handbook of critical care medicine

              Handbook  of       Critical  Care  Medicine                 Senaka  Rajapakse       Handbook  of  Critical  Care  Medicine                                     Handbook  of  Critical  Care  Medicine     First  edition  2009   Copyright  2009  Senaka  Rajapakse   All  rights  reserved   ISBN:  978-­‐955-­‐51749-­‐0-­‐9               Handbook  of   Critical  Care  Medicine             Senaka  Rajapakse   MBBS,  MD,  MRCP(UK)   Consultant  Physician   Senior  Lecturer   Department  of  Clinical  Medicine   Faculty  of  Medicine   University  of  Colombo   Sri  Lanka               First  Edition   2009                       to  my  father   Dr  Sirimananda  Rajapakse         who  taught  me  most  of  what  I  know   and  showed  me  where  to  learn  the  rest         Preface     The  management  of  critically  ill  patients  is  an  important  and  integral  part  of   internal   medicine   practice   Often,   junior   doctors   and   medical   students   receive   insufficient   training   in   this   area   of   medicine   There   are   important   differences  in  the  management  of  critically  ill  patients  when  compared  with   relatively  stable  patients,  and  these  differences  are  vital  in  saving  lives     Critical   care   medicine   is   different   from   most   other   disciplines   in   that   the   approach   is   more   problem   oriented,   rather   than   disease   or   condition   oriented  This  does  not  mean  that  the  role  of  the  ICU  clinician  is  simply  to   correct  parameters  which  are  out  of  normal  range  On  the  contrary,  a  clear   understanding   of   the   basis   of   the   clinical   manifestations   in   critically   ill   patients   is   essential   to   proper   management   Anticipation   and   forward   planning  in  care  is  also  vital,  as  is  the  rapidity  of  response  required  from  the   treating  team     While   we   are   often   familiar   with   diseases   and   conditions,   we   often   feel   challenged   when   faced   with   having   to   manage   a   critically   ill   patient   This   book  aims  to  give  junior  doctors  and  medical  students  an  introduction  to  the   practice   of   critical   care   medicine,   orienting   the   reader   towards   a   problem-­‐ solving  approach  It  is  hoped  that  this  book  will  serve  to  make  the  subject  of   critical  care  medicine  seem  less  threatening   I   gratefully   acknowledge   the   assistance   from   Dr   Dinoo   Kirthinanda   and   Dr   Sujani   Wijeratne,   Research   Associates,   who   helped   with   some   of   the   chapters   Special   thanks   also   go   to   Dr   Dinushi   Weerasinghe   who   meticulously  formatted  and  proofread  the  final  draft         Senaka  Rajapakse   2009                 Contents   Clinical  approach  to  the  critically  ill  patient   Homeostasis   Pyrexia   Severe  infection   Hypotension   Sepsis,  severe  sepsis,  septic  shock  and  multi-­‐organ  dysfunction   Evaluating  respiratory  disease  &  airway  management     Asthma  and  COPD   Respiratory  failure   Mechanical  ventilation   Pulmonary  embolism   Hypertensive  problems  in  critical  care   Acute  myocardial  ischaemia   Heart  failure   Arrhythmias   Acute  Renal  Failure   Altered  consciousness   Stroke   Neuromuscular  disorders     Abdominal  problems   Acute  Hepatic  Failure   Pancreatitis   Diabetic  Ketoacidosis   Hypoglycaemia   Sedation,  analgesia,  and  neuromuscular  paralysis     11   17   29   39   54   65   78   88   96   103   115   118   130   143   150   166   182   191   202   214   229   245   251   258   262     Contents   255   Handbook  of  Critical  Care  Medicine                 Management  of  DKA   Treatment  of  DKA  is  as  dangerous  as  DKA  itself  It  may  cause  life-­‐threatening,   predictable  hence  avoidable  acute  complications  such  as:   x   Hypokalemia   x   Hypoglycemia   x   Hyponatremia   x   Fluid  overload   Airway  management  is  the  primary  concern  in  any  patient  with  a  significantly   lowered  level  of  consciousness  Breathing  and  circulatory  stability  should  also   be  established  before  proceeding  to  specific  management   General  measures   x   x   Gain  IV  access  by  a  large  bore  cannula   If   patient’s   level   off   consciousness   is   altered,   insert   a   NG   tube   to   prevent  vomiting  &  aspiration   x   If   the   patient   is   in   a   state   of   respiratory   decompensation,   consider   intubation  and  ventilation   x   If  oliguria  is  present,  catheterize  and  monitor  urine  out  put   x   patient  should  be  kept  nil  by  mouth  at  least  6  hours  as  gastroparesis   is  common  in  DKA   There  are  three  main  problems  which  should  be  reversed  in  DKA     Hyperglycaemia       Dehydration       Acidosis   Hence  insulin  treatment  &  fluid  replacement  are  the  mainstay  of  treatment   As   the   half   life   of   soluble   human   insulin   is   short,   continuous   replacement   is   essential   Fluid  replacement:   Time  [duration]   30  minutes    hour    hours    hours    hours     0.9  NaCl   1L   1L   1L   1L   1L   KCL*   20  m  mol   20  m  mol   20  m  mol   20  m  mol   20  m  mol     DKA   256   Handbook  of  Critical  Care  Medicine               If  the  serum  K+  exceeds  5.5  mmol/L,  K+  should  not  be  to  the  replacement  fluid   However  the  levels  should  be  monitored  closely  as  it  may  drop  suddenly  due   to   insulin   treatment     If   the   K+   level   is   below   3.5   m   mol/L   at   the   beginning,   consider  giving  40  meq  of  KCl  per  each  litre  of  fluid  replaced   If   the   blood   pressure   drops   below   90   mmHg,   consider   giving   a   colloid   Clinically  monitor  the  following:   x   x   x   x   x   Blood  pressure   Pulse  rate  &  volume   Hydration  status   Apperarence  of  pulmonary  oedema     Urine  out  put     The  Insulin  infusion  should  be  continued  until  the  acidosis  resolves,  i.e.,  until   the  pH  and  anion  gap  are  normal,  even  if  the  blood  glucose  levels  are  normal     Complications   The  main  complications  of  DKA  and  its  treatment  are:   Complications  of  DKA  &  its  treatment   x   x   x   x   x   x   Hypokalemia   Hypophosphataemia   Metabolic  acidosis   Hypoglycaemia   Cerebral  oedema  especially  in  children   Thromboembolism  due  to  dehydration  &  sluggish  perfusion             DKA   257     Handbook  of  Critical  Care  Medicine             Insulin  replacement   Blood  glucose   concentration   [mmol/L]   Rate  of  Insulin   Comments   [units/Kg/hour]   Rate  of  Insulin  for   Route  of  insulin   a  60  Kg  person   [units/hour]   >20   0.1     20-­‐15   0.07     Up  to  11  mmol/L  use  NaCl  as  the   replacement  fluid   15-­‐11   0.05     11-­‐07   0.03     07-­‐05   0.02