parameters for evaluating new fever in critically ill adult 为评估在危重成人新发烧实践参数课件

Approach of Infected patient in Critical Care Unit Mazen Kherallah, MD, FCCP Consultant, Infectious Disease 101:1644-55. SIRS: More Than Just a Systemic Inflammatory Response nSIRS: A clinical response arising from a nonspecific insult manifested by 2 of the following: Temperature 38C or 36C HR 90 beats/min Respirations 20/min WBC count 12,000/mL or 4,000/mL or 10% immature neutrophils nRecent evidence indicates that hemostatic changes are also involved Adapted from: Bone RC et al. Chest. 1992;101:1644-55. Opal SM et al. Crit Care Med. 2000;28:S81-2. Severe Sepsis: Acute Organ Dysfunction and Disordered Hemostasis nSevere Sepsis: Sepsis with signs of organ dysfunction in 1 of the following systems: Cardiovascular Renal Respiratory Hepatic Hemostasis CNS Unexplained metabolic acidosis Adapted from: Bone RC et al. Chest. 1992;101:1644-55. Sepsis Syndromes Infection Sepsis Severe Sepsis Septic Shock Microbiological Phenomenon Infection + SIRS Sepsis + End-Organ Damage Severe Sepsis + Refractory Hypotension Sepsis Parameters: nLeukocytosis with left shift nBandemia nToxic granulation nElevated sed. Rate nC- reactive protein nAcute phase reactant: fibrinogen, haptoglobin, nIL1, IL6, IL8 2. Organ Localization of infection nSkin nSoft tissue nCNS nUpper airway nLower airway nHead and neck nMediastinal nGI nLiver nBiliary tract nIntra-abdominal nBones and joints nUrinary tract nGenital tract nBlood stream infection nSystemic 3. Tissue Localization of Infection nSkin and soft tissue: Superficial epidermal layers (impetigo) Deeper epidermal layers (Icthyma) Superficial subcutaneous: Erysipelas Deeper subcut.: cellulitis Folliculitis Hydradenitis Fascia: Fasciitis Fat: panuculitis nLower respiratory tract: Alveolar: consolidative pneumonia Interstitial: atypical pneumonia Pleural: empyema 4. Suspected Microbiology of Infection nHost factors Immunosuppression Age Gender Previous antibiotics Co-morbidity: nSSD nDM nCGD nEnvironmental Community: ncontacts nTravel nAnimals Hospital: nLocation Nursing homes 4. Suspected Microbiology of Infection nCommunity acquired pneumonia: Lobar pneumonia Streptococcus Pn. H. flu Moraxella catarrhalis Staphylococcal Klebsiella nCommunity acquired pneumonia: interstitial: Mycoplasma Pn. Legionella Viral 4. Suspected Microbiology of Infection nIntra-abdominal infection E. coli Klebsiella B. fragilis Enterococcus Candida nUrinary tract infection E. coli Proteus Enterococcus 4. Suspected Microbiology of Infection nMeningitis: 38.0C, or two consecutive elevation of 38.3C nThe lower the temperature that is used to define fever, the more sensitive and less specific the indicator is for detecting an infectious etiology Initiating Fever Evaluation Normal Body Temperature nNormal body temperature is 37.0C nVaries by 0.5C to 1C according to circadian rhythm and menstrual cycle nExercise can increase temperature by 2C to 3C Initiating Fever Evaluation Variation of Temperature in ICU nSpecialized mattresses nHot lights nAir conditioning nCardiopulmonary bypass nPeritoneal lavage nDialysis and continuous hemofiltration nDrugs altering thermoregulatory mechanisms Initiating Fever Evaluation Non-infectious Causes of Fever can be Life-threatening nAdrenal insufficiency nThyroid storm nMalignant hyperthermia nHeat stroke Initiating Fever Evaluation Infected Patient but Afebrile nElderly nOpen abdominal wounds nLarge burns nExtracorporeal membrane oxygenation nPatients taking anti-inflammatory or anti -pyretic drugs Initiating Fever Evaluation Temperature Measurement nMost accurately measured using intravascular or bladder thermistor nMouth, rectal or external auditory measurements using electronic probes is acceptable in appropriate patients nAxillary measurements should not be used Initiating Fever Evaluation Clinical Evaluation nA new onset of temperature to or above 38.3C is reasonable trigger for a clinical assessment but not necessarily a laboratory or radiological evaluation nClinical assessment may reveal a purulent wound or phlebitic leg, then diagnosis and therapy for that infectious process should commence Bacterial Synergistic Gangrene Anaerobic Cellulitis Initiating Fever Evaluation Obtaining Blood Cultures Skin Preperation nThe site of venipunture should be cleaned with either 10% povidone iodine or 1-2% tincture of iodine. If the patient is allergic to iodine alcohol 70% swabs should be used nThe access to intravascular device and to the stopper on the culture bottle should be cleaned with 70% alcohol nIodophors must be allowed to dry to provide maximal antiseptic activity Initiating Fever Evaluation Obtaining Blood Cultures Blood Volume nOne blood culture is defined as a sample of blood drawn at a single time at a single site nOne milliliter of blood is needed per five milliliter of media n5 ml of blood is injected into each of two or three bottles for routine blood culture n10-15 ml per one set of blood cultre Initiating Fever Evaluation Obtaining Blood Cultures Number of Cultures 80:254-258 Diagnostic Strategy based on Clinical Evaluation only Andrews et al, chest 1981;80:254-258 Autopsy Results Chastre et al. Evaluation of bronchoscopic techniques for the diagnosis of nosocomial pneumonia. Am J Respir Crit Care Med 1995; 152:231-240 Diagnostic Strategy based on Invasive Evaluation n Bronchoalveolar Lavage Chastre et al. Evaluation of bronchoscopic techniques for the diagnosis of nosocomial pneumonia. Am J Respir Crit Care Med 1995; 152:231-240 Diagnostic Strategy based on Invasive Evaluation Protected Brush Specimen Diagnostic Strategy based on Invasive Evaluation Protected Brush Specimen Drawbacks: False Negative Results nBronchoscopy performed at an early stage of infection with bacterial burden below the concentration necessary to reach diagnostic significance nSpecimens obtained from unaffected segments nSpecimens incorrectly processed nSpecimens obtained after initiation of a new antimicrobial therapy nRepresents a good alternative in patients with very unstable conditions and in patients for whom it is not possible to delay the initiation of antimicrobial treatment while awaiting bronchoscopy nDiagnosis can be missed, especially in the case of upper lobes or left lung infection Intermediate Strategy Based on Quantitative Culture of Nonbronchoscopic Samples Quantitative Cultures of Nonbronchoscopic Distal Protected Specimen 68% VS 84% Jourdain et al. Role of quantitative cultures of Endotracheal aspirates for the diagnosis of nosocomial pneumonia. Am J Resp Crit Care Med 1995; 152:241-246 Quantitative Cultures of Endotracheal aspirates Intermediate Strategy Based on Quantitative Culture of Nonbronchoscopic Samples Diarrhea & Fever in ICU nDiarrhea is caused by enteral feeding or drugs nThe only common enteric cause of fever in the ICU is Clostridium difficile nC. difficile accounts for about 25% of all cases of antibiotic-related diarrhea Pseudomembraneous Colitis Methylene Blue Stain Cytotoxin Effect on Baby Hamster kidney Cells UTI & Fever in ICU nThe presence of pyuria can help establish the importance of urinary bacteria nLeukocyte esterase dipstick test is easy and simple nGram stain of a centrifuged urine sediment may provide clues to the type of microorganisms present Other Causes of Fever in ICU Respiratory nTracheobronchitis nEmpyema nLung abscess nSinusitis Other Causes of Fever in ICU Wound & Soft Tissue nWound infection nDecubitus ulcers nCellulitis nDeep-seated abscess: sub-diaphragmatic Other Causes of Fever in ICU Gastrointestinal nIschemic colitis nAcalculous cholecystitis nCholangitis nTransfusion-related hepatitis: CMV, hepatitis C, and hepatitis B nIntraabdominal abscess nDiverticulitis Other Causes of Fever in ICU Prosthetic Devices nCardiac valve/pacemaker nJoint replacement prosthesis nPeritoneal dialysis catheter nCNS intraventricular shunt Non-Infectious Source of Fever in ICU Drugs nAntibiotics: B-lactam agents nAnti-epileptic drugs: phenytoin nAntiarrythmics: quinidine and procainamide nAntihypertensive: methyldopa Non-Infectious Source of Fever in ICU Post-operative nUp till 72 hours postoperative nAtelectasis nPost-peri