Hyperventilation During Manual Ventilation Can Be Reduced Using a Novel Ventilator but Not With Education Interventions.

INTRODUCTION: Traumatic brain injury (TBI) is the leading cause of combat casualties in modern war with an estimated 20% of casualties experiencing head injury. Since the release of the Brain Trauma Foundation's Guidelines for the Management of Severe Traumatic Brain Injury in 1995, recommendations for management of TBI have included the avoidance of routine hyperventilation. However, both published and anecdotal data suggest that many patients with TBI are inappropriately ventilated during transport, thereby increasing the risk of morbidity and mortality from secondary brain injury. MATERIALS AND METHODS: Enlisted Air Force personnel with prior emergency medical technician training completing a 3-week trauma course were evaluated on their ability to provide manual ventilation. Participants provided manual ventilation using either an in-situ endotracheal tube (ETT) or standard face mask on a standardized simulated patient manikin with TBI on the first and last days of the course. Manual ventilation was provided via a standard manual ventilator and a novel manual ventilator designed to limit tidal volume (VT) and respiratory rate (RR). Participants were given didactic and hands-on training on the third day of the course. Half of the participants were given simulator feedback during the hands-on training. All students provided 2 minutes of manual ventilation with each respirator. Data were collected on the breath-to-breath RR, VT, and peak airway pressures generated by the participant for each trial and were averaged for each trial. A minute ventilation (MV) was then derived from the calculated RR and VT. RESULTS: One hundred fifty-six personnel in the trauma course were evaluated in this study. Significant differences were found in the participant's performance with manual ventilation with the novel compared to the traditional ventilator. Before training, MV with the novel ventilator was less than with the traditional ventilator by 2.1 ± 0.4 L/min (P = .0003) and 1.6 ± 0.5 L/min (P = .0489) via ETT and face mask, respectively. This effect persisted after training with a difference between the devices of 1.8 ± 0.4 L/min (P = .0069) via ETT. Both traditional education interventions (didactics with hands-on training) and simulator-based feedback did not make a significant difference in participant's performance in delivering MV. CONCLUSIONS: The use of a novel ventilator that limits RR and VT may be useful in preventing hyperventilation in TBI patients. Didactic education and simulator-based feedback training may not have significant impact on improving ventilation practices in prehospital providers.

The Impact of Postoperative Intensive Care Unit Admission on Postoperative Hospital Length of Stay and Costs: A Prespecified Propensity-Matched Cohort Study.

BACKGROUND: In this prespecified cohort study, we investigated the influence of postoperative admission to the intensive care unit versus surgical ward on health care utilization among patients undergoing intermediate-risk surgery. METHODS: Of adult surgical patients who underwent general anesthesia without an absolute indication for postoperative intensive care unit admission, 3530 patients admitted postoperatively to an intensive care unit were matched to 3530 patients admitted postoperatively to a surgical ward using a propensity score based on 23 important preoperative and intraoperative predictor variables. Postoperative hospital length of stay and hospital costs were defined as primary and secondary end points, respectively. RESULTS: Among patients with low propensity for postoperative intensive care unit admission, initial triage to an intensive care unit was associated with increased postoperative length of stay (incidence rate ratio, 1.69 [95% CI, 1.59-1.79]; P < .001) and hospital costs (incidence rate ratio, 1.92 [95% CI, 1.81-2.03]; P < .001). By contrast, postoperative intensive care unit admission of patients with high propensity was associated with decreased postoperative length of stay (incidence rate ratio, 0.90 [95% CI, 0.85-0.95]; P < .001) and costs (incidence rate ratio, 0.92 [95% CI, 0.88-0.97]; P = .001). Decisions regarding postoperative intensive care unit resource utilization were influenced by individual preferences of anesthesiologists and surgeons. CONCLUSIONS: In patients with an unclear indication for postoperative critical care, intensive care unit admission may negatively impact postoperative hospital length of stay and costs. Postoperative discharge disposition varies substantially based on anesthesia and surgical provider preferences but should optimally be driven by an objective assessment of a patient's status at the end of surgery.

Preoperative risk stratification of critically ill patients.

STUDY OBJECTIVE: Risk assessment historically emphasized cardiac morbidity and mortality in elective, outpatient, non-cardiac surgery. However, critically ill patients increasingly present for therapeutic interventions. Our study investigated the relationship of American Society of Anesthesiologists (ASA) class, revised cardiac risk index (RCRI), and sequential organ failure assessment (SOFA) score with survival to discharge in critically ill patients with respiratory failure. DESIGN: Retrospective cohort analysis over a 21-month period. SETTING: Five adult intensive care units (ICUs) at a single tertiary medical center. PATIENTS: Three hundred fifty ICU patients in respiratory failure, who underwent 501 procedures with general anesthesia. MEASUREMENTS: Demographic, clinical, and surgical variables were collected from the pre-anesthesia evaluation forms and preoperative ICU charts. The primary outcome was survival to discharge. MAIN RESULTS: Ninety-six patients (27%) did not survive to discharge. There were significant differences between survivors and non-survivors for ASA (3.7 vs. 3.9, p=0.001), RCRI (1.6 vs. 2.0, p=0.003), and SOFA score (8.1 vs. 11.2, p<0.001). Based on the area under the receiver operating characteristic curve for these relationships, there was only modest discrimination between the groups, ranging from the most useful SOFA (0.68) to less useful RCRI (0.60) and ASA (0.59). CONCLUSIONS: This single center retrospective study quantified a high perioperative risk for critically ill patients with advanced airways: one in four did not survive to discharge. Preoperative ASA score, RCRI, and SOFA score only partially delineated survivors and non-survivors. Given the existing limitations, future research may identify assessment tools more relevant to discriminating survival outcomes for critically ill patients in the perioperative environment.

Transient Intraoperative Central Diabetes Insipidus in Moyamoya Patients Undergoing Revascularization Surgery: A Mere Coincidence?

We present 2 patients with Moyamoya disease undergoing revascularization surgery who developed transient intraoperative central diabetes insipidus with spontaneous resolution in the immediate postoperative period. We speculate that patients with Moyamoya disease may be predisposed to a transient acute-on-chronic insult to the arginine vasopressin-producing portion of their hypothalamus mediated by anesthetic agents. We describe our management, discuss pertinent literature, and offer possible mechanisms of this transient insult. We hope to improve patient safety by raising awareness of this potentially catastrophic complication.

Faecal contamination of drinking water in a Brazilian shanty town: importance of household storage and new human faecal marker testing.

Worldwide, contaminated drinking water poses a major health threat, particularly to child development. Diarrhoea represents a large part of the water-related disease burden and enteric infections have been linked to nutritional and growth shortfalls as well as long-term physical and cognitive impairment in children. Previous studies detailed the frequency of infection and the consequences for child health in a shanty town in north-east Brazil. To determine the frequency of contaminated water, we measured faecal contamination in primary drinking water samples from 231 randomly selected households. Risk for contamination was compared across source and storage types. Nearly a third of the study households (70/231: 30.3%) had contaminated drinking water; the source with the highest frequency of contamination was well water (23/24: 95.8%). For tap water, the type of storage had a significant effect on the susceptibility to contamination (chi(2) = 12.090; p = 0.007). The observed pattern of contamination demonstrated the relative potential contributions of both source and storage. With evidence that supports the inclusion of source and storage in water quality surveys, this study, like others, suggests that contaminated drinking water in storage vessels may be an important factor for the documented diarrhoea disease burden in the Brazilian shanty town.