Biomedical subjects

Paolo Severgnini

Publications and source records attributed to Paolo Severgnini.

7 recordsLinked to original sources

PubMed2005

An integrated approach to prevent and treat respiratory failure in brain-injured patients.

PURPOSE OF REVIEW: Brain-injured patients are at increased risk of extracerebral organ dysfunction, in particular ventilator-associated pneumonia. The purpose of this review is to discuss functional abnormalities, clinical treatment, and possible prevention of respiratory function abnormalities in brain-injured patients. RECENT FINDINGS: Ventilator-associated pneumonia worsens the neurologic outcome and increases the intensive care unit and hospital stay, costs, and risk of death. The respiratory dysfunction can be due to several causes, but atelectasis and/or consolidation of the lower lobes predominates in the most severe cases. Strategies should be implemented to prevent lung infections and accelerate weaning from mechanical ventilation to reduce the incidence of respiratory dysfunction and ventilator-associated pneumonia. SUMMARY: An integrated approach including appropriate ventilatory, antibiotic, and fluid management could be extremely useful, not only to prevent and more rapidly treat respiratory failure but also to improve neurologic outcome and reduce hospital stay. Further studies are warranted to better elucidate the pathophysiology and clinical treatment of respiratory dysfunction in brain-injured patients.

Brain Injuries↗

PubMed2004

Tracheostomy must be individualized!

Tracheostomy is one of the most frequent procedures carried out in critically ill patients with major advantages compared to translaryngeal endotracheal intubation such as reduced laryngeal anatomical alterations, reduced inspiratory load, better patient's tolerance and nursing. Thus, tracheostomy can enhance patient's care in patients who need prolonged mechanical ventilation and/or control of airways. The right timing of tracheostomy remains controversial, however it appears that early tracheostomy in selected severe trauma, burn and neurological patients could be effective to reduce the duration of mechanical ventilation intensive care stay and costs. Percutaneous tracheostomy techniques are becoming the procedure of choice in the majority of the cases, since they are safe, easy and quick, and complications are minor. However, percutaneous tracheostomies should be always performed by experienced physicians to avoid unnecessary additional complications. It is not clear the superiority of one percutaneous technique compared to another, but experience of the operator and clinical individual anatomical, physiopathological characteristics of the patient should be always considered. We believe that the operator should have experience of at least one intrusive and one extrusive percutaneous technique. The general "optimal" tracheostomy technique and timing do not exist, but tracheostomy should be targeted on the patient's individual clinical characteristics.

Humans↗

PubMed2004

In vitro and in vivo evaluation of a new active heat moisture exchanger.

INTRODUCTION: In order to improve the efficiency of heat moisture exchangers (HMEs), new hybrid humidifiers (active HMEs) that add water and heat to HMEs have been developed. In this study we evaluated the efficiency, both in vitro and in vivo, of a new active HME (the Performer; StarMed, Mirandola, Italy) as compared with that of existing HMEs (Hygroster and Hygrobac; Mallinckrodt, Mirandola, Italy). METHODS: We tested the efficiency by measuring the temperature and absolute humidity (AH) in vitro using a test lung ventilated at three levels of minute ventilation (5, 10 and 15 l/min) and at two tidal volumes (0.5 and 1 l), and in vivo in 42 patients with acute lung injury (arterial oxygen tension/fractional inspired oxygen ratio 283 +/- 72 mmHg). We also evaluated the efficiency in vivo after 12 hours. RESULTS: In vitro, passive Performer and Hygrobac had higher airway temperature and AH (29.2 +/- 0.7 degrees C and 29.2 +/- 0.5 degrees C, [P < 0.05]; AH: 28.9 +/- 1.6 mgH2O/l and 28.1 +/- 0.8 mgH2O/l, [P < 0.05]) than did Hygroster (airway temperature: 28.1 +/- 0.3 degrees C [P < 0.05]; AH: 27 +/- 1.2 mgH2O/l [P < 0.05]). Both devices suffered a loss of efficiency at the highest minute ventilation and tidal volume, and at the lowest minute ventilation. Active Performer had higher airway temperature and AH (31.9 +/- 0.3 degrees C and 34.3 +/- 0.6 mgH2O/l; [P < 0.05]) than did Hygrobac and Hygroster, and was not influenced by minute ventilation or tidal volume. In vivo, the efficiency of passive Performer was similar to that of Hygrobac but better than Hygroster, whereas Active Performer was better than both. The active Performer exhibited good efficiency when used for up to 12 hours in vivo. CONCLUSION: This study showed that active Performer may provide adequate conditioning of inspired gases, both as a passive and as an active device.

Acute Disease↗

PubMed2004

Noninvasive positive pressure ventilation using a helmet in patients with acute exacerbation of chronic obstructive pulmonary disease: a feasibility study.

BACKGROUND: Noninvasive positive pressure ventilation (NPPV) with a facemask (FM) is effective in patients with acute exacerbation of their chronic obstructive pulmonary disease. Whether it is feasible to treat these patients with NPPV delivered by a helmet is not known. METHODS: Over a 4-month period, the authors studied 33 chronic obstructive pulmonary disease patients with acute exacerbation who were admitted to four intensive care units and treated with helmet NPPV. The patients were compared with 33 historical controls treated with FM NPPV, matched for simplified acute physiologic score (SAPS II), age, PaCO2, pH, and PaO2:fractional inspired oxygen tension. The primary endpoints were the feasibility of the technique, improvement of gas exchange, and need for intubation. RESULTS: The baseline characteristics of the two groups were similar. Ten patients in the helmet group and 14 in the FM group (P = 0.22) were intubated. In the helmet group, no patients were unable to tolerate NPPV, whereas five patients required intubation in the FM group (P = 0.047). After 1 h of treatment, both groups had a significant reduction of PaCO2 with improvement of pH; PaCO2 decreased less in the helmet group (P = 0.01). On discontinuing support, PaCO2 was higher (P = 0.002) and pH lower (P = 0.02) in the helmet group than in the control group. One patient in the helmet group, and 12 in the FM group, developed complications related to NPPV (P < 0.001). Length of intensive care unit stay, intensive care unit, and hospital mortality were similar in both groups. CONCLUSIONS: Helmet NPPV is feasible and can be used to treat chronic obstructive pulmonary disease patients with acute exacerbation, but it does not improve carbon dioxide elimination as efficiently as does FM NPPV.

Acidosis, Respiratory↗

PubMed2003

Noninvasive positive pressure ventilation delivered by helmet vs. standard face mask.

OBJECTIVE: This bench and human study compared large and small helmets with face mask (FM) for delivery of noninvasive positive pressure ventilation. DESIGN: A lung simulator was employed, and the human study involved six healthy subjects. We evaluated a continuous high-flow (CPAPHF), low flow (CPAPLF), ventilator (CPAPVENT) CPAP, and pressure support ventilation (PSV 10 and 20 cmH2O). In the human study we used CPAPHF, CPAPVENT, and PSV 5 cmH2O. PEEP was 5 cmH2O. MEASUREMENTS: In the bench study during CPAP we measured the negative airway pressure time product (areaCPAP), i.e., the area of airway pressure (Paw) under PEEP and during PSV the pressure airway time product (areaPSV), i.e., the area of Paw from onset to end of inspiratory flow. In the human study we measured the breathing pattern and work of breathing (WOB). RESULTS: In the bench study during CPAPLF the helmets had a lower areaCPAP than the FM, while during CPAPHF the three interfaces had similar areaCPAP. Using CPAPVENT and PSV the FM reduced areaCPAP and increased areaPSV compared to helmets. At 20 cmH2O of PSV using helmets areaPSV was similar to that obtained at 10 cmH2O of PSV using the FM. In human study using CPAPHF and CPAPVENT the tree interfaces had similar effects on breathing pattern and WOB, while using PSV the FM reduced WOB more than helmets. CONCLUSIONS: During CPAPLF helmets were more efficient than FM, while during CPAPHF the three interfaces were comparable. Using CPAPVENT and PSV, FM was more efficient than helmets

Equipment Design↗

PubMed2003

Non-invasive ventilation delivered by conventional interfaces and helmet in the emergency department.

Non-invasive positive pressure ventilation is increasingly used as a first-line treatment for respiratory failure. Non-invasive positive pressure ventilation can reduce the complications of endotracheal intubation such as barotrauma, nosocomial infections and the need for sedation. Non-invasive positive pressure ventilation has been shown to reduce the rate of endotracheal intubation in acute cardiogenic pulmonary oedema (27%), in chronic obstructive pulmonary disease (21%), and in acute respiratory failure (17%). Non-invasive positive pressure ventilation can be successfully delivered in the emergency department or in the general ward. However, the criteria for interrupting non-invasive positive pressure ventilation must be stricter (i.e. failure to improve gas exchange within 30 min) than in the general ward. One of the main reasons for the failure of non-invasive positive pressure ventilation lies in the technical problems caused by the face mask. We recently developed a new interface, the 'helmet', to deliver non-invasive positive pressure ventilation. When using the helmet instead of a face mask an increase of 10 cm H(2)O of pressure support and a fast pressurization rate are recommended. In a lung model and in healthy individuals the helmet reduced inspiratory effort. In hypoxemic patients the helmet reduced the intubation rate and the incidence of face mask-related complications. We believe that the helmet can extend the application of non-invasive positive pressure ventilation in different categories of patients with respiratory failure.

Clinical Protocols↗

PubMed2002

New treatment of acute hypoxemic respiratory failure: noninvasive pressure support ventilation delivered by helmet--a pilot controlled trial.

OBJECTIVE: To assess the efficacy of noninvasive pressure support ventilation (NPSV) using a new special helmet as first-line intervention to treat patients with hypoxemic acute respiratory failure (ARF), in comparison to NPSV using standard facial mask. DESIGN AND SETTING: Prospective clinical pilot investigation with matched control group in three intensive care units of university hospitals. PATIENTS AND METHODS: Thirty-three consecutive patients without chronic obstructive pulmonary disease and with hypoxemic ARF (defined as severe dyspnea at rest, respiratory rate >30 breaths/min, PaO2:FiO2 < 200, and active contraction of the accessory muscles of respiration) were enrolled. Each patient treated with NPSV by helmet was matched with two controls with ARF treated with NPSV via a facial mask, selected by simplified acute physiologic score II, age, PaO2/FiO2, and arterial pH at admission. Primary end points were the improvement of gas exchanges, the need for endotracheal intubation, and the complications related to NPSV. RESULTS: The 33 patients and the 66 controls had similar characteristics at baseline. Both groups improved oxygenation after NPSV. Eight patients (24%) in the helmet group and 21 patients (32%) in the facial mask group (p = .3) failed NPSV and were intubated. No patients failed NPSV because of intolerance of the technique in the helmet group in comparison with 8 patients (38%) in the mask group (p = .047). Complications related to the technique (skin necrosis, gastric distension, and eye irritation) were fewer in the helmet group compared with the mask group (no patients vs. 14 patients (21%), p = .002). The helmet allowed the continuous application of NPSV for a longer period of time (p = .05). Length of stay in the intensive care unit, intensive care, and hospital mortality were not different. CONCLUSIONS: NPSV by helmet successfully treated hypoxemic ARF, with better tolerance and fewer complications than facial mask NPSV.

Adult↗