Amiram Lev

Survival of critically ill patients hospitalized in and out of intensive care units under paucity of intensive care unit beds

Objective:The demand for intensive care beds far exceeds their availability in many European countries. Consequently, many critically ill patients occupy hospital beds outside intensive care units, throughout the hospital. The outcome of patients who fit intensive care unit admission criteria but are hospitalized in regular wards needs to be assessed for policy implications. The object was to screen entire hospital patient populations for critically ill patients and compare their 30-day survival in and out of the intensive care unit. Design:Screening teams visited every hospital ward on four selected days in five acute care Israeli hospitals. The teams listed all patients fitting a priori developed study criteria. One-month data for each patient were abstracted from the medical records. Setting:Five acute care Israeli hospitals. Patients:All patients fitting a priori developed study criteria. Interventions:None. Measurements and Main Results:Survival in and out of the intensive care unit was compared for screened patients from the day a patient first met study criteria. Cox multivariate models were constructed to adjust survival comparisons for various confounding factors. The effect of intensive care unit vs. other departments was estimated separately for the first 3 days after deterioration and for the remaining follow-up time. Results showed that 5.5% of adult hospitalized patients were critically ill (736 of 13,415). Of these, 27% were admitted to intensive care units, 24% to specialized care units, and 49% to regular departments. Admission to an intensive care unit was associated with better survival during the first 3 days of deterioration, after we adjusted for age and severity of illness (p = .018). There was no additional survival advantage for intensive care unit patients (p = .9) during the remaining follow-up time. Conclusions:The early survival advantage in the intensive care unit suggests a window of critical opportunity for these patients. Under economic constraints and dearth of intensive care unit beds, increasing the turnover of patients in the intensive care unit, thus exposing more needy patients to the early benefit of treatment in the intensive care unit, may be advantageous.

Hemofiltration in septic ards. the artificial kidney as, an artificial endocrine lung

Twenty-four patients with high microvascular permeability pulmonary edema were initially treated by means of conventional supportive therapy for 1-12 days. Continued deterioration was treated by predilutional hemofiltration and induced a dramatic improvement in 22/24 patients. Survival was 92%. Sieving coefficients for autacoids and middle molecular weight vasoactive peptides involved in the development of high microvascular permeability pulmonary edema were higher than 0.88 indicating that clearing from blood of these peptides during one pass through the hemofilter is similar to that obtained during one pass through the pulmonary normal microvasculature. Hemofiltration seems to be a significant breakthrough in the treatment of ARDS secondary to severe sepsis.

Sequential hemofiltration in nonoliguric high capillary permeability pulmonary edema of severe sepsis: preliminary report.

Five patients with nonoliguric adult respiratory distress syndrome (ARDS) secondary to severe sepsis showed improved blood oxygenation after up to 36 h of conventional therapy and mechanical ventilation with optimal positive end-expiratory pressure. However, metabolic acidosis was unchanged, and blood urea had increased. Some patients showed hemodynamic signs of incipient heart failure. After sequential hemofiltration, the altered physiologic shunt and blood pH returned to normal. Chest x-rays showed clearing of interstitial pulmonary edema. Patients recovered from ARDS in spite of fluid accumulation. Mechanical ventilation was stopped up to 8.5 h after the last hemofiltration. We postulate that convective ultrafiltration clears the blood of circulating low- and middle-weight vasoactive molecules implicated in the development of high microvascular permeability acute pulmonary edema secondary to sepsis.

Sequential plasmafilter-dialysis with slow continuous hemofiltration: additional treatment for sepsis-induced AOSF patients

Abstract Five patients with sepsis-induced acute organ system failure were treated by sequential plasmafilterdialysis with slow continuous hemofiltration in addition to conventional therapy. In this way, we were able to associate the possible clearance of mediators and toxic substances achieved by plasmapheresis with an improved clearance of nitrogen waste products, since we added diffusion to the convective effect of hemofiltration. The hypercatabolism was well controlled, and there was a significant improvement in cardiorespiratory parameters at the same time. These patients were retrospectively compared with four conventionally treated patients (100% mortality) and with six others treated by association of conventional therapy and continuous arteriovenous hemodialysis (50% mortality). Despite the small numbers of patients treated and the need of additional studies, our good results (all the patients survived) encourage us to use this approach as an adjunct of conventional therapeutic measures in oliguric and hypercatabolic AOSF patients.

Traumatic respiratory insufficiency: comparison of conventional mechanical ventilation to high-frequency positive pressure with low-rate ventilation.

Eleven patients suffering severe traumatic respiratory insufficiency were mechanically ventilated using a new system which combined high-frequency positive-pressure ventilation (HFPPV) with low-rate conventional mechanical ventilation (LRCMV). Ten similar patients were ventilated by conventional mechanical ventilation (CMV) with PEEP. HFPPV patients were fully conscious and cooperative during ventilation and did not need sedatives or muscle relaxants. Arterial oxygenation was significantly (p < .005) better in HFPPV than CMV patients (89.91 ± 10.24 vs. 78.43 ± 11.13 torr, respectively), and pulmonary shunt was also better in the HFPPV group (13.1 ± 4.7% vs. 20.4 ± 6.4%, p < .01). Moreover, inspired oxygen concentrations were lower (Pao2/Fio2 197.8 ± 51.3 in the HFPPV group vs. 130 ± 46.6 in the CMV group, p < .005) and the time required for mechanical ventilation was shorter (4.2 ± 0.91 vs. 6.1 ± 0.8 days, p < .1). All HFPPV patients immediately began breathing spontaneously when they were disconnected from the ventilator. We suggest this method as a better ventilatory mode for patients suffering traumatic respiratory insufficiency.

The use of conventional ventilators for high frequency positive pressure ventilation.

Ten randomly selected patients were ventilated for defined periods with 2 ventilatory modes: (a) high frequency positive pressure ventilation (HFPPV) (frequency 66-70 min; tidal volume 1-3 ml/kg body weight), (b) conventional IPPV (frequency 16/min; tidal volume (VT) 10-15 ml/kg). This was done successfully using conventional ventilators, and keeping other variables (FIO2, PEEP) constant. Various ventilatory and hemodynamic variables were measured and compared during both modes of ventilation. The most prominent finding was a considerable reduction of cardiac output (CO) and stroke volume (SV) during intermittent positive pressure ventilation (IPPV) compared with HFPPV. Peak tracheal pressure was significantly lower during HFPPV. An increase in mean systemic arterial pressure and in oxygen transport was observed during HFPPV, whereas transpulmonary shunt and pulmonary vascular resistance (PVR) decreased during HFPPV. These findings are in accordance with previously reported advantages of HFPPV, and might be of importance in the treatment of patients with bronchopleural fistula, adult respiratory distress syndrome (ARDS), left ventricular failure and other conditions in which conventional positive pressure ventilation (PPV) fails.

Mechanical ventilation in fiberoptic-bronchoscopy: comparison between high frequency positive pressure ventilation and normal frequency positive pressure ventilation.

High frequency positive pressure ventilation (HFPPV) was compared with normal frequency positive pressure ventilation (NFPPV) during diagnostic fiberoptic-bronchoscopy. HFPPV was achieved by a simple modification of the Minivent, and gave satisfactory alveolar ventilation and oxygenation. In all 11 patients and over periods of at least 40 min, HFPPV gave normal Paco2 and high levels of Pao2. Arterial blood pressures were higher and the airway pressures were lower than during NFPPV.

Hemofiltration in severe high microvascular permeability pulmonary edema secondary to rickettsial spotted fever

Two patients, affected by spotted fever, developed low pulmonary capillary wedge pressure (PCWP) pulmonary edema with severe hypoxemia. Conventional specific and supportive therapy, including mechanical ventilation, failed to induce significant respiratory and hemodynamic improvement which was dramatically reached by means of hemofiltration. Removal of circulating middle molecular weight peptides by the convective mass transfer, characteristic of hemofiltration, offers a new and effective therapeutic approach for the adult respiratory distress syndrome secondary to rickettsial diseases.

Differential lung ventilation: a review and 2 case reports

The respiratory parameters of some of the patients with acute respiratory failure deteriorates while using conventional ventilation. These patients suffer unilateral lung disease and the failure to respond favourably to therapy is due to increased intrapulmonary shunt. There is a reflex vasodilation in the injured lung. Functional residual capacity is reduced in the injured lung and the compliance decreases. Gas flow is then deviated to the other lung, thus increases alveolar collapse and decreases regional compliance in the injured lung. These events cause severe hypoxemia. We present here two cases with unilateral lung disease that failed to respond to conventional mechanical ventilation. Asynchronized differential lung ventilation was found to be the therapeutic answer to the problem. We discuss the pathophysiology of unilateral lung injury and the physiology of differential lung ventilation.

The effect of different oral hygiene treatments on the occurrence of ventilator associated pneumonia (VAP) in ventilated patients

Background: We compared the incidence of ventilator associated pneumonia (VAP) among patients treated with comprehensive oral care to those treated with conventional methods of oral care. Methods: We conducted a prospective, controlled study in an intensive care unit of 90 ventilated patients. Patients in the study group received a comprehensive oral hygiene treatment regimen that involved tooth brushing, suctioning, sodium bicarbonate, rinsing with an antiseptic solution containing 1.5% hydrogen peroxide and a mouth moisturiser. Patients in the control group received a more conventional treatment that included cleaning with a sponge and atraumatic clamp, and rinsing with a 0.2% solution of chlorhexidine gluconate. Results: Among the 90 patients admitted to the ICU, 8.9% of the study group developed VAP compared with 33.3% of the control group (p< 0.004). The development of VAP per 1,000 ventilation days was 10.2 in the study group, and 29.5 in the control group (p< 0.06). The mean number of ventilation days and the mean number of hospitalisation days were also lower in the study group. Conclusions: In patients who are ventilated, a comprehensive oral hygiene treatment regimen that includes tooth brushing, suctioning and rinsing with an antiseptic is more effective in preventing VAP than more conventional protocols.