78 R. Chawla and S. Todi

Step 13: Prevent venous thromboembolism

Approximately 90% of PEs originate from DVT of proximal leg veins, which are preventable with adequate prophylaxis. See the Chap. 79 on comprehensive ICU care.

Summary of management of suspected pulmonary embolism is given in Fig. 9.1.

Suggested Reading

1.Jaff MR, McMurtry MS, Archer SL, Cushman M, Goldenberg N, Goldhaber SZ. Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association. Circulation. 2011;123(16):1788–830.

Most up-to-date guidelines for the diagnosis and management of PE.

2.Agnelli G, Becattini C. Acute pulmonary embolism. N Engl J Med. 2010;363:266–74.

3.Stein PD, Chenevert TL, Fowler SE, Goodman LR, Gottschalk A, Hales CA, et al. PIOPED III Investigators. Gadolinium-enhanced magnetic resonance angiography for pulmonary embolism: a multicenter prospective study (PIOPED III). Ann Intern Med. 2010;152(7):434–43, W1 42–43.

This study shows that the technically adequate magnetic resonance angiography has a sensitivity of 78% and a specificity of 99%. Technically adequate magnetic resonance angiography and venography have a sensitivity of 92% and a specificity of 96%, but 52% of patients have technically inadequate results.

4.Kuderer NM, Ortel TL, Francis CW. Impact of venous thromboembolism and anticoagulation on cancer and cancer survival. J Clin Oncol. 2009;27(29):4902–11.

This meta-analyses performed for the American Society of Clinical Oncology and the Cochrane Collaboration suggest overall favorable effects of anticoagulation on survival of patients with cancer, mainly with LMWH.

5.Todd JL, Tapson VF. Thrombolytic therapy for acute pulmonary embolism: a critical appraisal. Chest. 2009;135(5):1321–9.

This article reviews historical aspects and current evidence for thrombolytic therapy in acute PE with specific attention to bleeding risk, and data regarding hemodynamic parameters and mortality.

6.Kearon C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ, American College of Chest Physicians. Antithrombotic therapy for venous thromboembolic disease. Chest. 2008;133:454–545.

This study about treatment for venous thromboembolic disease is part of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

7.Stein PD, Fowler SE, Goodman LR, Gottschalk A, Hales CA, Hull RD, et al. PIOPED II Investigators. Multidetector computed tomography for acute pulmonary embolism. N Engl J Med. 2006;354(22):2317–27.

In this study, the sensitivity of CT angiography (CTA) is 83% and the specificity is 96%. In patients with suspected PE, multidetector CTA-CTV has a higher diagnostic sensitivity than does CTA alone, with similar specificity.

8.Gould MK, Dembitzer AD, Doyle RL, Hastie TJ, Garber AM. Low-molecular-weight heparins compared with unfractionated heparin for treatment of acute deep venous thrombosis. A metaanalysis of randomized, controlled trials. Ann Intern Med. 130(10):800–9.

This meta-analysis shows that LMWH treatment reduces mortality rates after acute DVT. These drugs seem to be as safe as UFH with respect to major bleeding complications and appear to be as effective in preventing thromboembolic recurrences.

Severe Community-Acquired	10
Pneumonia

Subhash Todi and Rajesh Chawla

A 50-year-old male smoker presented to the emergency department with fever and acute shortness of breath for the past 2 days. He had a respiratory rate of 30/ min, blood pressure of 140/90, pulse 110/min regular, and SpO2 88% on 2 L nasal cannula. He was alert and communicating. He had a history of hypertension and diabetes. He had brought a chest X-ray, which showed left lower zone opacity.

Community-acquired pneumonia is a common illness affecting 2–3 million patients each year in the USA. Only about 20% of patients require hospitalization, of which approximately 10–20% require intensive care unit (ICU) care. Mortality in hospitalized patients can be up to 30%, of which majority occur in patients admitted to the ICU.

Step 1: Initiate resuscitation

The patient should be resuscitated as described in Chap. 78.

Step 2: Assessment of severity

Many scoring systems have been suggested to assess the severity of communityacquired pneumonia (CAP). This is best done by a simple CURB-65 score. The CURB-65 score is based on five easily measurable factors (score 1 for each factor).

•Confusion

•Urea (>20 mg/dL)

•Respiratory rate more than 30 breaths/min

S. Todi, M.D., M.R.C.P. (*)

Critical Care & Emergency, A.M.R.I. Hospital, Kolkata, India e-mail: [e-mail]

R. Chawla, M.D., F.C.C.M.

Department of Respiratory, Critical Care & Sleep Medicine, Indraprastha Apollo Hospitals, New Delhi, India

R. Chawla and S. Todi (eds.), ICU Protocols: A stepwise approach,	79
DOI 10.1007/978-81-322-0535-7_10, © Springer India 2012

80	S. Todi and R. Chawla

•Blood pressure (systolic <90 mmHg or diastolic <60 mmHg)

•Age more than 65 years

The patient with a score of 3 or more should be assessed for intensive care unit

(ICU) care. The simplified version of CURB -65 is CRB-65 which has similar predictability of severity and mortality in hospital settings.

Step 3: Start empiric antibiotics

•While initial resuscitation is going on, the cornerstone of the therapy for suspected infection is prompt and empiric antibiotics at the earliest.

•Ideally, one should send blood and sputum culture prior to starting antibiotics, but if these are delayed beyond 1 h for logistic reasons, antibiotics should be given without delay. The initial choice of antibiotics is of utmost importance because an inappropriate choice can increase mortality.

•A detailed history should be taken to identify patients who are at a high risk of drug-resistant infection, as mentioned below.

–Previous hospitalization in 9 months

–Previous antibiotics in 3 months

–Comorbidity—liver failure, renal failure, chronic obstructive pulmonary disease (COPD), heart failure, diabetes, asplenia

–Steroid use, immunosuppressive drugs

–Details of the antibiotics used recently

•Principles of choosing an antibiotic (Tables 10.1, 10.2 and 10.3):

–Cover common organisms responsible for pneumonia: both typical and atypical.

Table 10.1 Common organisms responsible for severe pneumonia, requiring ICU admission

Streptococcus pneumoniae 17%

Legionella 10%

Staphylococcus aureus (methicillin-sensitive S. aureus) 5%

Gram-negative bacilli (non-ESBL) 5%

Haemophilus influenzae 3%

Respiratory viruses 4%

Gram-negative bacilli (ESBL)

Pseudomonas

Community-acquired methicillin-resistant S. aureus (MRSA)

Unknown 41%

Table 10.2 Antibiotic choices in patients with no risk factors

A beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus azithromycin

Or

A beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus a respiratory fluoroquinolone (levofloxacin,moxifloxacin)

Or

For penicillin-allergic patients, a respiratory fluoroquinolone and aztreonam

10 Severe Community-Acquired Pneumonia	81

Table 10.3 Antibiotic choice in a patient at risk of drug-resistant infection

1. If ESBL or pseudomonas is a concern

An antipneumococcal, antipseudomonal beta-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin (750 mg)

Or

The above beta-lactam plus an aminoglycoside and azithromycin

Or

The above beta-lactam plus an aminoglycoside and an antipneumococcal fluoroquinolone (for penicillin-allergic patients, substitute aztreonam for beta-lactam)

2. If MRSA is a concern

Add vancomycin or linezolid

–Cover resistant organisms such as extended-spectrum beta-lactamases (ESBL), in patients at risk.

–Avoid the antibiotic class to which patients have recently been exposed.

–Use parenteral antibiotics.

–Use antibiotics in adequate dose and frequency (see Chap. 49).

–Follow antibiotic policy of your unit/hospital for severe pneumonia.

Step 4: Order investigations

While initial resuscitation and empirical antibiotics are being given, basic diagnostic workup should be performed. The workup should include the following:

•Complete blood cell count

•Blood culture—two sets

•C-reactive protein

•Urea, creatinine

•Liver function test, prothrombin time

•Serum electrolytes

•Arterial blood gas, lactate

•Urine for microscopy

•Chest X-ray, electrocardiogram

•Echocardiogram; optional if patient is in septic shock

•Sputum sample should be a representative one and should reach the laboratory without delay

•Sputum—Gram stain, aerobic culture and sensitivity (C&S)

•Sputum cytology

•Urine for Legionella antigen, pneumococcal antigen (if available)

Step 5: Further supportive therapy needs to be instituted simultaneously

•Severe pneumonia with septic shock and multiorgan failure should be treated according to sepsis guidelines (Chap. 50).

•Aerosolized nebulization of bronchodilators should be routinely used especially if a patient has a history of COPD or asthma.

82	S. Todi and R. Chawla
Table 10.4 Noninfectious	Heart failure
causes	Cryptogenic organizing pneumonia
	Malignancy
	Pulmonary embolism
	Pulmonary eosinophilic pneumonia
	Hypersensitivity pneumonitis
	Vasculitis—Wegner’s granulomatosis

•Noninvasive ventilation: For patients with increased work of breathing, especially in COPD with acute exacerbation, a trial of noninvasive ventilation is worthwhile. These patients should be closely monitored for subjective improvement and an improving blood gas at 2 h. If there is no improvement, they should be intubated and ventilated without delay.

•Steroids: Continue equivalent dose of intravenous steroids if the patient is receiving it for asthma or COPD and give low-dose intravenous steroids in patient with vasopressor-resistant septic shock.

•Other general supportive ICU measures should be instituted (see Chap. 78).

Step 6: Consider the following for a patient not responding to initial therapy

With appropriate antibiotic therapy, some improvement in patient’s clinical course should be seen within 48–72 h. This should be assessed clinically, as radiographic resolution takes more time.

For nonresponders the following conditions should be considered:

•Organisms not covered by empiric choice of antibiotics.

•Atypical organisms—tuberculosis, strongyloidosis, melioidosis, H1N1 influenza, etc.

•Complicated pneumonia—lung abscess, Empyema, intrabronchial obstruction, resistant organisms.

•Nosocomial problem—secondary infection.

•Alternative diagnosis—look for noninfectious causes in nonresponding patients and investigate appropriately (Table 10.4).

Step 7: Further investigations

Further diagnostic workup should be undertaken judiciously keeping the cost factor in mind to differentiate the possibilities in nonresponders.

•Bronchoscopy with bronchoalveolar lavage.

•In intubated patients, endotracheal suction or nonbronchoscopic lavage may be sent for quantitative culture.

•Serology for HIV1 and II, H1N1, antinuclear factor, antineutrophil cytoplasmic antibodies, Legionella

•Nasal swab for MRSA, viral panel

•Pro-brain natriuretic peptide (BNP) levels

•D-dimer, leg venous Doppler

•Ultrasonogram (USG) chest/computed tomographic scan (CT) chest

•Procalcitonin