Chest
Clinical Investigations in Critical CareThe Effects of Neuromuscular Paralysis on Systemic and Splanchnic Oxygen Utilization in Mechanically Ventilated Patients
Section snippets
Materials and Methods
This study was conducted in the Medical and Surgical ICUs at St. Vincent Hospital, a university-affiliated teaching hospital in Worcester, Mass. Approval to conduct this study was obtained from our Institutional Review Board.
During the study period, all patients admitted to our ICUs with the sepsis syndrome18 and acute respiratory failure, who had a pulmonary artery catheter in situ and required neuromuscular blockade to facilitate mechanical ventilation, were screened for inclusion into this
Results
Eight patients were studied: three men and five women. The mean age of the patients was 63±8 years. The patients' clinical characteristics are listed in Table 1. The patients were all seriously ill, with a mean acute physiology and chronic health evaluation II score of 22 ±4. All patients had significant lung injury requiring a mean fraction of inspired oxygen of 0.7±0.14 and positive end-expiratory pressure of 11.8±2.4 cm H2O to maintain adequate oxygenation (arterial oxygen saturation >90%).
Discussion
In this study, we have demonstrated that neuromuscular paralysis will decrease total body oxygen consumption and increase pHi in critically ill patients with evidence of splanchnic ischemia, during assisted, volume-cycled mechanical ventilation. Presumably, by eliminating the work of breathing during AC ventilation, there is a redistribution of blood from the respiratory muscles to the splanchnic and other nonvital vascular beds.
The results of this study are supported by both clinical and
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Advances in Ventilator Management for Patients with Acute Respiratory Distress Syndrome
2022, Clinics in Chest MedicineCitation Excerpt :This can lead to further barotrauma, atelectrauma, and biotrauma, resulting in a release of inflammatory mediators and end-organ dysfunction.8,61 Other physiologic benefits may include reduced respiratory and skeletal muscle oxygen consumption, leading to an increase in mixed venous oxygen62 and, possibly, anti-inflammatory effects.63 Despite this sound physiologic rationale and RCT evidence, the clinical use of continuous NMBA in ARDS is not widespread.
Acute respiratory distress syndrome
2021, The LancetCitation Excerpt :When oxygen consumption and associated carbon dioxide production increase, total ventilation must increase to maintain constant arterial PaCO2 and pH. Hence, controlling oxygen consumption might have a possible benefit, especially in the early phase of ARDS.122 Several approaches are possible such as reducing body temperature,123 sedation,124 and neuromuscular blockade.125 Neuromuscular blockade also has the potential benefit of reducing ventilator dyssynchrony, which could lead to inadvertently high tidal volumes and transpulmonary pressures.
Resuscitation of the Critically Ill Older Adult
2021, Emergency Medicine Clinics of North AmericaRespiratory oxygen uptake is associated with survival in a cohort of ventilated trauma and burn patients
2018, American Journal of Emergency MedicineCitation Excerpt :While lactic acid has been associated with increased mortality in trauma and burn patients [9], respiratory oxygen uptake's impact on survival has not been studied. While patients in our study had multiple reasons to have decreased oxygen extraction including sedation, paralysis, hypo nutrition, mechanical ventilation, and sepsis, [10] [11] currently there is no evidence to support that respiratory uptake of oxygen correlates with the oxygen extraction ratio in circulating blood. Since 55% of our cohort died from sepsis, it is possible that decreased respiratory uptake is an early marker of sepsis.
Perioperative hemodynamic optimization: A revised approach
2014, Journal of Clinical AnesthesiaCitation Excerpt :At face value, it would appear to be counterintuitive that anesthesia would result in an oxygen debt. General anesthesia and neuromuscular blockade (NMB) reduce metabolic rate and oxygen consumption while DO2 remains largely unchanged [23,24]. Hypothermia occurs frequently during anesthesia, which further reduces metabolic oxygen requirements [25,26].
Energy expenditure in patients with severe head injury: Controlled normothermia with sedation and neuromuscular blockade
2013, Journal of Critical CareCitation Excerpt :In sedated patients, body temperature may be the main determinant of energy expenditure [17]. Some studies have found a reduction in Vo2 after application of NMB [18-23]. MacCall et al [23] showed that NMB in severe head-injured patients decreased energy expenditure to PEE levels, independent of morphine use, body temperature, and feeding.