Helmet c-PAP Versus NIPPV in Association with Early Respiratory Physiotherapy and Mobilization for Treating SARS-CoV-2 ARDS: A Case-control Prospective Single-center Study.

Introduction: Early noninvasive respiratory support (NIRS) is correlated with a success rate of 60-75% in patients experiencing SARS-CoV-2 ARDS. We conducted a prospective case-control study to assess differences in outcomes between Helmet c-PAP (H-c-PAP) and noninvasive positive pressure ventilation (NIPPV). Methods: All patients with SARS-CoV-2 ARDS, treated with H-c-PAP or NIPPV between October 2021 and April 2022 were sampled. We recorded: demographics, comorbidities, clinical, respiratory, sepsis, NIRS parameters, and outcomes. A "NIRS team" followed the patients in respiratory support supplying them with early and timely intensive physiotherapy i-PKT as well. The Cox's proportional hazard model was applied for multivariate analyses. Results: 368 patients were admitted to our hospital medical ward. 85 patients were treated with H-c-PAP and 145 underwent NIPPV. 138 patients needing oxygen supplementation alone were excluded. The two groups were homogeneously distributed and ICU admission rates were lower in the H-c-PAP one (9.4 vs 11% P = .001) while mortality was higher in the NIPPV group (22.7 vs 9.4%, P = .001). The two multivariate models, that had overall mortality as primary outcome, identified age, H-c-PAP daily, i-PKT and ICU admission as independent variables impacting on the outcome. Age was no longer a significant independent predictor after the inclusion of elderly patients (age >80). The third model showed daily i-PKT could prevent ICU admission whereas the length of NIRS was inversely proportional to outcome. Conclusions: A "NIRS multidisciplinary team" made it possible to adopt an early and timely combination of NIRS and i-PKT resulting in the saving of both patient lives and ICU resources.

Bacterial infections in critically ill patients with SARS-2-COVID-19 infection: results of a prospective observational multicenter study.

PURPOSE: To investigate the prevalence, incidence and characteristics of bacterial infections and their impact on outcome in critically ill patients infected with COVID-19. METHODS: We conducted a prospective observational study in eight Italian ICUs from February to May 2020; data were collected through an interactive electronic database. Kaplan-Meier analysis (limit product method) was used to identify the occurrence of infections and risk of acquisition. RESULTS: During the study period 248 patients were recruited in the eight participating ICUs. Ninety (36.3%) patients developed at least one episode of secondary infection. An ICU length of stay between 7 and 14 days was characterized by a higher occurrence of infectious complications, with ventilator-associated pneumonia being the most frequent. At least one course of antibiotic therapy was given to 161 (64.9%) patients. Overall ICU and hospital mortality were 33.9% and 42.9%, respectively. Patients developing bacteremia had a higher risk of ICU mortality [45.9% vs. 31.6%, odds ratio 1.8 (95% CI 0.9-3.7), p = 0.069] and hospital mortality [56.8% vs. 40.3%, odds ratio 1.9 (95% CI 1.1-3.9), p = 0.04]. CONCLUSION: In critically ill patients infected with COVID-19 the incidence of bacterial infections is high and associated with worse outcomes. Regular microbiological surveillance and strict infection control measures are mandated.

Tracheostomy in critically ill patients with SARS 2 COVID-19 infection: a prospective observational multi-center study of short- and long-term outcomes.

Background: We report the characteristics, timing, and factors related to the decision to perform a tracheostomy in patients with confirmed COVID-19 infection admitted to eight Italian intensive care units (ICUs). Materials and methods: Prospective observational cohort study of patients with COVID-19 disease on mechanical ventilation. Long-term functional impairment (up to 180 days' post-hospital discharge) was assessed using the Karnofsky scale. Kaplan-Meier analysis assessed differences in survival and freedom from tracheostomy in relation to ICU stay. Cox regression model was used to assess which variables impacted on tracheostomy as a categorical outcome. Results: A total of 248 patients were recruited in the eight participating ICUs. Patients undergoing tracheostomy (n = 128) had longer ICU (25 (18-36) vs. 10 (7-16), P = 0.001) and hospital (37 (26.5-50) vs. 19 (8.5-34.5) P = 0.02) stays. ICU and hospital mortality of patients tracheostomized was 34% and 37%, respectively. Cumulative survival Kaplan-Meier analysis documented improved survival rates in patients undergoing tracheostomy (Log-Rank, Mantel-Cox = 4.8, P = 0.028). Median Karnofsky scale values improved over time but were similar between survivors receiving or not receiving tracheostomy. No healthcare worker involved in the tracheostomy procedure developed COVID-19 infection during the study period. Conclusions: Patients with COVID-19 infection who underwent tracheostomy had a better cumulative survival but similar long-term functional outcomes at 30, 60, and 180 days after hospital discharge.

Ceftazidime-Avibactam Use for Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Infections: A Retrospective Observational Multicenter Study.

BACKGROUND: A growing body of observational evidence supports the value of ceftazidime-avibactam (CAZ-AVI) in managing infections caused by carbapenem-resistant Enterobacteriaceae. METHODS: We retrospectively analyzed observational data on use and outcomes of CAZ-AVI therapy for infections caused by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) strains. Multivariate regression analysis was used to identify variables independently associated with 30-day mortality. Results were adjusted for propensity score for receipt of CAZ-AVI combination regimens versus CAZ-AVI monotherapy. RESULTS: The cohort comprised 577 adults with bloodstream infections (n = 391) or nonbacteremic infections involving mainly the urinary tract, lower respiratory tract, and intra-abdominal structures. All received treatment with CAZ-AVI alone (n = 165) or with ≥1 other active antimicrobials (n = 412). The all-cause mortality rate 30 days after infection onset was 25% (146/577). There was no significant difference in mortality between patients managed with CAZ-AVI alone and those treated with combination regimens (26.1% vs 25.0%, P = .79). In multivariate analysis, mortality was positively associated with presence at infection onset of septic shock (P = .002), neutropenia (P < .001), or an INCREMENT score ≥8 (P = .01); with lower respiratory tract infection (LRTI) (P = .04); and with CAZ-AVI dose adjustment for renal function (P = .01). Mortality was negatively associated with CAZ-AVI administration by prolonged infusion (P = .006). All associations remained significant after propensity score adjustment. CONCLUSIONS: CAZ-AVI is an important option for treating serious KPC-Kp infections, even when used alone. Further study is needed to explore the drug's seemingly more limited efficacy in LRTIs and potential survival benefits of prolonging CAZ-AVI infusions to ≥3 hours.

Noninvasive Monitoring After Azathioprine Withdrawal in Patients With Inflammatory Bowel Disease in Deep Remission.

BACKGROUND & AIMS: There is uncertainty regarding the optimal duration of treatment with azathioprine (AZA) in ulcerative colitis (UC) and Crohn's disease (CD). We analyzed the clinical course and predictors of relapse after AZA withdrawal in patients in sustained deep remission. METHODS: A prospective study was performed on patients who stopped their treatment with AZA while being in steroid-free, extended deep remission (normal clinical, endoscopic, and histologic indexes, C-reactive protein, and fecal calprotectin [FC]). Standard biochemical tests and FC were measured at 3 and 6 months, then every 6 months. Bowel ultrasounds and ileocolonoscopy were performed every 6 and 12 months, respectively. Multivariate analysis for predictors of relapse was performed using a Cox proportional hazards model and hazard ratios were calculated. Spearman nonparametric correlation test was also used. The accuracy of significant predictors was calculated. RESULTS: Fifty-seven patients with inflammatory bowel disease stopped AZA after median 7 years (range, 5-19) and were followed up for median 50 months (range, 25-85). Twenty-six patients (18/31 UC, 8/26 CD; P = .003) relapsed, within a median 15 months (range, 2-37). FC was the only variable significantly correlated with later relapse of both diseases (UC: hazard ratio, 3.3; 95% confidence interval, 1.2-10; CD: hazard ratio, 4.5; 95% confidence interval, 1.4-12.5). The sensitivity, specificity, and positive and negative predictive values of FC were 50%, 100%, 100%, and 59% in UC and 50%, 94%, 80%, and 81% in CD. CONCLUSIONS: More than half patients with UC and one-third of patients with CD relapse after AZA withdrawal despite previous deep remission. FC positivity is associated with high risk of relapse, allowing early correction of the therapeutic strategy.

Therapeutic Drug Monitoring of Dalbavancin Treatment in Severe Necrotizing Fasciitis in 3 Critically Ill Patients: A Grand Round.

BACKGROUND: Dalbavancin, albeit indicated for the treatment of skin structure infections, is used for a much wider range of infections. This drug is characterized by a long half-life (more than 200 hours), a favorable safety profile, and an activity against a wide array of gram-positive organisms, including several strains of Staphylococci and Enterococci. METHODS: In this study, we presented 3 cases of critically ill patients treated with dalbavancin. All patients were therapeutically monitored for plasma dalbavancin concentrations; ultrafiltrate dalbavancin concentrations were assessed in a patient undergoing continuous renal-replacement therapy. Dalbavancin concentrations were measured using a validated liquid chromatographic method coupled with mass spectrometry. RESULTS: All 3 severely ill patients experiencing necrotizing fasciitis were successfully treated during the acute phase with dalbavancin. Dalbavancin clearance in patient 3 (0.334 L/h) was considerably increased compared with values measured in the other 2 patients (0.054 and 0.075 L/h) and with data reported in the literature (0.04-0.06 L/h). CONCLUSIONS: Our case reports presented preliminary evidence that dalbavancin can be considered a therapeutic option for necrotizing fasciitis in intensive care unit patients. The role of hypoalbuminemia during dalbavancin exposure merits further investigation.

Efficacy of Ceftazidime-Avibactam Salvage Therapy in Patients With Infections Caused by Klebsiella pneumoniae Carbapenemase-producing K. pneumoniae.

Background: Ceftazidime-avibactam (CAZ-AVI) has been approved in Europe for the treatment of complicated intra-abdominal and urinary tract infections, as well as hospital-acquired pneumonia, and for gram-negative infections with limited treatment options. CAZ-AVI displays in vitro activity against Klebsiella pneumoniae carbapenemase (KPC) enzyme producers, but clinical trial data on its efficacy in this setting are lacking. Methods: We retrospectively reviewed 138 cases of infections caused by KPC-producing K. pneumoniae (KPC-Kp) in adults who received CAZ-AVI in compassionate-use programs in Italy. Case features and outcomes were analyzed, and survival was then specifically explored in the large subcohort whose infections were bacteremic. Results: The 138 patients started CAZ-AVI salvage therapy after a first-line treatment (median, 7 days) with other antimicrobials. CAZ-AVI was administered with at least 1 other active antibiotic in 109 (78.9%) cases. Thirty days after infection onset, 47 (34.1%) of the 138 patients had died. Thirty-day mortality among the 104 patients with bacteremic KPC-Kp infections was significantly lower than that of a matched cohort whose KPC-Kp bacteremia had been treated with drugs other than CAZ-AVI (36.5% vs 55.8%, P = .005). Multivariate analysis of the 208 cases of KPC-Kp bacteremia identified septic shock, neutropenia, Charlson comorbidity index ≥3, and recent mechanical ventilation as independent predictors of mortality, whereas receipt of CAZ-AVI was the sole independent predictor of survival. Conclusions: CAZ-AVI appears to be a promising drug for treatment of severe KPC-Kp infections, especially those involving bacteremia.

Pulse photoplethysmographic amplitude and heart rate variability during laparoscopic cholecystectomy: A prospective observational study.

BACKGROUND: Surgical stress affects the autonomic nervous system by increasing sympathetic outflow. One method of monitoring sympathetic activity is pulse photoplethysmographic analysis. From this two indices can be derived - autonomic nervous system state (ANSS) and ANSS index (ANSSi). It has recently been claimed that these indices can be used to measure sympathetic activity in anaesthetised patients, but their validity has not yet been demonstrated. OBJECTIVE: To measure changes in pulse photoplethysmographic indices and determine any agreement with autonomic nervous system modulation of the cardiovascular system in healthy study participants during surgery under general anaesthesia. DESIGN: Prospective observational study. SETTING: Single-centre study based at a tertiary care centre in Milan, Italy. PATIENTS: Healthy patients undergoing general anaesthesia for elective laparoscopic cholecystectomy. INTERVENTIONS: ANSS, ANSSi, and heart rate variability (HRV) were analysed at three main times: baseline, after induction of general anaesthesia, and after pneumoperitoneum insufflation. MAIN OUTCOME MEASURES: The magnitude of changes in photoplethysmographic and HRV indices was measured. The agreement between pulse photoplethysmographic and HRV-derived indices was assessed by Bland-Altman plots. RESULTS: In total, 52 patients were enrolled and their data analysed. Both pulse photoplethysmographic and HRV indices changed during the study phases. An agreement was found between ANSSi and low frequency spectral components of HRV [bias 10.2nu, 95% confidence interval (CI) -13 to 33.4], high frequency spectral components of HRV (bias 6.1 nu, 95% CI -16.3 to 28.6), and low frequency/high frequency ratio (bias 16.1nu, 95% CI -1.4 to 33.5). The agreement was weaker between ANSSI and HRV indices. CONCLUSION: The study endorses the use of pulse photoplethysmographic indices ANSS and ANSSi as surrogates to estimate changes of autonomic modulation of the cardiovascular system in healthy adults during surgery under general anaesthesia.Orcid ID: orcid.org/0000-0002-9616-803X.

Imported Plasmodium vivax malaria with severe thrombocytopaenia: can it be severe malaria or not?

BACKGROUND: Thrombocytopaenia is the most frequent malaria-associated haematologic alteration observed with all five Plasmodium parasites causing disease in humans. Although not included in the World Health Organization criteria for severe Plasmodium falciparum malaria, severe thrombocytopaenia has been increasingly mentioned as an indicator of P. vivax malaria severity. CASE: Here, it is described a case of imported P. vivax malaria in a 37-year old man from Pakistan who presented with severe thrombocytopaenia (5 × 10(9)/L). He was admitted to the intensive care unit and initially treated with a 1-day course of intravenous quinine followed by oral chloroquine and primaquine. The patient's platelet count increased as early as 4 hours after treatment inception and the clinical course was favourable and uneventful. DISCUSSION: This case report, along with a review of published cases focusing on the relationship between thrombocytopaenia and severe P. vivax malaria, suggests that the prognostic role of severe thrombocytopaenia is ambiguous in absence of severe haemorraghic complications and its use as diagnostic criterion of malaria severity may lead to overestimation of severe P. vivax malaria cases. CONCLUSION: Due to the lack of high quality studies it is at present unclear if severe thrombocytopaenia in the setting of P. vivax malaria should be considered indicative of severe malaria.

Bacteraemia incidence, causative organisms and resistance patterns, antibiotic strategies and outcomes in a single university hospital ICU: continuing improvement between 2000 and 2013.

OBJECTIVES: The optimal duration of antibiotic treatment in patients with bloodstream infections remains contentious, with concerns regarding both undertreatment and the encouragement of antibiotic resistance. In our ICU we traditionally use short-course antibiotic monotherapy as the mainstay of treatment. We sought to document the impact of this strategy on pathogen type, resistance patterns and patient outcomes. A comparison was made against data collected during a similar exercise in 2000. METHODS: We retrospectively reviewed data on all patients with community-, hospital- and ICU-acquired bacteraemia over a 6 month period (1 December 2012 to 31 May 2013) in a general medical-surgical ICU in a London university hospital. Causative pathogens, resistance patterns, use and duration of monotherapy or combination therapy, breakthrough and relapse rates, and patient outcomes were assessed. RESULTS: The 2013 cohort comprised 113 episodes in 87 patients. Short-course monotherapy (median course 4-5 days) was used in 65.7% of episodes (73.5% in 2000). As with the 2000 cohort, the incidence of antimicrobial resistance, fungaemia, bacteraemia breakthrough and relapse remained low. Of note, there was a decreasing incidence of ICU-acquired MRSA, MDR Gram-negative bacteraemia and fluconazole-resistant candidaemia. Hospital mortality was 32% (45% in 2000). CONCLUSIONS: Our strategy predominantly utilizing short-course antibiotic monotherapy remains effective in achieving good clinical outcomes among patients with bloodstream infections, with low rates of antibiotic resistance and clinical relapse. Prospective trials of short-course monotherapy are warranted to assess clinical efficacy and antimicrobial resistance.

Pulse Photoplethysmographic Analysis Estimates the Sympathetic Activity Directed to Heart and Vessels.

BACKGROUND: Novel pulse photoplethysmographic-derived indices have been proposed as tools to measure autonomic nervous system (ANS) modulation in anesthetized and awake patients, but nowadays their experimental validation is lacking. The authors aimed to investigate the ability of pulse photoplethysmographic amplitude (PPGA), ANS state (ANSS), and ANSS index (ANSSi) to measure changes of ANS modulation in response to sympathetic stimulation. METHODS: Ten awake healthy volunteers underwent two passive head-up tilts at 45° and 90°. The heart rate variability (HRV) and systolic arterial pressure variability were analyzed in the frequency domain as a measure of ANS modulation directed to the heart and the vessels. HRV, baroreflex sensitivity, and pulse photoplethysmographic indices were measured at baseline and after tilt maneuvers. The agreement between HRV-derived indices and pulse photoplethysmographic indices was assessed using Bland-Altman plots. RESULTS: PPGA, ANSS, and ANSSi changed significantly during the study protocol. Head-up tilt decreased PPGA and ANSS and increased ANNSi. There was a good agreement between ANSSi and baroreflex sensitivity explored in the high-frequency band (bias, 0.23; 95% CI, -22.7 to 23.2 normalized units) and between ANSSi and the sympathovagal modulation directed to the heart (bias, 0.96; 95% CI, -8.7 to 10.8 normalized units). CONCLUSIONS: In controlled experimental conditions, novel pulse plethysmographic indices seem to estimate the changes of the sympathetic outflow directed to the vessels and the sympathovagal balance modulating heart rate. These indices might be useful in the future to monitor the fluctuation of sympathetic activity in anesthetized patients.

Comparison of the Surgical Pleth Index with autonomic nervous system modulation on cardiac activity during general anaesthesia: A randomised cross-over study.

BACKGROUND: Surgical plethysmographic index (SPI) has been proposed as a tool to measure the nociception/antinociception balance during general anaesthesia. Untreated nociception may increase sympathetic tone, but the relationship between SPI and the autonomic nervous system (ANS) is poorly understood. OBJECTIVE: We hypothesised that two different levels of SPI might be associated with differences in ANS modulation, measured by the frequency domain analysis of heart rate variability (HRV). DESIGN: A randomised, cross-over group study, conducted between February and November 2009. SETTING: University tertiary referral hospital in Milan, Italy. PATIENTS: Forty-two adult patients undergoing scheduled laparoscopic abdominal surgery. INTERVENTIONS: ECG, noninvasive arterial blood pressure and SPI were recorded during balanced general anaesthesia with inhaled sevoflurane and intravenous remifentanil. After pneumoperitoneum induction, the remifentanil infusion rate was set to obtain two different levels of SPI (>50, HI-SPI, and <50, LO-SPI) for each patient. MAIN OUTCOME MEASURES: Arterial pressure, heart rate (HR), low-frequency and high-frequency spectral components, the low frequency/high frequency ratio (measure of sympathovagal balance) and whole power spectrum density of HRV were measured at the two different levels of SPI. RESULTS: Thirty-nine patients were included in the final analysis. During LO-SPI, HR and systolic and mean blood pressures were significantly lower than HI-SPI. The median low frequency/high frequency ratio was reduced during LO-SPI [1.29 interquartile range (IQR) 0.66 to 2.05) vs. 2.36 (1.30 to 3.62), P = 0.008]. The sensitivity analysis revealed a significant correlation between SPI changes and changes of all ANS indices, arterial pressure and HR, with a slightly better correlation for low frequency/high frequency (Spearman ρ = 0.70, IQR 0.484 to 0.834, P < 0.001). CONCLUSION: In the context of a balanced general anaesthesia in healthy patients undergoing laparoscopic abdominal surgery, ANS modulation seems to correlate with changes in SPI. Further studies are warranted to assess whether this may reflect a change in nociception/antinociception balance or a pharmacodynamic effect of remifentanil.

A master regulator of opioid reward in the ventral prefrontal cortex.

In addition to their intrinsic rewarding properties, opioids can also evoke aversive reactions that protect against misuse. Cellular mechanisms that govern the interplay between opioid reward and aversion are poorly understood. We used whole-brain activity mapping in mice to show that neurons in the dorsal peduncular nucleus (DPn) are highly responsive to the opioid oxycodone. Connectomic profiling revealed that DPn neurons innervate the parabrachial nucleus (PBn). Spatial and single-nuclei transcriptomics resolved a population of PBn-projecting pyramidal neurons in the DPn that express µ-opioid receptors (µORs). Disrupting µOR signaling in the DPn switched oxycodone from rewarding to aversive and exacerbated the severity of opioid withdrawal. These findings identify the DPn as a key substrate for the abuse liability of opioids.

Outcomes and Predictors of Mortality in Patients With KPC-Kp Infections Treated With Meropenem Vaborbactam: An Observational Multicenter Study.

Background: Meropenem-vaborbactam is a recent and promising option for the treatment of KPC-producing Klebsiella pneumoniae (KPC-Kp) infections, including those resistant to ceftazidime-avibactam. Methods: We conducted a retrospective analysis of observational data from 19 Italian hospitals on use and outcomes of patients treated with meropenem-vaborbactam for at least ≥24 hours for KPC-Kp infections. Crude and propensity-weighted multiple Cox regression models were performed to ascertain risk factors independently associated with 30-day mortality. Results: The cohort included 342 adults with bloodstream infections (n = 172) and nonbacteremic infections (n = 170), of which 107 were lower respiratory tract infections, 30 were complicated urinary tract infections, and 33 were infections involving other sites. Most infections (62.3%) were managed with meropenem-vaborbactam monotherapy, or in combination with at least 1 other active drug (usually fosfomycin, tigecycline, or gentamicin) (37.7%). The 30-day mortality rate was 31.6% (108/342). In multiple Cox regression model, 30-day mortality was independently associated with septic shock at infection onset, Charlson comorbidity index ≥ 3, dialysis, concomitant COVID-19, and INCREMENT score ≥ 8. Administration of meropenem-vaborbactam within 48 hours from infection onset was a negative predictor of mortality. All predictors, except administration of meropenem-vaborbactam within 48 hours, remained significant when the multiple Cox regression model was repeated after adjustment for the propensity score for receipt of combination therapy. Conclusions: Despite the limits of a retrospective study, the data derived from this multicenter cohort provide additional evidence on the efficacy of meropenem-vaborbactam in treating severe KPC-Kp infections, even when used as monotherapy.

A dopaminergic reward prediction error signal shapes maternal behavior in mice.

How social contact is perceived as rewarding and subsequently modifies interactions is unclear. Dopamine (DA) from the ventral tegmental area (VTA) regulates sociality, but the ongoing, unstructured nature of free behavior makes it difficult to ascertain how. Here, we tracked the emergence of a repetitive stereotyped parental retrieval behavior and conclude that VTA DA neurons incrementally refine it by reinforcement learning (RL). Trial-by-trial performance was correlated with the history of DA neuron activity, but DA signals were inconsistent with VTA directly influencing the current trial. We manipulated the subject's expectation of imminent pup contact and show that DA signals convey reward prediction error, a fundamental component of RL. Finally, closed-loop optogenetic inactivation of DA neurons at the onset of pup contact dramatically slowed emergence of parental care. We conclude that this component of maternal behavior is shaped by an RL mechanism in which social contact itself is the primary reward.

A circuit from the locus coeruleus to the anterior cingulate cortex modulates offspring interactions in mice.

Social sensitivity to other individuals in distress is crucial for survival. The anterior cingulate cortex (ACC) is a structure involved in making behavioral choices and is influenced by observed pain or distress. Nevertheless, our understanding of the neural circuitry underlying this sensitivity is incomplete. Here, we reveal unexpected sex-dependent activation of ACC when parental mice respond to distressed pups by returning them to the nest ("pup retrieval"). We observe sex differences in the interactions between excitatory and inhibitory ACC neurons during parental care, and inactivation of ACC excitatory neurons increased pup neglect. Locus coeruleus (LC) releases noradrenaline in ACC during pup retrieval, and inactivation of the LC-ACC pathway disrupts parental care. We conclude that ACC maintains sex-dependent sensitivity to pup distress under LC modulation. We propose that ACC's involvement in parenting presents an opportunity to identify neural circuits that support sensitivity to the emotional distress of others.

Antibiotic Therapy Strategies for Treating Gram-Negative Severe Infections in the Critically Ill: A Narrative Review.

INTRODUCTION: Not enough data exist to inform the optimal duration and type of antimicrobial therapy against GN infections in critically ill patients. METHODS: Narrative review based on a literature search through PubMed and Cochrane using the following keywords: "multi-drug resistant (MDR)", "extensively drug resistant (XDR)", "pan-drug-resistant (PDR)", "difficult-to-treat (DTR) Gram-negative infection," "antibiotic duration therapy", "antibiotic combination therapy" "antibiotic monotherapy" "Gram-negative bacteremia", "Gram-negative pneumonia", and "Gram-negative intra-abdominal infection". RESULTS: Current literature data suggest adopting longer (≥10-14 days) courses of synergistic combination therapy due to the high global prevalence of ESBL-producing (45-50%), MDR (35%), XDR (15-20%), PDR (5.9-6.2%), and carbapenemases (CP)/metallo-ß-lactamases (MBL)-producing (12.5-20%) Gram-negative (GN) microorganisms (i.e., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumanii). On the other hand, shorter courses (≤5-7 days) of monotherapy should be limited to treating infections caused by GN with higher (≥3 antibiotic classes) antibiotic susceptibility. A general approach should be based on (i) third or further generation cephalosporins ± quinolones/aminoglycosides in the case of MDR-GN; (ii) carbapenems ± fosfomycin/aminoglycosides for extended-spectrum ß-lactamases (ESBLs); and (iii) the association of old drugs with new expanded-spectrum ß-lactamase inhibitors for XDR, PDR, and CP microorganisms. Therapeutic drug monitoring (TDM) in combination with minimum inhibitory concentration (MIC), bactericidal vs. bacteriostatic antibiotics, and the presence of resistance risk predictors (linked to patient, antibiotic, and microorganism) should represent variables affecting the antimicrobial strategies for treating GN infections. CONCLUSIONS: Despite the strategies of therapy described in the results, clinicians must remember that all treatment decisions are dynamic, requiring frequent reassessments depending on both the clinical and microbiological responses of the patient.

Development and Validation of a New Tool to Improve the Accuracy of the Hospital Mass-Casualty Incident Response Plan Activation: The PEMAAF Score.

INTRODUCTION: Effective response to a mass-casualty incident (MCI) entails the activation of hospital MCI plans. Unfortunately, there are no tools available in the literature to support hospital responders in predicting the proper level of MCI plan activation. This manuscript describes the scientific-based approach used to develop, test, and validate the PEMAAF score (Proximity, Event, Multitude, Overcrowding, Temporary Ward Reduction Capacity, Time Shift Slot [Prossimità, Evento, Moltitudine, Affollamento, Accorpamento, Fascia Oraria], a tool able to predict the required level of hospital MCI plan activation and to facilitate a coordinated activation of a multi-hospital network. METHODS: Three study phases were performed within the Metropolitan City of Milan, Italy: (1) retrospective analysis of past MCI after action reports (AARs); (2) PEMAAF score development; and (3) PEMAAF score validation. The validation phase entailed a multi-step process including two retrospective analyses of past MCIs using the score, a focus group discussion (FGD), and a prospective simulation-based study. Sensitivity and specificity of the score were analyzed using a regression model, Spearman's Rho test, and receiver operating characteristic/ROC analysis curves. RESULTS: Results of the retrospective analysis and FGD were used to refine the PEMAAF score, which included six items-Proximity, Event, Multitude, Emergency Department (ED) Overcrowding, Temporary Ward Reduction Capacity, and Time Shift Slot-allowing for the identification of three priority levels (score of 5-6: green alert; score of 7-9: yellow alert; and score of 10-12: red alert). When prospectively analyzed, the PEMAAF score determined most frequent hospital MCI plan activation (>10) during night and holiday shifts, with a score of 11 being associated with a higher sensitivity system and a score of 12 with higher specificity. CONCLUSIONS: The PEMAAF score allowed for a balanced and adequately distributed response in case of MCI, prompting hospital MCI plan activation according to real needs, taking into consideration the whole hospital response network.