Oxygen consumption is depressed in patients with lactic acidosis due to biguanide intoxication

INTRODUCTION: Lactic acidosis can develop during biguanide (metformin and phenformin) intoxication, possibly as a consequence of mitochondrial dysfunction. To verify this hypothesis, we investigated whether body oxygen consumption (VO2), that primarily depends on mitochondrial respiration, is depressed in patients with biguanide intoxication. METHODS: Multicentre retrospective analysis of data collected from 24 patients with lactic acidosis (pH 6.93 +/- 0.20; lactate 18 +/- 6 mM at hospital admission) due to metformin (n = 23) or phenformin (n = 1) intoxication. In 11 patients, VO2 was computed as the product of simultaneously recorded arterio-venous difference in O2 content [C(a-v)O2] and cardiac index (CI). In 13 additional cases, C(a-v)O2, but not CI, was available. RESULTS: On day 1, VO2 was markedly depressed (67 +/- 28 ml/min/m2) despite a normal CI (3.4 +/- 1.2 L/min/m2). C(a-v)O2 was abnormally low in both patients either with (2.0 +/- 1.0 ml O2/100 ml) or without (2.5 +/- 1.1 ml O2/100 ml) CI (and VO2) monitoring. Clearance of the accumulated drug was associated with the resolution of lactic acidosis and a parallel increase in VO2 (P < 0.001) and C(a-v)O2 (P < 0.05). Plasma lactate and VO2 were inversely correlated (R2 0.43; P < 0.001, n = 32). CONCLUSIONS: VO2 is abnormally low in patients with lactic acidosis due to biguanide intoxication. This finding is in line with the hypothesis of inhibited mitochondrial respiration and consequent hyperlactatemia

How to communicate with families living in complete isolation

The global emergency caused by the SARS-CoV-2 pandemic has suddenly changed how we communicate with families in all the CoViD19 care settings, on account of the need to maintain complete social isolation. Far-reaching mental suffering manifests itself in widespread anxiety. Health workers are isolated from their families, and must manage the consequences of this isolation just like the patients under their care. Patients and their families perceive not only the clinical results but also the personal attitudes, closeness and psychological support from the care teams. This perception of genuine participation by the health worker in the course of the treatment is especially important when a patient dies, and may influence the whole process of grief

Association of COVID-19 Vaccinations With Intensive Care Unit Admissions and Outcome of Critically Ill Patients With COVID-19 Pneumonia in Lombardy, Italy

IMPORTANCE Data on the association of COVID-19 vaccination with intensive care unit (ICU) admission and outcomes of patients with SARS-CoV-2-related pneumonia are scarce. OBJECTIVE To evaluate whether COVID-19 vaccination is associated with preventing ICU admission for COVID-19 pneumonia and to compare baseline characteristics and outcomes of vaccinated and unvaccinated patients admitted to an ICU. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study on regional data sets reports: (1) daily number of administered vaccines and (2) data of all consecutive patients admitted to an ICU in Lombardy, Italy, from August 1 to December 15, 2021 (Delta variant predominant). Vaccinated patients received either mRNA vaccines (BNT162b2 or mRNA-1273) or adenoviral vector vaccines (ChAdOx1-S or Ad26.COV2). Incident rate ratios (IRRs) were computed from August 1, 2021, to January 31, 2022; ICU and baseline characteristics and outcomes of vaccinated and unvaccinated patients admitted to an ICU were analyzed from August 1 to December 15, 2021. EXPOSURES COVID-19 vaccination status (no vaccination, mRNA vaccine, adenoviral vector vaccine). MAIN OUTCOMES AND MEASURES The incidence IRR of ICU admission was evaluated, comparing vaccinated people with unvaccinated, adjusted for age and sex. The baseline characteristics at ICU admission of vaccinated and unvaccinated patients were investigated. The association between vaccination status at ICU admission and mortality at ICU and hospital discharge were also studied, adjusting for possible confounders. RESULTS Among the 10 107 674 inhabitants of Lombardy, Italy, at the time of this study, the median [IQR] agewas 48 [28-64] years and 5 154 914 (51.0%) were female. Of the 7 863 417 individuals who were vaccinated (median [IQR] age: 53 [33-68] years; 4 010 343 [51.4%] female), 6 251 417 (79.5%) received an mRNA vaccine, 550 439 (7.0%) received an adenoviral vector vaccine, and 1 061 561 (13.5%) received a mix of vaccines and 4 497 875 (57.2%) were boosted. Compared with unvaccinated people, IRR of individuals who received an mRNA vaccine within 120 days from the last dosewas 0.03 (95% CI, 0.03-0.04; P &lt;.001), whereas IRR of individuals who received an adenoviral vector vaccine after 120 days was 0.21 (95% CI, 0.19-0.24; P &lt;.001). There were 553 patients admitted to an ICU for COVID-19 pneumonia during the study period: 139 patients (25.1%) were vaccinated and 414 (74.9%) were unvaccinated. Compared with unvaccinated patients, vaccinated patients were older (median [IQR]: 72 [66-76] vs 60 [51-69] years; P &lt;.001), primarily male individuals (110 patients [ 79.1%] vs 252 patients [60.9%]; P &lt;.001), with more comorbidities (median [IQR]: 2 [1-3] vs 0 [0-1] comorbidities; P &lt;.001) and had higher ratio of arterial partial pressure of oxygen (PaO2) and fraction of inspiratory oxygen (FiO(2)) at ICU admission (median [IQR]: 138 [100-180] vs 120 [90-158] mm Hg; P =.007). Factors associated with ICU and hospital mortality were higher age, premorbid heart disease, lower PaO2/FiO(2) at ICU admission, and female sex (this factor only for ICU mortality). ICU and hospital mortality were similar between vaccinated and unvaccinated patients. CONCLUSIONS AND RELEVANCE In this cohort study, mRNA and adenoviral vector vaccines were associated with significantly lower risk of ICU admission for COVID-19 pneumonia. ICU and hospital mortality were not associated with vaccinated status.These findings suggest a substantial reduction of the risk of developing COVID-19-related severe acute respiratory failure requiring ICU admission among vaccinated people

Enteral versus intravenous approach for the sedation of critically ill patients: a randomized and controlled trial

Background. ICU patients must be kept conscious, calm, and cooperative even during the critical phases of illness. Enteral administration of sedative drugs might avoid oversedation, and would be as adequate as intravenous for awake patients, with fewer side effects and lower costs. This study compares two sedation strategies, in order to early reach and maintain the light sedation target. Methods. Multicenter, single-blind randomized and controlled trial carried out in 12 Italian ICUs, involving patients with expected mechanical ventilation duration >72 hours at ICU admission and predicted mortality >12% (Simplified Acute Physiology Score II >32 points) during the first 24 ICU hours. Patients were randomly assigned to receive intravenous (midazolam, propofol) or enteral (hydroxyzine, lorazepam, and melatonin) sedation. Primary outcome: percentage of work shifts with an observed Richmond Agitation-Sedation Scale (RASS) = target RASS \ub1 1. Secondary outcomes: protocol feasibility, delirium- and coma-free days, costs of drugs, length of ICU and hospital stay, ICU, hospital, and one-year mortality. Results. 348 patients were enrolled. There were no differences in the primary outcome: enteral 89.8 [74.1-100], intravenous 94.4 [78-100]%, p=0.20. Enteral-treated patients had more protocol violations: 81 (46.6%) vs 7 (4.2%), p<0.01, more self-extubations: 4 (2.4%) vs 14 (8.1%), p=0.03, a lighter sedative target (RASS = 0): 93 [71-100] vs 83 [61-100]%, p<0.01, and lower total costs for drugs: 2.39 [0.75- 9.78] vs 4.15 [1.20 -20.19] \u20ac/day with mechanical ventilation (p=0.01). Conclusions. Although enteral sedation of critically ill patients is cheaper and permits a lighter sedation target, it is not superior to intravenous sedation for reaching the RASS target. Trial registration. ClinicalTrials.gov, Clinical Trial #NCT01360346, registered 25 March 2011, https://clinicaltrials.gov/ct2/show/NCT01360346. Registered on 25 March 2011

Diaphragm ultrasound as indicator of respiratory effort in critically ill patients undergoing assisted mechanical ventilation: a pilot clinical study

Introduction Pressure-support ventilation, is widely used in critically ill patients; however, the relative contribution of patient\u2019s effort during assisted breathing is difficult to measure in clinical conditions. Aim of the present study was to evaluate the performance of ultrasonographic indices of diaphragm contractile activity (respiratory excursion and thickening) in comparison to traditional indices of inspiratory muscle effort during assisted mechanical ventilation. Method Consecutive patients admitted to the ICU after major elective surgery who met criteria for a spontaneous breathing trial with pressure support ventilation were enrolled. Patients with airflow obstruction or after thoracic/gastric/esophageal surgery were excluded. Variable levels of inspiratory muscle effort were achieved by delivery of different levels of ventilatory assistance by random application of pressure support (0, 5 and 15 cmH2O). The right hemidiaphragm was evaluated by B- and M-mode ultrasonography to record respiratory excursion and thickening. Airway, gastric and oesophageal pressures, and airflow were recorded to calculate indices of respiratory effort (diaphragm and esophageal pressure\u2013time product). Results 25 patients were enrolled. With increasing levels of pressure support, parallel reductions were found between diaphragm thickening and both diaphragm and esophageal pressure\u2013time product (respectively, R = 0.701, p < 0.001 and R = 0.801, p < 0.001) during tidal breathing. No correlation was found between either diaphragm or esophageal pressure\u2013time product and diaphragm excursion (respectively, R = 120.081, p = 0.506 and R = 0.003, p = 0.981), nor was diaphragm excursion correlated to diaphragm thickening (R = 0.093, p = 0.450) during tidal breathing. Conclusions In patients undergoing in assisted mechanical ventilation, diaphragm thickening is a reliable indicator of respiratory effort, whereas diaphragm excursion should not be used to quantitatively assess diaphragm contractile activity

Melatonin Pharmacological Blood Levels Increase Total Antioxidant Capacity in Critically Ill Patients

In this study, the aim was to test the biochemical effects of melatonin supplementation in Intensive Care Unit (ICU) patients, since their blood levels are decreased. Sixty-four patients were enrolled in the study. From the evening of the 3rd ICU day, patients were randomized to receive oral melatonin (3 mg, group M) or placebo (group P) twice daily, at 20:00 and 24:00, until discharged. Blood was taken (at 00:00 and 14:00), on the 3rd ICU day to assess basal nocturnal melatonin values, and then during the treatment period on the 4th and 8th ICU days. Melatonin, total antioxidant capacity, and oxidative stress were evaluated in serum. Melatonin circadian rhythm before treatment was similar in the two groups, with a partial preservation of the cycle. Four hours from the 1st administration (4th ICU day, 00:00), melatonin levels increased to 2514 (982.3; 7148) pg·mL(-1) in group M vs. 20.3 (14.7; 62.3) pg·mL(-1) in group P (p < 0.001). After five treatment days (8th ICU day), melatonin absorption showed a repetitive trend in group M, while in group P nocturnal secretion (00:00) was impaired: 20 (11.5; 34.5) pg·mL(-1) vs. 33.8 (25.0; 62.2) on the 3rd day (p = 0.029). Immediately from the beginning of treatment, the total antioxidant capacity was significantly higher in melatonin treated subjects at 00:00; a significant correlation was found between total antioxidant capacity and blood melatonin values (ρ = 0.328; p < 0.001). The proposed enteral administration protocol was adequate, even in the early phase, to enhance melatonin blood levels and to protect the patients from oxidative stress. The antioxidant effect of melatonin could play a meaningful role in the care and well-being of these patients