The incidence of Acute Mountain Sickness (AMS) is increasing. In a military context our current o... more The incidence of Acute Mountain Sickness (AMS) is increasing. In a military context our current operational areas include mountainous regions with the implications of AMS including loss of operational tempo and logistical overstretch. Oxygen saturation and heart rate variability have in some studies been predictive of AMS while in others not. No single factor has been demonstrated consistently to be predictive of developing AMS. During an expedition to climb Mt Aconcagua (6959m) we explored the relationship between cardiorespiratory variables and AMS. In 11 subjects we measured simple physiological variables and Lake Louise Score both pre and post a standardised exercise challenge at on arrival at different altitudes and after a period of acclimatization. The changes in cardiorespiratory variables we observed with altitude were consistent with previous studies. Heart rate, respiratory rate and blood pressure increased whilst oxygen saturation reduced. Over time at altitude, respiratory rate and heart rate were maintained whilst there was a reduction in blood pressure towards sea level values. Oxygen saturations improved over time at altitude and the change in heart rate on exercise was reduced with acclimatization. In this small pilot study individuals with AMS may have a greater heart rate response to exercise than non-AMS subjects and this may warrant further investigation. The incidence of AMS in our study was low reflecting a conservative ascent profile. Further larger studies are necessary to fully assess the predictive value of cardiorespiratory variables in AMS.
There is no current consensus within the anaesthetic and perioperative research community on what... more There is no current consensus within the anaesthetic and perioperative research community on what outcomes are important, nor how to measure them. This leads to het-erogeneity of outcome reporting in randomised controlled trials (RCTs), and selective outcome reporting – i.e. a bias towards reporting only statistically significant outcomes [1]. Here we describe an initiative to develop a Core Out-come Set for Anaesthetic and Perioperative Research.
The primary driver of length of stay after bowel surgery, particularly colorectal surgery, is the... more The primary driver of length of stay after bowel surgery, particularly colorectal surgery, is the time to return of gastrointestinal (GI) function. Traditionally, delayed GI recovery was thought to be a routine and unavoidable consequence of surgery, but this has been shown to be false in the modern era owing to the proliferation of enhanced recovery protocols. However, impaired GI function is still common after colorectal surgery, and the current literature is ambiguous with regard to the definition of postoperative GI dysfunction (POGD), or what is typically referred to as ileus. This persistent ambiguity has impeded the ability to ascertain the true incidence of the condition and study it properly within a research setting. Furthermore, a rational and standardized approach to prevention and treatment of POGD is needed. The second Perioperative Quality Initiative brought together a group of international experts to review the published literature and provide consensus recommendati...
Anaesthesia, Pain, Intensive Care and Emergency Medicine — A.P.I.C.E., 2002
Major gastrointestinal (GI) surgery is high risk, producing significant physiological disturbance... more Major gastrointestinal (GI) surgery is high risk, producing significant physiological disturbance in patients who are often frail prior to surgery. It is associated with considerable morbidity and mortality [1, 2]. Fluid therapy is a fundamental part of the management of the high-risk surgical patient [3]. Detailed knowledge of the pharmacology of the available intravenous solutions should guide their use. It is now clear that differentiation between the properties of the carrier solution and the dissolved colloid is of fundamental importance. Preoperative risk assessment should lead to institution of adequate perioperative monitoring to guide fluid therapy and allocation of an appropriate level of postoperative care, which in many cases will be in a dedicated critical care facility. Fluid therapy should be titrated to rational, physiological endpoints and not dictated by a recipe. Pro-active “optimization” of intravascular volume and organ blood flow has been shown to improve outcome. A “big picture” look at the available literature suggests that the “when” and “how much” of fluid therapy are far more important than the “what”.
Journal of the Intensive Care Society, Jul 1, 2014
In recent years there has been a gradual shift away from using uncontrolled high concentrations o... more In recent years there has been a gradual shift away from using uncontrolled high concentrations of inspired oxygen in some acute illnesses. Oxygen is perhaps the most frequently used drug in medicine, and understanding the balance of benefits and harms is essential knowledge for all anaesthetists and intensivists. While current teaching and practice emphasise avoiding hypoxaemia over concerns about hyperoxaemia, it may transpire that oxygen excess is more harmful than previously thought. As with many interventions in intensive care medicine, striving to achieve physiological normality may sometimes do more harm than good, and tolerance of abnormal values may on occasion be in patients' best interests. Incorporating Single Best Answers (see page 197: answers on page 237).
The authors present a case of a young, non-diabetic Caucasian male patient with long-standing dep... more The authors present a case of a young, non-diabetic Caucasian male patient with long-standing depression who had recently been started on venlafaxine. He presented to the emergency department with central abdominal pain, drowsiness and vomiting with a raised serum amylase. He was diagnosed with acute pancreatitis (AP) that was confirmed following an abdominal ultrasound and CT. His initial biochemistry was immeasurable in the first 12 h of admission due to macroscopically visible hyperlipidaemia. In the absence of any other causes of AP, hyperlipidaemia was the most likely aetiology. He was transferred to the intensive care unit where he was managed by lipidic restriction, fluid resuscitation and 3 consecutive days of plasma exchange. Plasma triglyceride levels were reduced from 42.9 to 2.4 mmol/l following plasma exchange. He made a full recovery and at discharge was investigated for familial hypertriglyceridaemia and referred to a multi-disciplinary team for follow-up. His venlafa...
Cellular hypoxia is a fundamental mechanism of injury in the critically ill. The study of human r... more Cellular hypoxia is a fundamental mechanism of injury in the critically ill. The study of human responses to hypoxia occurring as a consequence of hypobaria defines the fields of high-altitude medicine and physiology. A new paradigm suggests that the physiological and pathophysiological responses to extreme environmental challenges (for example, hypobaric hypoxia, hyperbaria, microgravity, cold, heat) may be similar to responses seen in critical illness. The present review explores the idea that human responses to the hypoxia of high altitude may be used as a means of exploring elements of the pathophysiology of critical illness.
The present article outlines the basic principles of Evidence Based Medicine (EBM) and how they s... more The present article outlines the basic principles of Evidence Based Medicine (EBM) and how they should guide clinical practice. The evidence supporting a selection of perioperative interventions is assessed against objective criteria. Many of the perioperative interventions that have been widely adopted into clinical practice are supported by very limited evidence. Conversely a high level of evidence supports other interventions that have not been so widely adopted. This may be due to concerns about limitations in the design and conduct of some of the clinical trials.
The management of elevated blood acid (metabolic acidosis) is poorly understood and standard ther... more The management of elevated blood acid (metabolic acidosis) is poorly understood and standard therapies are often initiated without consideration of the underlying pathophysiology.
The incidence of Acute Mountain Sickness (AMS) is increasing. In a military context our current o... more The incidence of Acute Mountain Sickness (AMS) is increasing. In a military context our current operational areas include mountainous regions with the implications of AMS including loss of operational tempo and logistical overstretch. Oxygen saturation and heart rate variability have in some studies been predictive of AMS while in others not. No single factor has been demonstrated consistently to be predictive of developing AMS. During an expedition to climb Mt Aconcagua (6959m) we explored the relationship between cardiorespiratory variables and AMS. In 11 subjects we measured simple physiological variables and Lake Louise Score both pre and post a standardised exercise challenge at on arrival at different altitudes and after a period of acclimatization. The changes in cardiorespiratory variables we observed with altitude were consistent with previous studies. Heart rate, respiratory rate and blood pressure increased whilst oxygen saturation reduced. Over time at altitude, respiratory rate and heart rate were maintained whilst there was a reduction in blood pressure towards sea level values. Oxygen saturations improved over time at altitude and the change in heart rate on exercise was reduced with acclimatization. In this small pilot study individuals with AMS may have a greater heart rate response to exercise than non-AMS subjects and this may warrant further investigation. The incidence of AMS in our study was low reflecting a conservative ascent profile. Further larger studies are necessary to fully assess the predictive value of cardiorespiratory variables in AMS.
There is no current consensus within the anaesthetic and perioperative research community on what... more There is no current consensus within the anaesthetic and perioperative research community on what outcomes are important, nor how to measure them. This leads to het-erogeneity of outcome reporting in randomised controlled trials (RCTs), and selective outcome reporting – i.e. a bias towards reporting only statistically significant outcomes [1]. Here we describe an initiative to develop a Core Out-come Set for Anaesthetic and Perioperative Research.
The primary driver of length of stay after bowel surgery, particularly colorectal surgery, is the... more The primary driver of length of stay after bowel surgery, particularly colorectal surgery, is the time to return of gastrointestinal (GI) function. Traditionally, delayed GI recovery was thought to be a routine and unavoidable consequence of surgery, but this has been shown to be false in the modern era owing to the proliferation of enhanced recovery protocols. However, impaired GI function is still common after colorectal surgery, and the current literature is ambiguous with regard to the definition of postoperative GI dysfunction (POGD), or what is typically referred to as ileus. This persistent ambiguity has impeded the ability to ascertain the true incidence of the condition and study it properly within a research setting. Furthermore, a rational and standardized approach to prevention and treatment of POGD is needed. The second Perioperative Quality Initiative brought together a group of international experts to review the published literature and provide consensus recommendati...
Anaesthesia, Pain, Intensive Care and Emergency Medicine — A.P.I.C.E., 2002
Major gastrointestinal (GI) surgery is high risk, producing significant physiological disturbance... more Major gastrointestinal (GI) surgery is high risk, producing significant physiological disturbance in patients who are often frail prior to surgery. It is associated with considerable morbidity and mortality [1, 2]. Fluid therapy is a fundamental part of the management of the high-risk surgical patient [3]. Detailed knowledge of the pharmacology of the available intravenous solutions should guide their use. It is now clear that differentiation between the properties of the carrier solution and the dissolved colloid is of fundamental importance. Preoperative risk assessment should lead to institution of adequate perioperative monitoring to guide fluid therapy and allocation of an appropriate level of postoperative care, which in many cases will be in a dedicated critical care facility. Fluid therapy should be titrated to rational, physiological endpoints and not dictated by a recipe. Pro-active “optimization” of intravascular volume and organ blood flow has been shown to improve outcome. A “big picture” look at the available literature suggests that the “when” and “how much” of fluid therapy are far more important than the “what”.
Journal of the Intensive Care Society, Jul 1, 2014
In recent years there has been a gradual shift away from using uncontrolled high concentrations o... more In recent years there has been a gradual shift away from using uncontrolled high concentrations of inspired oxygen in some acute illnesses. Oxygen is perhaps the most frequently used drug in medicine, and understanding the balance of benefits and harms is essential knowledge for all anaesthetists and intensivists. While current teaching and practice emphasise avoiding hypoxaemia over concerns about hyperoxaemia, it may transpire that oxygen excess is more harmful than previously thought. As with many interventions in intensive care medicine, striving to achieve physiological normality may sometimes do more harm than good, and tolerance of abnormal values may on occasion be in patients' best interests. Incorporating Single Best Answers (see page 197: answers on page 237).
The authors present a case of a young, non-diabetic Caucasian male patient with long-standing dep... more The authors present a case of a young, non-diabetic Caucasian male patient with long-standing depression who had recently been started on venlafaxine. He presented to the emergency department with central abdominal pain, drowsiness and vomiting with a raised serum amylase. He was diagnosed with acute pancreatitis (AP) that was confirmed following an abdominal ultrasound and CT. His initial biochemistry was immeasurable in the first 12 h of admission due to macroscopically visible hyperlipidaemia. In the absence of any other causes of AP, hyperlipidaemia was the most likely aetiology. He was transferred to the intensive care unit where he was managed by lipidic restriction, fluid resuscitation and 3 consecutive days of plasma exchange. Plasma triglyceride levels were reduced from 42.9 to 2.4 mmol/l following plasma exchange. He made a full recovery and at discharge was investigated for familial hypertriglyceridaemia and referred to a multi-disciplinary team for follow-up. His venlafa...
Cellular hypoxia is a fundamental mechanism of injury in the critically ill. The study of human r... more Cellular hypoxia is a fundamental mechanism of injury in the critically ill. The study of human responses to hypoxia occurring as a consequence of hypobaria defines the fields of high-altitude medicine and physiology. A new paradigm suggests that the physiological and pathophysiological responses to extreme environmental challenges (for example, hypobaric hypoxia, hyperbaria, microgravity, cold, heat) may be similar to responses seen in critical illness. The present review explores the idea that human responses to the hypoxia of high altitude may be used as a means of exploring elements of the pathophysiology of critical illness.
The present article outlines the basic principles of Evidence Based Medicine (EBM) and how they s... more The present article outlines the basic principles of Evidence Based Medicine (EBM) and how they should guide clinical practice. The evidence supporting a selection of perioperative interventions is assessed against objective criteria. Many of the perioperative interventions that have been widely adopted into clinical practice are supported by very limited evidence. Conversely a high level of evidence supports other interventions that have not been so widely adopted. This may be due to concerns about limitations in the design and conduct of some of the clinical trials.
The management of elevated blood acid (metabolic acidosis) is poorly understood and standard ther... more The management of elevated blood acid (metabolic acidosis) is poorly understood and standard therapies are often initiated without consideration of the underlying pathophysiology.
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Papers by Mike Grocott