Endotracheal tube cuff pressure changes during manual cuff pressure control manoeuvres: An in-vitro assessment

BACKGROUND

Endotracheal tube (ETT) cuffs are designed to seal the lower airway for precise ventilation and to protect against ingress of pathogens from the pharyngeal space. Therefore, a minimal continuous cuff pressure must be maintained. Aim of this study was to analyse the course of cuff pressure in an in-vitro model during manual cuff pressure control manoeuvres.

METHODS

An artificial trachea was intubated with an appropriately sized ETT and cuff pressure set to 20 cm H₂ O. Thirty-two experienced ICU nurses each performed six cuff pressure control manoeuvres (three times in two different ETTs) using a manual cuff pressure manometer. Course of cuff pressure from connecting the manometer to disconnecting it from the cuff pilot balloon was recorded using a pressure transducer.

RESULTS

There were 190 cuff pressure control manoeuvres suitable for analysis. In all control manoeuvres a cuff pressure below 20 cm H₂ O was noted. In 20.0% of the control manoeuvres the cuff pressure dropped below 10 cm H₂ O. Cuff pressure drops were mainly caused by initially connecting the manometer to the pilot balloon, less frequently by manipulating the pressure gauge of the manometer. Disconnecting the manometer after the control manoeuvre caused a cuff pressure drop in 78.1% of cases, contributing to a final cuff pressure below 20 cm H₂ O in 31.3% of control manoeuvres.

CONCLUSION

Routine manual cuff pressure control manoeuvres in ETT cuffs result in considerable cuff pressure drops. This may have an impact on silent aspiration of pharyngeal contents passing along the cuff into the lower airway.

Viscoelastic Monitoring to Guide the Correction of Perioperative Coagulopathy and Massive Transfusion in Patients with Life-Threatening Hemorrhage

The resuscitation of patients with traumatic hemorrhage remains a challenging clinical scenario. The appropriate and aggressive support of the patient's coagulation is of critical importance. Conventional coagulation assays present several shortcomings in this setting. The integration of viscoelastic monitoring in clinical practice has the potential to result in significant improvements. In order to be successful, the provider must understand basics of the methodology, read outs, and the limitations of the technique.

Factors influencing the level of patients using the internet to gather information before anaesthesia: a single-centre survey of 815 patients in Switzerland : The internet for patient information before anaesthesia

Background

Aim of this study was to identify factors associated with patients using the internet to find information about their upcoming surgery in general, and more specifically about anaesthesia.

Methods

With Ethics committee approval, 1000 consecutive patients seen before elective surgery in the anaesthesia preoperative clinic of a Swiss Level 2 hospital were asked to complete a questionnaire. Primary outcome were patients using the internet to gather any medical information related to their upcoming hospital stay, secondary outcome patients using the internet to gather information regarding the upcoming anaesthesia. Multiple regression was performed to identify independent factors associated with internet use.

Results

Eighty-two percent of the patients (n = 815) participated. 97% of those were ASA physical status 1 or 2; 83% (n = 676) had experience with previous anaesthetics, 86% (n = 700) reported to use the internet in general. Overall, about one-third of the participants used the internet to learn more about their medical condition, 26% regarding their upcoming surgical procedure. Only 7% (n = 55) obtained information about the anaesthetic. In multivariate analyses, factors associated with internet use were generally doing so, and planned moderate compared to minor surgery; not using the internet was associated with previous anaesthetic experience. Of those who did not use the Internet to learn about their anaesthetic, 34% indicated that they would have visited a trusted website.

Conclusion

Only few patients used the internet to obtain information about their upcoming procedure and the anaesthetic part played an even smaller role. However, many patients would have appreciated guidance to find trustworthy internet sites.

Trial registration

German Clinical Trials Register (DRKS00005434; date of registration: 27^th December 2013); date of enrolment of first patient: 1st August 2013; study retrospectively registered.

Midazolam plasma concentration after anesthesia premedication in clinical routine - an observational study : Midazolam plasma concentration after anesthesia premedication

BACKGROUND

Midazolam is commonly used as a pre-anesthesia anxiolytic. It`s elimination may not be fast enough for short procedures. In orally premedicated patients we obtained midazolam plasma concentrations at the end of surgical procedures and compared those to concentrations at anesthesia induction.

METHODS

The study was conducted prospectively with consent of the local ethics committee (Ethikkomission Kanton Thurgau, Switzerland) and carried out with written informed consent of each patient. Female patients aged 20 to 60 years undergoing elective procedures with general anesthesia were included, and were divided in two groups according to the planned surgical time: group S (<30 min) and group L (90-120 min), respectively. All patients received 7.5 mg Midazolam po as premedication. Blood samples were drawn at anesthesia induction, and at the end of surgery. Data were compared with t-test (independent samples; significance level p <0.05).

RESULTS

Twenty-five patients per group were included. Four patients were excluded from analysis, since midazolam was not detectable in any samples. Time of premedication to the 1st blood sample was not statistically different between groups, neither were Midazolam plasma levels at this time point (p = 0.94). None of the patients from group L (n = 24), but five patients in group S (n = 22) did have a higher plasma level of Midazolam at the end of the case compared to the beginning.

CONCLUSIONS

The elimination half-life of oral Midazolam can lead to higher plasma levels at the end of a short procedure compared to those at induction of anesthesia.

TRIAL REGISTRATION

German Clinical Trials Register (Deutsches Register Klinischer Studien), DRKS00005429 ; date of registration 3^rd January 2014.

Postoperative delirium assessed by post anesthesia care unit staff utilizing the Nursing Delirium Screening Scale: a prospective observational study of 1000 patients in a single Swiss institution

BACKGROUND

Delirium has become better studied, but is still only partially understood and significantly underestimated. There are some well-known risk factors, but little is known about the incidence of delirium in the diverse patient population of a post anesthesia care unit (PACU). The aim of this study was to investigate the presence of delirium using the Nursing Delirium Screening Scale (NU-DESC).

METHODS

1000 consecutive patients in the PACU were prospectively evaluated at the point when being ready to be transferred to the normal ward by the registered nurses of the PACU.

RESULTS

The data of 1,000 patients was recorded. 242 of the patients (24.2%) were preoperatively classified as ASA I physical status, 664 patients (66.4%) as ASA II. A total of 43 patients (4.3%) presented with a delirium at the time point where they would have been transferred to the normal ward (138.4 ± 55.2 min after arrival in the PACU). 287 patients (28.7%) of the entire group were over the age of 70 years. Considering only this subgroup, delirium was diagnosed in 30 individuals (10.5%).

CONCLUSIONS

Delirium screening with the NU-DESC, collected by nursing staff of a PACU is easily feasible and demonstrated a low incidence of delirium in the presented setting.

TRIAL REGISTRATION

German Clinical Trials Register (Deutsches Register Klinischer Studien, www.drks.de ; DRKS 000005426 ; date of registration 4th December 2013).

Anesthetic management of patients undergoing bariatric surgery: two year experience in a single institution in Switzerland

BACKGROUND

In the field of anesthesia for bariatric surgery, a wide variety of recommendations exist, but a general consensus on the perioperative management of such patients is missing. We outline the perioperative experiences that we gained in the first two years after introducing a bariatric program.

METHODS

The perioperative approach was established together with all relevant disciplines. Pertinent topics for the anesthesiologists were; successful airway management, indications for more invasive monitoring, and the planning of the postoperative period and deposition. This retrospective analysis was approved by the local ethics committee. Data are mean [SD].

RESULTS

182 bariatric surgical procedures were performed (147 gastric bypass procedures (GBP; 146 (99.3%) performed laparascopically). GBP patients were 43 [10] years old, 78% female, BMI 45 [7] kg/m(2), 73% ASA physical status of 2. 42 patients (28.6%) presented with obstructive sleep apnea syndrome. 117 GBP (79.6%) patients were intubated conventionally by direct laryngoscopy (one converted to fiber-optic intubation, one aspiration of gastric contents). 32 patients (21.8%) required an arterial line, 10 patients (6.8%) a central venous line. Induction lasted 25 [16] min, the procedure itself 138 [42] min. No blood products were required. Two patients (1.4%) presented with hypothermia (<35 °C) at the end of their case. The emergence period lasted 17 [9] min. Postoperatively, 32 patients (21.8%) were transferred to the ICU (one ventilated). The other patients spent 4.1 [0.7] h in the post anesthesia care unit. 15 patients (10.2%) required take backs for surgical revision (two laparotomies).

CONCLUSIONS

The physiology and anatomy of bariatric patients demand a tailored approach from both the anesthesiologist and the perioperative team. The interaction of a multi-disciplinary team is key to achieving good outcomes and a low rate of complications.

TRIAL REGISTRATION

DRKS00005437 (date of registration 16(th) December 2013).

Late pharmacologic conditioning with volatile anesthetics after cardiac surgery

INTRODUCTION

The aim of this randomized controlled trial was to investigate whether volatile anesthetics used for postoperative sedation have any beneficial effects on myocardial injury in cardiac surgery patients after on-pump valve replacement.

METHODS

Anesthesia was performed with propofol. After arrival in the intensive care unit (ICU), 117 patients were randomized to be sedated for at least 4 hours with either propofol or sevoflurane. Sevoflurane was administered by using the anesthetic-conserving device. Troponin T, creatine kinase, creatine kinase from heart muscle tissue, myoglobin, and oxygenation index were determined on arrival at the ICU, 4 hours after sedation, and in the morning of the first postoperative day (POD1). Primary end points were cardiac injury markers on POD1. As secondary end points oxygenation, postoperative pulmonary complications, and ICU and hospital stay were documented.

RESULTS

Fifty-six patients were analyzed in the propofol arm, and 46 patients in the sevoflurane arm. Treatment groups were comparable with regard to patient demographics and intraoperative characteristics. Concentration of troponin T as the most sensitive marker for myocardial injury at POD1 was significantly lower in the sevoflurane group compared with the propofol group (unadjusted difference, -0.4; 95% CI, -0.7 to -0.1; P < 0.01; adjusted difference, -0.2; 95% CI, -0.4 to -0.02; P = 0.03, respectively).

CONCLUSIONS

The data presented in this investigation indicate that late postconditioning with the volatile anesthetic sevoflurane might mediate cardiac protection, even with a late, brief, and low-dose application.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00924222.