Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult

Monitoring consciousness in intensive care medicine

Sedation and analgesia are important components of care for critically ill patients. Avoiding over-as well as undersedation is of utmost importance as both states carry considerable risks and may influence outcome. The management of sedation has changed dramatically over the past two decades from providing a dosage level by which the patient was kept in a deep stage of anaesthesia to a current dosing strategy allowing the administration of drugs in line with individual need, resulting in most cases in a slightly sedated, cooperative patient. The importance of monitoring the level of sedation and analgesia has only recently been realised. Most importantly, regularly determining the appropriate level of sedation and analgesia as well as monitoring the desired level of sedation will help to minimise the adverse effects of sedation. Clinical sedation scales are, however, subjective, and most lack proper validation. Thus, an objective measure of sedation, such as the use of processed electroencephalogram (EEG) parameters is desirable. Processed EEG algorithms such as the bispectral index were initially introduced into clinical practice as a tool to assess the depth of anaesthesia objectively in the operating room. However, patients under general anaesthesia differ from those in an intensive care unit. Accordingly, most results from studies evaluating the performance of processed EEG parameters in critically ill patients have not been satisfactory. At present, monitoring sedation with processed EEG parameters cannot generally be recommended. However, in special situations such as deep sedation and neuromuscular blockade, in which clinical sedation scales are prone to failure, the bispectral index may help to assess the level of sedation.

Comparison of seven anesthetic agents on outcome after experimental traumatic brain injury in adult, male rats

Isoflurane is commonly used in experimental traumatic brain injury (TBI), both before and early after injury, yet it is rarely used clinically. Narcotics and benzodiazepines are frequently used after injury in clinical TBI. We compared seven anesthetic/sedative agents applied after injury in the controlled cortical impact model: diazepam, fentanyl, isoflurane, ketamine, morphine, pentobarbital, and propofol. Our objective was to provide insight into the relative degrees of neuroprotection provided by these agents in a standard model of TBI. We hypothesized that the choice of anesthetic/sedative early after experimental TBI critically impacts outcome and that the agents most commonly used clinically may be less neuroprotective than isoflurane. Rats treated with isoflurane had the best cognitive recovery (p < 0.05) and hippocampal neuronal survival (p < 0.05). Conversely, rats treated with ketamine had the most hippocampal neuronal death (p < 0.05). Morphine or propofol, two agents commonly used clinically, were associated with the poorest motor function on post-trauma day 1-5 (p < 0.05). Our data support beneficial effects of isoflurane early after experimental TBI. Our data suggest that the early post-TBI use of isoflurane, despite practical logistical issues, could potentially provide clinical benefits in TBI--versus other commonly used sedatives or analgesics. Furthermore, the choice of post-injury sedation and analgesia could have important implications on attempts to translate novel therapies from bench to field or bedside.

Sedation and analgesia in German intensive care units: how is it done in reality? Results of a patient-based survey of analgesia and sedation

OBJECTIVE

This study carried out the first patient-oriented survey on the practice of analgesia and sedation in German intensive care units, examining whether the goals of early spontaneous breathing and awake, cooperative patients are achieved.

DESIGN

A postal survey was sent to 261 hospitals in Germany. Each hospital received three patient-oriented forms with questions regarding current agents and techniques for analgesia and sedation of a specific patient. Responses were obtained from 220 (84%) hospitals which returned 305 questionnaires.

RESULTS

Patients' Ramsay sedation scale was significantly higher in all phases of analgesia and sedation, indicating that the patients were more deeply sedated than currently intended by the therapist. Propofol was used for most of the patients during short-term sedation (57%) and during weaning (48%). The preferred agent for sedation longer than 72[Symbol: see text]h was midazolam (66%).

CONCLUSION

The choice of agents and techniques for analgesia and sedation in the intensive care unit thus follows the German guidelines. The fact that the patients were more deeply sedated than intended by the therapist in all phases of sedation may be due to the low use of sedation scales and clinical practice guidelines or to the lack of training in using these techniques.

Impact of systematic evaluation of pain and agitation in an intensive care unit*

OBJECTIVE

To measure the impact of implementation of the systematic evaluation of pain and agitation by nurses using the Behavioral Pain Scale (BPS), the Numerical Rating Scale (NRS) for pain, and the Richmond Agitation Sedation Scale (RASS) associated with medical staff education in analgesia and sedation management in intensive care unit (ICU) patients.

DESIGN

Two-phase, prospective, controlled study.

SETTING

Twelve-bed medical-surgical ICU in a university hospital.

PATIENTS

Consecutive patients staying >24 hrs in ICU.

INTERVENTIONS

BPS, NRS, and RASS were measured twice daily, at rest, by independent observers during 21 wks (control group) and after 4 wks of training, by nurses during 29 wks (intervention group). In the intervention group, the treating physician was alerted in case of pain defined by BPS>5 or NRS>3 or in case of agitation defined by RASS>1.

MEASUREMENTS AND MAIN RESULTS

A total of 230 patients were included (control group, n=100; intervention group, n=130). Baseline characteristics were not significantly different. The incidence of pain and agitation decreased significantly in the intervention group: 63% vs. 42% (p=.002) and 29% vs. 12% (p=.002), respectively. Rate of severe pain and agitation events defined by NRS>6 and RASS>2, respectively, also decreased significantly. There were significantly more therapeutic changes in the intervention group in the way of an escalation but also in the way of a de-escalation for analgesic and psychoactive drugs. Compared with the control group, there was a marked decrease in the duration of mechanical ventilation (120 [interquartile range 48-312] vs. 65 (24-192) hrs, p=.01) and nosocomial infections rate (17% vs. 8%, p<.05) in the intervention group. There was no significant difference in median length of stay (9 [4, 15] vs. 7 [4, 13] days) and mortality in ICU (12 vs. 15%).

CONCLUSIONS

Systematic evaluation of pain and agitation, and analgesics and sedatives need was associated with a decrease in incidence of pain and agitation, duration of mechanical ventilation and nosocomial infections.

Investigating nurses' perceptions of their role in managing sedation in intensive care: an exploratory study

Most patients who are admitted to intensive care in need of ventilator support may also require sedation. It is a part of the nurses' role to manage sedation therapy according to patients' needs, avoiding complications of over and under sedation. The purpose of the study was to explore nurses' perceptions of their role in sedation management. A convenience sample of 107 registered nurses in the intensive care unit of a large teaching hospital was accessed and a response rate of 86% (n=92) obtained. Results showed that the nurse has a major role in sedation management in the critically ill patient. Sedation scoring is used in the assessment of the patient's sedation level and sedation is then titrated by the nurse in collaboration with medical staff to an agreed target level. However, the impact of this role depends on the experience and confidence of the nurse as knowledge and skills are required in order to provide effective sedation for patients. Recommendations from this study are to incorporate a team approach within a locally devised sedation protocol. This should be supported by an education programme aiming to improve decision-making about sedation management at the bedside.

Withdrawal from lorazepam in critically ill children

BACKGROUND

Sedatives are used in critically ill children to facilitate mechanical ventilation. Although tolerance and withdrawal are associated with use of sedatives, information about withdrawal from benzodiazepines in children is limited.

OBJECTIVE

To document the occurrence of lorazepam withdrawal in critically ill children and identify predictors for the development of withdrawal.

METHODS

This prospective, investigational, open-label study enrolled pediatric patients receiving a continuous infusion of lorazepam for at least 72 hours. The lorazepam dosage was tapered in a uniform fashion over 6 days by decreasing the total daily dose by 50% every other day on 3 occasions; it was then discontinued. The occurrence of withdrawal from lorazepam was determined by pediatric intensive care unit attending physicians based on clinical judgment. Patients were assessed for withdrawal twice daily beginning 48 hours after the initiation of the lorazepam taper. Assessments were continued for 72 hours after lorazepam discontinuation or until the patient experienced withdrawal, whichever came first. Patient demographic, sedative dosing, and lorazepam serum concentration data were collected to identify risk factors for withdrawal.

RESULTS

Twenty-nine patients completed the study. They received lorazepam for a median duration of about 21 days, and withdrawal occurred in 7 patients. There were no significant differences in demographic variables, lorazepam dosage or other sedative therapy, or lorazepam serum concentrations between patients with withdrawal and those without withdrawal. No predictors of withdrawal were identified.

CONCLUSIONS

Withdrawal occurred in 24% of critically ill children receiving long-term sedation from lorazepam. Risk factors for withdrawal are unknown.

Propofol for sedation in neuro-intensive care

Interventions in the intensive care unit often require that the patient be sedated. Propofol is a widely used, potent sedative agent that is popular in critical care and operating room settings. In addition to its sedative qualities, propofol has neurovascular, neuroprotective, and electroencephalographical effects that are salutory in the patient in neurocritical care. However, the 15-year experience with this agent has not been entirely unbesmirched by controversy: propofol also has important adverse effects that must be carefully considered. This article discusses and reviews the pharmacology of propofol, with specific emphasis on its use as a sedative in the neuro-intensive care unit. A detailed explanation of central nervous system and cardiovascular mechanisms is presented. Additionally, the article reviews the literature specifically pertaining to neurocritical care use of propofol.

A randomized trial of intermittent lorazepam versus propofol with daily interruption in mechanically ventilated patients

OBJECTIVE

To compare duration of mechanical ventilation for patients randomized to receive lorazepam by intermittent bolus administration vs. continuous infusions of propofol using protocols that include scheduled daily interruption of sedation.

DESIGN

A randomized open-label trial enrolling patients from October 2001 to March 2004.

SETTING

Medical intensive care units of two tertiary care medical centers.

PATIENTS

Adult patients expected to require mechanical ventilation for >48 hrs and who required > or =10 mg of lorazepam or a continuous infusion of a sedative to achieve adequate sedation.

INTERVENTIONS

Patients were randomized to receive lorazepam by intermittent bolus administration or propofol by continuous infusion to maintain a Ramsay score of 2-3. Sedation was interrupted on a daily basis for both groups.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was median ventilator days. Secondary outcomes included 28-day ventilator-free survival, intensive care unit and hospital length of stay, and hospital mortality. Median ventilator days were significantly lower in the daily interruption propofol group compared with the intermittent bolus lorazepam group (5.8 vs. 8.4, p = .04). The difference was largest for hospital survivors (4.4 vs. 9.0, p = .006). There was a trend toward greater ventilator-free survival for patients in the daily interruption propofol group (median 18.5 days for propofol vs. 10.2 for lorazepam, p = .06). Hospital mortality was not different.

CONCLUSIONS

For medical patients requiring >48 hrs of mechanical ventilation, sedation with propofol results in significantly fewer ventilator days compared with intermittent lorazepam when sedatives are interrupted daily.

[Validation of the french translated Richmond vigilance-agitation scale]

OBJECTIVE

To test reliability of the Richmond Agitation Sedation Scale (RASS) after French translation.

STUDY DESIGN

Prospective psychomotor evaluation study.

PATIENTS AND METHODS

Two bilingual physicians performed the translation from English to French language. The French version was then translated to English by a bilingual non physician ("backtranslation") and compared to the original version. The translated scale was tested according to usual guidelines concerning the translation of neuropsychological evaluation tools. The French version of RASS was tested on the morning of every fifth or sixth day, and 30-min after any procedure, in 43 consecutive patients admitted to a 12-bed medical-surgical intensive care unit during two months, by a group of four observers: the principal investigator, two anaesthesiology residents and one pharmacology student. Inter-rater reliability was tested using the simple and weighted Kappa coefficients (with their 95% confidence interval). A consensual and detailed "operating instructions" guide of RASS, intended for medical and nursing staff, has been added in the Annexe section.

RESULTS

Four hundred twenty measures were performed during 105 grouped observations. Reliability of the French version of RASS was substantial. Simple Kappa coefficient, testing the concordance between observers, was ranged from 0.72 (0.62-0.81) to 0.87 (0.79-0.94) and weighted Kappa coefficient from 0.95 (0.92-0.98) to 0.99 (0.98-0.99).

CONCLUSIONS

The French translation of RASS was acceptable. The translated scale preserved substantial inter-rater reliability. Monitoring of vigilance status in intensive care settings can be performed with this reliable clinical tool.

Consensus guidelines on sedation and analgesia in critically ill children

OBJECTIVE

The United Kingdom Paediatric Intensive Care Society Sedation, Analgesia and Neuromuscular Blockade Working Group is a multi-disciplinary expert panel created to produce consensus guidelines on sedation and analgesia in critically ill children and forward knowledge in these areas. Sedation and analgesia are recognised as important areas of critical care practice and adult clinical practice guidelines in these fields remain amongst the most popular of those produced by the Society of Critical Care Medicine. However, similar clinical practice guidelines have not previously been produced for the critically ill paediatric patient.

DESIGN

A modified Delphi technique was used to allow the Working Group to anonymously consider draft recommendations in three Delphi rounds with predetermined levels of agreement. This process was supported by a total of four consensus conferences. Once consensus had been reached, a systematic review of the available literature was carried out.

OUTCOME

A set of consensus guidelines was produced including 20 key recommendations, 10 relating to the provision of analgesia and 10 relating to the sedation of critically ill children. An evaluation of the existing literature supporting these recommendations is provided.

CONCLUSIONS

Multi-disciplinary consensus guidelines for maintenance sedation and analgesia in critically ill children have been successfully produced and are supported by levels of evidence (excluding sedation and analgesia for procedures and excluding neonates). The working group has highlighted the paucity of high-quality evidence in these important clinical areas and this emphasises the need for further randomised clinical trials in this area.

Sedation during mechanical ventilation: A trial of benzodiazepine and opiate in combination*

OBJECTIVE

To compare the efficacy of continuous intravenous sedation with midazolam alone vs. midazolam plus fentanyl ("co-sedation") during mechanical ventilation.

DESIGN

A randomized, prospective, controlled trial.

SETTING

A ten-bed medical intensive care unit at a university hospital.

PATIENTS

Thirty patients with respiratory failure who were expected to require >48 hrs of mechanical ventilation and who were receiving a sedative regimen that did not include opiate pain control.

INTERVENTIONS

An intravenous infusion of either midazolam alone or co-sedation was administered by a nurse-implemented protocol to achieve a target Ramsay Sedation Score set by the patient's physician. Study duration was 3 days, with a brief daily "wake-up."

MEASUREMENTS AND MAIN RESULTS

We recorded the number of hours/day that patients were "off-target" with their Ramsay Sedation Scores, the number of dose titrations per day, the incidence of patient-ventilator asynchrony, and the time required to achieve adequate sedation as measures of sedative efficacy. We also recorded sedative cost in U.S. dollars and adverse events including hypotension, hypoventilation, ileus, and coma. Compared with the midazolam-only group, the co-sedation group had fewer hours per day with an "off-target" Ramsay Score (4.2 +/- 2.4 and 9.1 +/- 4.9, respectively, p < .002). Fewer episodes per day of patient-ventilator asynchrony were noted in the co-sedation group compared with midazolam-only (0.4 +/- 0.1 and 1.0 +/- 0.2, respectively, p < .05). Co-sedation also showed nonsignificant trends toward a shorter time to achieve sedation, a need for fewer dose titrations per day, and a lower total sedative drug cost. There was a trend toward more episodes of ileus with co-sedation compared with midazolam-only (2 vs. 0).

CONCLUSIONS

In mechanically ventilated patients, co-sedation with midazolam and fentanyl by constant infusion provides more reliable sedation and is easier to titrate than midazolam alone, without significant difference in the rate of adverse events.

Sedative and Analgesic Medications: Risk Factors for Delirium and Sleep Disturbances in the Critically Ill

Sedatives and analgesics are routinely used in critically ill patients, although they have the potential for side effects, such as delirium and sleep architecture disruption. Although it should be emphasized that these medications are extremely important in providing patient comfort, health care professionals must also strive to achieve the right balance of sedative and analgesic administration through greater focus on reducing unnecessary or overzealous use. Ongoing clinical trials should help us to understand whether altering the delivery strategy, via daily sedation interruption, or protocolized target-based sedation or changing sedation paradigms to target different central nervous system receptors can affect cognitive outcomes and sleep preservation in our critically ill patients.

Memory in relation to depth of sedation in adult mechanically ventilated intensive care patients

OBJECTIVE

To investigate the relationship between memory and intensive care sedation.

DESIGN AND SETTING

Prospective cohort study over 18[Symbol: see text]months in two general intensive care units (ICUs) in district university hospitals.

PATIENTS

313 intubated mechanically ventilated adults admitted for more than 24 h, 250 of whom completed the study.

MEASUREMENTS

Patients (n=250) were interviewed in the ward 5 days after discharge from the ICU using the ICU Memory Tool. Patient characteristics, doses of sedative and analgesic agents, and sedation scores as measured by the Motor Activity Assessment Scale (MAAS) were collected from hospital records after the interview.

RESULTS

Patients with no recall (18%) were significantly older, had higher baseline severity of illness, and experienced fewer periods of wakefulness (median proportion of MAAS score 3; 0.37 vs. 0.70) than those who had memories of the ICU (82%). Multivariate analyses showed that increasing proportion of MAAS 0-2 and older age were significantly associated with having no recall. Patients with delusional memories (34%) had significantly longer ICU stay (median 6.6 vs. 2.2 days), higher baseline severity of illness, higher proportions of MAAS scores 4-6, and more administration of midazolam than those with recall of the ICU without delusional memories.

CONCLUSIONS

Heavy sedation increases the risk of having no recall, and longer ICU stay increases the risk of delusional memories. The depth of sedation during total ICU stay as recorded with the MAAS may predict the probability of having memories of the ICU.

Adverse responses: sedation, analgesia and neuromuscular blocking agents in critically ill children

Advanced practice nurses (APNs) prescribe sedation, analgesia, and neuromuscular blocking agents in the management of critically ill children. Although most children are unscathed from the use of the medications, some suffer adverse responses. This article elucidates adverse responses to these medications for the APN, including withdrawal syndrome, muscle weakness, decreased gastric motility, corneal abrasions, and costs associated with these morbidities.

The reliability and validity of a new and simple method to measure sedation levels in intensive care patients: A pilot study

BACKGROUND

Since more sophisticated ventilation techniques have enabled patients to comply with the ventilator with little or no sedation, deep sedation levels can easily be avoided. However, successful ventilation techniques also expanded the treatment possibilities for more severely ill patients who require deeper sedation levels. We developed a new sedation score to improve the prevention of oversedation and to simplify scoring practice in the intensive care unit (ICU).

OBJECTIVE

The study's objective was to establish the validity and reliability of a new sedation score (Sedic score) for critically ill, sedated adult patients.

METHODS

We prospectively evaluated the reliability and validity of the Sedic score. The study took place in a 30-bed ICU in a university teaching hospital. Forty-six consecutive mechanically ventilated and sedated ICU patients were included. The constructed scale consists of five levels of stimuli and five levels of responses. Sedation levels are defined by the sum of stimulus and response. The reliability of the Sedic score was assessed by simultaneous measurement by the research nurse and attending nurse (n=70). VALIDITY was expressed as (1) the hierarchic relation between stimulus and response (n=443), (2) the prediction of wake-up time by the Sedic score (n=46), and (3) the association between the Sedic score and the Ramsay scale (n=88).

RESULTS

The method showed excellent reliability.

VALIDITY

Weighted kappa between stimulus and response was .82. Multivariate analysis: (recovery time as independent variable) regression line (Y=-2.53+ 2.16 * beta; P<.001) (r2=42%). Correlation between the Sedic scores and the Ramsay scores was r(s) .74 (P=.01). Sixty-seven percent of the patients with a maximum Ramsay score of 6 had scores ranging between 6 and 10 on the Sedic scale, indicating that the Ramsay scale has a serious ceiling effect.

CONCLUSION

The Sedic score demonstrates sufficient reliability and validity, and correlates well with wake-up time. It allows for frequent use by nurses to avoid oversedation in patients.

A Feasibility Study of Methodological Issues and Short-Term Outcomes in Seriously Injured Older Adults

• Background For any given traumatic injury, older adults experience a longer hospitalization, more complications, and higher mortality than do younger patients.

• Objectives To prospectively identify problems in designing follow-up studies in seriously injured older adults without head injury and to examine outcomes after serious trauma in older adults who were sent to a level I trauma center.

• Methods A short-term descriptive follow-up design was used in which each patient served as his or her baseline. Eligible patients had injuries that required admission to an intensive care unit, a hospital length of stay longer than 72 hours, or surgery. Patients with isolated hip fractures, central nervous system injuries, and burn injuries were excluded. Data were collected by using standardized instruments during the acute hospital stay and 3 months after discharge from the hospital.

• ResultsDuring a representative 2-month period, 21% of a potential 77 subjects died in the hospital, 44% had cognitive impairment that precluded participation, and 17% declined to participate. Twenty older adults (mean age 73.5 years) who were injured in motor vehicle crashes (45%), falls (35%), or pedestrian accidents (15%) or who had gunshot wounds (5%) were enrolled. Ten percent died after discharge. Levels of physical disability at 3 months after discharge were higher than those before the injury (score on Sickness Impact Profile physical subscale 24.5 vs 10.9, P = .02), and psychological distress (Impact of Event Scale score 20.9) remained elevated.

• Conclusion Mortality, disability, and posttraumatic psychological distress after discharge are problems in seriously injured older adults.

Consciousness, coma, and caring for the brain-injured patient

In this article, a preliminary conceptual framework is presented for exploring nursing interventions and research aimed at improving care of the unconscious brain-injured patient during the early subacute phase of brain injury. The cue-response framework presented is derived from multidisciplinary sources and has specific clinical relevance to critical care nurses caring for unconscious brain-injured patients. A key aspect of this framework is the attention focused on the timing of nursing interventions in response to how nurses interpret the physical, physiological, and secondary cues they observe when caring for comatose patients. A case exemplar is used to present one example of how this framework may be used in the clinical setting.

Melatonin: possible implications for the postoperative and critically ill patient

There is increasing interest in the hormone melatonin in postoperative and critically ill patients. The roles of melatonin in the regulation of the sleep-wake cycle, resetting of circadian rhythm disturbances and its extensive antioxidant activity have potential applications in these patient groups. The interaction between melatonin and the stresses of surgery and critical illness are explored in the context of circadian rhythms, sleep disorders and delirium. The antioxidant activity is discussed in terms of the reduction of ischaemic reperfusion injury, prevention of multi-organ failure and treatment of sepsis. Unfortunately, there is currently insufficient evidence that exogenous melatonin is effective in preventing or treating postoperative delirium. Similarly, in the critically ill patient, sleep disorders are associated with disrupted melatonin circadian secretion, but there is a paucity of data to support routine exogenous melatonin supplementation. More clinical evidence to confirm the potential benefits of melatonin therapy is required before it can be routinely used in the postoperative or critically ill patient.

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.

Nurses’ and physicians’ sedation practices in Danish ICUs in 2003

OBJECTIVE

The aim of the study was to describe and compare physicians' and nurses' estimated use of sedatives and analgesics in patients requiring mechanical ventilation in Danish Intensive Care Units (ICUs) in 2003.

DESIGN

Questionnaires were mailed in January 2003 to all Danish ICUs providing mechanical ventilation (n = 48). One physician and one nurse at each site were included in the study.

RESULTS

Thirty-nine questionnaires were returned by physicians (response rate 81%) and 43 by the nurses (response rate 90%). Physicians and nurses agreed that sedation related decisions are predominately made during rounds and that most decisions are made by physicians and nurses collaboratively. Only 9% of the nurses and 23% of the physicians reported using a written protocol for sedation, while 30% of the nurses and 44% of the physicians reported the use of sedation scoring systems. The study generally supported the hypothesis, that nurses' and physicians' would respond similarly, but there were, however, significant variations, regarding formal sedation practices.

CONCLUSIONS

Sedation decisions are made collaboratively by nurses and physicians, while sedation protocols and scoring systems are still not systematically implemented in Danish ICUs. The most common drugs for sedation of the mechanically ventilated patient are propofol and fentanyl by continuous infusion. It is recommended that the ICUs collaborate on developing evidence-based standards for sedation and that clinical databases are introduced, which may be used to assess the efficacy of such standards.

Delirium: acute cognitive dysfunction in the critically ill

PURPOSE OF REVIEW

The management of sepsis and the multiple organ dysfunction syndrome has traditionally been centered on dysfunction of organs other than the brain (e.g., heart, lungs, or kidneys), although the brain is one of the most prevalent organs involved. Recent studies indicate that nonpulmonary acute organ dysfunction may contribute significantly to mortality and other important clinical outcomes. Acute confusional states (delirium) occur in 10 to 60% of the older hospitalized population and in 60 to 80% of patients in the intensive care unit, yet go unrecognized by the managing physicians and nurses in 32 to 66% of cases. Delirium is an important independent prognostic determinant of hospital outcomes, including duration of mechanical ventilation, nursing home placement, functional decline, and death. Recently, new monitoring instruments have been validated for monitoring of delirium in noncommunicative patients receiving mechanical ventilation. Hence, critical care physicians and nurses should routinely assess their patients for delirium and develop strategies for its prevention and treatment.

RECENT FINDINGS

This state-of-the-art review discusses in depth the delirium monitoring instruments, the pathophysiology and risk factors of delirium, its prognostic implications, and strategies (including ongoing clinical trials) to prevent and treat delirium.

SUMMARY

Delirium is extremely common and has significant prognostic implications in critically ill patients. Routine monitoring and a multimodal approach to prevent or reduce the prevalence of delirium are of paramount importance.

Patients’ Recollections of Therapeutic Paralysis in the Intensive Care Unit

• Background Neuromuscular blocking agents used for therapeutic purposes, such as facilitating mechanical ventilation and relieving life-threatening agitation, paralyze patients but leave them fully conscious. Aggressive sedation or analgesia is necessary to reduce awareness, relieve fear, produce comfort, decrease anxiety, induce unconsciousness, and minimize possible complications such as posttraumatic stress syndrome. Little information is available on the extent to which patients experience awareness during therapeutic paralysis.

• Objectives To determine and describe the remembered experiences of critical care patients who were given neuromuscular blocking agents and sedatives and/or analgesics to facilitate mechanical ventilation, improve hemodynamic stability, and improve oxygenation.

• Methods A phenomenological approach with in-depth interviews with 11 patients was used. Data were analyzed by using the constant comparative approach.

• Results A total of 4 themes and 3 subthemes were identified. The first theme was back and forth between reality and the unreal, between life and death; the subtheme was having weird dreams. The second theme was loss of control; the 2 subthemes were (1) fighting or being tied down and (2) being scared. The third theme was almost dying, and the fourth theme was feeling cared for.

• Conclusions Patients can remember having both negative and positive experiences during neuromuscular blockade. Steps to improve the experiences of patients receiving neuromuscular blockers include improving assessment parameters, developing and using sedation/analgesia guidelines, and investing in quality improvement programs to provide assessment of awareness during therapeutic paralysis and follow-up and referral as necessary. Ways to decrease the use of neuromuscular blockers would also be useful.

Fentanyl-induced hemodynamic changes after esophagectomy or cardiac surgery

STUDY OBJECTIVE

The goal of this study was to characterize the hemodynamic response to propofol vs propofol with fentanyl when used for sedation after esophagectomy or cardiac surgery.

DESIGN

Prospective, randomized, controlled study.

SETTING

University Hospital, Intensive Care Unit.

PATIENTS

Thirty patients undergoing elective cardiac surgery and 26 patients undergoing esophagectomy were examined.

INTERVENTION

Patients were randomized to receive propofol (0.5 mg/kg bolus over 10 minutes, followed by continuous infusion at 1 mg/kg per hour) with or without fentanyl (2.0 microg/kg per hour) to achieve sedation overnight while in the intensive care unit. Randomization was performed in a double-blind manner.

MEASUREMENT

Mean arterial pressure (MAP) was monitored throughout the treatment period, and sedation level was measured. Sedation level was targeted to achieve a Ramsay score of 4.

MAIN RESULTS

The number of patients experiencing a greater than 20% drop in baseline MAP was higher in cardiac patients receiving propofol alone (11 of 15 patients, 73%) than in cardiac patients receiving propofol with fentanyl (4 of 15 patients, 27%). Furthermore, the time of optimal sedation was lower in the cardiac patients who received propofol than in cardiac patients who received propofol with fentanyl group (propofol alone, 79%; propofol with fentanyl, 88%). In contrast, there was no difference in the number of esophagectomy patients experiencing a greater than 20% drop in baseline MAP or in the mean time of optimal sedation when comparing the 2 treatment regimens.

CONCLUSIONS

Propofol has a differential effect on hemodynamics and sedation when comparing patients after cardiac surgery and esophagectomy.

Management of the Pediatric Postoperative Cardiac Surgery Patient

Optimal management of the postoperative pediatric cardiac surgical patient requires a thorough understanding of patient anatomy, physiology, surgical repair or palliation, and clinical condition. This necessitates a dedicated team of clinicians including skilled nurses, physicians, and respiratory therapists specialized in the care of patients who have complex congenital heart disease. This article provides an overview of the multisystemic risk factors and consequences associated with cadiopulmonary bypass and cardiac surgery. An evaluation of cardiac hemodynamics and a review of major organ systems are included. Essential assessment information and interventional strategies for managing the pediatric postoperative cardiac surgery patient are detailed.

A prospective study of agitation in a medical-surgical ICU: incidence, risk factors, and outcomes

STUDY OBJECTIVES

Although agitation is thought to be common in the ICU, it has been poorly studied. We evaluated the incidence, risks factors, and outcomes of agitation in ICU.

DESIGN

Prospective observational study.

INTERVENTIONS

None.

METHOD

All consecutive ICU admissions over an 8-month period were analyzed.

MEASUREMENTS AND RESULTS

Two hundred eleven patients were admitted a total of 216 times during the period of the study. Twenty-nine patients were excluded from the study because their pathology findings did not allow an evaluation of their level of consciousness; 182 patients were actually enrolled. Agitation developed in 95 of 182 patients (52%). Agitation began 4.4 +/- 5.6 days (+/- SD) after admission to the ICU and lasted 3.9 +/- 4.1 days. Patients with agitation had a higher Simplified Acute Physiology Score II on ICU admission than those who did not have agitation (40 +/- 16 vs 33 +/- 13, p < 0.01). By stepwise logistic regression, the independent risks factors for development of agitation included psychoactive drug use at the time of ICU admission (odds ratio, 5.63; 95% confidence interval [CI], 1.32 to 23.70), history of alcohol abuse (odds ratio, 3.32; 95% CI, 1.12 to 10.00), dysnatremia (odds ratio, 4.95; 95% CI, 1.95 to 12.54), fever (odds ratio, 4.52; 95% CI, 1.80 to 11.49), use of sedatives in the ICU (odds ratio, 4.03; 95% CI, 1.62 to 10.40), and sepsis (odds ratio, 2.61; 95% CI, 1.03 to 6.58). Agitation was associated with a prolonged ICU stay (16 +/- 19 days vs 6 +/- 6 days, p = 0.0001), nosocomial infections (34% vs 7%, p < 0.0001), unplanned extubations (17% vs 2%, p = 0.003), and unplanned central venous catheter removal (16% vs 1%, p = 0.001), but not with mortality (12% in the agitation group vs 8% in patients without agitation).

CONCLUSIONS

Agitation is a common event in a mixed medical-surgical ICU. It is associated with adverse outcomes including prolonged stay, nosocomial infections, and unplanned extubations. A better knowledge of incidence and risk factors should facilitate identification of patients at risk and decrease the incidence of agitation.

Trends in sedation practices in Danish intensive care units in 2003: a national survey

OBJECTIVE

The aim of the study was to explore trends and changes in sedation practices for mechanically ventilated patients in Danish intensive care units (ICUs) and to compare sedation practices in 1997 and 2003.

DESIGN

The study was a follow-up survey with a descriptive and comparative cross-sectional multicenter design.

SETTING

Questionnaires were mailed in January 2003 to all Danish ICUs providing mechanical ventilation (n=48).

PARTICIPANTS

One head physician at each ICU in Denmark. INTERVENTIONS, MEASUREMENTS, AND RESULTS: Thirty-nine questionnaires were returned, yielding a response rate of 81%, representing 82% of Danish ICU beds. The main findings were a significant increase in the use of sedation scoring systems and a significant reduction of sedation and analgesia in relation to various modalities of mechanical ventilation and disease groups. Other important findings were a significant reduction in the use of benzodiazepines and opioids and a significant increase in the use of propofol in relation to all ventilator modes. The administration routes of sedative agents remained unchanged.

CONCLUSIONS

Sedatives and analgesics are still widely used in Danish ICUs. The trend is toward lighter sedation along with a shift from benzodiazepines toward propofol and from morphine toward fentanyl given by continuous infusion. More attention needs to be directed toward sedation standards and scoring systems in order to reduce the risk associated with sedation in mechanically ventilated patients.

Impact of tracheotomy on sedative administration, sedation level, and comfort of mechanically ventilated intensive care unit patients*

OBJECTIVE

To assess the impact of tracheotomy on sedative administration, sedation level, and autonomy of mechanically-ventilated intensive care unit (ICU) patients.

DESIGN, SETTING, AND PATIENTS

In this observational study, the charts of all consecutive patients undergoing mechanical ventilation requiring tracheotomy over a 14-month period in our 18-bed tertiary care ICU were reviewed retrospectively. Patients' sedation levels (according to the Riker's 7-level sedation-agitation score) and intravenous (fentanyl and midazolam) and oral (clorazepate and haloperidol) sedative administration were measured daily during the 7 days before and after tracheotomy. We also recorded patients for whom chair positioning and oral alimentation became possible in the days following tracheotomy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Tracheotomy was performed on 72 (23.1%) of the 312 patients undergoing mechanical ventilation for > or = 48 hrs. After tracheotomy, median (25th, 75th percentiles) fentanyl and midazolam administration decreased from 866 (191, 1672) to 71 (3, 426) microg/(patient.day) and from 44 (16, 128) to 7 (1, 42) mg/(patient.day) (p < .001), respectively. Concomitant median time spent heavily sedated decreased from 7 (3, 17) to 1 (0, 6) hrs/day (p < .001), with no increase in agitation time. During the 7 days following tracheotomy, partial oral alimentation became possible for 35 patients (48.6%) and out-of-bed positioning became possible for 16 patients (22.2%).

CONCLUSION

On the basis of these observations, we conclude that tracheotomized mechanically ventilated ICU patients required less intravenous sedative administration, spent less time heavily sedated, and achieved more autonomy earlier.

Can electroencephalographic analysis be used to determine sedation levels in critically ill patients?

Prolonged use of sedative drugs frequently leads to oversedation of intensive care patients. Clinical assessment scales are not reliable in deeply sedated patients. Parameters obtained from spectral and bispectral analysis of electroencephalogram (EEG) records have been combined to create an index (BIS) to monitor anesthesia depth. The role of such parameters in monitoring the depth of the sedation in intensive care unit (ICU) patients has yet to be determined. We designed the present prospective study to redefine and calculate available spectral and bispectral parameters from raw EEG records and estimate their clinical relevance for the diagnosis of under- or oversedation levels in ICU patients. Forty adult patients receiving continuous midazolam and morphine sedation were included. We obtained 167 clinical evaluations of sedation level using Ramsay and COMFORT scales along with an EEG record of 300 s. Six spectral parameters-relative power of 4 frequency bands (beta, alpha, Theta, and delta), 95th percentile of the power spectrum (SEF95), and 50th percentile of the power spectrum (SEF50) and four bispectral parameters, real triple product, bispectrum (Bispectrum), bicoherence, and ratio 10-were calculated. The relevance of each of these parameters and combinations in predicting too light (Ramsay 1 and 2) or deep (Ramsay 5 and 6) sedation levels was assessed. These calculations were performed before and after exclusion of the agitated patients, whose COMFORT 4 score was above 2. The most relevant parameters for predicting levels of deep sedation (Ramsay 5 and 6) were ratio 10 (area under the curve = 0.763; 95% confidence interval, 0.679-0.833) and SEF95 (area under the curve = 0.687; 95% confidence interval, 0.597-0.767). The most relevant parameters for predicting light levels of sedation (Ramsay 1 and 2) were also ratio 10 (area under the curve = 0.829; 95% confidence interval, 0.695-0.917) and SEF95 (area under the curve = 0.798; 95% confidence interval, 0.650-0.898). There is a modest improvement in relevance of their linear combination in predicting sedation level. Results were similar after exclusion of agitated patients. We conclude that various calculated EEG descriptive parameters exhibited large interindividual variability. There was a strong correlation between EEG spectral and bispectral parameters. Bispectral analysis slightly improves the predictive power of simple spectral analysis in distinguishing too light or deep sedation levels in ICU patients.

IMPLICATIONS

Spectral edge frequency 95 and Ratio 10 are the most relevant electroencephalogram (EEG) indexes for monitoring the level of sedation in intensive care unit patients but calculated EEG values exhibited large interindividual variability. Bispectral analysis of EEG provides a slight improvement over simple spectral analysis.

Pharmacoeconomic Modeling of Lorazepam, Midazolam, and Propofol for Continuous Sedation in Critically Ill Patients

STUDY OBJECTIVE

To compare the expected costs of short-, intermediate-, and long-term sedation (< 24, 24-72, and > 72 hrs, respectively) with propofol, lorazepam, and midazolam in an intensive care unit.

METHODS

Decision-analysis models were constructed for each sedative and each duration by using institutional costs associated with drug administration and adverse events (including personnel time). Costs were expressed in 2002 U.S. dollars. Adverse events were agitation, hypertriglyceridemia and/or pancreatitis, hypotension, nutritional changes, ventilator-associated pneumonia, and prolonged awakening and/or extubation. MEDLINE and EMBASE databases were searched to obtain durations of sedation, the incidence of outcomes, and cost estimates of outcomes. The ability to maintain specific levels of sedation was assumed equivalent among the sedatives. Univariate sensitivity analyses were conducted to determine the cost-driving variables, and probabilistic sensitivity analyses were conducted by using second-order Monte Carlo simulations.

RESULTS

Weighted mean durations of sedation from 50 studies were 13.46 (short term), 45.27 (intermediate term), and 119.78 (long term) hours. Expected costs for sedation with lorazepam, midazolam, and propofol, respectively, were 497 dollars, 294 dollars, and 272 dollars short term; 932 dollars, 587 dollars, and 674 dollars intermediate term; and 1604 dollars, 1737 dollars, and 2033 dollars long term. Propofol was least costly in 86% of the short-term simulations, midazolam was least costly in 97.5% of the intermediate-term simulations, and lorazepam was least costly in 84% of the long-term simulations. The most important cost-driver for all sedatives was drug cost. Prolonged extubation after sedation was an important cost-driver for lorazepam and midazolam, especially as sedation was lengthened.

CONCLUSION

Propofol, midazolam, and lorazepam had the lowest expected costs for short-, intermediate-, and long-term sedation, respectively. Many factors aside from drug costs influenced the cost of sedation.

Propylene Glycol–Induced Lactic Acidosis in a Patient with Normal Renal Function: A Proposed Mechanism and Monitoring Recommendations

OBJECTIVE:

To report a case of severe propylene glycol–induced lactic acidosis not attributable to renal dysfunction that was secondary to administration of high-dose intravenous lorazepam.

CASE SUMMARY:

A 24-year-old female with community-acquired pneumonia presented with severe acute respiratory distress syndrome. To maintain adequate sedation and ventilation and reduce airway pressure, several relaxation strategies were used including high-dose intravenous lorazepam, fentanyl, and cisatracurium. After 18 days of high-dose continuous infusion of lorazepam (maximum dose 50 mg/h), the patient developed severe lactic acidosis secondary to propylene glycol toxicity, the main diluent of lorazepam. The acidosis temporarily resolved with bicarbonate administration and discontinuation of lorazepam. Her renal function remained stable for a time (serum creatinine 0.5 mg/dL, blood urea nitrogen 10 mg/dL, urine output 100–200 mL/h). However, after several more days, the patient's condition deteriorated, and she ultimately died.

DISCUSSION:

Previous cases of propylene glycol toxicity secondary to high-dose lorazepam infusion have occurred in patients with compromised renal function. Our patient's renal function remained stable throughout the hospital course, which caused us to look further for an explanation for the propylene glycol–induced lactic acidosis. Based on the Naranjo probability scale, propylene glycol was determined to be the probable cause of lactic acidosis. Since this case occurred, our intensive care unit has instituted recommendations for the prevention of lorazepam-associated propylene glycol toxicity.

CONCLUSIONS:

Our case highlights the development of propylene glycol–induced lactic acidosis secondary to high-dose lorazepam infusion not associated with renal dysfunction.

Propofol-Associated Hypertriglyceridemia and Pancreatitis in the Intensive Care Unit: An Analysis of Frequency and Risk Factors

STUDY OBJECTIVES

To characterize the frequency, severity, risk factors, and clinician response to propofol-associated hypertriglyceridemia and hypertriglyceridemia-associated pancreatitis.

DESIGN

Retrospective analysis.

SETTING

Medical and surgical intensive care units.

PATIENTS

One hundred fifty-nine adult intensive care patients administered propofol for 24 hours or longer and who had at least one serum triglyceride concentration.

MEASUREMENTS AND MAIN RESULTS

Patient records were reviewed to identify the frequency of hypertriglyceridemia (serum triglyceride concentration > or = 400 mg/dl) and pancreatitis (amylase concentration > or = 125 IU/L, lipase concentration > or = 60 IU/L, and abdominal computed tomography scan or clinical examination findings consistent with pancreatitis). Of the 159 patients, 29 (18%) developed hypertriglyceridemia; six (21%) of the 29 had a serum triglyceride concentration of 1000 mg/dl or greater. The median maximum serum triglyceride concentration was 696 mg/dl (range 403-1737 mg/dl). At the time when hypertriglyceridemia was detected, the median infusion rate of propofol was 50 microg/kg/minute (range 5-110 microg/kg/min). The median time from the start of propofol therapy to identification of hypertriglyceridemia was 54 hours (range 14-319 hrs). Propofol was discontinued within 24 hours of detecting the hypertriglyceridemia 84% of the time. Compared with those who did not develop hypertriglyceridemia, patients who developed hypertriglyceridemia were older, had a longer intensive care unit stay, and received propofol for a longer duration; they were also more likely to be admitted to the medical versus the surgical intensive care unit. Pancreatitis developed in three (10%) of the 29 patients with hypertriglyceridemia.

CONCLUSION

Hypertriglyceridemia and hypertriglyceridemia-associated pancreatitis are often seen in intensive care patients receiving propofol. Serum triglyceride concentrations should be routinely monitored in these patients. In addition, alternative sedation strategies should be considered when hypertriglyceridemia is detected.

Propylene Glycol Toxicity: A Severe Iatrogenic Illness in ICU Patients Receiving IV Benzodiazepines

STUDY OBJECTIVES

Benzodiazepines are commonly administered to medical ICU (MICU) patients. Propylene glycol (1,2-propanediol) is the solvent used to deliver lorazepam and diazepam IV. Although propylene glycol toxicity is increasingly recognized and reported, its incidence is unknown. Herein, we describe five MICU patients who acquired severe propylene glycol toxicity due to IV lorazepam or diazepam administration. Additionally, we evaluate the incidence of propylene glycol toxicity in MICU patients receiving IV lorazepam or diazepam.

DESIGN

Case series and prospective, observational study.

SETTING

Eighteen-bed MICU in a 550-bed urban academic hospital.

PATIENTS AND METHODS

MICU patients administered IV benzodiazepines during a 3-month period were enrolled. Patients were categorized according to the IV benzodiazepine that they received. Laboratory data and highlights of their clinical course were recorded daily. The incidence of propylene glycol toxicity was determined and the groups compared.

RESULTS

Forty-four patients were enrolled. Twenty-one patients received a benzodiazepine delivered in propylene glycol (lorazepam or diazepam), and 23 patients received a benzodiazepine delivered in an alternative solvent (midazolam). We found that four patients (19%) who received IV lorazepam or diazepam had metabolic evidence of propylene glycol toxicity. None of the patients had clinical deterioration. Neither metabolic abnormality nor clinical deterioration suggestive of propylene glycol toxicity were identified in subjects receiving IV midazolam.

CONCLUSION

Propylene glycol toxicity is a potentially life-threatening iatrogenic complication that is common and preventable. It should be considered whenever a patient has an unexplained anion gap, unexplained metabolic acidosis, hyperosmolality, and/or clinical deterioration. Close monitoring of all patients receiving IV lorazepam or diazepam for early evidence of propylene glycol toxicity is warranted.

The Effects of Liver and Renal Dysfunction on the Pharmacokinetics of Sedatives and Analgesics in the Critically Ill Patient

In critically ill patients, the duration of effect and dose-response relationship of sedative and analgesic drugs can be significantly affected by the presence of renal or hepatic dysfunction. Alterations in pharmacokinetics and pharmacodynamics vary according to the degree of organ impairment and presence of comorbid illnesses. This article reviews the principals that govern the absorption, distribution, metabolism, and elimination of sedatives and analgesics during renal and hepatic impairment. By anticipating changes in pharmacokinetics, and by routinely assessing the clinical response to therapy, unintended adverse consequences of sedative and analgesic drug therapy may be avoided.

Tolerance and Withdrawal Issues with Sedation

The stay in an ICU is a complex mixture of providing optimal care while keeping the patient safe. Means of reducing the anxiety associated with the ICU stay include frequent reorientation and maintenance of patient comfort with sedation supplemented by analgesia as needed. The most common agents used to provide sedation include benzodiazepines, propofol, and the newer dexmedetomidine. Others include barbiturate agents, neuroleptics, clonidine, etomidate, ketamine, and supplemental opioid analgesics for pain control. A common complication of sedation is tolerance, which can lead to withdrawal if the sedation is discontinued hastily. This article evaluates the occurrence of tolerance and withdrawal in the most commonly used sedatives in critically ill patients.

Toward Solving the Sedation-Assessment Conundrum: Bispectral Index Monitoring and Sedation Interruption

The sedation-assessment conundrum is defined by two diametrically opposed goals: to maintain an appropriate level of sedation, and to obtain a comprehensive neurologic examination that most accurately reflects the patient's neurologic status. A case presentation leads to a discussion of over-sedation and under-sedation issues that impact the care of critically ill patients. This information is useful in understanding the many methods of assessing sedation and interpreting individualized patient responses to sedation. The use of bi-spectral index monitoring and periods of sedation interruption are discussed within the context of addressing the sedation-assessment conundrum.

Best clinical practice with ziprasidone IM: update after 2 years of experience

Acute agitation is a common psychiatric emergency often treated with intramuscular (i.m.) medication when rapid control is necessary or the patient refuses to take an oral agent. Conventional i.m. antipsychotics are associated with side effects, particularly movement disorders, that may alarm patients and render them unreceptive to taking these medications again. Ziprasidone (Geodon) is the first second-generation, or atypical, antipsychotic to become available in an i.m. formulation. Ziprasidone IM was approved by the Food and Drug Administration in 2002 for the treatment of agitation in patients with schizophrenia. In October 2004, a roundtable panel of physicians with extensive experience in the management of acutely agitated patients met to review the first 2 years of experience with this agent. This monograph, a product of that meeting, discusses clinical experience to date with ziprasidone IM and offers recommendations on its use in various settings. In clinical trials, patients treated with ziprasidone IM demonstrated significant and rapid (within 15-30 minutes) reduction in agitation and improvement in psychotic symptoms, agitation, and hostility to an extent greater than or equal to that attained with haloperidol i.m. Tolerability of ziprasidone IM was superior to that of haloperidol IM, with a lower burden of movement disorders. Clinical trials have also shown that ziprasidone IM can be administered with benzodiazepines without adverse consequences. Transition from i.m. to oral ziprasidone has been well tolerated, with maintenance of symptom control. The most common adverse events associated with ziprasidone IM were insomnia, headache, and dizziness in fixed-dose trials and insomnia and hypertension in flexible-dose trials. No consistent pattern of escalating incidence of adverse events with escalating ziprasidone doses has been observed. Changes in QTc interval associated with ziprasidone at peak serum concentrations are modest and comparable to those seen with haloperidol IM. Results of randomized clinical trials of ziprasidone IM have been corroborated in studies in real-world treatment settings involving patients with extreme agitation or a recent history of alcohol or substance abuse. In these circumstances, clinically significant improvement was seen within 30 minutes of ziprasidone IM administration, without regard to the suspected underlying etiology of agitation. Agents with a good safety/tolerability profile, such as ziprasidone IM, may be more cost effective long term than older agents, due to reduced incidence of acute adverse effects (eg, acute dystonia) that often require extended periods of observation. Additional trials of ziprasidone IM in agitated patients in a variety of clinical setting are warranted to generate comparative risk/benefit data with conventional agents and other second-generation antipsychotics.

Daily interruption of continuous sedation

Sedatives administered by continuous intravenous infusion are an essential component of the care of patients requiring mechanical ventilation. Delayed awakening from sedation has been associated with prolonged stays in the hospital and the intensive care unit (ICU). Incorporation of a daily sedation interruption policy into a medical ICU guideline has significantly reduced ICU stay and days of mechanical ventilation, and has significantly increased the likelihood of planned extubation compared with no intervention. Furthermore, opioid administration and ICU complications were significantly reduced in patients receiving daily sedation interruption. Lack of long-term deleterious psychiatric effects, such as evidence of posttraumatic stress disorder or recall of events, has been documented with daily sedation interruption during the ICU stay. Resistance to the routine implementation of a daily sedation interruption policy arises from concerns about the need for greater resources and the risk of rebound agitation. The benefits have been documented only in a single center to date. However, the benefit: risk ratio is positive and warrants incorporation of daily sedation interruption into the routine care of patients who are critically ill and require mechanical ventilation.

Metabolic and endocrine effects of sedative agents

PURPOSE OF REVIEW

To bring to the attention of the clinician the metabolic effects of most common sedatives and analgesics used in critically ill patients.

RECENT FINDINGS

Most patients admitted to the intensive care unit require sedation and analgesia to reduce anxiety, agitation, and delirium and provide pain relief. Inappropriate sedation and analgesia techniques can cause harm to the already compromised patient if they do not take into account the metabolic effect they produce.

SUMMARY

Metabolically critical illness can be divided in two phases, and acute and a prolonged one. Whereas the acute or hypermetabolic phase is characterized by elevated circulating concentration of catabolic hormones and substrate utilization to provide energy to vital organs, the prolonged or catabolic phase of critical illness is marked by reduced endocrine stimulation and severe loss of body cell mass. The most common analgesic and sedative agents used in the intensive care unit, if used in small or moderate doses, do not interfere significantly with the metabolic milieu; however, prolonged infusions, and in high doses, without adequate monitoring of level of sedation and quality of analgesia, can precipitate morbid events. Further research is needed in the metabolic aspects of analgesia and sedation in the intensive care unit, particularly if a multimodal pharmacologic strategy is used whereby multiple interventions aim at minimizing the risk of overdosing and contributing to attenuation of the stress response associated with critical illness.