The use of neuromuscular blocking drugs in the intensive care unit: A US perspective

Surprisingly little is known about the use of neuromuscular blockers (NMBs) in intensive care units (ICUs) in the USA. Recently, Klessig et al. [1] surveyed anesthesiologists/intensivists in the USA and found that the 55% who responded used NMBs in the ICU in an average of 10 patients per ICU per month. Anxiolytics and analgesics were administered concomitantly with NMBs, but a majority of respondents did not use electrophysiologic measures of the degree of blockade. Another survey of predominantly medical ICUs also demonstrated widespread use of NMBs, but internists did not use sedation/analgesia as frequently as anesthesiologists for patients receiving NMBs, and infrequently monitored the degree of neuromuscular blockade [2]. Because these were retrospective surveys, we decided to monitor prospectively the use of NMBs in our ICUs. The use of NMBs was ascertained by daily review of pharmacy records and, when use was documented, the patients hospital records were reviewed. Where information was missing or not found, attending physicians were interviewed. On averages, one patient per month per ICU received NMBs. Approximately 5% of neonatal and pediatric, and 1% of adult, ICU patients received NMBs. Eighty-three percent of patients received NMBs to facilitate mechanical ventilation, and mortality was high (51%) in those critically ill patients. More than half the patients were treated for ≤24 h, the remainder for 2 days to >3 weeks. Twitch monitors were used for monitoring the degree of neuromuscular blockade in adult patients, and all patients received sedatives/analgesics. We estimated that the risk of clinically significant, prolonged neuromuscular blockade following the discontinuation of NMBs was 5% per year. Our data demonstrate that NMBs in our practice are used less frequently than previous surveys indicate, that it is possible to change behavior with respect to the use of monitors of neuromuscular treatment, and that clinically significant prolonged blockade was an infrequent but serious problem in this population of critically ill patients.     

Bispectral index monitoring during the administration of neuromuscular blocking agents in the pediatric intensive care unit patient

Bispectral index (BIS) values were prospectively recorded in pediatric intensive care unit patients receiving continuous infusion of a neuromuscular blocking agent. Sedation was provided by a continuous infusion of midazolam or propofol. The BIS number was recorded by a bedside computer every 10 seconds but was concealed from health care workers. BIS values were recorded for 476 hours (161 893 BIS values) in 12 patients. The BIS number was 50 to 70, 57% of the time; < or =49, 35% of the time; and > or =71, 8% of the time. When supplemental doses of sedatives were administered, the BIS number was >70, 64% of the time; 50 to 70, 31% of the time; and < or =49, 5% of the time. Oversedation was more likely with propofol than midazolam. During the use of neuromuscular blocking agents, oversedation is a common occurrence. Physiologic parameters are not an accurate means of assessing the depth of sedation.     

The use of erythropoiesis-stimulating agents in the intensive care unit

Anemia is common in critically ill patients, but treatment with red blood cell transfusions can have unwanted effects. Limiting the occurrence and severity of anemia by using erythropoietic agents (iron and/or recombinant erythropoietin), therefore, remains an attractive option during the intensive care unit stay but also after hospital discharge. Moreover, these agents may have additional beneficial properties. In this article the authors review the rationale for the administration of iron and/or erythropoietin in critically ill patients.     

Multiprofessional survey of protocol use in the intensive care unit

Purpose

To date, there has been no large multicenter, multiprofessional evaluation of protocol and guideline use in the intensive care unit (ICU). The primary purpose of this study was to describe national availability, development, implementation, and assessment of protocols in ICUs. A secondary objective was to compare perceived utility by ease of use, patient safety, cost containment, and compliance of protocols between nurses, physicians, and pharmacists.

Materials and Methods

The survey was developed and tested for validity by 15 clinicians who identified additional domains of interest. An additional 15 clinicians of the 3 different professions evaluated the survey for relevancy and appropriateness of responses. Three survey experts evaluated survey construction. The survey was uploaded to a Web survey tool and pilot tested for clarity and ease of completion.

Results

The overall response rate for the survey was 18.1% (n = 614). Popular methods of education for protocol implementation included staff meetings (85.3%) and unit-specific in-services (77.7%). Protocols were most often updated when new information was available (40.8%) or every 12 months (17.9%). The most common limitation to development and implementation was limited personnel resources (24.5%) and physicians not wanting to use them (21.3%), respectively. Clinicians indicated that protocols made their job easier and improved cost containment some or most of the time. Sepsis protocols were identified as most useful in promoting patient outcomes by all 3 professions.

Conclusions

The types of protocols available appear to be those assisting with management of high-alert medications. Overcoming the perceived barriers of protocol use within ICUs requires personnel for development and physician support. A better protocol review process may be necessary to assure optimal content, desired outcomes, and consistency with Institute for Safe Medication Practices guidelines.     

Canadian survey of the use of sedatives, analgesics, and neuromuscular blocking agents in critically ill patients

OBJECTIVES: To characterize the perceived utilization of sedative, analgesic, and neuromuscular blocking agents, the use of sedation scales, algorithms, and daily sedative interruption in mechanically ventilated adults, and to define clinical factors that influence these practices. DESIGN: Cross-sectional mail survey. PARTICIPANTS: Canadian critical care practitioners. MEASUREMENTS AND MAIN RESULTS: A total of 273 of 448 eligible physicians (60%) responded. Respondents were well distributed with regard to age, years of practice, specialist certification, size of intensive care unit and hospital, and location of practice. Twenty-nine percent responded that a protocol/care pathway/guideline for the use of sedatives or analgesics is currently in use in their intensive care unit. Daily interruption of continuous infusions of sedatives or analgesics is practiced by 40% of intensivists. A sedation scoring system is used by 49% of respondents. Of these, 67% use the Ramsay scale, 10% use the Sedation-Agitation Scale, 9% use the Glasgow Coma Scale, and 8% use the Motor Activity Assessment Scale. Only 3.7% of intensivists use a delirium scoring system in their intensive care units. Only 22% of respondents currently have a protocol for the use of neuromuscular blocking agents in their intensive care unit, and 84% of respondents use peripheral nerve stimulation for monitoring. In patients receiving neuromuscular blocking agents for >24 hrs, 63.7% of respondents discontinue the neuromuscular blocking agent daily. Intensivists working in university-affiliated hospitals are more likely to employ a sedation protocol and scale (p < .0001), as are intensivists working in larger intensive care units (>or=15 beds, p < .01). Intensivists with anesthesiology training (and no formal critical care training) are more likely to use a protocol and sedation scale, and critical care-trained intensivists are more likely to use daily interruption. Younger physicians (<40 yrs) are more likely to practice daily interruption (p = .0092). CONCLUSIONS: There is significant variation in critical care sedation, analgesia, and neuromuscular blockade practice. Given the potential effect of practices regarding these medications on patient outcome, future research and educational efforts related to evidence-based protocols for the use of these agents in mechanically ventilated patients might be worthwhile.     

Acute neuromuscular weakness in the intensive care unit

INTRODUCTION: Patients in the intensive care unit develop generalized weakness due to a number of factors. Neuromuscular weakness is a common cause of failure to wean from the ventilator and decreased limb movements. A rational approach to evaluation of weakness will help to identify most of the common causes of neuromuscular weakness in the intensive care unit. AIMS: This review provides an analysis of neuromuscular weakness and a practical algorithm to assist in diagnostic evaluation. CONCLUSIONS: The most common acquired causes of weakness in the critically ill patient in the intensive care unit are critical illness polyneuropathy and critical illness myopathy. In the intensive care unit setting, electrophysiological studies, biopsies, and imaging studies are often necessary to complement the clinical impression.     

Postal survey on the long-term use of neuromuscular block in the intensive care

Objective To assess the long-term use of neuromuscular blocking (NMB) agents in intensive care, expecially with reference to the potential problems of the long-term use of NMB drugs in the intensive care unit (ICU).Method A postal survey questionnaire was sent to 409 ICUs in Great Britain.Results Two hundred thirty-eight completed questionnaires were returned and analysed. Most ICUs were anaesthetist-led (85.8%) with only five ICUs being staffed by full-time intensivists. Facilitation of mechanical ventilation and increased intracranial pressure were the main indications for the prolonged use of neuromuscular blockade. Atracurium and vecuronium (83%) were administered most commonly by bolus alone (13.8%), bolus followed by continuous infusion (23.9%) or continuous infusion only (60.9%). The most frequently cited criteria for the use of either vecuronium or stracurium were their pharmacokinetics and haemodynamic stability. Neuromuscular block was most commonly monitored clinically (91.7%), with only 8.3% of the responders using a peripheral nerve stimulator. All responders indicated the concomitant use of sedatives (propofol/midazolam alone or in combination in 89.4% of responders) and/or opioids (morphine, fentanyl or alfentanil in 74.8% of respondents) with muscle relaxants.Conclusion Most responders agreed that while neuromuscular block in the ICU population may provide advantages, it cannot be considered benign. Indeed, a great majority consider that NMB agents should be used only as a last option andfor as short a period as possible.This paper was presented at the Joint meeting of the Intensive Care Society and Société de Réanimation de Langue Française, Brighton, May 1995     

Vasoactive drugs in the intensive care unit

PURPOSE OF THE REVIEW: Vasoactive drugs are the mainstay of hemodynamic management of vasodilatory shock when fluids fail to restore tissue perfusion. In this review, studies published during the past year that increase our understanding of the use of vasoactive drugs in the intensive care unit are discussed. RECENT FINDINGS: In septic shock, there is no benefit in increasing mean arterial pressure from 65 to 85 mmHg. Norepinephrine did not worsen renal function. Epinephrine induced visceral hypoperfusion and hyperlactatemia, and worsened organ function and survival compared with norepinephrine and vasopressin. There are a number of reports of the safety and efficacy of vasopressin but it is not currently recommended as first line therapy, and if used, should be given as a continuous low dose infusion. Terlipressin is showing promise but decreases cardiac output. Metaraminol is being investigated as an alternative to norepinephrine. Dopamine may improve splanchnic flow mainly by increasing cardiac output. Dobutamine improves oxygen delivery and may improve mesenteric blood flow. SUMMARY: Over the last 40 years, there have been few controlled clinical trials to guide clinicians on the use of vasoactive drugs of treating shock states. It is not known whether the currently favored combination of norepinephrine and dobutamine is superior to traditional therapy with dopamine. Epinephrine is not recommended as the first-line therapy. The role of vasopressin and terlipressin remains unknown. Three large ongoing clinical trials will be completed soon and the results should clarify the role of these various agents.     

Steroids and biologic agents in the intensive care unit

We have reviewed the actions, indications, and toxicity of steroids and several important biologic pharmaceutical agents used in critical care medicine. This is a rapidly expanding area of therapeutics. Space limitations prevent an exhaustive review of all biologic pharmaceuticals, such as tissue plasminogen activating substance, hormones (e.g., thyroid, insulin, growth hormone, erythropoietin), clotting factors, and blood products. The future of biologic pharmaceuticals appears to be bright in the face of new biotechnology, and the critical care physician can anticipate new and exciting treatments to evolve from current basic and clinical research into biologic agents.     

Neuromuscular blocking agents and sedative drugs. Clinical uses and toxic effects in the critical care unit

The use of sedatives and muscle relaxants is common in the ICU. Therapeutic goals should be carefully established. Monitoring of desired effects and toxic side effects is essential to avoid preventable morbidity.