Beach nourishment using sediments from relict sand deposit: Effects on subtidal macrobenthic communities in the Central Adriatic Sea (Eastern Mediterranean Sea-Italy)

Nowadays nourishment is the most popular shore reconstruction strategy to counteract erosion of coastal areas. Sediments used for nourishment can have terrestrial or marine origin. This study analysed the effects of nourishment with relict sand on the subtidal macrobenthic communities and on the surface sediment at 7 sites of the Marche Region (Central Adriatic Sea, Italy). Samples for biological and physical analyses were collected in each site before and after nourishment. One year after nourishment the presence of the relict sands used for the replenishment is still visible in the sediment of each site. In the same period macrobenthic communities are characterised by the dominance of a few species able to avoid burial and suffocation phenomena, showing a low variability respect to the communities present before.

Risk of pocket hematoma in patients on chronic anticoagulation with warfarin undergoing electrophysiological device implantation: a comparison of different peri-operative management strategies

OBJECTIVE

Periprocedural management of warfarin remains challenging in patients requiring electrophysiological device surgery. For patients at high risk of thromboembolic events, guidelines recommend bridging therapy with heparin; however, this strategy is associated with a high risk of pocket hematoma. This paper systematically reviews studies appraising the risk of pocket hematoma with different perioperative anticoagulation strategies.

METHODS

All relevant studies identified in MEDLINE/PubMed, The Cochrane Collaboration CENTRAL, clinicaltrials.org and in bibliographies of key articles. Estimates were combined using a fixed effects model. Heterogeneity was assessed by p values of χ2 statistics and I2. Publication bias was assessed by visual examination of funnel plots and by Egger test. Fifteen studies enrolling 5911 patients met all inclusion criteria and were included in this review.

RESULTS

Heparin bridging compared with no heparin was associated with increased risk of pocket hematoma (OR = 4.47, 95% CI 3.21-6.23, p < 0.00001), and prolonged hospital stay (9.13 ± 1.9 days vs. 5.11 ± 1 .39 days, p < 0.00001). Warfarin continuation was not associated with increased pocket hematoma compared to warfarin discontinuation (p = 0.38), but was associated with reduced risk of pocket hematoma compared with heparin bridging (OR = 0.37, 95% CI 0.2-0.69, p = 0.002). Thromboembolic complications were reduced with heparin bridging vs. no heparin (0.50% vs.1.07%, p = 0.02), and no significant differences were reported between heparin bridging vs. warfarin continuation (p = 0.83).

CONCLUSIONS

Heparin bridging is associated with a higher risk of pocket hematoma and a prolonged hospital stay. Perioperative continuation of warfarin reduces the occurrence of pocket hematoma compared with heparin bridging without any significant differences in thromboembolic complications.

Stress-related biomarkers of dream recall and implicit memory under anaesthesia

The aim of this study was to investigate whether auditory presentation of a story during general anaesthesia might influence stress hormone changes and thus affecting dream recall and/or implicit memory. One hundred and ten patients were randomly assigned either to hear a recording of a story through headphones or to have routine care with no auditory recording while undergoing laparoscopic cholecystectomy. Anaesthesia was standardised. Blood samples for cortisol and prolactin assays were collected 20 min before anaesthesia and 5 min after pneumoperitoneum. Dream recall and explicit/implicit memory were investigated upon awakening from anaesthesia and approximately 24 h after the end of the operation. Auditory presentation was associated with lower intra-operative serum prolactin concentration compared with control (p = 0.0006). Twenty-seven patients with recall of dreaming showed higher intra-operative prolactin (p = 0.004) and lower cortisol (p = 0.03) concentrations compared with those without dream recall. The knowledge of this interaction might be useful in the quest to ensure postoperative amnesia.

EPO modulation in a 14-days undersea scuba dive

Erythropoiesis is affected during deep saturation dives. The mechanism should be related to a downregulation of serum Erythropoietin (s-EPO) concentration or to a toxic effect of the hyperbaric hyperoxia. We evaluated s-EPO and other haematological parameters in 6 scuba divers before, during and after a 14-days guinness saturation dive (8-10 m). Athletes were breathing air at 1.8-2 ATA, under the control of a team of physicians. Serum parameters were measured before diving (T0) and: 7 days (T1), 14 days (T2) after the beginning of the dive and 2 h (T3) and 24 h (T4) after resurfacing. Hgb, and many other haematological parameters did not change whereas Ht, s-EPO, the ratio between s-EPO predicted and that observed and reticulocytes (absolute, percent) declined progressively from T0 to T3. At T4 a significant rise in s-EPO was observed. Hgb did not vary but erythropoiesis seemed to be affected as s-EPO and reticulocyte counts showed. All these changes were statistically significant. The experiment, conducted in realistic conditions of dive length, oxygen concentration and pressure, allows us to formulate some hypotheses about the role of prolonged hyperbarism on erythropoiesis. The s-EPO rise, 24 h after resurfacing, is clearly documented and related to the "Normobaric Oxygen Paradox". This evidence suggests interesting hypotheses for new clinical applications such as modulation of s-EPO production and Hgb content triggered by appropriate O₂ administration in pre-surgical patients or in some anemic disease.

Split spectrum: a multi-channel approach to elastic optical networking

This paper introduces Split Spectrum, which enhances elastic optical networking by splitting a bulk traffic demand into multiple channels, when a single-channel transmission is prohibited by distance or spectrum availability. We performed transmission simulations to determine the maximum reach as a function of modulation format (dual polarization BPSK, QPSK, 16QAM), baud-rate (from 5 to 28 GBd), and number of ROADMs, for a Nyquist WDM super-channel with subcarrier spacing equal to 1.2 × baud-rate. Performance evaluation on two representative topologies shows that, compared to the previously proposed elastic optical networking, Split Spectrum doubles the zero-blocking load and achieves 100% higher network spectral efficiency at zero-blocking loads as a result of extended transmission distance and efficient utilization of spectrum fragments.

Chest ultrasounds to guide manual reexpansion of a postoperative pulmonary atelectasis: a case report

Reexpansion of a pulmonary atelectasis is often difficult, even after removing possible causes of bronchial obstruction. Chest ultrasounds, inexpensive and readily available at the patient bedside, may offer valuable support to guide recruitment maneuvers. We report the case of a 57-year-old woman that developed a complete collapse of the left lung seven days after undergoing an intestinal resection for perforation. A mucous plug occluding the main bronchus was removed with bronchoscopy, but persistent hypoxemia required mechanical ventilation; 24 hours later, an attempt to wean the patient from the ventilator failed. Chest X-rays revealed the persistence of a partial collapse of the left inferior lobe associated with a pleural effusion. A chest ultrasound confirmed the presence of a lung consolidation and of a modest pleural effusion. Manual reexpansion was then attempted, and ventilatory pressures as well as the duration of forced inspirations were based on real-time ultrasound images. Complete reexpansion was achieved within a few minutes and confirmed by chest X-ray. The patient was weaned from mechanical ventilation on the same day and discharged from ICU three days later.

Use of corticosteroids in critically ill septic patients : a review of mechanisms of adrenal insufficiency in sepsis and treatment

Adrenal insufficiency has being reported with increased frequency in critical ill patients with sepsis and other inflammatory states. Its incidence varies widely depending on the criteria used to define it and the patient population studied. Increased glucocorticoid action is essential in the stress response to acute injury and even minor degrees of adrenal insufficiency can be fatal. Recently the so-called relative or functional adrenal insufficiency (CIRCI) has been described: in this syndrome cortisol levels may be low or high but nonetheless inadequate to meet the elevated metabolic demand. Since laboratory diagnosis of adrenal insufficiency is still controversial, the diagnosis of ICU associated adrenal insufficiency is essentially a clinical diagnosis. Whether exogenous corticosteroid support may be beneficial in critical illness is still matter of debate: most international guidelines recommend that the decision to treat patients with corticosteroids should be based on clinical criteria (low blood pressure poorly responsive to vasopressor despite adequate fluid resuscitation) rather than on tests of the hypothalamic-pituitary-adrenal axis alone. As regards specifically the role of steroids in the treatment of sepsis and septic shock, at present there are no strong evidence-based recommendations. More studies are needed to reach consensus about several issues: which is the best target population, whether a cosyntropin test should be used to guide treatment, whether fludrocortisones should be given along with hydrocortisone, and how long treatment should continue.

Intensive care after elective surgery: a survey on 30-day postoperative mortality and morbidity

BACKGROUND

Postoperative admission to the surgical intensive care unit (S-ICU) is routinely planned in order to prevent and treat early complications. Currently, limited studies have been conducted on this topic, and as such, early morbidity and mortality in patients undergoing postoperative intensive care were investigated.

METHODS

This prospective analysis was performed in the S-ICU of a University hospital and included 1045 consecutive patients. All patients underwent elective surgery and were admitted to the S-ICU on the basis of preoperative clinical assessment. On the second, seventh, and thirtieth postoperative days, the location of the patients was recorded (ICU, surgical ward, or home) as were any complications that occurred. Predicted mortality and morbidity were assessed using the POSSUM score.

RESULTS

The observed postoperative mortality rate was 2.4% (95% CI: 1.5-3.3%), which was much lower than the rate predicted by both POSSUM (6.2%) and P-POSSUM (5.3%) analyses, and 36% of patients experienced complications, a percentage slightly higher than that predicted by POSSUM (30.2%). The first 48 hours following surgery were characterized by the highest mortality rate (2.85 deaths per thousand vs 0.7 per thousand by the third postoperative day) as well as the highest morbidity rate (7.7% vs 4.3% between the third and seventh postoperative days, and 0.9% between the eighth and thirtieth postoperative days). The presumed causes of early death were primarily secondary to cardiovascular complications (five out of six).

CONCLUSIONS

The first 48 hours after surgery is a critical period in high-risk patients, and a stay in the S-ICU should be seriously considered. Planned admission to the S-ICU may effectively decrease postoperative mortality, as suggested by the highly significant difference between expected and observed deaths following S-ICU admission.

All-optical 40 Gbits/s packet regeneration by means of cross-gain compression in a semiconductor optical amplifier

We experimentally demonstrate all-optical reshaping of 40 Gbits/s packets by using cross-gain compression in a semiconductor optical amplifier (SOA). This scheme, which is based on cross-saturation effects between two conjugate signals copropagating in a single SOA, is wavelength preserving and polarization independent and does not suffer from any transient effect at packet edges. We report evidence of noise redistribution and packet reshaping by means of the bit-error rate versus threshold measurements for different input optical signal-to-noise ratios.

Leptin and perioperative neuroendocrine stress response with two different anaesthetic techniques

BACKGROUND

Stress response to surgery is modulated by several factors, including magnitude of the injury, pain, type of procedure and choice of anaesthesia. Our purpose was to compare intra- and post-operative hormonal changes during total intravenous anaesthesia (TIVA) using propofol and remifentanil vs. sevoflurane anaesthesia in a low stress level surgical model (laparoscopy).

METHODS

We randomly allocated 18 patients undergoing laparoscopic surgery for benign ovarian cysts in two groups to receive either TIVA (group A=9) or sevoflurane anaesthesia (group B=9). Perioperative plasma levels of norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), cortisol and leptin were measured. Blood samples were collected pre-operatively (time 0), 30 min after the beginning of surgery (time 1), after extubation (time 2), and 2 h (time 3) and 4 h after surgery (time 4).

RESULTS

The comparative analysis between the groups shows significantly higher values of NE (P<0.001 at time 1 and P<0.01 at time 3), E (P<0.001 at times 1 and 2; P<0.01 at time 3 and P<0.05 at time 4), ACTH (P<0.001 at times 1 and 2; P<0.05 at time 3) and cortisol (P<0.001 at times 1 and 2; P<0.01 at time 3; P<0.05 at time 4) in group B. The serum values of leptin were not significantly different between the two groups.

CONCLUSION

The choice of anaesthesia does not seem to affect the leptin serum levels but influences the release of stress response markers: ACTH, cortisol, NE and E.

Exposure to noise during continuous positive airway pressure: influence of interfaces and delivery systems

BACKGROUND

We measured noise intensity and perceived noisiness during continuous positive airway pressure (CPAP) performed with two interfaces (face-mask, helmet) and four delivery systems.

METHODS

Eight healthy volunteers received CPAP in random order with: two systems provided with a flow generator using the Venturi effect and a mechanical expiratory valve (A: Venturi, Starmed; B: Whisperflow-2, Caradyne Ltd); one 'free-flow' system provided with high flow O(2) and air flowmeters, an inspiratory gas reservoir, and a water valve (C: CF800, Drägerwerk, AG); and a standard mechanical ventilator (Servoventilator 300, Siemens-Elema). Systems A, B, and C were tested with a face-mask and a helmet at a CPAP value of 10 cm H(2)O; the mechanical ventilator was only tested with the face mask. Noise intensity was measured with a sound-level meter. After each test, participants scored noisiness on a visual analog scale (VAS).

RESULTS

The noise levels measured ranged from 57+/-11 dBA (mechanical ventilator plus mask) to 93+/-1 and 94+/-2 dBA (systems A and B plus helmet) and were significantly affected by CPAP systems (A and B noisier than C and D) and interfaces (helmet CPAP noisier than mask CPAP). Subjective evaluation showed that systems A and B plus helmet were perceived as noisier than system C plus mask or helmet.

CONCLUSIONS

Maximum noise levels observed in this study may potentially cause patient discomfort. Less noisy CPAP systems (not using Venturi effect) and interfaces (facial mask better than helmet) should be preferred, particularly for long or nocturnal treatments.

A simple and low-power optical limiter for multi-GHz pulse trains

We study the limiting-amplification capability of a saturated Semiconductor Optical Amplifier (SOA) followed by an optical band-pass filter. We experimentally demonstrate that this simple optical circuit can be effectively exploited to realize a low-power optical limiter for amplitude-modulated pulse trains at multi-GHz repetition rate. We report very large amplitude-modulation-reduction factors for the case of 20 and 40 GHz pulse trains that are super-imposed with modulating frequencies ranging from 100kHz to several GHz.

Unusual presentation of leptospirosis in the late stage of pregnancy

Here we report a case of leptospirosis without fever during the late stage of pregnancy in which the initial clinical presentation was more suggestive of a pregnancy-related liver dysfunction rather than an infectious disease. A 32-year-old primipara at 37 week of gestation was hospitalised with a 10-day history of nausea, vomiting, and abdominal pain without fever. Initial routine blood tests showed hyperbilirubinemia, a moderate increase in transaminase levels, severe coagulopathy and an increased creatinine level. On clinical suspicion of pregnancy-related liver dysfunction such as HELLP syndrome (hemolysis, elevated liver enzyme levels, low platelet count) or acute fatty liver of pregnancy (AFLP), emergency caesarean section was performed and a healthy baby was delivered. Postoperatively, the patient was stable, but 5 days later she developed clouding of consciousness, severe jaundice and respiratory failure. At this time, an infectious disease was considered and leptospirosis was confirmed by serological tests. In conjunction with intensive care management, antibiotic therapy was given; the patient was discharged in good condition and her baby did not develop signs of active leptospirosis. While leptospirosis is rare in pregnancy, this is the first report of acute infection without fever mimicking the clinical pattern of HELLP syndrome or AFLP

A normal response to Synachten test does not rule out corticosteroid effectiveness in weaning from catecholamine after septic shock

Corticosteroids may improve haemodynamics and facilitate weaning from catecholamines in septic shock. According to some authors, such effects are only accomplished in the presence of absolute or relative adrenal insufficiency. Consequently, corticosteroids are usually given only to patients that present low blood cortisol values or show an inadequate response to cosyntropin (Synachten test). We report the case of a woman affected by septic shock secondary to pneumonia and dependent on norepinephrine infusion for 26 days, who was weaned from catecholamines with hydrocortisone, 100 mg/day i.v. She exhibited a normal response to Synachten, but corticosteroid therapy was continued because haemodynamics improved promptly. A pharmacological effect was hypothesized; the contemporary increase of platelet, decrease of white blood cells, and decrease of plasma fibrinogen supported this hypothesis.

Molecular Adsorbent Recirculating System in Liver Transplantation: Safety and Efficacy

We assessed the safety and clinical efficacy of the Molecular Adsorbent Recirculating System (MARS) in liver failure patients admitted to our intensive care unit (ICU) from May 2000 to February 2006. Of 28 adult patients with bilirubin >15 mg/dL and hepatic encephalopathy (HE) grade > or =2 or hepato-renal syndrome, 22 patients were included in the study, because 6 patients were older than 65 years of age or showed recent alcohol abuse or extrahepatic malignancy. Patients were assigned to 2 groups according to whether MARS therapy was associated with a transplantation procedure: 11 patients received MARS therapy and liver transplantation (OLT group) and 11 patients received MARS therapy alone (non-OLT group). Five of 11 patients in the OLT group were listed for transplantation and 6 patients with graft failure for retransplantation. The patients in the OLT and non-OLT groups were similar in MELD, SOFA, and SAPS scores. All patients were stable and free from complications. MARS significantly reduced bilirubin, bile acids, and blood urea nitrogen (BUN) levels in both groups (P < .05), whereas a significant decrease in ammonia level was observed in the OLT group. Patient survival rates at 3 and 6 months in the OLT group were 91% and 73%, respectively, and in the non-OLT group, 9% and 9%, respectively (P < .001). MARS was safe and well tolerated, improving biochemical parameters, neurological function, and pruritus. In terms of survival, the use of MARS alone was not effective due to the high rate of multiple organ failure. Nevertheless, the association of MARS with a transplant/retransplantation procedure was highly effective.

Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery: a prospective cohort study

BACKGROUND AND OBJECTIVES

The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery.

METHODS

rSO2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II-III; age: 72 +/- 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score >23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h.

RESULTS

Baseline rSO2 was 63 +/- 8%; cerebral desaturation (rSO2 decrease <75% of baseline or <80% in case of baseline rSO2 <50%) occurred in 16 patients (26%). The MMSE decreased from 28 +/- 1 before surgery to 27 +/- 2 on 7th postoperative day (P = 0.05). A decline in cognitive function (decrease in MMSE score > or = 2 points one week after surgery as compared to baseline value) was observed in six patients without intraoperative cerebral desaturation (13.6%) and six patients who had intraoperative cerebral desaturation (40%) (P = 0.057) (odds ratio: 4.22; CI95%: 1.1-16). Median (range) hospital stay was 14 (5-41) days in patients with an area under the curve of rSO2 <50% (AUCrSO2<50%) >10 min%, and 10 (4-30) days in those with an AUCrSO2<50% <10 min% (P = 0.0005).

CONCLUSIONS

In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.

Catholic university experience with molecular adsorbent recycling system in patients with severe liver failure

BACKGROUND AND AIM

Molecular adsorbent recycling system (MARS) treatment is able to remove both hydrosoluble and small- and medium-sized lipophilic toxins. MARS plays an important role in modifying liver failure complications, such as hepatorenal syndrome and hepatic encephalopathy. We sought to evaluate the clinical efficacy and safety of a MARS device in a consecutive series of hepatic failure patients.

MATERIALS

Twenty patients with acute liver failure, transplantation failure, or acute on chronic liver failure fulfilled the inclusion criteria of total bilirubin > or =10 mg/dL and at least one of the following: hepatic encephalopathy (HE) > or =II grade, hepatorenal syndrome (HRS) for chronic patients or total bilirubin > or =5 mg/dL and HE > or =I grade for acute patients.

RESULTS

MARS was able to reduce cholestatic parameters and improve neurologic status and renal function parameters in all treated patients. We also observed an improvement in the 3-month survival rate compared to the expected outcome in patients with MELD scores between 20 and 29, as well as 30 and 39.

CONCLUSIONS

Based on these results, we confirm the safety and clinical efficacy of MARS treatment, with the best results in patients with MELD score of 20 to 29. Further studies are necessary to confirm whether this treatment is able to modify patient outcomes and prognosis.

Improvement of mitochondrial function evaluated by ketoisocaproic acid breath test in patients with HCV infection undergoing albumin dialysis

BACKGROUND AND AIM

Oxidative injury occurs as a direct result of hepatitis C virus (HCV) core protein expression both in vitro and in vivo, and may be due to a direct effect on mitochondria. The ketoisocaproic acid (KICA) breath test is a simple, reliable, and noninvasive test to evaluate hepatic mitochondrial function. Albumin dialysis (MARS) is an effective bridge treatment for patients with acute failure superimposed on chronic liver disease. The aim of our study was to evaluate the improvement of mitochondrial function measured by KICA in patients undergoing MARS for acute-on-chronic HCV liver failure.

MATERIALS AND METHODS

Five patients with HCV chronic infection undergoing MARS treatment for acute decompensation were enrolled. Before and after each MARS treatment, patients underwent blood testing for the main hematochemical parameters as well as for mitochondrial function by the KICA breath test and the arterial ketone bodies ratio (AKBR).

RESULTS

MARS treatment effectively decreased the serum level of total bilirubin, bile acids, urea, and ammonium. Moreover, MARS treatment produced an increase in AKBR and in the cumulative percentage of (13)CO(2) recovered in exhaled air 2 hours after KICA ingestion.

CONCLUSION

Liver mitochondrial function appears to be beneficially affected by MARS treatment.

The decrease in cytokine concentration during albumin dialysis correlates with the prognosis of patients with acute on chronic liver failure

BACKGROUND AND AIM

The clearance of plasma cytokines by means of albumin dialysis (MARS) has been demonstrated in various studies involving patients affected by either acute liver failure (ALF) or acute on chronic liver failure. The aim of the study was to measure the plasma levels of TNF-alpha, IL-6, and IL-1beta in patients with ALF after each MARS treatment to evaluate the relationship between variations in cytokines levels and patient prognosis.

MATERIALS AND METHODS

Ten patients with ALF undergoing several MARS treatments were enrolled (group 1). Blood samples were collected before and after each MARS treatment to measure TNF-alpha, IL-6, and IL-1beta, and other hematochemical parameters. We also enrolled 10 patients with ALF who underwent standard therapy (group 2) as well as a control group of 10 healthy subjects matched for sex and age (group 3).

RESULTS

MARS reduced total bilirubin levels, biliary acids, BUN, ammonia, TNF-alpha, IL-6, and IL-1beta (P < .05). Moreover, the reduction in inflammatory cytokines levels and improved prognosis were related.

CONCLUSIONS

We confirmed the therapeutic efficacy of MARS treatment for ALF, which appeared to be related to removal of toxins and inflammatory cytokines determine that which patients prognosis.

Hypoalbuminaemia does not impair Diprifusor performance during sedation with propofol

BACKGROUND

About 98% of plasma propofol is bound to albumin. We investigated if severe hypoalbuminaemia may affect the accuracy of a target-controlled infusion (TCI) device, the Diprifusor, during sedation in critically ill patients.

METHODS

Ten critically ill hypoalbuminaemic patients (<24 g litre(-1)) and 10 critically ill normoalbuminaemic patients (>32 g litre(-1)) were included in this study. They underwent sedation with propofol, aimed at a Ramsey sedation score of 4-5. The Diprifusor was used to achieve target propofol plasma concentrations that ranged between 0.6 and 1.5 mg litre(-1). Propofol concentration was measured by high-performance liquid chromatography 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h and 8 h after starting TCI. The accuracy of TCI was evaluated by calculating performance errors [PE=100x(measured concentration-predicted concentration)/predicted concentration], absolute and relative individual median performance errors (MDAPE and MDPE) and divergence (the slope of individual regression lines between PEs and time).

RESULTS

PEs [median (range)] were -7 (-65, 79) in hypoalbuminaemic patients and -2 (-53, 188) in normoalbuminaemic patients; absolute PEs were 21 (1, 79) and 22 (0, 188). No significant difference was observed between the two groups. MDPE, MDAPE and divergence values were also similar. In most patients the accuracy of TCI increased with time because higher PE values were observed during the first 30 min.

CONCLUSIONS

Hypoalbuminaemia does not affect the accuracy of Diprifusor during sedation with propofol in critically ill patients.

Long-term idebenone treatment of vascular and degenerative brain disorders of the elderly

A multicentre study with an open experimental design was carried out on 118 patients suffering from mild to moderate cognitive decline due to cerebrovascular and degenerative disorders (chronic cerebrovascular disorders, CCVD; multi-infarct dementia, MID; aging brain, AB; dementia of Alzheimer's type, DAT). All patients, after a wash-out period of 3 weeks, were treated with idebenone (45 mg twice daily by oral route) for a period of 6 months. Behavioral and cognitive measures (Sandoz Clinical Assessment of Geriatrics, SCAG; Serial Learning Test) were applied to evaluate the long term therapeutical aspects. The results, analyzed by multivariate analysis of variance and chi2 test, showed a significant improvement of the cognitive profile in all patients, more evident in CCVD and AB groups. No remarkable side-effects were found in all groups of patients, thus confirming good tolerability of idebenone.

A prospective, randomized, double-blind comparison of epidural levobupivacaine 0.5% with epidural ropivacaine 0.75% for lower limb procedures

BACKGROUND AND OBJECTIVE

This prospective, randomized, observer-blinded study compared onset time and duration of epidural anaesthesia produced by with levobupivacaine and ropivacaine for lower limb surgery.

METHODS

ASA I-III adult patients undergoing elective lower limb procedures were randomized to receive epidural levobupivacaine 0.5% 15 mL (n = 30) or epidural ropivacaine 0.75% 15 mL (n = 35). A blinded observer evaluated onset time and regression of motor and sensory block, and intraoperative needs for fentanyl supplementation (0.1 mg intravenously).

RESULTS

With levobupivacaine, onset time was 29 +/- 24 min, with ropivacaine it was 25 +/- 22 min (P = 0.41). Complete resolution of motor block required 105 +/- 63 min with levobupivacaine and 95 +/- 48 min with ropivacaine (P = 0.86). The time for regression of sensory block to T12 was 185 +/- 77 min with levobupivacaine and 201 +/- 75 min with ropivacaine (P = 0.46). Analgesic supplementation was required in one patient receiving levobupivacaine (3.5%) and in two patients receiving ropivacaine (5.7%) (P = 0.99).

CONCLUSIONS

In adults undergoing lower limb surgery, levobupivacaine 0.5% 15 mL produces an epidural block with the same clinical profile as ropivacaine 0.75% 15 mL.

[Anesthesia and concomitant pathologies: anesthesia in the elderly patient]

With the increase in the average age of the population, more and more older persons undergo surgery. Major surgery, cardiovascular, orthopaedic and abdominal interventions expose the elderly patient to a significant risk for postoperative morbidity and mortality. This is not only related to the advanced age of these subjects, which is a recognized independent risk factor, but also to the aging process itself and to the greater prevalence of heart and lung diseases affecting this population segment. An important role is also played by the so-called physiologic modification found in subjects without recognized illnesses. Reduced organ function reserve requires accurate preoperative assessment that takes into account cardiovascular reserve and physiologic and pathologic alterations in the respiratory system that may predispose the patient to hypoxemia and favour the development of postoperative infection. Moreover, alterations in pharmacokinetics and pharmacodynamics require individualized drug dosing. Particular attention should also be directed at the prevention of postoperative cognitive disorders that favour the development of complications and negatively affect postoperative recovery of body function.

Comparison of positive end-expiratory pressure with reverse Trendelenburg position in morbidly obese patients undergoing bariatric surgery: effects on hemodynamics and pulmonary gas exchange

BACKGROUND

Anesthetized morbidly obese patients often exhibit impaired pulmonary gas exchanges, mostly because of a reduction in functional residual capacity. At present, several approaches are suggested to ventilate these patients.

METHODS

The efficiency of positive end-expiratory pressure (PEEP) and reverse Trendelenburg position (RTP) were compared in order to improve oxygenation in 20 morbidly obese patients undergoing bariatric surgery.

RESULTS

Both PEEP and RTP determined a significant decrease in alveolar-arterial oxygen difference and an increase in total respiratory compliance (Ctot). RTP resulted in lower airway pressures than PEEP with similar improvements in Ctot and oxygenation. Concerning hemodynamic parameters, cardiac output (CO) significantly decreased with both PEEP and RTP.

CONCLUSIONS

RTP and PEEP can be considered adequate ventilatory settings for morbidly obese patients, without any significant difference with regard to gas exchange improvement. However, the decrease in CO may partially counteract the beneficial effects on oxygenation of these ventilatory settings.

Sleep organization pattern as a prognostic marker at the subacute stage of post-traumatic coma

OBJECTIVES

The aim of this study is to identify the predictive indexes for post-traumatic coma prognosis, which is important to better direct acute and subacute treatments and rehabilitation efforts. The pattern of sleep organization is a potential prognostic marker, but its role has not been established yet in the context of modern critical care. In the present study, we used a new protocol to evaluate the prognostic value of the different levels of sleep-wake organization recorded at the subacute stage of post-traumatic coma.

METHODS

Twenty-four head-injured comatose patients were monitored with 24h polysomnographic recordings. The predictivity of the different levels of sleep-wake organization on polysomnography was compared with other possible prognostic indexes (i.e. neuroradiological findings, age and Glasgow Coma Scores (GCS)). Main outcome measures were survival and the degree of disability after recovery from coma.

RESULTS

The presence of organized sleep patterns, but not GCS, was highly predictive of better outcome (odds ratio=10.78, P=0.01), even after correction for potentially confounding variables with multivariate analysis.

CONCLUSIONS

Our study demonstrates that the sleep-wake organization pattern based on 24h polysomnographic recordings at the subacute stages of post-traumatic coma is a reliable prognostic marker, both for survival and for functional recovery.

Effects of low-dose alfentanil administration on central respiratory drive and respiratory pattern in spontaneously breathing ASA 1 patients

The aim of this study was to assess the short-term effects of the administration of low doses of alfentanil on respiratory drive and respiratory pattern. We studied 17 ASA I patients scheduled for minor surgery or endoscopic procedures. During spontaneous ventilation, Respiratory Rate, Tidal Volume, Total Respiratory Cycle, Inspiratory and Expiratory Time, Mean Inspiratory Flow, P0.1, S(a)O(2) and EtCO(2) were all measured. The inspired oxygen concentration was 21% and measurements were made at baseline, 5 min (T1), 10 min (T2) and 15 min (T3) following an intravenous bolus injection 10 microg.kg(-1) alfentanil. The administration of alfentanil produced a significant (p < 0.05) reduction in S(a)O(2), minute volume and P0.1. In ASA I spontaneously breathing patients, the pre-operative administration of low doses of alfentanil can initially reduce the respiratory centre activity leading to a reduction in minute volume and S(a)O(2). We therefore recommend careful monitoring of cardio-respiratory function in ASA I patients, following the administration of alfentanil.

Effects of acid-base abnormalities on blood capacity of transporting CO(2): adverse effect of metabolic acidosis

OBJECTIVE

To investigate the effects of some acid-base abnormalities on blood capacity of transporting CO(2).

DESIGN

Prospective study.

SETTING

General and Cardiosurgical ICUs of a University hospital.

PATIENTS

Six groups of ten patients characterized by: metabolic alkalosis; respiratory alkalosis; absence of acid-base abnormalities; metabolic acidosis; uncompensated respiratory acidosis; and compensated respiratory acidosis.

MEASUREMENTS AND RESULTS

The CO(2) dissociation curve, Haldane effect, and the ratio Ra-v between Ca-vCO(2) and Pa-vCO(2) were calculated from arterial and mixed-venous blood gas analyses. The CO(2) dissociation curve was shifted upwards by metabolic alkalosis and compensated respiratory acidosis and downwards by metabolic acidosis. The slope of the curve was unaffected, but CO(2) transport not due to Haldane effect was significantly lower in respiratory acidosis since the slope was less steep at higher PCO(2) values. In comparison with controls, patients affected by metabolic acidosis showed lower Haldane effect values (0.18+/-0.15 vs 0.59+/-0.26 ml of CO(2) per ml of arterial-mixed venous O(2) content difference; P <.05) and Ra-v values (0.43+/-0.10 vs 0.84+/-0.17 ml of CO(2) transported by 100 ml of blood per Torr of arterial-mixed venous PCO(2) gradient; P <.05).

CONCLUSIONS

Our findings suggest that acid-base abnormalities, particularly metabolic acidosis, markedly affect blood capacity of transporting CO(2) and may worsen tissue hypercarbia associated with hypoperfusion. However, because of possible errors due to small measurements and the assumptions of the method, in the future definitive clarification will require the construction of original CO(2) dissociation curves for each acid-base abnormality.

Closed versus open suctioning techniques

Airway suctioning is classically performed with the disconnection of the patient from the ventilator and the introduction of the suction catheter into the endotracheal tube. Alternatively, it can be accomplished with a closed suctioning system included in the ventilatory circuit, allowing to introduce the suction catheter into the airways without disconnecting the patient from the ventilator. The closed-suction system has some advantages compared to the conventional, open-suction technique. It can be helpful in limiting environmental, personnel and patient contamination and in preventing the loss of lung volume and the alveolar derecruitment associated with standard suctioning in the severely hypoxemic patients. However, the impact of the closed system on ventilator-associated pneumonia as well as its cost-effectiveness and the influence of such devices with ventilatory support remain to be assessed.

Predictors of failure of noninvasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a multi-center study

CONTEXT

In patients with hypoxemic acute respiratory failure (ARF), randomized studies have shown noninvasive positive pressure ventilation (NPPV) to be associated with lower rates of endotracheal intubation. In these patients, predictors of NPPV failure are not well characterized.

OBJECTIVE

To investigate variables predictive of NPPV failure in patients with hypoxemic ARF.

DESIGN

Prospective, multicenter cohort study.

SETTING

Eight Intensive Care Units (ICU) in Europe and USA.

PATIENTS

Of 5,847 patients admitted between October 1996 and December 1998, 2,770 met criteria for hypoxemic ARF. Of these, 2,416 were already intubated and 354 were eligible for the study.

RESULTS

NPPV failed in 30% (108/354) of patients. The highest intubation rate was observed in patients with ARDS (51%) or community-acquired pneumonia (50%). The lowest intubation rate was observed in patients with cardiogenic pulmonary edema (10%) and pulmonary contusion (18%). Multivariate analysis identified age > 40 years (OR 1.72, 95% CI 0.92-3.23), a simplified acute physiologic score (SAPS II) > or = 35 (OR 1.81, 95% CI 1.07-3.06), the presence of ARDS or community-acquired pneumonia (OR 3.75, 95% CI 2.25-6.24), and a PaO2:FiO2 < or = 146 after 1 h of NPPV (OR 2.51, 95% CI 1.45-4.35) as factors independently associated with failure of NPPV. Patients requiring intubation had a longer duration of ICU stay ( P < 0.001), higher rates of ventilator-associated pneumonia and septic complications ( P < 0.001), and a higher ICU mortality ( P < 0.001).

CONCLUSIONS

In hypoxemic ARF, NPPV can be successful in selected populations. When patients have a higher severity score, an older age, ARDS or pneumonia, or fail to improve after 1 h of treatment, the risk of failure is higher.

Volatile anesthesia in bariatric surgery

BACKGROUND

Obesity causes anesthesiologists a broad variety of perioperative theoretical and practical problems. The aim of this study was to compare two protocols of anesthesia employing Isoflurane and Sevoflurane and evaluate the cardiorespiratory parameters, postoperative recovery and analgesia.

METHODS

90 patients underwent biliopancreatic diversion. 60 patients (group A) received Isoflurane and 30 patients (group B) were anesthetized with Sevoflurane. Intraoperative monitoring consisted of EKG, invasive arterial pressure, SpO2, EtCO2, Etanest, Spirometry, urinary output and TOF. Cardiorespiratory parameters and end tidal expiratory concentrations of volatile agents were collected during specific phases of surgery: 1) before induction of anesthesia, 2) after intubation, 3) after skin incision, 4) after positioning of costal retractors, 5) in the reverse Trendelenburg position, 6) end of surgery. During the postoperative period the Aldrete test was carried out to evaluate the recovery from anesthesia. VAS was administered for 6 hours after the end of surgery to set the quality of analgesia.

RESULTS

No statistically significant differences in cardiorespiratory parameters were found between the two groups. Extubation time was significantly less in the Sevoflurane Group than in the Isoflurane (15 +/- 7 min vs 24 +/- 5 min, p < 0.05). The Sevoflurane Group showed an Aldrete score significantly higher than the Isoflurane (8.8 +/- 0.3 vs 8.1 +/- 0.4, p < 0.05). VAS values did not show statistical differences.

CONCLUSION

The introduction of Sevoflurane, a volatile agent with rapid pharmacokinetic properties, seems to offer an interesting application in these patients.

[NIV in the treatment of acute exacerbation of COPD and status asthmaticus]

The authors describe the application of NIV as a useful tool to correct hypercarbia, gas exchanges and to reduce the complications caused by mechanical ventilation with ETT in patients with acute exacerbation of COPD and acute asthma attack.

[Home mechanical ventilation: the extra-hospital phase]

Home mechanical ventilation is the choice option, when there are no contraindications of medical or socio-economic order, in all cases of impossible complete weaning from ventilatory support. Easy to use, reliable and size limited positive pressure ventilators lead to a spread diffusion of this technique. In the patient/ventilator interface, tracheostomy is the golden choice for patient with great reduction in spontaneous ventilatory ability. For all other patients, perfectioning of non-invasive access (nasal and oral nasal mask) represent an effective progress. Major limitations in home ventilation are still, up to present, the lack of multidisciplinary structures able to give territorial assistance. Home ventilation therapy in the experience of the Policlinico Universtitario "La Sapienza", Rome is presented.

[Changes in acid-base equilibrium and CO2 output induced by bicarbonate infusion]

BACKGROUND

Bicarbonate therapy for metabolic acidosis can cause tissue hypercapnia. We tested the hypothesis that CO2 retention is initially confined to blood and that tissue hypercapnia is consequent to blood hypercapnia.

METHODS

DESIGN

prospective study.

SETTING

general Intensive Care Unit in an University Hospital.

PATIENTS

ten patients, aged 34-84, undergoing fixed mechanical ventilation for stroke, respiratory failure, polytrauma, or coma and presenting fairly stabilized circulatory condition were included in the study providing that definite exclusion criteria were absent. Sodium bicarbonate, 0.08, 0.17, and 0.25 mEq/kg, was infused in 5 minutes during stages A, B, and C. During each stage, before and after bicarbonate infusion, heart rate, arterial pressure, central venous pressure, and PetCO2 were registered and arterial and central venous haemogasanalysis were performed. CO2 output was measured during and after bicarbonate infusion and total CO2 output over basal values was calculated.

RESULTS

Heart rate, arterial pressure, central venous pressure did not change in any stage, while PetCO2 increased in all. Following bicarbonate infusion, pH increased more in venous than in arterial blood and was significantly affected by the amount of bicarbonate infused. In arterial blood both PCO2 and total CO2 content (TCO2) increased. In venous blood PCO2 did not change while TCO2 increased so that arterial-venous rl CO2 difference was unaffected. CO2 output changed in no patient but two during stage A, and increased by 0.54 +/- 0.16 mL/kg during stage B and by 1.18 +/- 0.26 mL/kg during stage C so that 14.5 +/- 4.3 and 21.2 +/- 4.7% of given bicarbonate was released as CO2 through the lungs. CO2 output increased after a latency that was significantly shorter during stage C (145 +/- 51 sec) than during stage B (226 +/- 53 sec).

CONCLUSIONS

Since arterial-venous TCO2 difference was unaffected and haemodynamic parameters were stable, the conclusion is drawn that CO2 and bicarbonate did not diffuse out of vascular compartment during this study. However CO2 and bicarbonate diffusion out of blood would have occurred if bicarbonate infusion had continued, because CO2 excess was released through the lungs after a latency and extended after the infusion. Consequently, tissue hypercapnia during bicarbonate infusion could probably be prevented by improving CO2 release through the lungs, i.e. by hyperventilating the patient.