A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

Adaptive Pressure Control-Continuous Mandatory Ventilation Versus Volume Control-Continuous Mandatory Ventilation: Factors Associated With Initiation, Maintenance, and Adjustment

BACKGROUND

Adaptive pressure control-continuous mandatory ventilation (APC-CMV) is a frequently utilized ventilator mode in ICU settings. This analysis compared APC-CMV and traditional volume control-continuous mandatory ventilation (VC-CMV) mode, describing factors associated with initiation, maintenance, and changes in settings of each mode.

METHODS

We analyzed ventilator data from a retrospective electronic health record data set collected as part of a quality improvement project in a single academic ICU. The majority ventilator mode was defined as the mode comprising the highest proportion of mechanical ventilation time. Multivariable logistic regression was used to identify variables associated with initial and majority APC-CMV or VC-CMV modes. Wilcoxon rank-sum tests were used to compare ventilator setting changes/d and sedation as a function of APC-CMV and VC-CMV majority modes.

RESULTS

Among 1,213 subjects initiated on mechanical ventilation from January 2013-March 2017, 68% and 24% were initiated on APC-CMV and VC-CMV, respectively, which composed 62% and 21% of the majority ventilator modes. Age, sex, race, and ethnicity were not associated with the initial or majority APC-CMV or VC-CMV modes. Subjects initiated on APC-CMV spent 88% of the mechanical ventilation time on APC-CMV mode. Compared to VC-CMV, subjects with APC-CMV majority mode experienced more ventilator setting changes/d (1.1 vs 0.8, P < .001). There were no significant differences in sedative medications when comparing subjects receiving APC-CMV versus VC-CMV majority modes.

CONCLUSIONS

APC-CMV was highly utilized in the medical ICU. Subjects on APC-CMV had more ventilator setting changes/d than those on VC-CMV. APC-CMV offered no advantage of reduced setting adjustments or less sedation compared to VC-CMV.

Comparison of Bilevel Volume Guarantee and Pressure-Regulated Volume Control Modes in Preterm Infants

The present study aimed to compare the bilevel volume guarantee (VG) and pressure-regulated volume control (PRVC) modes of the GE® Carescape R860 model ventilator and test the safety and feasibility of these two modes in preterm neonates. Infants who were less than 30 weeks of gestational age were included. After randomization, initial ventilator settings were adjusted for each patient. After the first 2 h of ventilation, the patients were switched to the other ventilator mode for 2 h. The ventilator parameters, vital signs, and blood gas values were evaluated. The study included a total of 28 patients, 14 in the PRVC group and 14 in the bilevel VG group. The mean birth weight was 876 g (range: 530-1170) and the mean gestational age was 26.4 weeks (range: 24-29). The patients' peak inspiratory pressure (PIP2 and PIP3) was lower after ventilation in bilevel VG mode than in PRVC mode (13 vs. 14 cmH2O, respectively; paired samples t-test, p = 0.008). After 2 h of bilevel VG ventilation, the mean heart rate decreased from 149/min to 140/min (p = 0.001) and the oxygen saturation increased from 91% to 94% (p = 0.01). Both the PRVC and bilevel VG modes of GE ventilators can be used safely in preterm infants, and bilevel VG mode was associated with more favorable early clinical findings. Studies including more patients and comparing with other modes will clarify and provide further evidence on this subject.

Influence of ventilatory strategies on outcomes and length of hospital stay: assist-control and synchronized intermittent mandatory ventilation modes

The use of synchronized intermittent mandatory ventilation with pressure support ventilation (SIMV + PSV) mode has been discontinued. This study analyzed the association between medical outcomes related to the use of assist-control (A/C) and SIMV + PSV in an intensive care unit. In this observational and retrospective study, modes of ventilation and medical data were collected from electronic medical records for three consecutive years and were related to medical outcomes (mortality), duration of mechanical ventilation, length of hospital stay and the need for tracheostomy. Participants were divided into groups according to the modes of ventilation: A/C and SIMV + PSV. Statistical analyses were performed in the R environment. Alpha = 0.05. The using chi-square, Fisher's exact, Mann-Whitney and Kruskal-Wallis tests were used. 345 adult participants were included; 211/345 (61.16%) were males. Of the participants, 151/345 (43.77%) were on SIMV + PSV and 194/345 (56.23%) were on A/C. The comparative analysis between the modes of ventilation showed no significant differences in length of hospital stay (p = 0.675), duration of mechanical ventilation (p = 0.952), mortality (p = 0.241), failed extubation (p = 0.411) and the need for tracheostomy (p = 0.301). SIMV + PSV as a mode of ventilation showed similar statistical results to the A/C mode, when compared to analyzed medical outcomes.

Advanced Modes of Mechanical Ventilation: Introduction for the Critical Care Pharmacist

Mechanical ventilation continues to be an evolving modality in the critical care environment. Technological advances in microprocessor-controlled ventilation integrated with the complexity of new ventilator modes has provided the multidisciplinary team opportunities to further improve the care of the critically ill ventilator patients. As members of the critical care multidisciplinary team, pharmacists require a basic understanding of both conventional and advanced modes of mechanical ventilation in order to assist in optimizing medication use and ultimately patient health-care outcomes. Pharmacists have a key responsibility to practice vigilance to maintain safe drug therapy use by preventing drug-drug or drug-disease interactions and optimal dose selection based upon pharmacokinetics and pharmacodynamics principles. Pharmacists also assist in the development of drug utilization guidelines and pharmacological ventilator-weaning protocols based upon evidence-based practice. The result of these responsibilities must include the continued longitudinal assessment and reporting of quality measures to assess ventilator weaning, time to liberation of mechanical ventilation, and length of care in intensive care unit. The purpose of this article is to provide the clinical pharmacist a guide to a basic understanding of advanced modes of mechanical ventilation in adults and to apply the knowledge gained to assist in the care of the critical care patients.