-SCHASHA-

Usage of Antibiotics in the Wards

1. 63/Malay/Male ; U/L DM 

    P/w : right sided headache and ear lobe pain x 3/7 and fever x 2/7

    Dx : Right neck cellulitis secondary to uncontrolled DM

    Abx : IV Ampicillin-Sulbactam (Unasyn) 1.5 g TDS 

   

    Discussion: 

Ampicillin is a penicillin which exerts its actions by inhibiting the synthesis of bacterial cell wall (bactericidal) while Sulbactam is an irreversible inhibitor of many beta-lactamases that occur in penicillin-resistant organisms. When coupled together, Sulbactam enhances the effect of Ampicillin. Unasyn has shown to make resistant strains more susceptible to the combination of the drugs than to the beta-lactam antibiotic alone. Unasyn has an effect of a wide range of both Gram +ve and –ve bacteria such as Staph. aureus or epidermidis, S pneumoniae, H. influenzae along with many penicillin-resistant or methicillin-resistant strains .

This antibiotic was appropriately given to this patient with cellulitis which often sees Streptococci species as the most common offending organism.  In some cases of cellulitis that may be complicated with abscesses, it is often safer to cover these patients with antibiotics that work against a wide range of bacteria. Unasyn allows a better coverage by increasing the antimicrobial spectrum.

2. 73/Malay/Male ; K/C/O Left cerebral pontine angle tumour with post craniotomy & post tracheostomy

    P/w : pain at tracheostomy site x 1/7 and productive cough x 2/7 (greenish, foul smelling sputum)

    Ix : Sputum C&S – Pseudomonas sp.

    Dx : Bronchopneumonia secondary to infected tracheostomy site

    Abx : IV Cefepime 2g BD

    Discussion: 

Cefepime is a 4^th generation cephalosporin that exerts bactericidal effects against Gram –ve bacteria such as E. coli, Klebsiella sp., Pseudomonas sp. and Enterobacter sp. Gram +ve species that are susceptible are Staph. aureus, Strep. pneumoniae or Strep. pyogenes.

Cefepime is a good choice for an aerobic bacteria such as Psedumonas sp. as it exerts rapid penetration into the cell walls of Gram –ve bacterial walls. Cefepime has proven effectiveness against moderate to severe pneumonias caused by such an microorganism.

3. 50/Malay/Male ; U/L DM 

    P/w : Right sided chest pain x 2/7 with SOB and productive cough x 2/7

    Ix : Sputum cuture - H. influenzae

    Dx : Sepsis secondary to lung empyema

    Abx : IV Ceftriaxone 2g BD

    Discussion: 

Ceftriaxone is a 3^rd generation cephalosporin exhibits bactericidal activity against the synthesis of cell walls. It is highly effective against Gram –ve bacteria that are resistant against other beta-lactam antibiotics. Example of organisms are Klebsiella sp. Haemophilus sp. or Neisseria sp.

This is an appropriate choice of antibiotic as septicaemia should be treated with broad-spectrum antibiotics. Ceftriaxone is known to have increased potency against Gram –ve microorganisms and it is stable against the hydrolysis of many beta-lactamases (including penicillinases and cephalosporinases).

4. 71/Chinese/Female ; U/L Bronchial asthma & HPT

    P/w: SOB and productive cough x 1/7

    Dx: Bronchospasm secondary to CAP

    Abx: IV Ceftriaxone 2g OD 

    Discussion: 

In patients with community-acquired pneumonia, common causative organisms are Strep. penumoniae (penicillin-sensitive/resistant strains), Haemophilus influenzae (ampicillin-sensitive/resistant strains), and M. catarrhalis. Patients with uncomplicated CAP can be given Ceftriaxone either alone or with a combination with a macrolide such as Azithromycin. As discussed earlier, Ceftriaxone has strong activity against H. Influenza. It also works well against Strep. Pneumoniae, M. catarrhalis which are seen in CAP. Its once-daily regime allows the avoidance of otherwise complex hospital regimes for the treatment of CAP. When it combination with a macrolide-containing antibiotic, it has shown to have a better outcome for CAP patients.

Ceftriaxone is a good choice for this patient with CAP. With that said, another acceptable choice could be a fluoroquinolone such as Moxifloxacin which shows activity against penicillin- and macrolide-resistant strains of S. pneumoniae and beta-lactamase-producing Haemophilus.

5. 56/Malay/Female ; U/L DM, HPT, IHD, ESRF

    P/w : SOB x 3/7

    Ix : Pleural fluid analysis- Gram +ve cocci

    Dx : Right sided pleural effusion secondary to CAP 

    Abx : IV Ampicillin-Sulbactam (Unasyn) 1.5g OD

    Discussion: 

Unasyn as discussed above, covers a wide range of both Gram +ve and Gram –ve bacteria. It is a good choice of antibiotic as the occurrence of penicillin-resistant strains of organisms is becoming more common. A combination of Ampicillin and Sulbactam will provide a wider antibacterial coverage.

6. 70/Malay/Female ; U/L DM, HPT, post-APR for lower rectal tumour

    P/w : Generalized body weakness + lethargy x 1/7 and pain upon urination 

    Ix : UFEME - nitrites and leucoyctes, blood glucose: 2.3mmol/L

    Dx : Hypoglycemia due to poor oral intake & UTI

    Abx : IV Cefuroxime 1.5g TDS

    Discussion: 

UTI is most commonly caused by Gram –ve organisms such as E. coli. Cefuroxime, a 2^nd generation of cephalosporin works actively against these organisms by inhibiting the synthesis of the cell walls.

It is an appropriate choice of antibiotic although there are other choices such as Trimethoprim-Sulfamethoxazole (Bactrim) or a fluoroquinolone like Ciprofloxacin.

7. 41/Indonesian/Male ; No known medical illnesses

    P/w : vomiting x 1/7 (10 times) associated with fever x 2/7

    Ix : UFEME - leucocytes and nitrites

    Dx : AGE and UTI

    Abx : IV Ampicillin-Sulbactam (Unasyn) 1.5g TDS

    Discussion: 

Unasyn can be used in uncomplicated UTI that is most often caused by Gram –ve microbes. However, UTI in men should not be disregarded and recurrent UTI ought to be investigated. Most AGE are viral in origin and self-limiting, hence the antibiotic may not impose any benefits.

8. 56/Malay/Female ; U/L ESRF, DM, HPT

    P/w: SOB x 2/7, associated with productive cough x 2/7 and fever x 1/7 

    Ix: CXR - pneumonic changes, pleural fluid analysis - exudative features +     Gram positive cocci

    Dx: Right sided pleural effusion secondary to CAP

    Abx: IV Amoxicillin-Clavulanate (Augmentin) 1g OD and T. EES 800mg BD

    Discussion: 

Augmentin is an antibiotic with a broad coverage of antimicrobial activity due to its combination of Amoxicillin and Clavulanate. Clavulanate on its own has little atibacterial activity as a beta-lactamase inhibitor. But, together with Amoxillin, it possesses a syngergistic effect. It anticipates the resistance of organisms towards Amoxicillin thus, improving bactericidal activity. Hence, it covers both Gram +ve and Gram –ve organisms. Erythromycin works effectively against Gram +ve and Gram –ve bacteria.

In this case, it is appropriate to use a combination of Augmentin and EES, as to provide the patient with good coverage to clear off the respiratory infection that has caused the complication of pleural effusion.

9. 76/Malay/Female ; U/L HPT, OA, UV prolapse, COAD

    P/w : Productive cough x 2/7 (yellowish), associated with fever and SOB x 1/7

    Ix : CXR - left lower zone air bronchogram, UFEME - leucocytes, nitrites 

    Dx : CAP and UTI 

    Abx : IV Azithromycin 500mg OD and IV Amoxicillin-Clavulanate (Augmentin) 1.2g TDS

    Discussion: 

As mentioned above, Augmentin is clinically active against a wide range of Gram +ve and Gram –ve bacteria. Azithromycin, works on both Gram +ve and Gram –ve bacteria but has a stronger effect against Gram –ve organisms.

Since UTI is often caused by Gram –ve bacteria and CAP can be caused by both Gram +ve and Gram –ve microbes, this is an appropriate choice of antibiotic as it provides coverage for both infections.

10. 69/Malay/Female ; U/L HPT, Bronchial asthma

      P/w : SOB x 1/7, Fever x 3/7, cough x 1/52

      Ix : CXR - pneumonic changes, WBC - neutrophilic leucocytosis

      Dx : AEBA secondary to CAP

      Abx : IV Amoxicillin-Clavulanate (Augmentin) 1g TDS and T. EES 800mg BD 

       Discussion:  

Augmentin is usually effective against beta-lactamases producing strains such as S. pneumoniae, M. Catarrhalis and H. Influenza which are common organisms in CAP. EES as mentioned works effectively against organisms such as Corynebacterim, Gram +ve cocci, M. pneumoniae and Gram –ve microbes.

A combination of both these antibiotics is appropriate to cover both Gram +ve and –ve organisms commonly found in CAP.

      

CASE 2 : Dengue Fever in Late Febrile Phase With Warning Signs

Admission Day - Day 1 (12/3/14)

NCC, a 13 year old Chinese school-going boy with no known medical illnesses, presented to the hospital with fever for 4 days. A high grade fever that was continuous throughout the day and associated with chills, rigors, headache, dizziness, bilateral lower limb rash, vomiting and diarrhoea was noted. He also noticed a decrease in frequency of urination. However, there were no complains of myalgia, arthralgia, spontaneous bleeding episodes or abdominal pain. The patient reveals that a recent case of dengue fever was reported in his neighbourhood about 2 weeks prior to his illness.
Upon arrival at the ED, his BP was 109/65 mmHg and temperature was 38.3°C. He had clear consciousness and was haemodynamically stable (good pulse volume, warm and pink peripheries, and brisk capillary refill time). Physical examination of all systems was unremarkable. Dengue fever was suspected and blood investigations were ordered. Serial full blood count readings revealed a progressive decline in total white cell (ranging between 2.3 to 2.6 x 10^9/L) and platelet count (ranging between 107 to 123 x 10^9/L). Haematocrit levels were normal. Dengue NS1 antigen serology test was positive. There was no liver involvement or coagulation abnormalities. Malaria fever was excluded by obtaining a negative result on BFMP.

The patient was diagnosed to be in late febrile phase of dengue fever with warning signs.

His management included disease notification and fluid therapy. He was given IV fluids, 2 units of Normal saline in 24 hours and Paracetamol. Adequate oral fluid intake was encouraged. Strict input/output charting was noted with careful observation for bleeding tendencies.

Day 2 (13/3/14)

Patient complained of still being feverish with 2 episodes of vomiting and 3 episodes of diarrhoea (not blood stained). No other warning signs were observed. Patient is able to tolerate orally well with increase in appetite, but with minimal fluid intake. On examination, BP was noted to be on the low side of 81/47 mmHg with a temperature of 37.4°C. Other vital signs were within normal range. Urine output showed satisfactory diuresis. Flushing of the skin was evident on all 4 limbs, chest and back.
Total white cell count showed an increasing trend, although still on the low side, ranging between 2.9 to 3.4 x 10^9/L. Haematocrit levels were stable. Platelet showed a rise in counts, between 128 and 132 x 10^9/L. A repeat BFMP came back negative.
IV 2 units of normal saline in 24 hours was continued with the continuation of Paracetamol. Patient was advised to increase oral fluid intake for about 2L/day to help increase his BP.

Day 3 (14/3/14)

Patient was well looking with no active complains. He was afebrile and no longer had episodes of vomiting or diarrhoea. Urine output was good. No other warning signs were evident. He had regained his appetite. Vital signs were within normal range.
Total white cell count had normalised at 5.5 x 10^9/L. Haematocrit levels were normal. Platelet counts were showing a rising trend compared to the previous days although still on the lower side, at 140 x 10^9/L.
IV fluids were stopped and patient was allowed for discharge that evening. He was advised to continue his fluid intake. He was given a follow-up appointment upon discharge.

CASE 1 : Breakthrough Seizure d/t Non-compliance to Anti-epileptic with U/L Recurrent Post-stroke Epilepsy and HPT

Admission Day - Day 1 (3/3/14)

This 67 year old Malay man, with underlying hypertension, a history of CVA and recurrent post-stroke epilepsy since 2013, presented to the hospital following 2 episodes of generalized tonic-clonic seizure he experienced at home 30 minutes prior to admission. Although on daily medications for his epilepsy, he had not taken his anti-epileptic drug for days before his fitting episode. He is an active smoker who has smoked for about 50 years with an average of 40 sticks/day. When first seen in the hospital, he was confused, disorientated, tachypnoeic and afebrile. His GCS was 12/15 and spO2 was 95% under room air and he was put on oxygen supplementation via nasal prongs. Neurological examination showed no neurological deficits caused by his prior CVA or his current seizure episode. Investigations showed a low serum calcium of 2.09 mmol/L, low serum inorganic phosphate of 0.77 mmol/L and a plasma glucose reading was not available. He was diagnosed to have a breakthrough seizure due to non-compliance to medication and was started on IV Diazepam and IV Normal Saline. He was also given T. Phenytoin, T. Acetylsalicylic acid, and T. Simvastatin. Strict fit charting and GCS monitoring were observed. A CT brain was to be done if there is a further fall in GCS. 

Day 2 (4/3/14) 

Currently, patient is comfortable and his GCS has improved to 15/15. He slept well and had passed motion once. Vital signs were stable and physical examination revealed no positive findings. SpO2 levels had improved to 98% under room air and nasal prongs were removed. His IV fluids were also removed. A plasma glucose level was still not performed and there is no repeat blood test for his low serum calcium and inorganic phosphate levels. Upon asking, patient denied having done any CT brain earlier. No CT brain was ordered for this admission. Current medications is continued.

Day 3 (5/3/14)

Patient was seen by Dr P'ng and allowed for discharge. Vital signs were stable. Patient and his daughter were explained the importance of compliance to his medications. He was discharged with T. Phenytoin, T. Acetyl Salicylic acid, T. Simvastatin and a follow-up appointment on 1/4/14 to review his Therapeutic Drug Monitoring (TDM) Phenytoin test results. The final diagnosis made was breakthrough seizure due to non-compliance to medications with underlying CVA, recurrent post-stroke epilepsy and hypertension.