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

Quantifying agitation in sedated ICU patients using digital imaging

Agitation is a significant problem in the Intensive Care Unit (ICU), affecting 71% of sedated adult patients during 58% of ICU patient-days. Subjective scale based assessment-methods focused primarily on assessing excessive patient motion are currently used to assess the level of patient agitation, but are limited in their accuracy and resolution. This research quantifies this approach by developing an objective agitation measurement from patient motion that is sensed using digital video image processing. A fuzzy inference system (FIS) is developed to classify levels of motion that correlate with observed patient agitation, while accounting for motion due to medical staff working on the patient. Clinical tests for five ICU patients have been performed to verify the validity of this approach in comparison to agitation graded by nursing staff using the Riker Sedation-Agitation Scale (SAS). All trials were performed in the Christchurch Hospital Department of Intensive Care, with ethics approval from the Canterbury Ethics Committee. Results show good correlation with medical staff assessment with no false positive results during calm periods. Clinically, this initial agitation measurement method promises the ability to consistently and objectively quantify patient agitation to enable better management of sedation and agitation through optimised drug delivery leading to reduced length of stay and improved outcome.

Sleep during mechanical ventilation

PURPOSE OF REVIEW

This review addresses the growing interest in the study of sleep during critical illness.

RECENT FINDINGS

We know that sleep, in all of its measurable aspects, is severely deranged in critically ill patients during mechanical ventilation. There is growing evidence that mode of mechanical ventilation, medications, and acuity of illness may contribute to such sleep derangements and that conventional factors such as noise and health care delivery may be playing a much smaller role than previously thought. Alternatively, changes in sleep-wakefulness state can alter patient-ventilator interaction, which may in turn influence physicians' decision-making. Sleep organization may predict functional outcome in patients with head trauma. Additionally, there is evidence that poor sleep is an important factor influencing long-term quality of life in survivors of critical illness.

SUMMARY

A more complete understanding of the etiopathogenesis of sleep derangements during mechanical ventilation may identify new interventions to help improve sleep, and possibly favorably influence short-term and long-term outcomes.

Sedation Assessment in Critically Ill Adults: 2001–2004 Update

OBJECTIVE

To review recently published literature on the validity and reliability of sedation assessment tools in critically ill adults and evaluate the potential advantages and disadvantages of each.

DATA SOURCES

A computerized search of MEDLINE and PubMed (2001–May 2004) was conducted.

STUDY SELECTION AND DATA EXTRACTION

Sedation assessment tools used in adult intensive care units (ICUs) were identified.

DATA SYNTHESIS

Six subjective and 3 objective assessment tools were identified. Four subjective assessment tools have reliability and 4 have validity data published that were not previously available. There are reliability data to further support the use of the previously published Motor Activity Assessment Scale. Additional reliability data exist for the Ramsay Scale and Glasgow Coma Scale. Conflicting evidence is available with the use of the Bispectral Index monitor in the ICU. Recently, the Patient State Index and Auditory Evoked Potentials were introduced for objective monitoring in critically ill patients.

CONCLUSIONS

Increasing data on sedation assessment were published over the last few years, probably in response to supporting evidence that goal-driven sedation therapy improves patient outcomes. Reliability and/or validity testing exists for many of these scales. Several useful tools are available to guide sedation therapy in critically ill patients.

Sedation, analgesia, and neuromuscular blockade in sepsis: An evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for sedation, analgesia, and neuromuscular blockade in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSION

There is no preferred sedative or analgesic agent for use in the critically ill septic patient during mechanical ventilation. Protocols should be utilized for administration of sedation with predefined sedation scale targets. Either intermittent bolus sedation or continuous infusion sedation to predetermined end points with daily interruption/lightening of continuous infusion sedation with awakening and re-titration, if necessary, are recommended. Neuromuscular blockade should be avoided if possible and, if used continuously, requires twitch monitoring.

Sedation assessment: easier said than done!

Sedation assessment commonly is performed in critically ill patients to evaluate their need for, and response to, sedation therapy. Although many sedation assessment scales have been published, few have been tested properly to assure their appropriateness for use in critically ill patients. This article highlights the published sedation assessment scales that have the strongest scientific basis, identifies limitations of the current scales, and suggests characteristics for future sedation assessment scales that would overcome many of the current problems.

Clinical management of cardiogenic shock associated with prolonged propofol infusion

This case report details the development of cardiogenic shock after craniotomy in a patient sedated with a propofol infusion. The patient survived with the assistance of extracorporeal membrane oxygenation. A literature review summarizes the syndrome of cardiogenic shock associated with prolonged propofol infusion. This is the first report of survival in this syndrome resuiting from mechanical circulatory support.

Palliative care in the intensive care unit: barriers, advances, and unmet needs

The concept that critical illness and terminal illness are necessarily distinct entities has given way to the understanding that they often exist on the same spectrum. Consequently, there is growing consensus that palliative treatment must coexist with attempts at restorative treatment in the intensive care unit (ICU). Palliative care in the ICU has evolved from a relatively one-dimensional construct of terminal sedation in dying patients to a multidisciplinary field addressing symptom control, physician-patient-family communication,spiritual needs, and the needs of health care providers. As ongoing research efforts yield new insights, our ability to practice evidence-based palliative care in the ICU will grow, and new avenues for improvement will become evident.

Relationship of continuous infusion lorazepam to serum propylene glycol concentration in critically ill adults*

OBJECTIVES

The primary objective was to evaluate the relationship between high-dose lorazepam and serum propylene glycol concentrations. Secondary objectives were a) to document the occurrence of propylene glycol accumulation associated with continuous high-dose lorazepam infusion; b) to assess the relationship between lorazepam dose, serum propylene glycol concentrations, and propylene glycol accumulation; and c) to assess the relationship between the osmol gap and serum propylene glycol concentrations.

DESIGN

Prospective, observational study.

SETTING

Tertiary care, medical intensive care unit.

PATIENTS

Nine critically ill adults receiving high-dose lorazepam (> or =10 mg/hr) infusion.

INTERVENTIONS

Cumulative lorazepam dose (mg/kg) and the rate of infusion (mg.kg(-1).hr(-1)) were monitored from initiation of lorazepam infusion until 24 hrs after discontinuation of the high-dose lorazepam infusion. Serum osmolarity was collected at 48 hrs into the high-dose lorazepam infusion and daily thereafter. Serum propylene glycol concentrations were drawn at 48 hrs into the high-dose lorazepam infusion, and the presence of propylene glycol accumulation, as evidenced by a high anion gap (> or =15 mmol/L) metabolic acidosis with elevated osmol gap (> or =10 mOsm/L), was assessed at that time.

MEASUREMENTS AND MAIN RESULTS

The mean cumulative high-dose lorazepam received and mean high-dose lorazepam infusion rate were 8.1 mg/kg (range, 5.1-11.7) and 0.16 mg.kg(-1).hr (-1)(range, 0.11-0.22), respectively. A significant correlation between high-dose lorazepam infusion rate and serum propylene glycol concentrations was observed (r =.557, p =.021). Osmol gap was the strongest predictor of serum propylene glycol concentrations (r =.804, p =.001). Propylene glycol accumulation was observed in six of nine patients at 48 hrs. No significant correlation between duration of lorazepam infusion and serum propylene glycol concentrations was observed (p =.637).

CONCLUSION

Propylene glycol accumulation, as reflected by a hyperosmolar anion gap metabolic acidosis, was observed in critically ill adults receiving continuous high-dose lorazepam infusion for > or =48 hrs. Study findings suggest that in critically ill adults with normal renal function, serum propylene glycol concentrations may be predicted by the high-dose lorazepam infusion rate and osmol gap.

Quantifying agitation in sedated ICU patients using heart rate and blood pressure

Agitation is a significant problem in the intensive care unit (ICU), affecting 71% of sedated adult patients during 58% of ICU patient-days (Fraser and Riker 2001 NY Health-Syst. Pharm. 20 17-24). Subjective scale-based assessment methods are currently used to assess the level of patient agitation, but are limited in their accuracy and resolution. This research develops an objective agitation measurement method using heart rate variability (HRV), systolic blood pressure (BP) and blood pressure variability (BPV) data, processed by wavelet transforms and autoregressive signal processing. A fuzzy inference system (FIS) is developed to classify changes in these signals that correlate with observed patient agitation, and combine them into a final agitation level. Proof of concept clinical trials on 13 normal subjects and 5 ICU patients has been performed to verify the validity of this approach in comparison with agitation graded by nursing staff using the Riker sedation-agitation scale (SAS). Results show good correlation with medical staff assessment with no false positive results during calm periods. Clinically, this initial agitation measurement method promises the ability to consistently and objectively quantify patient agitation to enable better management of sedation and agitation through optimized drug delivery leading to reduced length of stay.

Pain management in the intensive care unit

Pain management is an essential component of quality care delivery for the critically ill patient. Because outcomes are difficult to predict in the intensive care unit (ICU), high-quality pain management and palliative therapy should be a goal for every patient. For those patients actively dying, palliation may be among the main benefits offered by the health care team. Appropriate palliation of pain begins with the use of effective strategies for recognizing, evaluating,and monitoring pain. Skill in pain management requires knowledge of both pharmacologic and nonpharmacologic therapies. This article focuses on expertise in the use of opiates to facilitate confident and appropriate pain therapy. To optimize palliative therapy, symptoms are best addressed by interdisciplinary care teams guided by models that acknowledge a continuum of curative therapies and palliative care.

Delirium and sedation

Critically ill patients nearing the end of life frequently present with needs for aggressive sedation and analgesia. Optimizing patient comfort while permitting effective communication are challenging goals in this patient population. This article discusses delirium and sedation as it applies to dying patients, and provides recommendations for effective management strategies to optimize the experience of such patients at the end of life.

Abdominal muscle action during expiration can impair pressure controlled ventilation

Pressure controlled ventilation, and pressure support for spontaneous breathing are often used in intensive care because coordination of the ventilator with patient efforts can improve comfort and possibly reduce sedation. However we report a series of 10 patients whose efforts did not synchronise with pressure controlled ventilation. This was incorrectly diagnosed as inadequate sedation, and treated with increased sedation or muscle paralysis. Better recognition of this condition showed that slow respiratory rates and increased abdominal muscle action during expiration can affect pressure-controlled ventilation and pressure assisted breathing. If the condition is not recognised, treatment for poor synchronisation may delay weaning or be inappropriate.

Comparing Dexmedetomidine Prescribing Patterns and Safety in the Naturalistic Setting Versus Published Data

BACKGROUND:

In clinical practice, new drugs may be used differently than the product labeling recommends. Furthermore, it often takes several years of use before adverse drug reactions (ADRs) are reported.

OBJECTIVE:

To compare prescribing patterns and safety of the newly released drug dexmedetomidine as observed in clinical practice with published data on the drug.

METHODS:

Information from a convenience sample of adults receiving dexmedetomidine as part of routine patient care at 10 institutions was retrospectively collected from June 27, 2001, to May 31, 2002. Investigators reviewed medical records daily and entered dosing information, patient demographics, and predefined categories of ADR severity and probability anonymously via the Internet on a secure server.

RESULTS:

Only 33% of the total sample (n = 136) of patients received a loading infusion of dexmedetomidine; however, maintenance dosing was usually within product labeling guidelines. Of note, 27.2% of patients received dexmedetomidine above the maximum dose and 33.8% received the drug beyond 24 hours. Some patients (15.4%) were never mechanically ventilated, while 59.5% received dexmedetomidine following extubation for an average of 11.3 hours. ADRs were reported in 30% of patients: 20% of the reactions required treatment or increased length of stay. Hypotension was the most common ADR, occurring in 22.7% of patients. Bradycardia was reported in 4.4% of patients. The rate and type of ADRs were similar in patients receiving dexmedetomidine >24 hours compared with the total population.

CONCLUSIONS:

Dexmedetomidine is prescribed within product labeling guidelines except for low use of a loading dose, some patients received the drug at doses above the maximum, and others received it for longer than 24 hours. Since ADR rates are similar to those of other published reports, dexmedetomidine maintained its expected safety profile in our patients.

Management of sedation in mechanically ventilated patients

PURPOSE OF REVIEW

There are many new and exciting studies in the sedation literature. Recent studies of new scoring systems to monitor sedation, new medications, and new insights into post-intensive care unit (ICU) sequelae have brought about interesting ideas for achieving an adequate level of sedation of our patients while minimizing complications.

RECENT FINDINGS

The recent literature focuses on monitoring the level of a patient's sedation with new bedside clinical scoring systems and new technology. Outcomes studies have highlighted problems with both inadequate sedation and excessive sedation in regard to patients' post-ICU psychological health. More insight into drug withdrawal and addiction as complications of ICU care were examined. A new medication for sedation in the ICU has been approved for use, but its role is not yet defined.

SUMMARY

Many patients in the ICU receive mechanical ventilation and will require sedative medications. A frequently overlooked cause of agitation in the ventilated patient is pain, and assessing the adequacy of analgesia is an important part of the continuous assessment of a patient. The goal of sedation is to provide relief while minimizing the development of drug dependency and oversedation. Careful monitoring with bedside scoring systems, the appropriate use of medications, and a strategy of daily interruption can lead to diminished time on the ventilator and in the ICU.

A content analysis of forms, guidelines, and other materials documenting end-of-life care in intensive care units

OBJECTIVE

The purpose of this study was to determine the extent to which data entry forms, guidelines, and other materials used for documentation in intensive care units (ICUs) attend to 6 key end-of-life care (EOLC) domains: 1) patient and family-centered decision making, 2) communication, 3) continuity of care, 4) emotional and practical support, 5) symptom management and comfort care, and 6) spiritual support. A second purpose was to determine how these materials might be modified to include more EOLC content and used to trigger clinical behaviors that might improve the quality of EOLC.

PARTICIPANTS

Fifteen adult ICUs-8 medical, 2 surgical, and 4 mixed ICUs from the United States, and 1 mixed ICU in Canada, all affiliated with the Critical Care End-of-Life Peer Workgroup

METHODS

Physician-nurse teams in each ICU received detailed checklists to facilitate and standardize collection of requested documentation materials. Content analysis was performed on the collected documents, aimed at characterizing the types of materials in use and the extent to which EOLC content was incorporated.

MEASUREMENTS AND MAIN RESULTS

The domain of symptom management and comfort care was integrated most consistently on forms and other materials across the 15 ICUs, particularly pain assessment and management. The 5 other EOLC domains of patient and family centered decision-making, communication, emotional and practical support, continuity of care, and spiritual support were not well-represented on documentation. None of the 15 ICUs supplied a comprehensive EOLC policy or EOLC critical pathway that outlined an overall, interdisciplinary, sequenced approach for the care of dying patients and their families. Nursing materials included more cues for attending to EOLC domains and were more consistently preprinted and computerized than materials used by physicians. Computerized forms concerning EOLC were uncommon. Across the 15 ICUs, there were opportunities to make EOLC- related materials more capable of triggering and documenting specific EOLC clinical behaviors.

CONCLUSIONS

Inclusion of EOLC items on ICU formatted data entry forms and other materials capable of triggering and documenting clinician behaviors is limited, particularly for physicians. Standardized scales, protocols, and guidelines exist for many of the EOLC domains and should be evaluated for possible use in ICUs. Whether such materials can improve EOLC has yet to be determined.

Sleep disruption in critically ill patients--pharmacological considerations

Sleep disturbances are common in critically ill patients and contribute to morbidity. Environmental factors, patient care activities and acute illness are all potential causes of disrupted sleep. Additionally, it is important to consider drug therapy as a contributing factor to this adverse experience, which patients perceive as particularly stressful. Sedative and analgesic combinations used to facilitate mechanical ventilation are among the most sleep disruptive drugs. Cardiovascular, gastric protection, anti-asthma, anti-infective, antidepressant and anticonvulsant drugs have also been reported to cause a variety of sleep disorders. Withdrawal reactions to prescribed and occasionally recreational drugs should also be considered as possible triggers for sleep disruption. Tricyclic antidepressants and benzodiazepines are commonly prescribed in the treatment of sleep disorders, but have problems with decreasing slow wave and rapid eye movement sleep phases. Newer non-benzodiazepine hypnotics offer little practical advantage. Melatonin and atypical antipsychotics require further investigation before their routine use can be recommended.

Consciousness monitoring in ventilated patients: bispectral EEG monitors arousal not delirium

OBJECTIVE

Bispectral index (BIS) is being evaluated as a monitor of consciousness, yet it is unclear what components of consciousness (i.e., arousal vs. content of consciousness) the BIS measures. This study compared BIS levels to well-validated clinical measures of arousal and the presence or absence of delirium.

DESIGN

A prospective, blinded, observational cohort study.

PATIENTS

124 mechanically ventilated, adult, medical ICU patients.

MEASUREMENTS AND RESULTS

Using BIS 3.4 and BIS-XP 4.0 algorithms, BIS values were calculated immediately prior to clinical assessments. The clinical assessments included the Richmond Agitation-Sedation Scale (RASS) and presence or absence of delirium using the Confusion Assessment Method for the ICU. A total of 484 assessments were collected among 124 patients. BIS-XP values demonstrated greater correlation with RASS than BIS 3.4 ( R(2)=0.36 vs. 0.20), although considerable overlap of BIS-XP scores remained across RASS levels. Median BIS-XP values for delirious and nondelirious observations were 74 and 96, respectively, while BIS 3.4 values were 91 and 96, respectively. However, neither BIS 3.4 nor BIS-XP were significantly associated with delirium after controlling for RASS value.

CONCLUSIONS

In comparison with clinical measures of arousal in mechanically ventilated patients, BIS-XP algorithm demonstrated stronger correlation with RASS levels than did BIS 3.4, yet marked overlap across different levels of arousal persist using both algorithms. After controlling for level of arousal, neither BIS-XP nor BIS 3.4 algorithms distinguished between the presence and absence of delirium.

Comparative tolerability of sedative agents in head-injured adults

Sedative agents are widely used in the management of patients with head injury. These drugs can facilitate assisted ventilation and may provide useful reductions in cerebral oxygen demand. However, they may compromise cerebral oxygen delivery via their cardiovascular effects. In addition, individual sedative agents have specific and sometimes serious adverse effects. This review focuses on the different classes of sedative agents used in head injury, with a discussion of their role in the context of clinical pathophysiology. While there is no sedative that has all the desirable characteristics for an agent in this clinical setting, careful titration of dose, combination of agents, and a clear understanding of the pathophysiology and pharmacology of these agents will allow safe sedative administration in head injury.

Torsade de pointes associated with the administration of intravenous haloperidol:a review of the literature and practical guidelines for use

Haloperidol is the most commonly used medication for the treatment of delirium and psychosis in the critically ill patient. Whilst generally considered to be safe, haloperidol has been associated with a number of important cardiovascular side effects. The major toxicities include hypotension, cardiac arrhythmias and prolongation of the corrected QT (QTc) interval. In particular, torsade de pointes, a polymorphic ventricular tachyarrhythmia, has been associated with both intravenous and oral haloperidol administration. The management of torsade de pointes consists of discontinuation of the possible offending agent(s), correction of electrolyte abnormalities, administration of magnesium sulfate and, if necessary, overdrive pacing. Although clinicians should be aware of this potentially lethal complication of intravenous haloperidol therapy, it should not deter clinicians from using intravenous haloperidol to treat acute agitation in the critically ill patient with a normal QTc.

Pharmacology and pharmacokinetics of sedatives and analgesics

The agents used for sedation and analgesia during endoscopy have complex pharmacokinetic and pharmacodynamic properties. Knowledge of these characteristics is necessary for determining the proper agent and dose for specific patient needs. Short-acting agents, such as fentanyl, midazolam, and propofol, provide rapid sedation with a short duration of action that allows patients to return to normal functioning rapidly. When designing a dosing regimen with these agents, age and organ (liver, kidney) function of patients and concomitant medications that may interfere with metabolic and elimination pathways must be considered.

Costs associated with delirium in mechanically ventilated patients*

OBJECTIVE

To determine the costs associated with delirium in mechanically ventilated medical intensive care unit patients.

DESIGN

Prospective cohort study.

SETTING

A tertiary care academic hospital.

PATIENTS

Patients were 275 consecutive mechanically ventilated medical intensive care unit patients.

INTERVENTIONS

We prospectively examined patients for delirium using the Confusion Assessment Method for the Intensive Care Unit.

MEASUREMENTS AND MAIN RESULTS

Delirium was categorized as "ever vs. never" and by a cumulative delirium severity index. Costs were determined from individual ledger-level patient charges using cost-center-specific cost-to-charge ratios and were reported in year 2001 U.S. dollars. Fifty-one of 275 patients (18.5%) had persistent coma and died in the hospital and were excluded from further analysis. Of the remaining 224 patients, delirium developed in 183 (81.7%) and lasted a median of 2.1 (interquartile range, 1-3) days. Baseline demographics were similar between those with and without delirium. Intensive care unit costs (median, interquartile range) were significantly higher for those with at least one episode of delirium ($22,346, $15,083-$35,521) vs. those with no delirium ($13,332, $8,837-$21,471, p <.001). Total hospital costs were also higher in those who developed delirium ($41,836, $22,782-$68,134 vs. $27,106, $13,875-$37,419, p =.002). Higher severity and duration of delirium were associated with incrementally greater costs (all p <.001). After adjustment for age, comorbidity, severity of illness, degree of organ dysfunction, nosocomial infection, hospital mortality, and other potential confounders, delirium was associated with 39% higher intensive care unit (95% confidence interval, 12-72%) and 31% higher hospital (95% confidence interval, 1-70%) costs.

CONCLUSIONS

Delirium is a common clinical event in mechanically ventilated medical intensive care unit patients and is associated with significantly higher intensive care unit and hospital costs. Future efforts to prevent or treat intensive care unit delirium have the potential to improve patient outcomes and reduce costs of care.

Transdermal buprenorphine

Buprenorphine is a low molecular weight, lipophilic, opioid analgesic. Recently, a transdermal matrix patch formulation of buprenorphine has become available in three dosage strengths designed to release buprenorphine at 35, 52.5 and 70 micro g/h over a 72-hour period. At least satisfactory analgesia with minimal requirement for rescue medication (</=0.2 mg/day sublingual buprenorphine) was achieved by 34-50% of patients with chronic pain treated with transdermal buprenorphine 35, 52.5 or 70 micro g/h and 31% of placebo recipients, in one double-blind, placebo-controlled, randomised trial. In one trial involving patients unsuccessfully treated with weak opioids or morphine, 36.6% and 47.5% of buprenorphine 35 micro g/h and 52.5 micro g/h recipients, respectively, experienced at least satisfactory analgesia and received </=0.2 mg/day of sublingual buprenorphine compared with 16.2% of placebo recipients (both p </= 0.032). The requirement for rescue medication was reduced from baseline in >50% of patients treated with transdermal buprenorphine, in two trials. Furthermore, despite the availability of rescue medication to all patients, those receiving transdermal buprenorphine tended to experience greater pain relief, reduced pain intensity and longer pain-free sleep. Transdermal buprenorphine was generally well tolerated. Systemic adverse events were typical of opioid treatment or were attributable to the underlying disease.

Ketamine suppresses endotoxin-induced NF-kappaB activation and cytokines production in the intestine

BACKGROUND

Ketamine has been advocated for anesthesia in endotoxemic and other severely ill patients because it is a cardiovascular stimulant. However, ketamine also suppresses serum levels of endotoxin-induced tumor necrosis factor-alpha, and reduces mortality in mice in endotoxin shock. Our study was designed to investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and nuclear factor kappa B (NF-kappaB) activation in vivo.

METHODS

Adult male Wistar rats were randomly divided into six groups: saline controls; rats challenged with endotoxin (5 mg kg(-1)) and treated with saline; challenged with endotoxin (5 mg kg(-1)) and treated with ketamine (0.5 mg kg(-1)); challenged with endotoxin (5 mg kg(-1)) and treated with ketamine (5 mg kg(-1)); challenged with endotoxin (5 mg kg(-1)) and treated with ketamine (50 mg kg(-1)); and saline injected and treated with ketamine (50 mg kg(-1)). TNF-alpha, IL-6 and NF-kappaB were investigated in the tissues of the intestine (jejunum) after 1, 4 and 6 h.

RESULTS

Endotoxin caused transient production of TNF-alpha and IL-6 and activation of NF-kappaB in the intestine at peak times of 1, 4 and 1 h, respectively. Ketamine 0.5 mg kg(-1) suppressed endotoxin-induced TNF-alpha elevation and inhibited NF-kappaB activation in the intestine; a dose of 5 mg kg(-1) was required to inhibit IL-6.

CONCLUSION

Ketamine suppresses the production of proinflammatory cytokines such as TNF-alpha and IL-6 in the intestine, possibly via inhibition of NF-kappaB.

Assessment of Anxiety in Intensive Care Patients By Using the Faces Anxiety Scale

• Background Anxiety is difficult to detect in patients receiving mechanical ventilation because clinical signs are confounded and patients often cannot respond to validated anxiety measures. Most patients can respond to the single-item Faces Anxiety Scale.

• Objectives To assess the validity of the Faces Anxiety Scale, the frequency and severity of state anxiety, and correlates of anxiety in intensive care patients.

• Methods A research assistant made a single clinical judgment of anxiety in the range of 1 to 10 on the basis of patients’ nonverbal responses (ie, nods) to 9 questions about mood and their physical and behavioral signs. Patients then responded to the Faces Anxiety Scale. Demographic, clinical, and pharmacological data were obtained from the patients’ charts.

• Results Mean age of the 106 patients was 61 years; 62% were men. Admission diagnoses were cardiovascular in 26% of patients, respiratory in 26%, trauma in 18%, neurological in 12%, gastrointestinal in 12%, and other in 6%. At the time of anxiety assessment, 89% were receiving mechanical ventilation. The correlation between patients’ self-reports of anxiety on the Anxiety Faces Scale and the research assistant’s assessments was 0.64 (P &lt; .001). Some anxiety was reported by 85% of patients (mean level 2.9; SD 1.2). Anxiety levels were lower in patients who had recently received sedatives or opioids but were not related to heart rate or blood pressure.

• Conclusions The Faces Anxiety Scale is a valid means of measuring anxiety in intensive care patients. Anxiety is common in these patients and is often moderate to severe.

Severe agitation among ventilated medical intensive care unit patients: frequency, characteristics and outcomes

OBJECTIVE

To determine the frequency, characteristics and outcomes of severe agitation among ventilated medical intensive care unit (MICU) patients.

DESIGN

Prospective cohort study.

SETTING

Eighteen-bed MICU in 964-bed tertiary care center.

PATIENTS

All ventilated patients, aged 18 years or older and admitted for more than 24 h between January 1, 2001 and May 8, 2001.

INTERVENTIONS

None.

MEASUREMENTS

Data were collected daily by concurrent chart abstractions. Variables included sociodemographic, clinical, laboratory, pharmacologic and non-pharmacologic interventions, ventilator settings and adverse events. Severe agitation, the main outcome variable, was defined as two or more Motor Activity Assessment Scale (MAAS) scores above 4 in a 24-h period and sedative and/or narcotic doses above the established sedation and analgesia protocol or a combination of two or more sedatives.

RESULTS

Twenty-three (16.1%) of 143 enrolled patients exhibited severe agitation. Agitated patients were younger (hazard ratio [HR] 1.32), more likely to be admitted from an outside hospital ICU (HR 2.48), had lower pH (HR 1.55) and PaO(2)/FIO(2) less than 200 mmHg (HR 2.59). Agitated patients had longer MICU stays (median 12 versus 5 days, p<0.0001) and more ventilator days (median 14 versus 6, p<0.0001). Agitated patients were more likely to self-extubate (26% versus 6%, p=0.002). Benzodiazepines, narcotics and neuromuscular blocking agents were administered more frequently and at higher doses, but haloperidol was not.

CONCLUSION

Severe agitation occurs commonly in critically ill patients and is associated with adverse events including longer ICU stays, duration of mechanical ventilation and self-extubation.

Management of respiratory failure in status asthmaticus

Status asthmaticus is a life-threatening episode of asthma that is refractory to usual therapy. Recent studies report an increase in the severity and mortality associated with asthma. In the airways, inflammatory cell infiltration and activation and cytokine generation produce airway injury and edema, bronchoconstriction and mucus plugging. The key pathophysiological consequence of severe airflow obstruction is dynamic hyperinflation. The resulting hypoxemia, tachypnea together with increased metabolic demands on the muscles of respiration may lead to respiratory muscle failure. The management of status asthmaticus involves intensive pharmacological therapy particularly with beta-adrenoceptor agonists (beta-agonists) and corticosteroids. Albuterol (salbutamol) is the most commonly used beta2-selective inhaled bronchodilator in the US. Epinephrine (adrenaline) or terbutaline, administered subcutaneously, have not been shown to provide greater bronchodilatation compared with inhaled beta-agonists. Corticosteroids such as methylprednisolone should be administered early. Aerosolized corticosteroids are not recommended for patients with status asthmaticus. Inhaled anticholinergic agents may be useful in patients refractory to inhaled beta-agonists and corticosteroids. In patients requiring mechanical ventilation, the strategy aims to avoid dynamic hyperinflation by enhancing expiratory time to allow complete exhalation. Complications of dynamic inflation are hypotension and barotrauma. Sedation with opioids, benzodiazepines or propofol is required to facilitate ventilator synchrony but neuromuscular blockade should be avoided as myopathy has been a reported complication. Overall, in the management of patients with status asthmaticus, the challenge to the pulmonary/critical care clinician is to provide optimal pharmacological and ventilatory support and avoid the adverse consequences of dynamic hyperinflation.

Intensive care sedation of mechanically ventilated patients: a national Swedish survey

Sedation in critically ill patients is a complex issue and at the same time an important concept for ensuring patient comfort. The aim of this study was to review the current practice of sedation for patients on mechanical ventilation in Swedish intensive care units (ICUs). Questionnaires were sent by post to head nurses in 89 ICUs with mechanically ventilated patients. By August 2000, 87 (98%) questionnaires had been returned. The results show that mechanically ventilated patients were routinely sedated in 91% of ICUs. Midazolam or propofol in combination with an opioid were the drugs preferred by 76%. Heavy sedation was most usual in 63% of ICUs but, when asked about the sedation level preferred by nurses, 78% chose light sedation (P=0.001). Only 16% used sedation scales. This study indicates that local habits and personal attitudes seem to have a great impact on sedation routines. It therefore appears worthwhile for ICUs to review their practice and, if necessary, to consider implementing sedation scales and sedation guidelines. Research pertaining to potential complications and patient comfort in relation to different sedation levels as well as further validation of the efficacy of sedation scales is needed.

Improving care for patients dying in the intensive care unit

It is impossible for ICU clinicians to avoid caring for dying patients and their families. For many, this is an extremely rewarding aspect of their clinical practice. There is ample evidence that there is room to improve the care of patients who are near death in the ICU. Despite the considerable holes in our knowledge about optimal care of dying critically ill patients, there is considerable agreement on the general principles of caring for these patients and about how to measure the outcomes of palliative care in the ICU. Practical approaches to improving the quality of end-of-life care exist and should be implemented.

Sleep in the intensive care unit

Abnormalities of sleep are extremely common in critically ill patients, but the mechanisms are poorly understood. About half of total sleep time occurs during the daytime, and circadian rhythm is markedly diminished or lost. Judgments based on inspection consistently overestimate sleep time and do not detect sleep disruption. Accordingly, reliable polygraphic recordings are needed to measure sleep quantity and quality in critically ill patients. Critically ill patients exhibit more frequent arousals and awakenings than is normal, and decreases in rapid eye movement and slow wave sleep. The degree of sleep fragmentation is at least equivalent to that seen in patients with obstructive sleep apnea. About 20% of arousals and awakenings are related to noise, 10% are related to patient care activities, and the cause for the remainder is not known; severity of underlying disease is likely an important factor. Mechanical ventilation can cause sleep disruption, but the precise mechanism has not been defined. Sleep disruption can induce sympathetic activation and elevation of blood pressure, which may contribute to patient morbidity. In healthy subjects, sleep deprivation can decrease immune function and promote negative nitrogen balance. Measures to improve the quantity and quality of sleep in critically ill patients include careful attention to mode of mechanical ventilation, decreasing noise, and sedative agents (although the latter are double-edged swords).

The Impact of Bispectral Index Monitoring on Rates of Propofol Administration

The purpose of this article is to examine the efficacy of Bispectral Index (BIS) monitoring as a tool for adjusting the amount of propofol patients receive to maintain a safe and adequate level of sedation in a neurocritical care setting. The BIS monitor is utilized as an adjunct for anesthesia monitoring in the operating room setting and is currently being investigated as a tool for objective sedation monitoring in the critical care setting. 1-6 Sedation is discussed in terms of patient safety and comfort. A secondary data analysis was used to test the hypothesis that BIS monitoring provides a more objective form of sedation assessment that will lead to a decrease in overall rates of propofol administration and fewer incidences of oversedation. Data were abstracted from a quality improvement study of propofol use adjusted to BIS values in patients whose sedation levels were previously adjusted to a goal Ramsay score. The results suggest that there are potential benefits to incorporating BIS into routine sedation assessment in the neurocritical care setting.

Current opinions regarding the importance, diagnosis, and management of delirium in the intensive care unit: A survey of 912 healthcare professionals*

OBJECTIVE

Recently published clinical practice guidelines of the Society of Critical Care Medicine recommend monitoring for the presence of delirium in all mechanically ventilated patients because of the potential for adverse outcomes associated with this comorbidity, yet little is known about healthcare professionals' opinions regarding intensive care unit delirium or how they manage this organ dysfunction. The aim of this survey was to assess the medical community's beliefs and practices regarding delirium in the intensive care unit.

DESIGN

Survey administration was conducted both without a delirium definition (phase 1) and then with a definition of delirium (phase 2).

SETTING

Critical care meetings and continuing medical education/board review courses from October 2001 to July 2002.

PARTICIPANTS

A convenience sample of physicians (n = 753), nurses (n = 113), pharmacists (n = 13), physician assistants (n = 12), respiratory care practitioners (n = 8), and others (n = 13).

INTERVENTIONS

Survey.

MEASUREMENTS AND MAIN RESULTS

Participants completed 912 of the surveys. The majority (68%) of respondents thought that >25% of adult mechanically ventilated patients experience delirium. Delirium was considered a significant or very serious problem in the intensive care unit by 92% of healthcare professionals, yet underdiagnosis was acknowledged by 78%. Only 40% reported routinely screening for delirium, and only 16% indicated using a specific tool for delirium assessment. Delirium was considered important in the outcome of elderly and young patients by 89% and 60% of the respondents, respectively (p <.0001). The most serious complications these professionals associated with delirium were prolonged mechanical ventilation, self-injury, and respiratory difficulties. Delirium was treated with haloperidol by 66% of the respondents, with lorazepam by 12%, and with atypical antipsychotics by <5%. More than 55% administered haloperidol and lorazepam at daily doses of < or =10 mg, but some used >50 mg/day of either medication.

CONCLUSIONS

Most healthcare professionals consider delirium in the intensive care unit a common and serious problem, although few actually monitor for this condition and most admit that it is underdiagnosed. Data from this survey point to a disconnect between the perceived significance of delirium in the intensive care unit and current practices of monitoring and treatment.

Olanzapine vs haloperidol: treating delirium in a critical care setting

OBJECTIVE

To compare the safety and estimate the response profile of olanzapine, a second-generation antipsychotic, to haloperidol in the treatment of delirium in the critical care setting.

DESIGN

Prospective randomized trial.

SETTING

Tertiary care university affiliated critical care unit.

PATIENTS

All admissions to a medical and surgical intensive care unit with a diagnosis of delirium.

INTERVENTIONS

Patients were randomized to receive either enteral olanzapine or haloperidol.

MEASUREMENTS

Patient's delirium severity and benzodiazepine use were monitored over 5 days after the diagnosis of delirium.

MAIN RESULTS

Delirium Index decreased over time in both groups, as did the administered dose of benzodiazepines. Clinical improvement was similar in both treatment arms. No side effects were noted in the olanzapine group, whereas the use of haloperidol was associated with extrapyramidal side effects.

CONCLUSIONS

Olanzapine is a safe alternative to haloperidol in delirious critical care patients, and may be of particular interest in patients in whom haloperidol is contraindicated.

Remifentanil for analgesia-based sedation in the intensive care unit

Providing effective analgesia and adequate sedation is a generally accepted goal of intensive care medicine. Due to its rapid, organ independent and predictable metabolism the short acting opioid remifentanil might be particularly useful for analgesia-based sedation in the intensive care unit (ICU). This hypothesis was tested by two studies in this issue of Critical Care. The study by Breen et al. shows that remifentanil does not exert prolonged clinical effects when continuously infused in renal failure patients, although the weak acting metabolite remifentanil acid accumulates. The study by Muellejans et al. reports a multicenter trial comparing a remifentanil versus a fentanyl based regimen in ICU patients. With both substances a target analgesia and sedation level was reached, and no major differences were found when frequent assessments of the sedation level and according readjustments of doses were performed. These results are in accordance with other studies suggesting that the adherence to a clear analgesia-based sedation protocol might be more important then the choice of medications itself.

Management of agitation in the intensive care unit

Although the effective evaluation and management of agitated patients often receives less attention than other aspects of critical illness, it is among the most important and rewarding challenges that face critical care physicians. Key features of effective management include a thorough, organized search for potentially dangerous and correctable causes; a sound understanding of the pharmacology of analgesics and sedatives; and keeping a steady eye on appropriate management goals. In turn, the reward for excellent care will be shorter lengths of stay, more rapid liberation from mechanical ventilation, improved cognition, cost savings, and, perhaps, improved survival.

Pain in the older adult in the intensive care unit

Effective pain management of the older adult begins with pain assessment using the proper tools. Understanding the complexities of the older adult in the ICU is the first step; this can be done by integrating the evidence-based practice guidelines provided by the American Geriatrics Society, the Joint Commission on Accreditation of Health Care Organizations (JCAHO pain standards: www.jcaho.org/standard/pm_hap.html), and the Society of Critical Care Medicine into physicians' and nurses' practice. Joint Commission on Accreditation of Health Care Organizations now recommends considering pain as the "fifth vital sign" (JCAHO pain standards: www.jcaho.org/standard/pm_hap.html). In summary, Park et al highlight key concepts that must be considered for all effective treatment plans: "anticipation, recognition, quantification, treatment and reassessment of the needs of the patient." Only then can we anticipate the impacts of chronic and critical illnesses and realize reliable and superior comfort for the elderly.

The pathophysiology of propofol infusion syndrome: a simple name for a complex syndrome

Propofol infusion syndrome (PRIS) is a rare and often fatal syndrome described in critically ill children undergoing long-term propofol infusion at high doses. Recently several cases have been reported in adults, too. The main features of the syndrome consist of cardiac failure, rhabdomyolysis, severe metabolic acidosis and renal failure. To date 21 paediatric cases and 14 adult cases have been described. These latter were mostly patients with acute neurological illnesses or acute inflammatory diseases complicated by severe infections or even sepsis, and receiving catecholamines and/or steroids in addition to propofol. Central nervous system activation with production of catecholamines and glucocorticoids, and systemic inflammation with cytokine production are priming factors for cardiac and peripheral muscle dysfunction. High-dose propofol, but also supportive treatments with catecholamines and corticosteroids, act as triggering factors. At the subcellular level, propofol impairs free fatty acid utilisation and mitochondrial activity. Imbalance between energy demand and utilisation is a key pathogenetic mechanism, which may lead to cardiac and peripheral muscle necrosis. Propofol infusion syndrome is multifactorial, and propofol, particularly when combined with catecholamines and/or steroids, acts as a triggering factor. The syndrome can be lethal and we suggest caution when using prolonged (>48 h) propofol sedation at doses higher than 5 mg/kg per h, particularly in patients with acute neurological or inflammatory illnesses. In these cases, alternative sedative agents should be considered. If unsuitable, strict monitoring of signs of myocytolysis is advisable.

Use of complementary and alternative therapies to promote sleep in critically ill patients

The efficacy of complementary and alternative therapies for sleep promotion in critically ill patients is largely unexamined. We found only seven studies (three on environmental interventions and one each on massage, music therapy, therapeutic touch, and, melatonin) that examined the effect of complementary and alternative therapies. A number of studies, however, have shown that massage, music therapy. and therapeutic touch promote relaxation and comfort in critically ill patients, which likely leads to improved sleep. Massage, music therapy, and therapeutic touch are safe for critically ill patients and should be routinely applied by ICU nurses who have received training on how to administer these specialized interventions. Environmental interventions, such as reducing noise, playing white noise such as ocean sounds, and decreasing interruptions to sleep for care, also are safe and logical interventions that ICU nurses should use to help patients sleep. Progressive muscle relaxation has been extensively studied and shown to be efficacious for improving sleep in persons with insomnia; however, progressive muscle relaxation requires that patients consciously attend to relaxing specific muscle groups and practice these techniques, which may be difficult for critically 11 patients. We do not currently recommend aromatherapy and alternative sedatives, such as valerian and melatonin, for sleep promotion in critically ill patients because the safety of these substances is unclear. In summary, we recommend that ICU nurses implement music therapy, environmental interventions, therapeutic touch, and relaxing massage to promote sleep in critically ill patients. These interventions are safe and may improve patient sleep, although randomized controlled trials are needed to test their efficacy. Aromatherapy and alternative sedatives require further investigation to determine their safety and efficacy.