Cardiorespiratory consequences of attenuated fentanyl and augmented rocuronium dosing during protocolised prehospital emergency anaesthesia at a regional air ambulance service: a retrospective study.

BACKGROUND: Pre-Hospital Emergency Anaesthesia (PHEA) has undergone significant developments since its inception. However, optimal drug dosing remains a challenge for both medical and trauma patients. Many prehospital teams have adopted a drug regimen of 3 mcg/kg fentanyl, 2 mg/kg ketamine and 1 mg/kg rocuronium ('3:2:1'). At Essex and Herts Air Ambulance Trust (EHAAT) a new standard dosing regimen was introduced in August 2021: 1 mcg/kg fentanyl, 2 mg/kg ketamine and 2 mg/kg rocuronium (up to a maximum dose of 150 mg) ('1:2:2'). The aim of this study was to evaluate the cardiorespiratory consequences of a new attenuated fentanyl and augmented rocuronium dosing regimen. METHODS: A retrospective study was conducted at EHAAT as a service evaluation. Anonymized records were reviewed from an electronic database to compare the original ('3:2:1') drug dosing regimen (December 2019-July 2021) and the new ('1:2:2') dosing regimen (September 2021-May 2023). The primary outcome was the incidence of absolute hypotension within ten minutes of induction. Secondary outcomes included immediate hypertension, immediate hypoxia and first pass success (FPS) rates. RESULTS: Following exclusions (n = 121), 720 PHEA cases were analysed (360 new vs. 360 original, no statistically significant difference in demographics). There was no difference in the rate of absolute hypotension (24.4% '1:2:2' v 23.8% '3:2:1', p = 0.93). In trauma patients, there was an increased first pass success (FPS) rate with the new regimen (95.1% v 86.5%, p = 0.01) and a reduced incidence of immediate hypoxia (7.9% v 14.8%, p = 0.05). There was no increase in immediate hypertensive episodes (22.7% vs. 24.2%, p = 0.73). No safety concerns were identified. CONCLUSION: An attenuated fentanyl and augmented rocuronium dosing regimen showed no difference in absolute hypotensive episodes in a mixed cohort of medical and trauma patients. In trauma patients, the new regimen was associated with an increased FPS rate and reduced episodes of immediate hypoxia. Further research is required to understand the impact of such drug dosing in the most critically ill and injured subpopulation.

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study.

BACKGROUND: Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations. METHODS: A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI). RESULTS: 30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension. CONCLUSION: Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Predictors of post-intubation hypotension in trauma patients following prehospital emergency anaesthesia: a multi-centre observational study.

BACKGROUND: Post-intubation hypotension (PIH) after prehospital emergency anaesthesia (PHEA) is prevalent and associated with increased mortality in trauma patients. The objective of this study was to compare the differential determinants of PIH in adult trauma patients undergoing PHEA. METHODS: This multi-centre retrospective observational study was performed across three Helicopter Emergency Medical Services (HEMS) in the UK. Consecutive sampling of trauma patients who underwent PHEA using a fentanyl, ketamine, rocuronium drug regime were included, 2015-2020. Hypotension was defined as a new systolic blood pressure (SBP) < 90 mmHg within 10 min of induction, or > 10% reduction if SBP was < 90 mmHg before induction. A purposeful selection logistic regression model was used to determine pre-PHEA variables associated with PIH. RESULTS: During the study period 21,848 patients were attended, and 1,583 trauma patients underwent PHEA. The final analysis included 998 patients. 218 (21.8%) patients had one or more episode(s) of hypotension ≤ 10 min of induction. Patients > 55 years old; pre-PHEA tachycardia; multi-system injuries; and intravenous crystalloid administration before arrival of the HEMS team were the variables significantly associated with PIH. Induction drug regimes in which fentanyl was omitted (0:1:1 and 0:0:1 (rocuronium-only)) were the determinants with the largest effect sizes associated with hypotension. CONCLUSION: The variables significantly associated with PIH only account for a small proportion of the observed outcome. Clinician gestalt and provider intuition is likely to be the strongest predictor of PIH, suggested by the choice of a reduced dose induction and/or the omission of fentanyl during the anaesthetic for patients perceived to be at highest risk.

Outcomes of critically ill COVID-19 patients managed in a high-volume severe respiratory failure and ECMO centre in the United Kingdom.

During the Coronavirus Disease 2019 (COVID-19) pandemic institutions have needed to develop pragmatic clinical pathways to balance the excess critical care demand and local resources. In this single-centre retrospective cohort study we describe the outcomes of COVID-19 patients admitted to Guy's and St. Thomas' NHS Foundation Trust (GSTT) critical care service. Patients were managed according to a local respiratory failure management pathway that was predicated on timely invasive ventilation when indicated and tailored ventilatory strategies according to pulmonary mechanics. Between 2 March and 25 May 2020 GSTT critical care service admitted 316 patients with confirmed COVID-19. Of the 201 patients admitted directly through the Emergency Department (ED) with a completed critical care outcome, 71.1% survived to critical care discharge. These favourable outcomes may serve to inform the wider debate on optimal organ support in COVID-19.

Veno-venous extracorporeal membrane oxygenation in coronavirus disease 2019: a case series.

BACKGROUND: The use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) in severe hypoxaemic respiratory failure from coronavirus disease 2019 (COVID-19) has been described, but reported utilisation and outcomes are variable, and detailed information on patient characteristics is lacking. We aim to report clinical characteristics, management and outcomes of COVID-19 patients requiring VV-ECMO, admitted over 2 months to a high-volume centre in the UK. METHODS: Patient information, including baseline characteristics and clinical parameters, was collected retrospectively from electronic health records for COVID-19 VV-ECMO admissions between 3 March and 2 May 2020. Clinical management is described. Data are reported for survivors and nonsurvivors. RESULTS: We describe 43 consecutive patients with COVID-19 who received VV-ECMO. Median age was 46 years (interquartile range 35.5-52.5) and 76.7% were male. Median time from symptom onset to VV-ECMO was 14 days (interquartile range 11-17.5). All patients underwent computed tomography imaging, revealing extensive pulmonary consolidation in 95.3%, and pulmonary embolus in 27.9%. Overall, 79.1% received immunomodulation with methylprednisolone for persistent maladaptive hyperinflammatory state. Vasopressors were used in 86%, and 44.2% received renal replacement therapy. Median duration on VV-ECMO was 13 days (interquartile range 8-20). 14 patients died (32.6%) and 29 survived (67.4%) to hospital discharge. Nonsurvivors had significantly higher d-dimer (38.2 versus 9.5 mg·L-1, fibrinogen equivalent units; p=0.035) and creatinine (169 versus 73 µmol·L-1; p=0.022) at commencement of VV-ECMO. CONCLUSIONS: Our data support the use of VV-ECMO in selected COVID-19 patients. The cohort was characterised by high degree of alveolar consolidation, systemic inflammation and intravascular thrombosis.

COVID-19-related organ dysfunction and management strategies on the intensive care unit: a narrative review.

The coronavirus disease 2019 (COVID-19) pandemic has resulted in a significant surge of critically ill patients and an unprecedented demand on intensive care services. The rapidly evolving understanding of pathogenesis, limited disease specific evidence, and demand-resource imbalances have posed significant challenges for intensive care clinicians. COVID-19 is a complex multisystem inflammatory vasculopathy with a significant mortality implication for those admitted to intensive care. Institutional strategic preparation and meticulous intensive care support are essential to maximising outcomes during the pandemic. The significant mortality variation observed between institutions and internationally, despite a single aetiology and uniform presentation, highlights the potential influence of management strategies on outcome. Given that optimal organ support and adjunctive therapies for COVID-19 have not yet been well defined by trial-based outcomes, strategies are predicated on existing literature and experiential learning. This review outlines the relevant pathophysiology and management strategies for critically ill patients with COVID-19, and shares some of the collective learning accumulated in a high volume severe respiratory failure centre in London.

Veno-arterio-venous ECMO for septic cardiomyopathy: a single-centre experience.

INTRODUCTION: The role of extracorporeal support for patients with septic shock remains unclear. METHODS: We conducted a retrospective analysis of our single-centre experience with veno-arterio-venous extracorporeal membrane oxygenation (VAV ECMO) in adult patients with severe respiratory failure and septic cardiomyopathy. Clinical data was extracted from electronic medical records including a dedicated ECMO referral and follow-up database. RESULTS: Twelve patients were commenced on VAV ECMO for septic cardiomyopathy for a median of four days (IQR 3.0 to 5.3) between 01/2014 and 12/2017. Five patients (41.7%) had a cardiac arrest prior to initiation of ECMO support. At baseline, median left ventricular ejection fraction was 16.25% (IQR 13.13 to 17.5) and median PaO2/FiO2 ratio was 9 kPa (IQR 6.5 to 12.0) [67.50 mmHg (IQR 48.75 to 90.00)]. The survival rate to hospital discharge for VAV ECMO was 75% in this cohort. None of the surviving patients died within the follow-up period (median six month). CONCLUSION: VAV ECMO is a feasible rescue strategy for a small proportion of patients with combined respiratory and cardiac failure secondary to septic shock with septic cardiomyopathy. We provide a detailed report of our experience with this technique. Further research is required comparing the different extracorporeal strategies directly to conventional resuscitation and against each other.

Traumatic brain injury: physiological targets for clinical practice in the prehospital setting and on the Neuro-ICU.

PURPOSE OF REVIEW: Over many years, understanding of the pathophysiology in traumatic brain injury (TBI) has resulted in the development of core physiological targets and therapies to preserve cerebral oxygenation, and in doing so prevent secondary insult. The present review revisits the evidence for these targets and therapies. RECENT FINDINGS: Achieving oxygen, carbon dioxide, blood pressure, temperature and glucose targets remain a key goal of therapy in TBI, as does the role of effective prehospital care. Physician led air ambulance teams reduce mortality. Normobaric hyperoxia is dangerous to the injured brain; as are both high and low carbon dioxide levels. Hypotension is life threatening and higher targets have now been suggested in TBI. Both therapeutic normothermia and hypothermia have a role in specific groups of patients with TBI. Although consensus has not been reached on the optimal intravenous fluid for resuscitation in TBI, vigilant goal-directed fluid administration may improve outcome. Osmotherapeutic agents such as hypertonic sodium lactate solutions may also have a role alongside conventional agents. SUMMARY: Maintaining physiological targets in several areas remains part of protocol led care in the acute phase of TBI management. As evidence accumulates however, the target values and therefore therapies may be set to change.

Systemic complications of traumatic brain injury.

PURPOSE OF REVIEW: Increased understanding of the pathophysiology in traumatic brain injury (TBI) has resulted in the development of core physiological targets and therapies to preserve cerebral oxygenation, and in doing so prevent secondary insult. This review addresses the many systemic complications of TBI that make achieving these targets challenging and can influence outcome. RECENT FINDINGS: There are a wide range of systemic complications following TBI. Complications involve the cardiovascular, respiratory, immunological, haematological and endocrinological systems amongst others, and can influence early management and long-term outcomes. SUMMARY: Effective management of TBI should go beyond formulaic-based pursuit of physiological targets and requires a detailed understanding of the multisystem response of the body.

Availability and use of capnography for in-hospital cardiac arrests in the United Kingdom.

BACKGROUND: Airway complications occur more frequently outside the operating theatre and in emergency situations. Capnography remains the gold standard for confirming correct endotracheal tube placement, retaining high sensitivity and specificity in cardiac arrest. The 2010 European Resuscitation Council guidelines for adult advanced life support recommended waveform capnography in this setting. We investigated current UK practice relating to the availability and use of this technology during cardiac arrest. METHODS: Between June and November 2014, a study was conducted of all UK acute hospitals with both a level three adult intensive care unit (ICU) and an emergency department (ED). A telephone questionnaire was administered examining intubation practice and utilisation of capnography within the ED, ICU and general wards. RESULTS: Two hundred and eleven hospitals met the inclusion criteria. The response rate was 100%. Arrests were mainly attended by anaesthesia (48%) and ICU physicians (38%) of registrar grade (56%). The ability to measure end tidal carbon dioxide (ETCO2) was available in all but 4 EDs; most used in waveform devices. Most ICUs were similar. However, in 67% of hospitals surveyed, it was not possible to measure ETCO2 in general wards. Where available, 87% used capnography to confirm ETT placement with less than 50% using ETCO2 to determine CPR effectiveness and 8% to prognosticate. CONCLUSIONS: We believe this is the first study of its kind to fully investigate the availability and use of capnography during cardiac arrest throughout the hospital. Whilst equipment provision appears adequate in critical care areas, it is insufficient in general wards.

Does the use of a bougie reduce the force of laryngoscopy in a difficult airway with manual in-line stabilisation?: a randomised crossover simulation study.

CONTEXT: Manual in-line stabilisation is usually used during tracheal intubation of trauma patients to minimise movement of the cervical spine and prevent any further neurological injury. Use of a bougie in combination with laryngoscopy may reduce the forces exerted on the cervical spine. OBJECTIVE: To evaluate the difference in force applied to the head and neck during tracheal intubation with a Macintosh laryngoscope with or without simultaneous use of a bougie. DESIGN: Randomised, crossover simulation study. SETTING: Simulation laboratory, Anaesthetic Department, Queen's Hospital, Romford between March and April 2012. PARTICIPANTS: Twenty anaesthetists, all with a minimum of 1 year of anaesthetic experience. INTERVENTIONS: Participants used either a Macintosh laryngoscope alone, or in combination with a bougie in a Laerdal SimMan manikin with a simulated difficult airway and manual in-line stabilisation. MAIN OUTCOME MEASURES: The force exerted during laryngoscopy. Success rate and time taken to tracheal intubation were also measured. RESULTS: Significantly less force was exerted utilising a Macintosh laryngoscope in combination with a bougie compared with the laryngoscope alone (24.9 versus 44.5 N; P < 0.001). The trachea was successfully intubated on all occasions within 120 s. The use of a bougie was associated with a nonsignificant reduction in the time to tracheal intubation. CONCLUSION: To minimise the force of laryngoscopy and movement of a potentially unstable cervical spine injury, consideration should be given to the early use of a bougie.

Comparison of the Macintosh, McCoy, Airtraq laryngoscopes and the intubating laryngeal mask airway in a difficult airway with manual in-line stabilisation: a cross-over simulation-based study.

CONTEXT: Patients with multisystem trauma undergoing intubation with manual in-line stabilisation (MILS) have a higher incidence of difficult or failed intubations. OBJECTIVE: To compare the effectiveness of the Macintosh laryngoscope with three other intubating devices in a high fidelity simulation model. DESIGN: Cross-over, simulation-based study. SETTING: Tertiary referral and level 1 trauma centre between June and November 2011. PARTICIPANTS: Thirty-five experienced airway physicians. INTERVENTION: Each participant performed tracheal intubations on a Laerdal SimMan manikin in both a normal airway and a difficult airway scenario with MILS. The devices utilised in a randomised order were the Macintosh, McCoy, Airtraq laryngoscopes and the intubating laryngeal mask airway (iLMA). MAIN OUTCOME MEASURES: The primary outcome was time to intubation. Success rates, grade of laryngoscopy and force of intubation were also measured. RESULTS: One hundred and forty intubations were attempted by 35 participants in both the normal and MILS scenarios. In the normal airway, there was no difference in success rates and time to intubation. In the difficult airway with MILS, there was no difference in success rates. However, the Airtraq was associated with a longer time to intubation than the Macintosh, McCoy and iLMA, 39.3, 26.7, 23.3, 39.3, 22.8 s, respectively (P < 0.0001). The Airtraq delivered the best glottic view and lowest force of intubation in both scenarios (P < 0.0001), but was associated with the only failed intubation in the study. The McCoy was associated with a significant improvement in the glottic visualisation (P < 0.05) and reduction in the force of intubation (P <0.0001) compared with the Macintosh. CONCLUSION: In this manikin study, the McCoy demonstrated multiple advantages over the Macintosh. The iLMA was associated with the fastest time to intubation and minimum force of insertion.

Updates in the management of intracranial pressure in traumatic brain injury.

PURPOSE OF REVIEW: Traumatic brain injury remains a common and often debilitating event across the world, producing significant burdens upon health and social care. Effective neurocritical care coupled with timely and appropriate neurosurgical intervention can produce significant improvements in patient outcome. There remains controversy about how best to manage intracranial pressure on the ICU; we review the recent literature addressing a number of key variables. RECENT FINDINGS: Treatment of elevations in intracranial pressure can begin at the roadside and end on the ICU unit via a number of routes. Prehospital physician-led care may produce significant benefits in outcome which extend beyond airway management. Routine use of cooling worsens the respiratory outcomes without large improvement in neurological endpoints. The use of brain tissue oxygen monitoring is extending and increasingly used to guide management. Decompressive craniectomy in refractory intracranial hypertension has been associated with poor functional outcomes; a large multicentre trial is currently comparing it against barbiturate coma. SUMMARY: The role of the neurointensivist in outcome for patients who suffer severe traumatic brain injury is key. Targeted therapies are allowing early detection and manipulation of brain ischaemia leading to more individualized treatment.

Pulmonary interstitial emphysema presenting in a woman on the intensive care unit: case report and review of literature.

INTRODUCTION: Pulmonary interstitial emphysema is a life-threatening form of ventilator-induced lung injury. We present one of the few reported adult cases of pulmonary interstitial emphysema in a woman with respiratory failure admitted to our intensive care unit. CASE PRESENTATION: An 87-year-old Caucasian woman with a diagnosis of community-acquired pneumonia was admitted to our intensive care unit requiring invasive ventilation. The combination of a poor oxygenation index and bilateral alveolar/interstitial infiltrates on a chest radiograph fulfilled the criteria for adult respiratory distress syndrome; the cause was thought to be a combination of the direct pneumonic pulmonary injury and extrapulmonary severe sepsis. By day seven, the fraction of inspired oxygen, peak airway and positive end expiratory pressures weaned sufficiently to allow an uncomplicated percutaneous tracheostomy. On day 10, problems with ventilation necessitated recruitment maneuvers with a Mapleson C circuit, after which dramatic surgical emphysema was noted. An upper airway bronchoscopy showed no obvious tracheal wall injury, and computed tomography of her chest showed extensive surgical emphysema, perivascular emphysema and peribronchial emphysema, which were consistent with a diagnosis of pulmonary interstitial emphysema. Over the following days, despite protective ventilatory strategies and intercostal tube thoracostomy, lung compliance along with oxygenation deteriorated and our patient died on day 14. CONCLUSION: The development of pulmonary interstitial emphysema is a rare but real risk when caring for patients with worsening lung compliance on the intensive care unit. Improved awareness of the condition, early protective ventilation strategies and timely treatment of any of the lethal complications will hopefully result in improved survival from the condition in adults.

Blunt traumatic pericardial rupture and cardiac herniation with a penetrating twist: two case reports.

BACKGROUND: Blunt Traumatic Pericardial Rupture (BTPR) with resulting cardiac herniation following chest trauma is an unusual and often fatal condition. Although there has been a multitude of case reports of this condition in past literature, the recurring theme is that of a missed injury. Its occurrence in severe blunt trauma is in the order of 0.4%. It is an injury that frequently results in pre/early hospital death and diagnosis at autopsy, probably owing to a combination of diagnostic difficulties, lack of familiarity and associated polytrauma. Of the patients who survive to hospital attendance, the mortality rate is in the order of 57-64%. METHODS: We present two survivors of BTPR and cardiac herniation, one with a delayed penetrating cardiac injury secondary to rib fractures. With these two cases and literature review, we hope to provide a greater awareness of this injury CONCLUSION: BTPR and cardiac herniation is a complex and often fatal injury that usually presents under the umbrella of polytrauma. Clinicians must maintain a high index of suspicion for BTPR but, even then, the diagnosis is fraught with difficulty. In blunt chest trauma, patients should be considered high risk for BTPR when presenting with:Cardiovascular instability with no obvious cause. Prominent or displaced cardiac silhouette and asymmetrical large volume pneumopericardium. Potentially, with increasing awareness of the injury and improved use and availability of imaging modalities, the survival rates will improve and cardiac Herniation could even be considered the 5th H of reversible causes of blunt traumatic PEA arrest.