The Little ICU Book of Facts and Formulas

Books now compete with web-based electronic resources, and the challenge for authors and publishers is how to provide accurate and timely information with sufficient depth and breadth to be useful in the workplace. A book of this type therefore has to compromise between size and detail, demonstrate balance in selection of material, and appeal to a globalised world. In many respects, Paul Marino succeeds in this task. 
 
The book is a condensed version of 'The ICU Book' by the same author. Intended as a compact bedside reference, it is presented as 15 chapters, each with up to 5 sub-sections. Chapters cover diverse subjects with an appendix of conversion tables, normal values and formulae. Algorithms are well referenced using current evidence. 
 
However, these strengths are offset by some notable omissions and imbalances. The haemodynamic monitoring section is exclusively based on the pulmonary artery flotation catheter (PAFC), disregarding other forms of monitoring – for example, oesophageal Doppler, LiDCO™ or PiCCO™. No reference is made to evidence regarding lack of clinical utility of the PAFC. The section on haemodynamic drugs lacks breadth, omitting discussion of epinephrine, vasopressin (mentioned briefly in the septic shock chapter), phosphodiesterase inhibitors or levosimendan. Sodium nitroprusside, however, receives four pages. 
 
The chapter on vascular access mentions the importance of aseptic technique, stating that handwashing, sterile gloves and full barrier precautions are 'recommended' for central venous catheter (CVC) insertion. A simple table mandating such measures would have greater impact, including the use of alcoholic chlorhexidine and a catheter cart facilitating prior preparation. There is no reference to the use of ultrasound guided CVC insertion. Conversely, there is an unnecessary page describing peripheral intravenous cannulation. 
 
The toxicology chapter omits important aspects of self-poisoning, namely tricyclic antidepressants and drugs of abuse. The chapter on antimicrobial therapy would have been improved by repeating the Surviving Sepsis Campaign recommendations in the septic shock section and by referencing the website, rather than the now outdated 2004 recommendations. Daily review and early termination of antimicrobials should be emphasised. 
 
The sequences of chapters and topic choices are disjointed. Topics including illness severity scoring, morbidity, mortality and treatment withdrawal would have been useful. Non-SI units in many equations make conversions inconveniently necessary for the European reader. The book is positioned as a primer in the basics of North American intensive care medicine. It is not entirely harmonised with European practice and readers may consider alternatives. That said, trainees would find it a handy reference at the ICU workstation.

Intensive care units (ICUs) are overwhelming on first encounter. Trainees and others often face severity of illnesses, care processes, and advanced technologies that offer intellectual, physical, and moral challenges. There is a need for a safety net, a quick reference that aspiring clinicians can have immediately at hand. This reference should be compact, portable, and easily accessible. Reading it should be simple, but it must include sufficient information that supports the provision of comprehensive clinical approaches to patients. This fine line between simplicity and a full range of information can be difficult to achieve, but when present in a reference text, it can be a powerful mechanism to relieve anxiety in trainees and facilitate excellent patient care.
Does The Little ICU Book of Facts and Formulas deliver simple answers to a broad range of critical care medicine questions? Perhaps for novice trainees, but not for those who have passed beyond their introductions to critical care medicine. For example, on the day I received this book, I evaluated a patient with suspected meningitis. I subsequently was unable to find a sentence or table describing cere-brospinal fluid analysis to differentiate the various causes of central nervous system infections.
The first few chapters of the text focus on basic issues of life in the ICU. They deal with behavioral issues relating to infection control and general prevention of ICU-related complications. All the relevant issues are addressed and supported by current data. The remaining initial chapters describe issues related to vascular access and hemodynamic monitoring. These chapters are comprehensive, including anatomy reviews, presentation of equipment, a stepwise technical approach, and general management and concerns. Basic biophysics is used appropriately to explain the reasons, methods, and limitation of each parameter.
The chapter on resuscitation in the ICU is well presented. It includes the biophysical rationale in fluid resuscitation, including recent practice guidelines for blood product transfusion and a discussion of the never-ending colloid versus crystalloid infusion controversy. Heart failure is included in this section, and the presentation contains an excellent physiologic explanation for both right and left ventricular dysfunction and a reasonable discussion of the differences between systolic and diastolic causes. However, it is when the book delves into management suggestions that both the power and limitations of a single author are manifest. For example, I believe that Marino's suggestion that the dose of furosemide recommended for heart failure (100 mg bolus then 40 mg/h that could be doubled in 12 h) would be considered to be highly unusual in the many practices.
I found that the Cardiology chapter contains an excellent overview of acute coronary syndromes and arrhythmias, and is based on recent data and recommendations. The Pulmonary chapter is adequate with its presentation of acute respiratory distress syndrome and chronic obstructive pulmonary disease, but its review of mechanical ventilation is cursory and lacks basic definitions and explanations of modes of ventilation, breath types, and commentary on cycling. The Acid-Base Disorders chapter definitely is one of the most concise yet helpful reviews in this text. It includes a rational clinical diagnostic path thorough enough to include the "delta gap" and other concepts. It would have been perfect if it mentioned Stewart's strong ion gap theory and the osmolal gap in ethylene glycol intoxication. Another excellent chapter describes renal and electrolyte disorders and renal replacement therapy. It is packed with theoretical information and a diagnostic pathway for renal failure. It would have been improved, however, if it contained more information on continuous veno-venous hemofiltration and dialysis. The chapter about inflammation is an excellent resume of current understanding of sepsis and septic shock. Similar kudos can be extended for the chapter on nutrition. The Neuro-Critical Care section of the book focuses on the management of specific pathologies such as delirium, cerebral ischemia, and seizures. Unfortunately, it lacks a description of the comprehensive approach to altered mental status or coma. Perhaps most disappointing in this section is the short shrift given to ICU sedation. The toxin chapter is very superficial and really only addresses acetaminophen overdose.
Overall, The Little ICU Book of Facts and Formulas is a reasonable critical care manual for novice trainees as they first encounter the ICU. The author's focus on physiologic disturbances and their causes as opposed to a cookbook compendium of facts and quick therapeutics supports the ability of this pocket-sized manual to describe why events happen. The author expressed a desire in the book's preface to make this a compact reference for the bedside. I believe that it is a good resource for medical students, interns, and residents to read before going into the ICU.