Factors that influence critical care nurses' management of sedation for ventilated patients in critical care: A qualitative study

BACKGROUND

Optimising sedation use is key to timely extubation. Whilst sedation protocols may be used to guide critical care nurses' management of sedation, sedation management and decision-making is complex, influenced by multiple factors related to patients' circumstances, intensive care unit design and the workforce.

AIM

To explore (i) critical care nurses' experiences managing sedation in mechanically ventilated patients and (ii) the factors that influence their sedation-related decision-making.

DESIGN

Qualitative descriptive study using semi-structured interviews. Data were analysed using Braun and Clarke's six-step thematic analysis.

SETTING AND PARTICIPANTS

This study was conducted in a 26-bed level 3 accredited ICU, in a private hospital in Melbourne, Australia. The majority of patients are admitted following elective surgery. Critical care nurses, who were permanently employed as a registered nurse, worked at least 16 h per week, and cared for ventilated patients, were invited to participate.

FINDINGS

Thirteen critical care nurses participated. Initially, participants suggested their experiences managing sedation were linked to local unit policy and learning. Further exploration revealed that experiences were synonymous with descriptors of factors influencing sedation decision-making according to three themes: (i) Learning from past experiences, (ii) Situational awareness and (iii) Prioritising safety. Nurses relied on their cumulative knowledge from prior experiences to guide decision-making. Situational awareness about other emergent priorities in the unit, staffing and skill-mix were important factors in guiding sedation decision-making. Safety of patients and staff was essential, at times overriding goals to reduce sedation.

CONCLUSION

Sedation decision making cannot be considered in isolation. Rather, sedation decision making must take into account outcomes of patient assessment, emergent priorities, unit and staffing factors and safety concerns.

IMPLICATIONS FOR CLINICAL PRACTICE

Opportunities for ongoing education are essential to promote nurses' situational awareness of other emergent unit priorities, staffing and skill-mix, in addition to evidence-based sedation management and decision making.

Guidelines for inhaled sedation in the ICU

INTRODUCTION AND OBJECTIVES

Sedation is used in intensive care units (ICU) to improve comfort and tolerance during mechanical ventilation, invasive interventions, and nursing care. In recent years, the use of inhalation anaesthetics for this purpose has increased. Our objective was to obtain and summarise the best evidence on inhaled sedation in adult patients in the ICU, and use this to help physicians choose the most appropriate approach in terms of the impact of sedation on clinical outcomes and the risk-benefit of the chosen strategy.

METHODOLOGY

Given the overall lack of literature and scientific evidence on various aspects of inhaled sedation in the ICU, we decided to use a Delphi method to achieve consensus among a group of 17 expert panellists. The processes was conducted over a 12-month period between 2022 and 2023, and followed the recommendations of the CREDES guidelines.

RESULTS

The results of the Delphi survey form the basis of these 39 recommendations - 23 with a strong consensus and 15 with a weak consensus.

CONCLUSION

The use of inhaled sedation in the ICU is a reliable and appropriate option in a wide variety of clinical scenarios. However, there are numerous aspects of the technique that require further study.

TIVA versus Inhalational Agents for Pediatric Cardiac Intensive Care

The field of pediatric intensive care has come a long way, especially with the recognition that adequate sedation and analgesia form an imperative cornerstone of patient management. With various drugs available for the same, the debate continues as to which is the better: total intravenous anesthesia (TIVA) or inhalational agents. While each have their own advantages and disadvantages, in the present era of balance toward the IV agents, we should not forget the edge our volatile agents (VAs) might have in special scenarios. And ultimately as anesthesiologists, let us not forget that be it knob and dial, or syringe and plunger, our aim is to put pain to sleep and awaken a new faith to breathe.

Delirium in older adults

This narrative review provides a broad examination of the most current concepts on the etiopathogenesis, diagnosis, prevention, and treatment of delirium, an acute neuropsychiatric syndrome characterized by fluctuating changes in cognition and consciousness. With the interaction of underlying vulnerability and severity of acute insults, delirium can occur at any age but is particularly frequent in hospitalized older adults. Delirium is also associated with numerous adverse outcomes, including functional impairment, cognitive decline, increased healthcare costs, and death. Its diagnosis is based on clinical and cognitive assessments, preferably following systematized detection instruments, such as the Confusion Assessment Method (CAM). Delirium and its consequences are most effectively fought using multicomponent preventive interventions, like those proposed by the Hospital Elder Life Program (HELP). When prevention fails, delirium management is primarily based on the identification and reversal of precipitating factors and the non-pharmacological control of delirium symptoms. Pharmacological interventions in delirium should be restricted to cases of dangerous agitation or severe psychotic symptoms.

Nursing implementation of a validated agitation and sedation scale: An evaluation of its outcomes on ventilator days and ICU length of stay

BACKGROUND

Intensive Care Units (ICU) often initiate mechanical ventilation (MV) in conjunction with sedation for patients who cannot maintain adequate oxygenation or ventilation on their own. Continuous use of sedation increases the likelihood of negative events associated with ventilators such as ventilator-associated pneumonia while, at the same time, continuing to increase the length of MV.

OBJECTIVES

This study sought to analyze the effects of implementing a mandated Richmond Agitation and Sedation Scale (RASS) entry with each sedative scan on a unit where no parameters were in place to monitor sedation levels.

METHODS

This was a retrospective cross-sectional study which included chart-review of a Medical ICU. The data was gathered on ventilator days and sedation use for patients prior to and after the implementation of the RASS.

RESULTS

A median weighted analysis and Mann-Whitney U test of 138 pre-RASS ventilator patients and 86 post-RASS ventilator patients appears to indicate that implementation of the RASS resulted in a 31% decrease of ventilator days (p = .0002). The pulmonary diagnosis subgroup showed a significant 39% reduction in ICU length of stay (U = 324, p = .042).

CONCLUSIONS

The results of this study lead to the conclusion that the implementation of the mandated RASS score entry limits over-sedation of ventilated patients, thereby reducing the number of MV days in the ICU. Sufficient evidence suggests that the mandated RASS entry also reduces the length of stay in the ICU.

Sedation and Delirium in the Intensive Care Unit—A Practice-Based Approach

Introduction: Critically ill patients often require sedation for comfort and to facilitate therapeutic interventions. Sedation practice guidelines provide an evidencebased framework with recommendations that can help improve key sedation-related outcomes. Materials and Methods: We conducted a narrative review of current guidelines and recent trials on sedation. Results: From a practice perspective, current guidelines share many limitations including lack of consensus on the definition of light sedation, optimal frequency of sedation assessment, optimal timing for light sedation and consideration of combinations of sedatives. We proposed several strategies to address these limitations and improve outcomes: 1) early light sedation within the first 48 hours with time-weighted monitoring (overall time spent in light sedation in the first 48 hours—sedation intensity—has a dose-dependent relationship with mortality risk, delirium and time to extubation); 2) provision of analgesia with minimal or no sedation where possible; 3) a goal-directed and balanced multimodal approach that combines the benefits of different agents and minimise their side effects; 4) use of dexmedetomidine and atypical antipsychotics as a sedative-sparing strategy to reduce weaning-related agitation, shorten ventilation time and accelerate physical and cognitive rehabilitation; and 5) a bundled approach to sedation that provides a framework to improve relevant clinical outcomes. Conclusion: More effort is required to develop a practical, time-weighted sedation scoring system. Emphasis on a balanced, multimodal appraoch that targets light sedation from the early phase of acute critical illness is important to achieve optimal sedation, lower mortality, shorten time on ventilator and reduce delirium. Ann Acad Med Singapore;49:215–25 Key words: Analgesia, Benzodiazepine, Critical Care, Dexmedetomidine, Propofol

Region specific differences in the effect of propofol on the murine colon result in dysmotility

Propofol is the most widely used intravenous anaesthetic agent for maintenance of anaesthesia and sedation. Studies in varying regions of the bowel have shown conflicting differences on the effects of propofol on motility. There the aim of this study was to understand the influence of propofol on colonic function and explore by which mechanism any changes occur. Functional studies were conducted using isolated colonic tissue from C57BL6 mice which were exposed to 5 μM propofol. Faecal pellet motility, colonic migratory motor complexes (CMMCs) and functional bioassays were utilised to monitor colonic function and nitric oxide production was monitored by amperometry. There was a signficant reduction in amplitude of CMMCs in the distal colon in the presence of 5 μM propofol, however no difference was observed in the proximal colon. A signficant increase in the 5-HT evoked contractions were observed in distal colon in the presence of 5 μM propofol. Additionally, a reduction in the NO production in the presence of 5 μM propofol was only observed in the distal colon. As a result, in the presence of 5 μM propofol, faecal pellet transit was increased, and velocity was reduced. At clinically relevant doses, propofol was shown to reduce colonic motility by inhibiting nitric oxide synthase in only the distal region of the colon. Our findings indicate that propofol has a considerable influence on colonic signalling mechanisms and impairs colonic motility, which may have implications in its clinical use especially for maintenance.

Safety and Effectiveness of Intravenous Chlorpromazine for Agitation in Critically Ill Patients

BACKGROUND

Agitation is common in the intensive care unit (ICU). Although antipsychotics are frequently used as first-line therapy, chlorpromazine has fallen out of favor due to risk of cardiovascular complications and severe hypotension. Although chlorpromazine is used anecdotally, there is a lack of data regarding its safety and effectiveness. The objective of this study was to investigate the use of intravenous (IV) chlorpromazine for agitation in the ICU setting.

METHODS

A retrospective review was performed at a tertiary care academic medical center. Patients were included if they received IV chlorpromazine in the ICU for agitation, infused at a rate of 1 mg/min. Primary end points were change in systolic blood pressure (SBP), heart rate (HR), and mean arterial pressure (MAP) within 4 hours of administration. Secondary end points included change in vasopressor and adjunct sedative medication requirements, achievement of Richmond-Agitation Sedation Scale (RASS) 0 to -1, and incidence of cardiac arrhythmias.

RESULTS

A total of 39 patients encompassing 107 IV chlorpromazine administrations were included. The median dose was 25 mg. Median vital signs prior to infusion were SBP 129 mm Hg, HR 90 beats/minute, and MAP 88 mm Hg. Over the subsequent 4 hours, SBP and HR did not change significantly (P = .83 and P = .10, respectively). Mean arterial pressure decreased from a median of 88 to 83 mm Hg (P = .04). There were no significant changes in vasopressor requirements, adjunct sedative medication requirements, or achievement of RASS goal. No patients developed symptomatic cardiac arrhythmias.

CONCLUSION

In our small retrospective study, the use of IV chlorpromazine at routine doses did not result in clinically significant hemodynamic changes when infused at a rate of 1 mg/min. Intravenous chlorpromazine may be considered as a potential treatment option for agitation in ICU patients with appropriate monitoring.

A Heartbeat Away From Consciousness: Heart Rate Variability Entropy Can Discriminate Disorders of Consciousness and Is Correlated With Resting-State fMRI Brain Connectivity of the Central Autonomic Network

Background: Disorders of consciousness are challenging to diagnose, with inconsistent behavioral responses, motor and cognitive disabilities, leading to approximately 40% misdiagnoses. Heart rate variability (HRV) reflects the complexity of the heart-brain two-way dynamic interactions. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals. We here investigate the complexity index (CI), a score of HRV complexity by aggregating the non-linear multi-scale entropies over a range of time scales, and its discriminative power in chronic patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), and its relation to brain functional connectivity. Methods: We investigated the CI in short (CIs) and long (CIl) time scales in 14 UWS and 16 MCS sedated. CI for MCS and UWS groups were compared using a Mann-Whitney exact test. Spearman's correlation tests were conducted between the Coma Recovery Scale-revised (CRS-R) and both CI. Discriminative power of both CI was assessed with One-R machine learning model. Correlation between CI and brain connectivity (detected with functional magnetic resonance imagery using seed-based and hypothesis-free intrinsic connectivity) was investigated using a linear regression in a subgroup of 10 UWS and 11 MCS patients with sufficient image quality. Results: Higher CIs and CIl values were observed in MCS compared to UWS. Positive correlations were found between CRS-R and both CI. The One-R classifier selected CIl as the best discriminator between UWS and MCS with 90% accuracy, 7% false positive and 13% false negative rates after a 10-fold cross-validation test. Positive correlations were observed between both CI and the recovery of functional connectivity of brain areas belonging to the central autonomic networks (CAN). Conclusion: CI of MCS compared to UWS patients has high discriminative power and low false negative rate at one third of the estimated human assessors' misdiagnosis, providing an easy, inexpensive and non-invasive diagnostic tool. CI reflects functional connectivity changes in the CAN, suggesting that CI can provide an indirect way to screen and monitor connectivity changes in this neural system. Future studies should assess the extent of CI's predictive power in a larger cohort of patients and prognostic power in acute patients.

The influence of alcohol abuse on agitation, delirium and sedative requirements of patients admitted to a general intensive care unit

Purpose

Patients with alcohol-related disease constitute an increasing proportion of those admitted to intensive care unit. There is currently limited evidence regarding the impact of alcohol use on levels of agitation, delirium and sedative requirements in intensive care unit. This study aimed to determine whether intensive care unit-admitted alcohol-abuse patients have different sedative requirements, agitation and delirium levels compared to patients with no alcohol issues.

Methods

This retrospective analysis of a prospectively acquired database (June 2012-May 2013) included 257 patients. Subjects were stratified into three risk categories: alcohol dependency (n = 69), at risk (n = 60) and low risk (n = 128) according to Fast Alcohol Screening Test scores and World Health Organisation criteria for alcohol-related disease. Data on agitation and delirium were collected using validated retrospective chart-screening methods and sedation data were extracted and then log-transformed to fit the regression model.

Results

Incidence of agitation (p = 0.034) and delirium (p = 0.041) was significantly higher amongst alcohol-dependent patients compared to low-risk patients as was likelihood of adverse events (p = 0.007). In contrast, at-risk patients were at no higher risk of these outcomes compared to the low-risk group. Alcohol-dependent patients experienced suboptimal sedation levels more frequently and received a wider range of sedatives (p = 0.019) but did not receive higher daily doses of any sedatives.

Conclusions

Our analysis demonstrates that when admitted to intensive care unit, it is those who abuse alcohol most severely, alcohol-dependent patients, rather than at-risk drinkers who have a significantly increased risk of agitation, delirium and suboptimal sedation. These patients may require closer assessment and monitoring for these outcomes whilst admitted.

Anaesthesia: what a surgeon needs to know

Surgeons and anaesthetists work closely together, sometimes in challenging circumstances. To help surgeons cooperate with anaesthetists to deliver high quality care for patients, a working knowledge of modern anaesthetic practice is useful. The specialty of anaesthetics is developing rapidly, and periodic updating of this knowledge is likely to be required. This article provides an update of anaesthetic practice for surgeons, covering the varied roles of anaesthetists, preoperative assessment, management on the day of surgery (induction, maintenance and reversal of anaesthetic), general anaesthesia, the role of regional blocks and sedation. It also discusses safety issues, the management of frail patients and future challenges.

Toxicity of inhaled agents after prolonged administration

Inhaled anesthetics have been utilized mostly for general anesthesia in the operating room and oftentimes for sedation and for treatment of refractory status epilepticus and status asthmaticus in the intensive care unit. These contexts in the ICU setting are related to potential for prolonged administration wherein potential organ toxicity is a concern. Over the last decade, several clinical and animal studies of neurotoxicity attributable to inhaled anesthetics have been emerging, particularly in extremes of age. This review overviews potential for and potential mechanisms of neurotoxicity and systemic toxicity of prolonged inhaled anesthesia and clinical scenarios where inhaled anesthesia has been used in order to assess safety of possible prolonged use for sedation. High dose inhaled agents are associated with postoperative cognitive dysfunction (POCD) and other situations. However, thus far no strong indication of problematic neuro or organ toxicity has been demonstrated after prolonged use of low dose volatile anesthesia.

Comparing effects between music intervention and aromatherapy on anxiety of patients undergoing mechanical ventilation in the intensive care unit: a randomized controlled trial

PURPOSE

Using patient-reported outcomes and physiological indicators to test the effects of music intervention and aromatherapy on reducing anxiety for intensive care unit (ICU) patients undergoing mechanical ventilation.

METHODS

Patients with ICU admission duration >24 h were randomly assigned to a Music intervention group (n = 41), Aromatherapy group (n = 47), or Control group (rest only; n = 44). Each patient in the Music group listened to music; each patient in the Aromatherapy group received lavender essential oil massage on his/her back for 5 min; each patient in the Control group wore noise-canceling headphones. Anxiety was measured using the Chinese version of the Stage-Trait Anxiety Inventory (C-STAI) and the Visual Analogue Scale for Anxiety (VAS-A) at baseline, post-test, and 30-min follow-up. Heart rate, breathing rate, and blood pressure were measured every 10 min from baseline to the 30-min follow-up.

RESULTS

The Music group had significantly better post-test VAS-A and C-STAI scores, and had lower heart rate and blood pressure than the Control group. The Aromatherapy group had significantly better VAS-A score and lower heart rate than the Control group. The 30-min follow-up showed that both Music and Aromatherapy groups had lower heart rate and blood pressure than the Control group.

CONCLUSIONS

Music and aromatherapy interventions were both effective for ICU patients. The effects of music intervention were greater than that of aromatherapy; both interventions maintained the effects for at least 30 min.

Prolonged infusion of sedatives and analgesics in adult intensive care patients: A systematic review of pharmacokinetic data reporting and quality of evidence

Although pharmacokinetic (PK) data for prolonged sedative and analgesic agents in intensive care unit (ICU) has been described, the number of publications in this important area appear relatively few, and PK data presented is not comprehensive. Known pathophysiological changes in critically ill patients result in altered drug PK when compared with non-critically ill patients. ClinPK Statement was recently developed to promote consistent reporting in PK studies, however, its applicability to ICU specific PK studies is unclear. In this systematic review, we assessed the overall ClinPK Statement compliance rate, determined the factors affecting compliance rate, graded the level of PK evidence and assessed the applicability of the ClinPK Statement to future ICU PK studies. Of the 33 included studies (n=2016), 22 (67%) were low evidence quality descriptive studies (Level 4). Included studies had a median compliance rate of 80% (IQR 66% to 86%) against the ClinPK Statement. Overall pooled compliance rate (78%, 95% CI 73% to 83%) was stable across time (P=0.38), with higher compliance rates found in studies fitting three compartments models (88%, P<0.01), two compartments models (83%, P<0.01) and one compartment models (77%, P=0.17) than studies fitting noncompartmental or unspecified models (69%) (P<0.01). Data unique to the interpretation of PK data in critically ill patients, such as illness severity (48%), organ dysfunction (36%) and renal replacement therapy use (32%), were infrequently reported. Discrepancy between the general compliance rate with ClinPK Statement and the under-reporting of ICU specific parameters suggests that the applicability of the ClinPK Statement to ICU PK studies may be limited in its current form.

Effects of Music Intervention on State Anxiety and Physiological Indices in Patients Undergoing Mechanical Ventilation in the Intensive Care Unit

Patients in intensive care units (ICUs) often experience stress and anxiety. Although stress and anxiety can be pharmacologically attenuated, some drugs cause adverse side effects such as bradycardia, immobility, and delirium. There is thus a need for an alternative treatment with no substantial adverse effects. Music intervention is a potential alternative. In the present study, we used cortisol levels, subjective questionnaires, and physiological parameters to explore the anxiety-reducing effects of music intervention in a sample of ICU patients on mechanical ventilation. Patients admitted to the ICU for ≥ 24 hr were randomly assigned to the music intervention ( n = 41) or control group ( n = 44). Music group patients individually listened to music from 4:00 to 4:30 p.m.; control group patients wore headphones but heard no music for the same 30 min. Anxiety was measured using serum cortisol levels, the Chinese Version of the State-Trait Anxiety Inventory, the Visual Analogue Scale for Anxiety, heart rate, and blood pressure. After adjusting for demographics, analysis of covariance showed that the music group had significantly better scores for all posttest measures ( p < .02) and pre–post differences ( p < .03) except for diastolic blood pressure. Because of music intervention’s low cost and easy administration, clinical nurses may want to use music to reduce stress and anxiety for ICU patients. A single 30-min session might work immediately without any adverse effects. However, the duration of the effect is unclear; thus, each patient’s mood should be monitored after the music intervention.

Obstructive Sleep Apnea and Modifications in Sedation: An Update

One factor that may contribute to an increased risk for airway compromise is obstructive sleep apnea (OSA). Sedation in this population carries an increased risk for hypopnea. Critical care nurses must decide on the amount and type of sedation to administer at the point of care. It is important for them to understand OSA and the routinely prescribed sedatives that may affect this disorder. This article discusses the pathophysiology of OSA and traits that may help identify patients with undiagnosed OSA. The most commonly prescribed sedative pharmacologic agents and adjunctive airway support mechanisms are reviewed for use in this population.

Assessing, monitoring and managing continuous intravenous sedation for critically ill adult patients and implications for emergency nursing practice: A systematic literature review

BACKGROUND

Critically ill mechanically ventilated patients in ED have complex needs; chief among these is adequate sedation in addition to effective pain-relief. Emergency nurses are increasingly responsible sedation and analgesia for this complex cohort of patients. The aim of this review was to examine (1) the evidence around assessing, monitoring and managing continuous intravenous sedation for critically ill adult patients, and (2) the implications for emergency nursing practice.

STUDY DESIGN

Systematic review.

METHOD

The review of literature extended from 1946 to 2013 and examined peer review journal articles, policy and guidelines to provide a more complex understanding of a phenomenon of concern. A total of 98 articles were incorporated and comprehensively examined.

RESULTS

Analysis of the literature identified several implications for emergency nursing practice and the management of continuous intravenous sedation: workload, education, monitoring and assessing sedation and policy.

CONCLUSION

Limited literature was found that directly addressed Australasian emergency nursing practices' in managing on-going intravenous sedation and analgesia for patients. Balancing patient sedation and analgesia requires highly complex knowledge, skills and expertise; the degree of education and training required is above that obtained during pre-registration nurse training. No state or national models of education or training were identified to support ED nurses' practices in managing sedation. Little research has addressed the safety of continuous sedation use in ED.

Comparison of clonidine and dexmedetomidine for short-term sedation of intensive care unit patients

BACKGROUND AND OBJECTIVES

Patients on mechanical ventilation in intensive care unit (ICU) are often uncomfortable because of anxiety, pain, and endotracheal intubation; therefore, require sedation. Alpha-2 agonists are known to produce sedation. We compared clonidine and dexmedetomidine as sole agents for sedation.

STUDY DESIGN

Prospective, randomized, controlled open-label study.

MATERIALS AND METHODS

A total of 70 patients requiring a minimum of 12 h of mechanical ventilation with concomitant sedation, were randomly allocated into two groups. Group C (n = 35) received intravenous (IV) clonidine (1 μg/kg/h titrated up to 2 μg/kg/h to attain target sedation), and Group D (n = 35) received IV dexmedetomidine for sedation (loading 0.7 μg/kg and maintenance 0.2 μg/kg/h titrated up to 0.7 μg/kg/h to achieve target sedation). A Ramsay Sedation Score of 3-4 was considered as target sedation. Additional sedation with diazepam was given when required to achieve target sedation. The quality of sedation, hemodynamic changes and adverse effects were noted and compared between the two groups.

RESULTS

Target sedation was achieved in 86% observations in Group D and 62% in Group C (P = 0.04). Additional sedation was needed by more patients in Group C compared with Group D (14 and 8 in Groups C and D, respectively, P = 0.034), mainly due to concomitant hypotension on increasing the dose of clonidine. Hypotension was the most common side-effect in Group C, occurring in 11/35 patients of Group C and 3/35 patients of Group D (P = 0.02). Rebound hypertension was seen in four patients receiving clonidine, but none in receiving dexmedetomidine.

CONCLUSION

Both clonidine and dexmedetomidine produced effective sedation; however, the hemodynamic stability provided by dexmedetomidine gives it an edge over clonidine for short-term sedation of ICU patients.

SEDASYS(®), airway, oxygenation, and ventilation: anticipating and managing the challenges

In May 2013, the FDA (Federal Drug Administration) approved SEDASYS(®), a device that enables non-anesthesia physicians to provide mild-to-moderate sedation to patients undergoing colonoscopy and esophagogastroduodenoscopy. SEDASYS(®) is the first among the devices being built to provide computer-assisted personalized sedation. Although the intention of this approval is to cut the anesthesia related expenses, it is likely to create new challenges to the users-both clinical and administrative-that might even increase the cost. Deep sedation is required frequently for a successful completion of the procedure, which poses unforeseen challenges. The present review aims to provide clear information to the users regarding pre-procedure assessment, possible sedation related complications and management options.

Sedative efficacy of propofol in patients intubated/ventilated after coronary artery bypass graft surgery

Background:

Sedation after open heart surgery is important in preventing stress on the heart. The unique sedative features of propofol prompted us to evaluate its potential clinical role in the sedation of post-CABG patients.

Objectives:

To compare propofol-based sedation to midazolam-based sedation after coronary artery bypass graft (CABG) surgery in the intensive care unit (ICU).

Patients and Methods:

Fifty patients who were admitted to the ICU after CABG surgery was randomized into two groups to receive sedation with either midazolam or propofol infusions; and additional analgesia was administered if required. Inclusion criteria were as follows: patients 40-60 years old, hemodynamic stability, ejection fraction (EF) more than 40%; exclusion criteria included patients who required intra-aortic balloon pump or inotropic drugs post-bypass. The same protocol of anesthetic medications was used in both groups. Depth of sedation was monitored using the Ramsay sedation score (RSS). Invasive mean arterial pressure (MAP) and heart rate (HR), arterial blood gas (ABG) and ventilatory parameters were monitored continuously after the start of study drug and until the patients were extubated.

Results:

The depth of sedation was almost the same in the two groups (RSS=4.5 in midazolam group vs 4.7 in propofol group; P = 0.259) but the total dose of fentanyl in the midazolam group was significantly more than the propofol group (12.5 mg/hr vs 4 mg/hr) (P = 0.0039). No significant differences were found in MAP (P = 0.51) and HR (P = 0.41) between the groups. The mean extubation time in patients sedated with propofol was shorter than those sedated with midazolam (102 ± 27 min vs 245 ± 42 min, respectively; P < 0.05) but the ICU discharge time was not shorter (47.5 hr vs 36.3 hr, respectively; P = 0.24).

Conclusions:

Propofol provided a safe and acceptable sedation for post-CABG surgical patients, significantly reduced the requirement for analgesics, and allowed for more rapid tracheal extubation than midazolam but did not result in earlier ICU discharge.

Evaluation of intravenous lipid emulsion on haloperidol-induced hypotension in rabbits

There are many reports on the effects of intravenous lipid emulsion (ILE) as an antidote in drug toxicity. Haloperidol (HAL) is a butyrophenone antipsychotic agent which is highly lipophilic. Hypotension is an important adverse effect of HAL administration and overdose. The aim of this study was to investigate the beneficial hemodynamic effects of ILE on acute HAL poisoning. We used six groups of five male rabbits. Two groups received aseptic distilled water intravenously followed by infusion of 18.6 ml/kg normal saline, as negative control group, or ILE 20% after 0.5 h. The third group received 18.6 ml/kg normal saline after HAL infusion (2.6 mg/kg). The other three groups received ILE 20% solution (6, 12, and 18.6 ml/kg) following HAL (2.6 mg/kg) administration. We measured blood pressure at 0, 0.5, 1, 2, 3, 4, 8, and 24 h after starting HAL administration, from left forelimb using a noninvasive method that was carried out automatically with a neonatal intensive care unit bedside monitor. ILE 20% at the dose of 18 ml/kg could return the reduced mean arterial pressure and diastolic blood pressure sooner than the other doses and normal saline. In conclusion, ILE could reverse HAL-induced hypotension same as the other lipophilic drugs. However, the clinical use of ILE for this purpose needs more evaluation to determine its exact indication and safety.

Interpatient variability in dexmedetomidine response: a survey of the literature

Fifty-five thousand patients are cared for in the intensive care unit (ICU) daily with sedation utilized to reduce anxiety and agitation while optimizing comfort. The Society of Critical Care Medicine (SCCM) released updated guidelines for management of pain, agitation, and delirium in the ICU and recommended nonbenzodiazepines, such as dexmedetomidine and propofol, as first line sedation agents. Dexmedetomidine, an alpha-2 agonist, offers many benefits yet its use is mired by the inability to consistently achieve sedation goals. Three hypotheses including patient traits/characteristics, pharmacokinetics in critically ill patients, and clinically relevant genetic polymorphisms that could affect dexmedetomidine response are presented. Studies in patient traits have yielded conflicting results regarding the role of race yet suggest that dexmedetomidine may produce more consistent results in less critically ill patients and with home antidepressant use. Pharmacokinetics of critically ill patients are reported as similar to healthy individuals yet wide, unexplained interpatient variability in dexmedetomidine serum levels exist. Genetic polymorphisms in both metabolism and receptor response have been evaluated in few studies, and the results remain inconclusive. To fully understand the role of dexmedetomidine, it is vital to further evaluate what prompts such marked interpatient variability in critically ill patients.

'Targeting' sedation: the lived experience of the intensive care nurse

AIMS AND OBJECTIVES

To discuss the findings from a phenomenological study that provides insights into the intensive care nurses' 'world' following changes in the sedation management of patients in an intensive care unit.

BACKGROUND

Intensive care sedation practices have undergone significant changes. Patients, where possible, are now managed on lighter levels of sedation, often achieved through the performance of sedation holds (SHs). The performance of SHs is normally carried out by the bedside nurse but compliance is reported to be poor. There has been little exploration of the nurses' experiences of these changes and the implications of SHs and subsequent wakefulness on their delivery of care.

DESIGN

Following ethical approval, 16 intensive care nurses, experienced and inexperienced, from within a general intensive care unit.

METHODS

A Heideggerian phenomenological approach was used. Data collection consisted of interviews guided by an aide memoir and a framework adapted from Van Manen informed the analysis.

RESULTS

The findings reveal new insights into the world of the intensive care nurse in the light of the changes to sedation management. They demonstrate that there have been unforeseen outcomes from well-intentioned initiatives to improve the quality of patients' care. There were implications from the changes introduced for the nurses care delivery. The main themes that emerged were 'working priorities' and 'unintended consequences', in turn revealing embedded tensions between evidence-based targets and holistic care.

CONCLUSIONS

Intensive care nurses find that the current approach to the changes in sedation management can threaten their professional obligation and personal desire to provide holistic care. The 'targeted' approach by healthcare organisations is perceived to militate against the patient-centred care they want to deliver.

RELEVANCE TO CLINICAL PRACTICE

Sedation management is complex and needs further consideration particularly the potential constraints 'target-led' care has on nursing practice.

Nurse perception of Bispectral Index monitoring as an adjunct to sedation scale assessment in the critically ill paediatric patient

BACKGROUND

Reliability of clinical scales and haemodynamic variables for assessing sedation depth in critically children is limited, particularly for those receiving neuromuscular blocking agents (NMBAs).

OBJECTIVE

To introduce and integrate the use of Bispectral Index (BIS) monitoring as adjunct to sedation scale assessment in intubated mechanically ventilated Paediatric Intensive Care Unit (PICU) patients.

METHODS

Quality improvement intervention including: BIS education for all PICU nurses; 8-week implementation of BIS monitoring guided by Paediatric BIS Sedation Protocol; evaluation by convenience sample of nurses (n=17).

MEASUREMENTS

15-Item survey assessing perceptions of BIS attributes was given to nurses after first 4 BIS encounters; nurse comments and project coordinator observations were recorded.

FINDINGS

Survey data (intermediate reliability and nurse attitude ratings and low ratings on other attributes; little change over time) revealed nurses' reservations about the usefulness of BIS as an adjunct to sedation scales, but qualitative data indicated that they valued BIS for assessing sedation depth in children receiving NMBAs.

CONCLUSIONS

Post-intervention, BIS monitoring was adopted in PICU for children receiving NMBAs. One year later, this practice is sustained, and the percentage of BIS-monitored patients has increased. Guidelines addressing the use of BIS in patients not receiving paralytics are needed.

Performance evaluation of a whole blood propofol analyser

The authors evaluated an analyser for the determination of propofol concentrations in whole blood. The Pelorus 1000 (Sphere Medical) measures propofol concentrations in around 5 min without the requirement for sample preparation. The performance of the analyser was characterised with respect to linearity, precision in control solutions and whole blood and method comparison to an HPLC based reference method. In addition, the effects of substances considered to potentially affect the assay method were investigated. The analyser was found to be linear up to 12 μg/ml (R2 = 0.9993), with a lower limit of quantification of 0.75 μg/ml. Total within device imprecision in control solutions was 0.11 μg/ml at 5.32 μg/ml and 0.17 μg/ml at 10.3 μg/ml. Within run precision in whole blood was 0.04 μg/ml at 2.84 μg/ml and 0.08 μg/ml at 6.68 μg/ml and for the reference method was 0.06 μg/ml and 0.12 μg/ml respectively. In comparison to the reference method, the overall bias of the Pelorus 1000 system over the range is estimated to be 0.15 μg/ml (95% confidence interval -0.11-0.41 μg/ml). The only cross interference of note is to a highly elevated level of conjugated bilirubin, while low haematocrit levels lead to a 0.13 μg/ml under reading with respect to the HPLC reference. The system fulfils the requirements for measurement of propofol concentrations in whole blood samples with precision and accuracy suitable for elucidating propofol pharmacokinetics at clinically relevant concentrations. With no requirement for sample preparation and a fast time to results, the analyser opens up the possibility of studies to measure and respond to blood propofol concentrations in patients in close to real time.