Andrew S Lane

The Lance-Adams Syndrome: Helpful or Just Hopeful, after Cardiopulmonary Arrest

In this case report, two patients are presented who developed myoclonic status epilepticus after severe hypoxic brain injury and were diagnosed as having Lance-Adams syndrome (post-hypoxic myoclonus). The diagnosis of Lance-Adams syndrome and the controversies and difficulties that surround its diagnosis and treatment and other aspects of prognostication in cardiac arrest are reviewed.

Tension pneumomediastinum: A literal form of chest tightness:

Tension pneumomediastinum is a rare and life-threatening complication of mediastinal emphysema which can occur with mechanical ventilation. We present a case of tension mediastinum associated with mechanical ventilation in a patient with Acute Respiratory Distress Syndrome due to Pneumocystis jirovecii pneumonia. We discuss the mechanism and pathophysiology of tension pneumomediastinum, the potential association with Pneumocystis jirovecii pneumonia and recruitment manouvres, and its definitive emergency treatment.

Dexmedetomidine for acute clonidine withdrawal following intrathecal pump removal: A drug beginning to find its expanding niche

Management of chronic non-cancer pain by intrathecal delivery is gaining increasing use despite lack of evidence of efficacy and long-term safety. The development of drug tolerance due to these devices can precipitate life-threatening withdrawal syndromes if drug delivery is ceased. Clonidine is a centrally acting a2 agonist and has level II evidence for intrathecal use, either as a single or combined agent in the management of chronic neuropathic pain. Serious complications from acute clonidine withdrawal due to intrathecal pump malfunction have been reported, such as the development of stress-induced cardiomyopathy. Previous case reports have described the use of intravenous clonidine and benzodiazepines to manage the acute withdrawal syndrome. We admitted a patient to the intensive care unit (ICU) due to life-threatening sequelae of acute clonidine and opioid withdrawal following the removal of an infected intrathecal pump 48h prior. The withdrawal was characterised by hyperactive delirium; blood pressure 280/190mmHg: sinus tachycardia 165 beats/min. The patient had been previously receiving; intravenous morphine infusion; twice daily oral dosing of clonidine; additional intravenous clonidine. She required intubation and ventilation to control her physiological derangement and delirium. The initial use of opioids, benzodiazepines and propofol did not result in a resolution of her severe tachycardia, and unfortunately led to hypotension requiring numerous aliquots of vasopressor medication. Dexmedetomidine was commenced at a dose of 1mg/kg/h with no initial bolus, enabling a cessation of the midazolam, and significant weaning of the propofol. After 60min, there was a sustained episode of hypotension leading to a reduction in the Dexmedatomidine dose to 0.4mg/kg/h, which achieved cardiovascular stability with a blood pressure of 150/90mmHg and a heart-rate of 64 beats/min. The patient was extubated 48h after intubation on 0.4mcg/kg/h dexmedetomidine and morphine 2mg/h. She discharged from ICU on day 3 pain-free, having being re-started on oral clonidine, and continued on intravenous opioids. The pharmacological profile of dexmedetomidine when compared to clonidine may confer possible benefits in this particular population due to an eight-fold greater selectivity and specificity for a2 versus a1 adrenoceptors, along with known nociceptive effects leading to a subsequent reduction in opioid requirements. The ability to titrate a continuous infusion rather than administer boluses of clonidine also offered greater cardiovascular stability. The use of dexmedetomidine for sedation in ventilated patients in ICU is approved by the food and drug administration (FDA), and the ongoing SPICE III study may further establish its role in sedation and prevention of delirium in ICU patients. Its use beyond this setting is also gaining interest with case series evaluating its role in acute alcohol withdrawal, and in procedural sedation to provide effective sedation and analgesia without causing significant respiratory depression and blunting of airway reflexes. While we are not claiming that dexmedetomidine is a ‘magic bullet’, however, it makes sense that with the changing ICU patient demographic, especially patients with a significant history of alcohol and substance abuse, we may need to tailor our traditional sedation regimens to optimise patient outcomes.

Diabetic ketoacidosis due to fulminant type 1 diabetes: A rare subtype of type 1 diabetes leading to unusual sequelae

Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes (T1D), which without treatment leads to death. Fulminant type 1 diabetes (FT1D) is a subtype characterised by a markedly rapid and almost complete destruction of pancreatic β-cells, with acute onset leading to severe metabolic derangement and commonly ICU admission. We present a case of an 18-year-old male presenting with FT1D with two rare complications of pneumomediastinum and stress-induced cardiomyopathy (SIC) with significant myocardial necrosis. We also discuss the aetiology of the pneumomediastinum; the latest thoughts on SIC: moving beyond the simple description of ‘Takotsubo cardiomyopathy’; the role of troponins in critical illness; and genetic predisposition for DKA due to FT1D.

The Use of Echocardiography in Diagnosis, Risk Stratification and Management of Pulmonary Embolism: A Retrospective Single-Centre Analysis

Pulmonary embolism (PE) is a life-threatening condition with high morbidity and mortality. The presence of systolic hypotension and/or right heart strain (RHS) is currently used to stratify patients and direct management. Echocardiography has a demonstrated role in the management of PE and has been used to guide therapies such as thrombolysis. We performed a retrospective study of all patients admitted to the Nepean Hospital Intensive Care Unit (ICU) with a diagnosis of acute pulmonary embolism between 1 January 2006 and 31 December 2011 to analyse if and how echocardiography was used in the diagnosis, classification and management of these patients. During this time, 59 patients were admitted with a diagnosis of acute PE or developed a PE in the intensive care unit, of whom 22 had a diagnosis of submassive PE, demonstrating RHS on echocardiography. Eleven of these patients received thrombolysis and survived to hospital discharge. The use of echocardiography identified greater numbers of patients with high risk pulmonary embolus, enabling risk stratification for thrombolysis with potential morbidity and mortality benefit.

The Learning Pathways Grid: Promoting Reflexivity Among Learners and Researchers in Patient Safety Simulations

The interview is an important data-gathering tool in qualitative research, since it allows researchers to gain insight into a person’s knowledge, understandings, perceptions, interpretations, and experiences. There are many definitions of reflexivity in qualitative research, one such definition being “Reflexivity is an attitude of attending systematically to the context of knowledge construction, especially to the effect of the researcher, at every step of the research processes.” The learning pathways grid (LPG) is a visual template used to assist analysis and interpretation of conversations, allowing educators, learners, and researchers, to discover links from cognition to action, usually in a retrospective manner. It is often used in simulation educational research, with a focus on understanding how learners access their cognitive frames and underlying beliefs. In this article, we describe the use of the LPG as a prospective adjunct to data collection for interviews and focus groups. We contextualize it within a study among medical interns and medical students who were engaged in high-fidelity simulation exploring open disclosure after a medication error. The LPG allowed future optimization of data collection and interpretation by ensuring reflexivity within the researchers, a vital part of research conduct. We conclude by suggesting the use of the LPG has a reasonable fit when taking a social constructivist approach and using qualitative analysis methods that make reflexivity explicit and visible, therefore ensuring it is truly considered, understood, and demonstrated by researchers.

Intermediate level training: A paradigm requiring reflective competence:

The role of echocardiography within the intensive care unit (ICU) has progressed dramatically in the past decade. It is now an expected part of the Intensivist’s armamentarium to diagnose and manage clinical conditions based on their ability to record and interpret ultrasound imaging. However, the acquisition of any new skill requires the responsibility to recognise the limitations of one’s knowledge, experience and expectations. We admitted a 64-year-old male to the ICU with a two-day history of vomiting, worsening renal function and hypotension. Initial transthoracic echo (TTE) was reported as showing; ventricular-septal-defect (VSD); dyskinesis of the IV septum; possible dissecting thoracic aortic aneurysm. However, on closer inspection of the parasternal long axis view, it was recognized that there was an abnormal echo-free space adjacent to the aorta (Figure 1); the Doppler jet originated from the echo-free space and not the left ventricle and occurred in diastole (Figures 2 and 3). The apical four-chamber view also demonstrated Doppler flow from the abnormal echo-free space to the right ventricle (RV) and right atrium (RA) (Figures 4 and 5). Transoesophageal echocardiogram (TOE) demonstrated the echo-free space to be pulsatile, representing a sinus of valsalva aneurysm (SOVA) originating near the right coronary cusp communicating with the RA/RV junction (Figure 6(a) and (b)). In a previous case, report of a ruptured SOVA being misdiagnosed as a VSD, it highlighted the need to demonstrate in which part of the cardiac cycle the abnormal jet is present (as above), however, the report also mentions the possibility of a coexisting VSD being masked by the ruptured SOVA, and another potential misdiagnosis being a coronary ateriovenous fistula. Our case and the case report highlight the learning-curve required when acquiring new skills, and the literature reinforces the danger of false positives (overcalling) and false-negatives (omission) as this skill is acquired . There is currently debate regarding the place for ‘intermediate level’ of training in echocardiography vs. simply ‘basic’ and ‘expert’; however, the desire for intermediate level training is not without risk. There has been discussion in the educational literature about the concept of the competency matrix (Figure 7). It states that a learner acquiring new skills begins at level of unconscious incompetence; however, this is not correct. Most learners commence a learning process knowing they do not know it. Therefore, they are consciously incompetent. It is as their skills progress and expectations of performance increase that learners are at risk of being unconsciously incompetent: they can actually regress to this level. Only with further training do they recognise this, and once again become consciously incompetent. The length of time learners spend in this stage depends on the strength of the stimulus to learn mastery. If a learner’s ceiling of desired mastery is ‘intermediate level’, then with no stimulus to achieve mastery at the ‘expert level’, the risk of ongoing unconscious incompetence is significant, leading to false-positives and false-negatives in interpretation. A practitioner who is at ‘intermediate level’ mastery needs to possess reflective competence to ensure that they recognise the constant potential of unconscious incompetence, and seek assistance when required. Our case demonstrated the requirement to utilise off-axis imaging and optimise Doppler settings. These skills require ‘expert level’ knowledge and experience. We are not arguing that ‘intermediate level’ training should be abandoned as a principle; however, it requires specific cognitive abilities of reflective competence to operate between the level of beginner and expert (Figure 7). Conscious incompetence: You become aware of how much you have to learn. You realise you require time and practice to progress. Conscious incompetence: You are starting to master the new skill, but you still have to actively think if you are doing it right. Unconscious competence: You don’t even think about your new skill anymore. The skills comes naturally as an expert. Reflective competence: The background cognitive quality that is required at all stages, that allows a

Thyroid storm causing placental abruption: Cardiovascular and management complications for the Intensivist

Thyroid storm is a rare and serious complication of pregnancy which can lead to spontaneous abortion, preterm delivery, preeclampsia and cardiac failure. It is also associated with high maternal and foetal mortality if not diagnosed and managed promptly. The diagnosis of thyroid storm in pregnancy can pose significant challenges due to its presentation being similar to other pregnancy-related complications. We present a patient who developed thyroid storm at 29 weeks of pregnancy, which resulted in pre-term delivery, cardiac failure and thyroidectomy. We discuss the treatment of thyroid storm in pregnancy, the decision making involved in proceeding to thyroidectomy or to use radio-iodine, and foetal thyroid status in thyrotoxicosis.

Ante-partum necrotising myometritis due to Streptococcal toxic shock

Group A streptococcus (GAS) causes severe infections in obstetric patients. A rare complication is rapidly progressive necrotising myometritis. Postpartum necrotising myometritis has been previously described; however, antenatal development of such a condition is extremely rare. We present a patient who developed antenatal necrotising myometritis and toxic shock syndrome (TSS) due to GAS during the first trimester of pregnancy, eventually requiring hysterectomy and bilateral oophorectomy. We discuss the rare complication of ante-partum necrotising myometritis, as well as the antibiotic therapy, and treatment of TSS associated with severe Group A Streptococcal infections.

Limbic Encephalitis and Refractory Status Epilepticus in the ICU: Classification, Diagnosis and Treatment

Limbic encephalitis is a rare auto-immune condition that usually presents subacutely with vague symptoms such as headache, confusion and memory loss.1 If not diagnosed early the sequelae can be severe, including refractory status epilepticus. The majority of cases are associated with underlying neoplasia. We present a case of voltage-gated potassium channel limbic encephalitis and its subsequent management during a long ICU admission. We discuss the classification, diagnosis and treatment of limbic encephalitis, review the use of sodium thiopental to achieve burst suppression in refractory status epilepticus, and the use of continuous EEG monitoring in the ICU.