TY  - CHAP
M1  - Book, Section
TI  - Case Study 12
A1  - Hoffman, Robert S.
A1  - Howland, Mary Ann
A1  - Lewin, Neal A.
A1  - Nelson, Lewis S.
A1  - Goldfrank, Lewis R.
PY  - 2015
T2  - Goldfrank's Toxicologic Emergencies, 10e
AB  - HistoryA  60  year-old  man  with  a  history  of  hypertension,  coronary  artery  disease,  congestive  heart  failure,  and  chronic  obstructive  pulmonary  disease  was  admitted  to  the  hospital  following  an  emergency  department  (ED)  presentation  for  shortness  of  breath.  Because  no  bed  was  available  on  the  inpatient  service,  he  was  boarded  in  the  ED  for  many  hours.  The  ED  physician  who  is  no  longer  caring  for  the  patient  received  a  call  from  the  laboratory  that  the  patient’s  serum  potassium  was  6.8  mEq/L  in  a  nonhemolyzed  specimen.  A  call  was  placed  to  the  patient’s  care  team,  but  after  several  minutes  there  was  no  response.Physical  ExaminationA  brief  examination  was  performed,  and  the  following  vital  signs  were  obtained:  blood  pressure,  166/92  mm  Hg;  pulse,  84  beats/minute;  respiratory  rate,  22  breaths/minute;  temperature,  99.2°F  (37.3°C);  oxygen  saturation,  93%  on  4  L  oxygen/minute  via  nasal  cannula.  The  patient  was  awake  and  alert  with  a  normal  ­neurologic  evaluation,  and  the  chest  ­examination  revealed  some  wheezing  and  rhonchi  and  a  regular  heart  rhythm  with  an  S3  gallop.  Electrocardiography  (ECG)  was  obtained  (Fig.  CS12–1).Immediate  ManagementThe  ED  physician  ordered  calcium  gluconate  (1  g),  regular  insulin  (10  units),  and  dextrose  (25  g)  all  to  be  given  via  the  intravenous  (IV)  route  to  treat  hyperkalemia.  Shortly  after  the  nurse  administered  the  medications,  the  patient  was  noted  to  have  a  generalized  seizure  and  lost  consciousness.  His  pulse  was  noted  to  decrease  and  his  QRS  complex  widened  (Fig.  CS12–2).  The  patient’s  permanent  pacemaker  captured  intermittently,  and  his  blood  pressure  fell  to  80/50  mm  Hg.  A  bolus  of  1  L  of  0.9%  sodium  chloride  was  ordered  and  the  patient  was  placed  on  100%  oxygen  via  a  nonrebreather  mask.  A  rapid  reagent  glucose  was  obtained  and  reported  as  98  mg/dL.What  Is  the  Differential  Diagnosis?The  toxic  syndrome  that  is  characterized  by  a  rapid  onset  of  a  seizure,  hypotension,  and  a  wide-complex  dysrhythmia  was  highly  suggestive  of  Na+  channel  blockade.  Common  Na+  channel  blockers  are  listed  in  Table  CS12–1  and  discussed  in  Chaps.  16,  48,  64,  and  71.  None  of  the  ordered  medications  typically  produce  this  effect.  Additional  considerations  were  that  the  administered  xenobiotic  would  have  to  be  available  in  an  intravenous  form  and  could  be  potentially  confused  with  hypertonic  dextrose  since  the  patient’s  glucose  was  not  elevated  as  would  have  been  expected  following  a  bolus  of  D50W  (Antidotes  in  Depth:  A12).Further  Diagnosis  and  TreatmentWhile  the  nurse  was  asked  to  review  the  medications  given,  the  physician  labelled  and  saved  the  syringes  used  to  deliver  the  original  medications  and  administered  a  bolus  of  2  ampules  (44  mEq  each)  of  hypertonic  sodium  bicarbonate.  Within  1  to  2  minutes  the  ECG  returned  to  baseline,  his  hemodynamic  parameters  improved,  and  his  mental  status  slowly  normalized.The  nurse  reported  that  the  drawer  in  the  automated  medicine  dispenser  was  filled  with  lidocaine  instead  of  dextrose  and,  and  that  the  vials  looked  similar  (Fig.  CS12–3).  The  patient  may  have  received  a  bolus  of  lidocaine.  This  was  confirmed  with  a  serum  lidocaine  concentration  of  4.9  mg/L  taken  about  1  hour  after  the  event.  Full  disclosure  was  made  to  the  patient  and  the  pharmacy  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - accessemergencymedicine.mhmedical.com/content.aspx?aid=1108438685
ER  -