Technologies to Optimize the Care of Severe COVID-19 Patients for Health Care Providers Challenged by Limited Resources.

Health care systems are belligerently responding to the new coronavirus disease 2019 (COVID-19). The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a specific condition, whose distinctive features are severe hypoxemia associated with (>50% of cases) normal respiratory system compliance. When a patient requires intubation and invasive ventilation, the outcome is poor, and the length of stay in the intensive care unit (ICU) is usually 2 or 3 weeks. In this article, the authors review several technological devices, which could support health care providers at the bedside to optimize the care for COVID-19 patients who are sedated, paralyzed, and ventilated. Particular attention is provided to the use of videolaryngoscopes (VL) because these can assist anesthetists to perform a successful intubation outside the ICU while protecting health care providers from this viral infection. Authors will also review processed electroencephalographic (EEG) monitors which are used to better titrate sedation and the train-of-four monitors which are utilized to better administer neuromuscular blocking agents in the view of sparing limited pharmacological resources. COVID-19 can rapidly exhaust human and technological resources too within the ICU. This review features a series of technological advancements that can significantly improve the care of patients requiring isolation. The working conditions in isolation could cause gaps or barriers in communication, fatigue, and poor documentation of provided care. The available technology has several advantages including (a) facilitating appropriate paperless documentation and communication between all health care givers working in isolation rooms or large isolation areas; (b) testing patients and staff at the bedside using smart point-of-care diagnostics (SPOCD) to confirm COVID-19 infection; (c) allowing diagnostics and treatment at the bedside through point-of-care ultrasound (POCUS) and thromboelastography (TEG); (d) adapting the use of anesthetic machines and the use of volatile anesthetics. Implementing technologies for safeguarding health care providers as well as monitoring the limited pharmacological resources are paramount. Only by leveraging new technologies, it will be possible to sustain and support health care systems during the expected long course of this pandemic.

A technical description of a novel pharmacological anesthesia robot.

To control the three components of general anesthesia (hypnosis, analgesia, and neuromuscular blockade), an automated closed-loop, anesthesia-drug delivery system (McSleepy) was developed. Bispectral index was used as the control variable for hypnosis, the analgoscore for analgesia, and phonomyography for neuromuscular blockade. McSleepy can be used to control the induction, maintenance and emergence from general anesthesia. To do so, a large touch screen is used to provide a user friendly interface, permitting bidirectional communication: the user giving information about the different stages of anesthesia, and the system prompting the anesthesiologist to perform certain actions such as mask ventilation, intubation or waking-up the patient using audio clips with voice commands. Several safety features were implemented to provide a secure and reliable anesthesia. Preliminary results of 15 patients are presented in this paper. Evaluation of McSleepy was done through an assessment of its clinical performance and using Varvel's performance indices. The system was found to be clinically useful by providing good precision in drug administration and reliable results for the duration of a general anesthesia.

A randomized controlled trial demonstrates that a novel closed-loop propofol system performs better hypnosis control than manual administration.

PURPOSE: The purpose of this randomized control trial was to determine the performance of a novel rule-based adaptive closed-loop system for propofol administration using the bispectral index (BIS(R)) and to compare the system's performance with manual administration. The effectiveness of the closed-loop system to maintain BIS close to a target of 45 was determined and compared with manual administration. METHODS: After Institutional Review Board approval and written consent, 40 patients undergoing major surgery in a tertiary university hospital were allocated to two groups using computer-generated block randomization. In the Closed-loop group (n = 20), closed-loop control was used to maintain anesthesia at a target BIS of 45, and in the Control group (n = 20), propofol was administered manually to maintain the same BIS target. To evaluate each technique's performance in maintaining a steady level of hypnosis, the BIS values obtained during the surgical procedure were stratified into four clinical performance categories relative to the target BIS: < or = 10%, 11-20%, 21-30%, or > 30% defined as excellent, good, poor, or inadequate control of hypnosis, respectively. The controller performance was compared using Varvel's controller performance indices. Data were compared using Fisher's exact test and the Mann-Whitney U test, P < 0.05 showing statistical significance. RESULTS: In the Closed-loop group, four females and 16 males (aged 54 +/- 20 yr; weight 79 +/- 7 kg) underwent anesthesia lasting 143 +/- 57 min. During 55%, 29%, 9%, and 7% of the total anesthesia time, the system showed excellent, good, poor, and inadequate control, respectively. In the Control group, five females and 15 males (aged 59 +/- 16 yr; weight 75 +/- 13 kg) underwent anesthesia lasting 157 +/- 81 min. Excellent, good, poor, and inadequate control were noted during 33%, 33%, 15%, and 19% of the total anesthesia time, respectively. In the Closed-loop group, excellent control of anesthesia occurred significantly more often (P < 0.0001), and poor and inadequate control occurred less often than in the Control group (P < 0.01). The median performance error and the median absolute performance error were significantly lower in the Closed-loop group compared with the Control group (-1.1 +/- 5.3% vs -10.7 +/- 13.1%; P = 0.004 and 9.1 +/- 1.9% vs 15.7 +/- 7.4%; P < 0.0001, respectively). CONCLUSION: The closed-loop system for propofol administration showed better clinical and control system performance than manual administration of propofol. (Clinical Trials gov. NCT 01019746).

Retrobulbar catheter anesthesia as a routine technique for retinal and vitreoretinal surgery.

To ascertain the safety of the retrobulbar catheter technique for intraoperative local anesthesia and titratable postoperative analgesia, 1,423 consecutive retinal or vitreoretinal surgeries were reviewed. Using a commercially available retrobulbar needle, a 28-gauge flexible catheter was introduced into the retrobulbar space before surgery and was removed the next morning. When pain occurred, a local anesthetic was re-injected intraoperatively or postoperatively through the catheter. None of the patients had intraoperative or postoperative complications. The retrobulbar catheter anesthesia may be a relatively safe procedure for prolonged intraoperative anesthesia and titratable postoperative analgesia in retinal and vitreoretinal surgery.

Simultaneous determination of neuromuscular blockade at the adducting and abducting laryngeal muscles using phonomyography.

UNLABELLED: Phonomyography (PMG) is a new method for measuring neuromuscular blockade (NMB) at the larynx. In this study, we used PMG to compare NMB at the posterior cricoarytenoid (PCA) and the lateral cricoarytenoid muscle (LCA) in humans. Twelve patients were included in this study. Endotracheal intubation was performed without aid of neuromuscular blocking drugs. One small condenser microphone was inserted beside the vocal cords into the muscular process at the base of the arytenoid cartilage to record acoustic responses of the LCA (vocal cord adduction), and a second microphone was placed behind the larynx to measure NMB of the PCA (vocal cord abduction). Stimulation of the recurrent laryngeal nerve was performed using superficial electrodes placed at the neck (midline between jugular notch and cricoid cartilage) using train-of-four (TOF) stimulation every 12 s. After supramaximal stimulation, mivacurium 0.1 mg/kg was injected and onset, peak effect, and offset of NMB measured and compared using t-test (P < 0.05). The data are presented as mean (SD). Peak effect, onset time, and early recovery to 25% of control twitch height were not significantly different between PCA and LCA at 86% (13) versus 78% (16), 2.3 min (0.45) versus 2.3 min (1.0), and 9.55 min (3.05) versus 8.5 min (4.7), respectively. However, recovery to 75%, 90% of control twitch height, and recovery to a TOF ratio of 0.8 were significantly longer at the PCA than at the LCA at 14 min (4) versus 11 min (5), 17 min (5) versus 11.8 min (5.6), and 17.5 min (5.6) versus 12.3 min (5.5), respectively. The authors conclude that recovery of NMB at the PCA takes longer than at the LCA in humans after mivacurium. IMPLICATIONS: After neuromuscular blockade in humans, the recovery of the ability to open the vocal cords takes longer than the ability to close the vocal cords.

Phonomyography and mechanomyography can be used interchangeably to measure neuromuscular block at the adductor pollicis muscle.

UNLABELLED: The standard of neuromuscular monitoring is the measurement of the force of contraction (mechanomyography, MMG). Phonomyography (PMG) consists of recording low-frequency sounds created during muscle contraction. In this study, we compared and used both methods to determine neuromuscular blockade (NMB) at the adductor pollicis muscle. In 14 patients, PMG was recorded via a small condenser microphone taped to the thenar mass, and a standard mechanomyographic device was applied to the same arm. In another group of 14 patients, only PMG was measured. After induction of anesthesia, the ulnar nerve was stimulated supramaximally using single twitch stimulation (0.1 Hz) for onset and train-of-four (TOF) stimulation every 12 s during offset of NMB produced by mivacurium 0.1 mg/kg. Onset and recovery indices measured by the 2 methods were compared using Student's t-test (P < 0.05). Similar comparisons were made between the two PMG groups (with or without special board). Agreement between PMG and MMG was examined using a Bland-Altman test. Onset was 165 (68) s versus 172 (67) s [mean (SD)], and maximum blockade was 89 (10)% versus 90 (11)%, for PMG and MMG respectively (NS). Time to 25%, 75%, and 90% recovery was 16.5 (4.2) min, 22.1 (6.9) min, and 24.5 (8.2) min, respectively for PMG, not different from 16.7 (4) min, 22.8 (8.1) min, and 24.8 (8.8) min for MMG. Mean bias was 0% with limits of agreement of -10 and + 10% of twitch height for all signals (MMG minus PMG). Time to TOF of 0.5, 0.7, 0.8, and 0.9, was 1 min faster with PMG than with MMG, with limits of agreement of -1.5 to 3.5 min. Pharmacodynamic data derived without or with special arm fixation were not significantly different. MMG and PMG can be used interchangeably to determine NMB at the adductor pollicis muscle. PMG is easier to apply, does not need a special monitoring board and could be a reliable monitor to determine NMB in daily routine. IMPLICATIONS: Mechanomyography and phonomyography (PMG), a novel method of monitoring neuromuscular blockade (NMB) by recording low-frequency sounds emitted by muscle contraction, can be used interchangeably to determine NMB at the adductor pollicis muscle. PMG is easier to apply, does not need a special monitoring board and could be a reliable monitor to determine NMB in daily routine.