Routine intra-operative assessment of pain and/or depth of anaesthesia by nurse anaesthetists in clinical practice

Physiological variables for the objective detection of nerve block failure in dogs

OBJECTIVE

To identify physiological variables for objectively detecting nociception indicative of intraoperative peripheral nerve block failure.

STUDY DESIGN

A double-blinded randomized clinical study.

ANIMALS

A sample of 14 male (40.8 ± 12 kg; mean ± standard deviation) and 16 female (34.3 ± 11.4 kg) client-owned dogs.

METHODS

Dogs were randomly assigned to one of three groups for psoas compartment and proximal sciatic nerve blocks (0.2 mL kg-1 per site): guided bupivacaine (GBB), or saline (GSB) block or a blind bupivacaine block (BBB). Guided blocks were performed using an ultrasound-peripheral nerve locator combination. Premedication consisted of medetomidine 0.01 mg kg-1 and morphine 0.3 mg kg-1. General anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Receiver operator characteristic curve analysis was used to compare actual values and change in values of physiological variables between GSB and GBB. The Youden index and associated criterion for each physiological variable were used to determine an objective measure for nociception. Fisher's exact t test, McNemar's test and Cohen's kappa statistical analysis were used to determine association, differences and inter-score reliability between the objective and subjective scoring for BBB.

RESULTS

Cardiovascular variables had good discriminating ability to identify a nociceptive response (p < 0.01). The Youden indices for mean (MAP) and diastolic (DAP) arterial pressure were most reliable in detecting nociception. The highest sensitivity was that of ΔMAP (100%) with good agreement between the subjective and objective scores of Δheart rate or systolic arterial pressure (SAP). The use of ΔMAP, ΔSAP, ΔDAP had the best ability in indicating peripheral nerve block failure (p < 0.001).

CONCLUSIONS AND CLINICAL RELEVANCE

Blood pressure values can detect a response to surgical stimulus in adequately anaesthetized dogs. The use of ΔMAP, ΔSAP or ΔDAP may be considered as objective measures to detect nerve block failure.

Virtual reality for interventional radiology patients: a preliminary study

PURPOSE

The aim of this prospective study was to evaluate the tolerance and feasibility of using virtual reality headsets with patients during interventional radiology procedures.

MATERIAL AND METHOD

In this single-center prospective study, the use of a virtual reality headset in addition to the usual analgesic and anxiolytic treatment was proposed to all patients presenting in the interventional radiology department from December 2020 to June 2022. Exclusion criteria were as follows: (1) patients with whom it was not possible to communicate (2) epileptic patients, (3) non-verbal patients, and (4) pregnant women. The main objective was to evaluate the safety of the procedure by screening complications during and after the procedure. The second objective was to evaluate feasibility, as defined by the number of patients using the helmet until the end of the procedure. Effectiveness (patient's self-evaluation of pain and anxiety), comfort, satisfaction, emotions felt, sense of security, and feeling of immersion were also evaluated. Caregivers completed a feedback questionnaire.

RESULTS

Virtual reality headsets were offered to 100 patients, 9 of whom declined. Procedures were achieved in 93.5% of cases: 6/91 patients removed the headset before the end of the procedure. There were minor adverse events in 2/85 (2.3%) procedures (discomfort and nausea) and no major adverse events. 93.9% of patients found an overall benefit, and 90.2% would recommend virtual reality to another patient. 94.4% of caregivers were satisfied with the virtual reality equipment. The mean pain level was 2.5 ± 2.7 before the procedure, 3.3 ± 2.5 during the procedure, and 1.6 ± 2.7 after the procedure. Mean anxiety scores were 4.6 ± 2.9 before the procedure, 3.1 ± 2.7 during the procedure, and 1.1 ± 1.9 after the procedure.

CONCLUSION

The use of virtual reality technology as a complement to traditional therapy for procedures under local anesthesia is feasible and safe in interventional radiology and can be beneficial for pain and anxiety management.

Effects of midazolam on cardiovascular responses and isoflurane requirement during elective ovariohysterectomy in dogs

Background

A prospective, randomized, placebo-controlled, blinded clinical study was conducted to determine whether a single dose of midazolam affects the cardiovascular response to surgical manipulation of the ovaries during elective ovariohysterectomy. Thirty-nine client-owned dogs undergoing elective ovariohysterectomy were recruited. After scoring cage demeanour, dogs were premedicated with acepromazine (0.03 mg kg^-1) and pethidine (3 mg kg^-1) intramuscularly into the quadriceps muscle and 20 min later sedation was scored. Anaesthesia was induced with propofol intravenously (IV) to effect. The study treatment (group M: midazolam (0.25 mg kg^-1); or group P: placebo (Hartmann’s solution) (0.125 ml kg^-1)) was administered IV before the intra-operative manipulation of the first ovary. Anaesthesia was maintained with isoflurane in oxygen. Morphine (0.3 mg kg^-1 IV) was administered prior to the start of surgery. The vaporizer setting was adjusted according to the depth of anaesthesia. If an end-tidal isoflurane concentration (FE’Iso) above 1.6% was required additional analgesia was provided with fentanyl (2 μg kg^-1). Dogs received meloxicam (0.2 mg kg^-1 IV) at the end of procedure. Heart rate, mean arterial blood pressure, respiratory rate and end-tidal partial pressure of carbon dioxide as well as FE’Iso were recorded and analysed.

Results

A statistical significant difference between groups was detected in FE’Iso, with group M requiring a significantly lower FE’Iso than group P (14.3%) after administration of midazolam. No differences between groups was shown for percentage change in heart rate and mean arterial blood pressure, or end-tidal carbon dioxide and requirement for mechanical ventilation, or rescue analgesia. There was no statistically significant difference in the incidence of complications in group M and P. Group M received significantly more succinylated gelatin solution pre-administration of midazolam than group P, but no differences in fluid administration post-administration of the study treatment (midazolam/placebo) were detected. No statistical significant difference was demonstrated for the use of anticholinergic agents, dobutamine or noradrenaline.

Conclusion

No significant effect on cardiovascular parameters could be observed with administration of midazolam, but a modest (14.3%) isoflurane-sparing effect was detected.

Critical care nurses' experiences: "a good relationship with the patient is a prerequisite for successful pain relief management"

There is a lack of studies describing how critical care nurses experience assessing and treating pain in patients receiving postoperative care in an intensive care unit (ICU). The aim of this study was to describe those experiences. Qualitative personal interviews with six critical care nurses in an ICU in northern Sweden were conducted during 2009. The interview texts were subjected to qualitative content analysis, which resulted in the formulation of one theme and four categories. It was important to be able to recognize signs of pain in patients unable to communicate verbally. In older patients, anxiety could be interpreted as an indication of pain. Pain was primarily assessed by means of a visual analog scale. Being unable to treat pain successfully was experienced as failing in one's work. Pharmacologic treatment was always the first choice for relief. The environment was experienced as a hindrance to optimal nursing care, because all postoperative patients shared a room with only curtains between them. The work of assessing and treating pain in patients receiving postoperative care is an important and frequent task for critical care nurses, and knowledge in the field is essential if the patients are to receive optimal nursing care and treatment. Patients cared for in an ICU might benefit from nonpharmacologic treatment. Being without pain after surgery implies increased well-being and shorter hospitalization for the patient.

The use of bispectral index monitoring in education - a tool to improve nurse-anaesthetists practice

AIM

This paper is a report of a study to investigate whether monitoring depth of anaesthesia by bispectral index would reduce recovery time and consumption of anaesthetic drugs in anaesthetics performed by student nurse-anaesthetists.

BACKGROUND

It is difficult to assess the depth of anaesthesia clinically. Studies have shown that experienced anaesthetists can titrate anaesthetics more accurately when using bispectral index monitors. It is not known if student nurse-anaesthetists can benefit from their use in a similar way.

METHOD

A multicentre study involving four hospitals was carried out during a 13-month period in 2003 and 2004. In total 25 nurses participated, each contributing with two procedures: one with monitoring and one without. The nurses had at least 10 months of experience in conducting anaesthesia and all had a theoretical introduction and a test session to become familiar with the equipment. The sequence was randomized and the observer was blinded to whether a monitor was used. Fifty patients were anaesthetized with propofol and fentanyl. Recovery time, consumption of anaesthetic drugs, and patient satisfaction were measured in both groups.

RESULTS

Recovery time was 11 minutes in the monitor group (range: 2-53 minutes) and 15 minutes in the control group, (range: 3-60 minutes). P = 0.26. There were no statistically significant differences in consumption of anaesthetic drugs or patient satisfaction in the two groups.

CONCLUSION

It was not possible to demonstrate a statistically significant reduction in recovery time or consumption of anaesthetic drugs when using bispectral index monitoring during training of student nurse-anaesthetists.

Monitoring analgesia

Analgesia (pain relief) amnesia (loss of memory) and immobilisation are the three major components of anaesthesia. The perception of pain, and therefore, the need for analgesia, is individual, and the monitoring of analgesia is indirect and, in essence, of the moment. Under general anaesthesia, analgesia is continually influenced by external stimuli and the administration of analgesic drugs, and cannot be really separated from anaesthesia: the interaction between analgesia and anaesthesia is inescapable. Autonomic reactions, such as tachycardia, hypertension, sweating and lacrimation, although non-specific, are always regarded as signs of nociception or inadequate analgesia. Autonomic monitoring techniques, such as the analysis of heart rate variability, laser Doppler flowmetry, phlethysmographically derived indices and the pupillary light reflex, may help to quantitate reactions of the autonomic nervous system. For the past few years, automated electroencephalographic analysis has been of great interest in monitoring anaesthesia and could be useful in adapting the peroperative administration of opioids. A range of information collected from the electroencephalogram, haemodynamic readings and pulse plethysmography might be necessary for monitoring the level of nociception during anaesthesia. Information theory, multimodal monitoring, and signal processing and integration are the basis of future monitoring.

The impact of chronic illness: partnerships with other healthcare professionals

Healthcare workforce shortfalls require a rethinking of models for delivering care to people with chronic disease. Chronic disease needs to be managed by a multiskilled team of healthcare professionals with specialist input. Education at undergraduate, graduate and postgraduate levels needs to prepare healthcare professionals for this new paradigm. Some tasks currently seen only as part of a doctor's purview could be performed by other trained professionals to allow doctors to concentrate on more appropriate activities. We need to explore new collaborations to deliver multidisciplinary healthcare for chronic disease and evaluate these for patient outcomes and cost effectiveness.