Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.

Early extubation with immediate non-invasive ventilation versus standard weaning in intubated patients for coronavirus disease 2019: a retrospective multicenter study

In patients intubated for hypoxemic acute respiratory failure (ARF) related to novel coronavirus disease (COVID-19), we retrospectively compared two weaning strategies, early extubation with immediate non-invasive ventilation (NIV) versus standard weaning encompassing spontaneous breathing trial (SBT), with respect to IMV duration (primary endpoint), extubation failures and reintubations, rate of tracheostomy, intensive care unit (ICU) length of stay and mortality (additional endpoints). All COVID-19 adult patients, intubated for hypoxemic ARF and subsequently extubated, were enrolled. Patients were included in two groups, early extubation followed by immediate NIV application, and conventionally weaning after passing SBT. 121 patients were enrolled and analyzed, 66 early extubated and 55 conventionally weaned after passing an SBT. IMV duration was 9 [6-11] days in early extubated patients versus 11 [6-15] days in standard weaning group (p = 0.034). Extubation failures [12 (18.2%) vs. 25 (45.5%), p = 0.002] and reintubations [12 (18.2%) vs. 22 (40.0%) p = 0.009] were fewer in early extubation compared to the standard weaning groups, respectively. Rate of tracheostomy, ICU mortality, and ICU length of stay were no different between groups. Compared to standard weaning, early extubation followed by immediate NIV shortened IMV duration and reduced the rate of extubation failure and reintubation.

Diaphragmatic Kinetics Assessment by Tissue Doppler Imaging and Extubation Outcome

BACKGROUND

The assessment of diaphragmatic kinetics through tissue Doppler imaging (dTDI) was recently proposed as a means to describe diaphragmatic activity in both healthy individuals and intubated patients undergoing weaning from mechanical ventilation. Our primary aim was to investigate whether the diaphragmatic excursion velocity measured with dTDI at the end of a spontaneous breathing trial (SBT) was different in subjects successfully extubated versus those who passed the trial but exhibited extubation failure within 48 h after extubation.

METHODS

We enrolled 100 adult subjects, all of whom had successfully passed a 30-min SBT conducted in CPAP of 5 cm H₂O. In cases of extubation failure within 48 h after liberation from invasive mechanical ventilation, subjects were re-intubated or supported through noninvasive ventilation. dTDI was performed at the end of the SBT to assess excursion, velocity, and acceleration.

RESULTS

Extubation was successful in 79 subjects, whereas it failed in 21 subjects. The median (interquartile range [IQR]) inspiratory peak excursion velocity (3.1 [IQR 2.0-4.3] vs 1.8 [1.3-2.6] cm/s, P < .001), mean velocity (1.6 [IQR 1.2-2.4] vs 1.1 [IQR 0.8-1.4] cm/s, P < .001), and acceleration (8.8 [IQR 5.0-17.8] vs 4.2 [IQR 2.4-8.0] cm/s², P = .002) were all significantly higher in subjects who failed extubation compared with those who were successfully extubated. Similarly, the median expiratory peak relaxation velocity (2.6 [IQR 1.9-4.5] vs 1.8 [IQR 1.2-2.5] cm/s, P < .001), mean velocity (1.1 [IQR 0.7-1.7] vs 0.9 [IQR 0.6-1.0] cm/s, P = .002), and acceleration (11.2 [IQR 9.1-19.0] vs 7.1 [IQR 4.6-12.0] cm/s², P = .004) were also higher in the subjects who failed extubation.

CONCLUSIONS

In our setting, at the end of SBT, subjects who developed extubation failure within 48 h after extubation experienced a greater diaphragmatic activation compared with subjects who were successfully extubated. (ClinicalTrials.gov registration NCT03962322.).

Effects of Varying Levels of Inspiratory Assistance with Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist on Driving Pressure in Patients Recovering from Hypoxemic Respiratory Failure

Background

Driving pressure can be readily measured during assisted modes of ventilation such as pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA). The present prospective randomized crossover study aimed to assess the changes in driving pressure in response to variations in the level of assistance delivered by PSV vs NAVA.

Methods

16 intubated adult patients, recovering from hypoxemic acute respiratory failure (ARF) and undergoing assisted ventilation, were randomly subjected to six 30-min-lasting trials. At baseline, PSV (PSV100) was set with the same regulation present at patient enrollment. The corresponding level of NAVA (NAVA100) was set to match the same inspiratory peak of airway pressure obtained in PSV100. Therefore, the level of assistance was reduced and increased by 50% in both ventilatory modes (PSV50, NAVA50; PSV150, NAVA150). At the end of each trial, driving pressure obtained in response to four short (2–3 s) end-expiratory and end-inspiratory occlusions was analyzed.

Results

Driving pressure at PSV50 (6.6 [6.1–7.8] cmH₂O) was lower than that recorded at PSV100 (7.9 [7.2–9.1] cmH₂O, P = 0.005) and PSV150 (9.9 [9.1–13.2] cmH₂O, P < 0.0001). In NAVA, driving pressure at NAVA50 was reduced compared to NAVA150 (7.7 [5.1–8.1] cmH₂O vs 8.3 [6.4–11.4] cmH₂O, P = 0.013), whereas there were no changes between baseline and NAVA150 (8.5 [6.3–9.8] cmH₂O vs 8.3 [6.4–11.4] cmH₂O, P = 0.331, respectively). Driving pressure at PSV150 was higher than that observed in NAVA150 (P = 0.011).

Conclusions

NAVA delivers better lung-protective ventilation compared to PSV in hypoxemic ARF patients.

Trial registration number and date of registration

The present trial was prospectively registered at www.clinicatrials.gov (NCT03719365) on 24 October 2018

Outcomes of COVID-19 patients treated with continuous positive airway pressure outside the intensive care unit

Aim

We aimed to characterise a large population of coronavirus disease 2019 (COVID-19) patients with moderate-to-severe hypoxaemic acute respiratory failure (ARF) receiving continuous positive airway pressure (CPAP) outside the intensive care unit (ICU), and to ascertain whether the duration of CPAP application increased the risk of mortality for patients requiring intubation.

Methods

In this retrospective, multicentre cohort study, we included adult COVID-19 patients, treated with CPAP outside ICU for hypoxaemic ARF from 1 March to 15 April, 2020. We collected demographic and clinical data, including CPAP therapeutic goal, hospital length of stay and 60-day in-hospital mortality.

Results

The study included 537 patients with a median (interquartile range (IQR) age of 69 (60-76) years. 391 (73%) were male. According to the pre-defined CPAP therapeutic goal, 397 (74%) patients were included in the full treatment subgroup, and 140 (26%) in the do not intubate (DNI) subgroup. Median (IQR) CPAP duration was 4 (1-8) days, while hospital length of stay was 16 (9-27) days. 60-day in-hospital mortality was 34% (95% CI 0.304-0.384%) overall, and 21% (95% CI 0.169-0.249%) and 73% (95% CI 0.648-0.787%) for full treatment and DNI subgroups, respectively. In the full treatment subgroup, in-hospital mortality was 42% (95% CI 0.345-0.488%) for 180 (45%) CPAP failures requiring intubation, and 2% (95% CI 0.008-0.035%) for the remaining 217 (55%) patients who succeeded. Delaying intubation was associated with increased mortality (hazard ratio 1.093, 95% CI 1.010-1.184).

Conclusions

We described a large population of COVID-19 patients treated with CPAP outside ICU. Intubation delay represents a risk factor for mortality. Further investigation is needed for early identification of CPAP failures.

Esophageal balloon calibration during Sigh: A physiologic, randomized, cross-over study

PURPOSE

Optimal esophageal balloon filling volume (V_best) depends on the intrathoracic pressure. During Sigh breath delivered by the ventilator machine, esophageal balloon is surrounded by elevated intrathoracic pressure that might require higher filling volume for accurate measure of tidal changes in esophageal pressure (Pes). The primary aim of our investigation was to evaluate and compare V_best during volume controlled and pressure support breaths vs. Sigh breath.

MATERIALS AND METHODS

Twenty adult patients requiring invasive volume-controlled ventilation (VCV) for hypoxemic acute respiratory failure were enrolled. After the insertion of a naso-gastric catheter equipped with 10 ml esophageal balloon, each patient underwent three 30-min trials as follows: VCV, pressure support ventilation (PSV), and PSV + Sigh. Sigh was added to PSV as 35 cmH₂O pressure-controlled breath over 4 s, once per minute. PSV and PSV + Sigh were randomly applied and, at the end of each step, esophageal balloon calibration was performed.

RESULTS

V_best was higher for Sigh breath (4.5 [3.0-6.8] ml) compared to VCV (1.5 [1.0-2.9] ml, P = 0.0004) and PSV tidal breath (1.0 [0.5-2.4] ml, P < 0.0001).

CONCLUSIONS

During Sigh breath, applying a calibrated approach for Pes assessment, a higher V_best was required compared to VCV and PSV tidal breath.

Critical Care Surge Capacity to Respond to the COVID-19 Pandemic in Italy: A Rapid and Affordable Solution in the Novara Hospital

The rapid insurgence and spread of coronavirus disease 2019 (COVID-19) exceeded the limit of the intensive care unit (ICU) contingency plan of the Maggiore della Carità University Hospital (Novara, Italy) generating a crisis management condition. This brief report describes how a prompt response to the sudden request of invasive mechanical ventilation (IMV) was provided by addressing the key elements of health care system surge capacity from contingency to crisis. In a short time and at a relatively low cost, a structural modification of a hospital aisle allowed to convert the general ICU into a COVID-19 unit, increasing the number of COVID-19 critical care beds by 107%.

Lung Ultrasound in Patients with Acute Respiratory Failure Reduces Conventional Imaging and Health Care Provider Exposure to COVID-19

Lung ultrasound gained a leading position in the last year as an imaging technique for the assessment and management of patients with acute respiratory failure. In coronavirus disease 2019 (COVID-19), its role may be of further importance because it is performed bedside and may limit chest X-ray and the need for transport to radiology for computed tomography (CT) scan. Since February 21, we progressively turned into a coronavirus-dedicated intensive care unit and applied an ultrasound-based approach to avoid traditional imaging and limit contamination as much as possible. We performed a complete daily examination with lung ultrasound score computation and systematic search of complications (pneumothorax, ventilator-associated pneumonia); on-duty physicians were free to perform CT or chest X-ray when deemed indicated. We compared conventional imaging exams performed in the first 4 wk of the COVID-19 epidemic with those in the same time frame in 2019: there were 84 patients in 2020 and 112 in 2019; 64 and 22 (76.2% vs. 19.6%, p < 0.001) had acute respiratory failure, respectively, of which 55 (85.9%) were COVID-19 in 2020. When COVID-19 patients in 2020 were compared with acute respiratory failure patients in 2019, the median number of chest X-rays was 1.0 (1.0-2.0) versus 3.0 (1.0-4.0) (p = 0.0098); 2 patients 2 (3.6%) versus 7 patients (31.8%) had undergone at least one thoracic CT scan (p = 0.001). A self-imposed ultrasound-based approach reduces the number of chest X-rays and thoracic CT scans in COVID-19 patients compared with patients with standard acute respiratory failure, thus reducing the number of health care providers exposed to possible contamination and sparing personal protective equipment.

Neurally adjusted ventilatory assist preserves cerebral blood flow velocity in patients recovering from acute brain injury

Neurally adjusted ventilatory assist (NAVA) has never been applied in patients recovering from acute brain injury (ABI) because neural respiratory drive could be affected by intracranial disease with detrimental effects on cerebral blood flow (CBF) velocity. Our primary aim was to assess the impact of NAVA and pressure support ventilation (PSV) on CBF velocity. In fifteen adult patients recovering from ABI and undergoing invasive assisted ventilation, PSV and NAVA were applied over 30-min-lasting trials, in the following sequence: PSV₁, NAVA, and PSV₂. While PSV was set to deliver a tidal volume ranging between 6 and 8 ml kg⁻¹ of predicted body weight, in NAVA the level of assistance was chosen to achieve the same inspiratory peak airway pressure as PSV. At the end of each trial, a sonographic evaluation of CBF mean velocity was bilaterally obtained on the middle cerebral artery and an arterial blood gas sample was taken for analysis. CBF mean velocity was 51.8 [41.9,75.2] cm  s⁻¹ at baseline, 51.9 [43.4,71.0] cm s⁻¹ in PSV₁, 53.6 [40.7,67.7] cm s⁻¹ in NAVA, and 49.5 [42.1,70.8] cm s⁻¹ in PSV₂ (p = 0.0514) on the left and 50.2 [38.0,77.7] cm s⁻¹ at baseline, 47.8 [41.7,68.2] cm s⁻¹ in PSV₁, 53.9 [40.1,78.5] cm s⁻¹ in NAVA, and 55.6 [35.9,74.1] cm s⁻¹ in PSV₂ (p = 0.8240) on the right side. No differences were detected for pH (p = 0.0551), arterial carbon dioxide tension (p = 0.8142), and oxygenation (p = 0.0928) over the entire study duration. NAVA and PSV preserved CBF velocity in patients recovering from ABI.

Trial registration: The present trial was prospectively registered at www.clinicatrials.gov (NCT03721354) on October 18th, 2018.

Oesophageal balloon calibration during pressure support ventilation: a proof of concept study

Oesophageal balloon calibration improves the oesophageal pressure (Pes) assessment during invasive controlled mechanical ventilation. The primary aim of the present investigation was to ascertain the feasibility of oesophageal balloon calibration during pressure support ventilation (PSV). Secondarily, the calibrated Pes (Pes_cal) was compared to uncalibrated one acquired at 4 ml-filling volume (Pes_V4), as per manufacturer recommendation. After a naso-gastric tube equipped with oesophageal balloon was correctly positioned in 21 adult patients undergoing invasive volume-controlled ventilation (VCV) for acute hypoxemic respiratory failure, the balloon was progressively inflated, applying a series of end-inspiratory and end-expiratory holds at each filling volume during VCV and PSV. Upon optimal balloon filling volume (V_best) was identified, Pes_cal was computed by correcting the Pes measured at V_best for the oesophageal wall pressure elicited at same filling volume. Finally, end-expiratory and end-inspiratory Pes_V4 were recorded too. A total of 42 calibrations, 21 per ventilatory mode, were performed. V_best was 1.9 ± 1.6 ml in VCV and 1.7 ± 1.6 ml in PSV (p = 0.5217). Pes_V4 was overestimated compared to Pes_cal at end-expiration and end-inspiration (p <0.0001 for all comparisons) in both VCV (13.4 ± 3.4 cmH₂O and 15.4 ± 3 cmH₂O vs. 8.5 ± 2.9 cmH₂O and 11.4 ± 3 cmH₂O) and PSV (14.7 ± 4.2 cmH₂O and 17 ± 3.9 cmH₂O vs. 8.9 ± 3.4 cmH₂O and 12.4 ± 3.9 cmH₂O). In PSV, oesophageal balloon calibration is feasible and allows to obtain a reliable Pes assessment compared to uncalibrated approach.

Estimating late spring frost-induced growth anomalies in European beech forests in Italy

Weather extremes and extreme climate events, like late spring frosts, are expected to increase in frequency and duration during the next decades. Although spring phenology of European beech is well adapted to escape freeze damages on longer time scales, the effects of occasional late spring frosts (LSF) are among the main climatic damages to these forests to such an extent that they limit beech distribution and elevation range, especially at its southern margin. The aim of this work was to evaluate the short-term effects of two consecutive LSF events occurred in 2016 and 2017 in Italy on the beech forest vegetation activity. Remotely sensed land surface temperature (LST) data were used to detect the pixels where LSF occurred, while enhanced vegetation index (EVI) data were used to quantify LSF effects by computing a spring vegetation activity anomaly index (sAI). In 2016 and 2017, the LSF covered, respectively, about 29% and 32% of the total Italian beech-dominated area. The two LSF widely differed in their spatial patterns and their effects. In 2016, the pixels belonging to the sAI classes with the highest spring anomalies were also those where prolonged LSF occur, while, in 2017, the pixels belonging to the highest sAI classes were those that underwent the shorter (but probably more intense) LSF events. Under scenarios of increased frequency risk of repeated LSF, the proposed methodology may represent an automatic and low-cost tool both for monitoring and predicting European beech growth patterns.

Body Perfusion during Adult Cardiopulmonary Bypass is Improved by Pulsatile flow with Intra-Aortic Balloon Pump

Purpose

To evaluate if the use of an intra-aortic balloon pump (IABP) during cardioplegic arrest improves body perfusion.

Methods

158 coronary artery bypass graft (CABG) patients were randomized to linear cardiopulmonary bypass (CPB) (n=71, Group A) or automatic 80 bpm intra-aortic ballon pump (IABP) induced pulsatile CPB (n=87, Group B). We evaluated hemodynamic response by Swan-Ganz catheter, inflammation by cytokines, coagulation and fibrinolysis, transaminase, bilirubin, amylase, lactate and renal function (estimated glomerular filtration rate (eGFR), creatinine, and incidence of renal insufficiency and failure).

Results

IABP induced Surplus Hemodynamic Energy was 15.8±4.9 mmHg, with higher mean arterial pressure during cross-clamping (p=0.001), and lower indexed systemic vascular resistances during cross-clamping (p=0.001) and CPB discontinuation (p=0.034). IL-2 and IL-6 were lower, while IL-10 proved higher in Group B (p<0.05). Group B showed lower chest drainage (p<0.05), transfusions (p<0.05), INR (p<0.05), and AT-III (p=0.001), together with higher platelets, aPTT (p<0.05), fibrinogen (p<0.05) and D-dimer (p<0.05). Transaminases, bilirubin, amylase, lactate were lower in Group B (p<0.05); eGFR was better in Group B from ITU-arrival to 48 hours, both in preoperative kidney disease Stages 1–2 (p<0.03) and Stage 3 (p<0.05), resulting in lower creatinine from ITU-arrival to 48 hours (p<0.03). Incidence of renal insufficiency (p=0.004) and need for renal replacement therapy (p=0.044) was lower in Group B Stage 3. Group B PaO2/FiO2 and lung compliance improved from aortic declamping to the first day (p<0.003) with shorter intubation time (p=0.01).

Conclusion

Pulsatile flow by IABP improves whole-body perfusion during CPB.

Antiepileptic drugs for central post-stroke pain management

Antiepileptic drugs (AEDs) are commonly prescribed for a wide range of disorders other than epilepsy, including both neurological and psychiatric disorders. AEDs play also a role in pharmacological management of neuropathic pain. Central post-stroke pain (CPSP) is a disabling morbidity occurring in 35% of patients with stroke. The pathophysiology of CPSP is not well known but central disinhibition with increased neuronal excitability has been suggested. AEDs include many different drugs acting on pain through several mechanisms, such as reduction of neuronal hyperexcitability. To our knowledge conclusive evidence has not been published yet. The aim of this review is to delineate efficacy and safety of AEDs in CPSP.

Postoperative pain treatment SIAARTI Recommendations 2010. Short version

The aim of these recommendations is the revision of data published in 2002 in the "SIAARTI Recommendations for acute postoperative pain treatment". In this version, the SIAARTI Study Group for acute and chronic pain decided to grade evidence based on the "modified Delphi" method with 5 levels of recommendation strength. Analgesia is a fundamental right of the patient. The appropriate management of postoperative pain (POP) is known to significantly reduce perioperative morbidity, including the incidence of postoperative complications, hospital stay and costs, especially in high-risk patients (ASA III-V), those undergoing major surgery and those hospitalized in a critical unit (Level A). Therefore, the treatment of POP represents a high-priority institutional objective, as well as an integral part of the treatment plan for "perioperative disease", which includes analgesia, early mobilization, early enteral nutrition and active physiokinesitherapy (Level A). In order to improve an ACUTE PAIN SERVICE organization, we recommend: --a plan for pain management that includes adequate preoperative evaluation, pain measurement, organization of existing resources, identification and training of involved personnel in order to assure multimodal analgesia, early mobilization, early enteral nutrition and active physiokinesitherapy (Level A); --the implementation of an Acute Pain Service, a multidisciplinary structure which includes an anesthetist (team coordinator), surgeons, nurses, physiotherapists and eventually other specialists; --referring to high-quality indicators in establishing an APS and considering the following key points in its organization (Level C): --service adoption; --identifying a referring anesthetist who is on call 24 hours a day; --patient care during the night and weekend; --sharing, drafting and updating written therapeutic protocols; --continuous medical education; --systematic pain assessment; --data collection regarding the efficacy and safety of the implemented protocols; --at least one audit per year. --a preoperative evaluation, including all the necessary information for the management of postoperative analgesia (Level C); --to adequately inform the patient about the risks and benefits of drugs and procedures used to obtain the maximum efficacy from the administered treatments (Level D). We describe pharmacological and loco-regional techniques with special attention to day surgery and difficult populations. Risk management pathways must be the reference for early identification and treatment of adverse events and chronic pain development.

Intensive versus conventional insulinotherapy after elective and on-pump myocardial revascularization: a prospective and randomized study

OBJECTIVES

Strict glycemic control is increasingly recognized as an important goal in a broad spectrum of critically ill patients. We analyzed the inflammatory and clinical response of patients submitted to intensive or conventional insulinotherapy in a specific clinical context.

MATERIALS AND METHODS

We analyzed a prospective and randomized collected database of an Intensive Care Unit (ICU) in a University Hospital. The database comprised a total of 50 patients aged 30 to 80 (ASA II-III) who underwent elective and on-pump myocardial revascularization from September 2006 to June 2008. On ICU admission, patients were randomly assigned to Group 1 (intensive insulinotherapy) or Group 2 (conventional insulinotherapy). Data collected included glucose and lactate blood levels, haemodynamic parameters, cytokines (TNFalpha, IL-6, IL-8, IL-10), C-Reactive Protein, white blood cells and platelets blood levels, body temperature, Sequential Organ Failure Assessment (SOFA) score, Infection Probability Score (IPS) and ICU length of stay (LOS). Within-between group analysis, one-way ANOVA and unpaired t-test were used when appropriate.

RESULTS

Pre- and perioperative variables were comparable between the two groups (p=NS for all measurements). Glucose and lactate blood levels were lower in Group 1 (p less than 0.0001). Stroke Volume Index was higher in Group 1 (p less than 0.05). Moreover, we observed statistically significant differences between groups in terms of inflammatory parameters and severity scores. No difference was observed in ICU LOS.

CONCLUSIONS

Intensive insulinotherapy after elective on-pump myocardial revascularization significantly modulates the inflammatory response. Different inflammatory patterns could correlate with different clinical response as suggested by SOFA and IP score analysis.

Inflammatory response after cardiopulmonary bypass: a randomized comparison between conventional hemofiltration and steroids

AIM

Recent reports have shown anti-inflammatory effects with conventional hemofiltration (CUF) in patients undergoing cardiopulmonary bypass (CPB). The aim of this study was to evaluate the immunological and the hemodynamic response to CUF or metilprednisolone in patients undergoing coronary artery bypass grafting.

METHODS

Twenty-four consecutive patients were prospectively randomized to receive CUF (12 patients, Group A) or metilprednisolone (12 patients, Group B). Hemodynamic response was evaluated by Swan-Ganz catheter, immunological response was analyzed by IL-2, IL-4, IL-6, TNF-alpha, IFN-gamma, IL-10 before anesthetic induction (T0), at aortic-declamping (T1), at the end of surgery (T2), ITU admission (T3) and 24 hours (T4). Troponin I was measured at the same time-points. Hematological and coagulative controls were performed.

RESULTS

Morbidity and mortality were comparable between the two groups. Group A demonstrated lower cardiac index at T1 (2.1 +/- 0.69 L/min m2 vs. 3.917 +/- 1.28, P = 0.034) without significantly higher indexed-systemic-vascular-resistances at the end of surgery (1 101 +/- 434.3 dyne s cm(-5) m(-2) vs. 797.7 +/- 316.67, P = 0.233). When proinflammatory and anti-inflammatory cytokines were considered, all improved during the postoperative time course, without differences between the 2 Groups (P = NS). Hematological and coagulative data were similar in the two groups, in terms of white blood cells, platelets, prothrombin time, and activated partial thromboplastin time (P = NS).

CONCLUSIONS

Anti-inflammatory action of CUF was comparable to steroids, thus determining a similar proinflammatory response to CPB. However, hemodynamics was slightly impaired by CUF. Therefore, there is no reason to prefer CUF to steroids in patients undergoing elective CABG.

Weaning from mechanical ventilation: an open issue

Weaning from mechanical ventilation represents one of the main challenges facing ICU physicians. Difficult weaning affects about 25% of critical patients undergoing mechanical ventilation. Its duration correlates on one hand with pathophysiological aspects of the underlying disease and, on the other hand, with other factors such as the development of neuromyopathy of the critically ill patient, prolonged use of sedative-hypnotic drugs and, most of all, physicians' reluctance to identify the correct timing of therapeutic steps for weaning and subsequent extubation. The goal of adopting weaning protocols is to overcome problems due to an exclusively clinical opinion. Protocols have to be used together with daily clinical evaluation of the patient and the procedure must be carried out by an ICU team of both medical and nursing staff. Attempts to wean a patient from a ventilator and extubate him should be made through a spontaneous breathing trial (SBT) with T-tube or pressure support ventilation (PSV) with pressure support of 7-8 cmH(2)O +/- PEEP =/> 4 cmH(2)O. Proper recourse to non invasive mechanical ventilation (NIMV) and an accurate timing for tracheostomy are effective tools which can be used by physicians to facilitate weaning and to improve patient outcomes.

Hemodynamic effects of levosimendan in patients with low-output heart failure after cardiac surgery

Following cardiac surgery, low-output syndrome is relatively common. Since this condition can lead to serious consequences, this postsurgical, low-output state should be reversed whenever possible. Patients with low-output syndrome need drug and fluid management aimed at enhancing cardiac contractility and at facilitating optimal myocardial loading. The objective of this pilot study was to evaluate whether benefits of levosimendan, a new calcium-sensitizing agent approved for treatment of patients with acute exacerbation of chronic heart failure, could be extended to patients with low-output syndrome following cardiac surgery. For this study, each patient was given levosimendan as a loading dose of 12 microg/kg over 10 minutes, followed by a continuous infusion of 0.1 microg/kg/min for 12 hours. Of 11 postsurgical patients with severely impaired cardiac output and hemodynamic compromise, 8 patients (73%) showed evidence of combined hemodynamic improvement (> 30% increase in cardiac index and PCWP corrected to < 18 mmHg) within 3 h after the start of levosimendan infusion. Specifically, cardiac index and stroke volume were significantly increased, while mean arterial pressure, indexed systemic vascular resistance, mean pulmonary pressure, right arterial pressure, and pulmonary capillary wedge pressure were all significantly lowered. Taken together, such changes showed enhanced cardiac output along with significantly decreased preload and afterload--conditions associated with recovery of cardiac function. Levosimendan is thus highly favorable for short-term treatment of patients with low cardiac output following cardiac surgery.

Polyphenol pattern and antioxidant activity of different tomato lines and cultivars

BACKGROUND/AIMS

Besides antioxidant vitamins and minerals, fruits and vegetables contain flavonoids and related phenolics. The biological activities of these polyphenols have become well known in recent years evidencing their beneficial effects on human health. In this context, the characterization of the flavonoids present in tomatoes is of great interest. Thus the polyphenol pattern (including flavonols, flavanones and cinnamate derivatives), lycopene and beta-carotene concentrations and the total antioxidant activity (TAA) of the phenolic fraction from different tomato lines and cultivars have been determined.

METHODS

The characterization was obtained by means of spectrophotometry and HPLC analyses.

RESULTS

Mean values for single flavonoids were 0.68 +/- 0.16 for naringenin, 0.74 +/- 0.12 for rutin and 0.32 +/- 0.06 for a rutin-pentoside. Mean total polyphenol content was 13.15 +/- 1.15 mg/100 g and mean TAA value was 1.3 +/- 0.10 mmol/g. The obtained TAA values resulted in good accordance with the total polyphenol content (R(2) = 0.7928). The main phenolic acids were chlorogenic (mean +/- SE 0.20 +/- 0.03) and caffeic acid (mean +/- SE 0.03 +/- 0.01). Mean levels of lycopene and beta-carotene were 5.38 +/- 0.90 and 1.18 +/- 0.40 mg/100 g, respectively.

CONCLUSIONS

Almost all the lines characterised by low carotenoid content produce high levels of polyphenols, and consequently have the most powerful antioxidant potential.

[Pharmacological sympathetic block in complex regional pain syndrome]

PURPOSE

The Complex Regional Pain Syndrome (CRPS) is a chronic pain state provoked by lesions of the soft tissues or of the bony tissues (type CRPS-I or reflex sympathetic dystrophy-RSD) or by lesions of the nerves (type CRPS-II or causalgia) with vegetative alterations (perspiration, vasomotory alterations) and trophic alterations (bony cutaneous atrophy, alopecia, articular contractures). The pharmacological block of the sympathetic nerves through a peripheral vein is inserted in the multidisciplinary approach that characterizes the therapy of this syndrome.

MATERIALS AND METHODS

A retrospective survey was carried out on a group of 185 patients affected by RDS/CRPS with block of the sympathetic nerves through a peripheral vein with guanethidine. Superior limb: Inflation of the tourniquet till disappearance of the radial wrist. Cannulation of a peripheral vein with Butterfly needle n. 23. Guanethidine 10 mg, lidocaine 20 mg, sodic heparin 500 u.i, NaCl 0.9% 20 ml. Injection in 5 minutes. Permanence of the pneumatic tourniquet inflated above systolic blood pressure for 15 minutes. Deflation slowly. Inferior limb: Inflation of the tourniquet till disappearance of the pedidium wrist. Cannulation of a peripheral vein with Butterfly needle n. 23. Guanethidine 20 mg, lidocaine 40 mg, sodic heparin 1000 u.i, NaCl 0.9% 40 ml. Injection in 5 minutes. Permanence of the pneumatic tourniquet inflated above systolic blood pressure for 15 minutes. Deflation slowly.

RESULTS

The first stage (hyperemic) showed the highest incidence of remissions: (83, 33%). Even in the second stage (dystrophic) the answer to the therapy has been fundamentally positive: (53, 68%). In the third stage (atrophic) the results have been more modest: (8, 33%).

CONCLUSIONS

The block of sympathetic system with guanethidine is still an important method in the therapy of the CRPS; in fact it is surely less invading than the blocks of the stellate ganglion or of the lumbar sympathetic.

Nitric oxide inhibits neutrophil adhesion during experimental extracorporeal circulation

BACKGROUND

Myocardial and pulmonary injuries often occur after cardiopulmonary bypass, mediated in part by neutrophil activation and adhesion to endothelial cells. The effects of nitric oxide (NO) administration on neutrophil adhesion to endothelial cells after simulated extracorporeal circulation were investigated.

METHODS

Two identical extracorporeal circulation circuits were primed with fresh human blood and circulated for 2 h at 37 degrees C. Nitric oxide at a 40-ppm concentration was added to one of the oxygenators in each pair. Neutrophil CD11b/CD18 expression and their adhesion to human umbilical vein endothelial cell monolayers were assayed in leukocytes isolated from samples drawn from the circuit 30, 60, 90, and 120 min after circulation began. In another series of experiments, blocking monoclonal antibodies to both neutrophil CD11b and CD18 were incubated with polymorphonuclear leukocytes after removal from the circuit before the adhesion assay.

RESULTS

After 60 min of circulation, the neutrophils from NO-treated circuits showed significantly reduced CD11b/CD18 surface expression compared with the control group. There was also a significant reduction in neutrophil-endothelial adhesion in the NO group after 120 min of circulation. Monoclonal antibodies to both CD11b and CD18 significantly inhibited the adhesion of polymorphonuclear leukocytes at endothelial cells after 120 min of circulation.

CONCLUSIONS

These results confirm that neutrophil activation occurs during cardiopulmonary bypass. The addition of NO to the circuits of extracorporeal circulation significantly affects neutrophil adhesion to endothelial cells.

Tracheal rupture secondary to orotracheal intubation

A case of tracheal rupture due to orotracheal intubation performed for anaesthesiological procedures is described. It is very likely that this rare complication was favoured by some anatomical factors, which were responsible for a difficult intubation. Tracheal rupture was diagnosed by endoscopy and treated by a decompressive tracheostomy.

[Multifactorial surgical risk index of the development of respiratory complications]

Respiratory events are between the most frequent postoperative complications. The preoperative conditions associated with postoperative respiratory failure were evaluated in a prospective study of 1182 patients from six Italian Surgical Units. Multiple regression logistic analysis was employed for statistical evaluation and a predictive prognostic score was derived. Only the presence of the following conditions was significant in affecting postoperative respiratory outcomes: preoperative respiratory and cardiac failure, hypotransferrinemia, prolonged surgical procedures (above the 2 hours) and peroperative bacterial contamination. Advanced age did not appear as a major risk factor. Studies on the predetermination of the pulmonary complications have been widely published. Historical risk factors include the presence of respiratory disease, smoking habits, obesity and thoracic or upper abdominal surgical procedures. Although the results of the present study need a prospective confirmation, the predictive scoring system proves to be a usefull tool that can be employed in most of the General Surgery Units.

Effect of chloramphenicol on the synthesis and stability of ribonucleic acid in Bacillus subtilis

The effect of chloramphenicol on the synthesis and accumulation of ribonucleic acid (RNA) in Bacillus subtilis was studied. In the presence of chloramphenicol, transfer RNA and ribosomal RNA were synthesized as rapidly 2 to 3 hr after challenge as they were just prior to the addition of the antibiotic. However, under the same conditions, net RNA accumulation ceased after only 30 to 45 min. The failure to accumulate RNA after this time resulted from a rapid degradation of ribosomal RNA synthesized in the presence of chloramphenicol and a slow degradation of mature ribosomes. Since transfer RNA was not appreciably degraded, the ratio of transfer RNA to total RNA increased during the challenge.

Medium-dependent alteration of lysine transfer ribonucleic acid in sporulating Bacillus subtilis cells

The presence of the altered lysine transfer ribonucleic acid (tRNA) in Bacillus subtilis spores is strongly dependent on the medium on which the cells were sporulated. Cells sporulated on synthetic media or dilute complex media contain little or none of the new component, whereas those sporulated on concentrated complex media accumulate the altered tRNA. The accumulation begins during the fifth or sixth stage of sporulation, the formation of the tunic, and the appearance of refractility, respectively. Mutants blocked early in sporulation differ in their ability to accumulate the altered tRNA when cultured on the same complex medium. Of the four mutants examined, one failed to accumulate any of the RNA, whereas a second contained the full complement characteristic of spores. The third and fourth mutant contained small amounts of the material. It is tentatively concluded that the accumulation of the altered lysine tRNA is not obligate to sporulation but is an epiphenomenon of the process.