients [2.3%] and major bleeding in a single patient [0.4%]). Of the seven patients with late major complications, three had two major complications. Half of the complications occurred by POD 3. CONCLUSION: GWB-PDT is a feasible and safe solution for tracheostomies in general-ward ventilated patients.

Feasibility of a single-stage tracheostomy decannulation protocol with endoscopy in adult patients.

OBJECTIVES/HYPOTHESIS: Gradual decrease in tube size and tube capping are considered the standard of care for tracheostomy decannulation. Both of these actions result in increased airway resistance. Immediate decannulation may offer a more tolerable approach. OBJECTIVE: To assess the feasibility of immediate tracheostomy decannulation compared with the traditional decannulation methods. METHODS: This study is a single institute, case-control retrospective study of patients between the years 2009 to 2014. The study group included all patients who underwent immediate decannulation, whereas the control group comprised patients who underwent traditional staged decannulation. An immediate decannulation protocol included admission to the intensive care unit, a comprehensive evaluation, decannulation, 24 hours of monitoring, and observation until discharge. RESULTS: Twenty-nine patients were included in the study group and 20 in the control group. No significant statistical difference was found between the two groups in the patients' medical history and tracheostomy data, except for the Acute Physiology and Chronic Health Evaluation II score and duration of the deflated cuff, which were significantly higher in the control group. A significant difference was found in the complication rate between the groups. In the staged decannulation group, four patients failed decannulation and required reinsertion of the tracheostomy cannula, whereas there were no such failures in the immediate decannulation group. Hospitalization duration after decannulation of the study group patients was significantly shorter than that of the control group. CONCLUSION: Immediate decannulation may offer a safe alternative for weaning from tracheostomy. It may also reduce the duration of the weaning process and hospitalization. LEVEL OF EVIDENCE: 3b Laryngoscope, 126:2057-2062, 2016.