Treating COVID-19 Patients in the Intensive Care Unit

Pengarang:
Mohd Zulfakar Mazlan, Wan Fadzlina Wan Muhd Shukeri, Mahamarowi Omar.
Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia.
Pengarang Koresponden:
Dr. Mohd Zulfakar Mazlan
Intensive Care Unit Coordinator
Department of Anaesthesiology and Intensive Care, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia.
Phone: + 60129091447/+ 6097676104
Email: zulfakar@usm.my

Introduction

Coronavirus disease (COVID-19) was first reported in China on 7 January 2020 in Wuhan city.1 Cases up to 6 May 2020, had already infected 3,759,967 people across the world. The United States of America had recorded the highest number of cases, 1,586,129, and 87,930 deaths with a 5.5%. fatality rate.1 However, a fatality rate as high as 13%–15% was reported in European countries such as Italy and the United Kingdom.1 In Malaysia, the first three cases were reported on 26 January 2020.2 The total number of cases was 6467 with 107 deaths, a fatality rate of 1.6%.1 In Malaysia, the mortality rate is less than 2%, which is below the average world fatality rate of 6.9%.7 Up to now, there have been no specific treatments for patients with COVID-19. Patients with symptoms such as fever, sore throat, cough, and shortness of breath will be treated symptomatically. People who have been exposed to the virus and have no symptoms need to be quarantined until the repeat test is negative. If patients’ oxygen requirements increase during the hospital stay, they will be transferred to an intensive care unit (ICU) bed for further management (Figure 1).

Treatment of COVID-19 Patients

All patients who fulfil the criteria for persons under investigation in the Ministry of Health COVID-19 guideline need to be screened regardless of whether they are symptomatic or asymptomatic. After a confirmatory test is performed and is positive, patients will be classified into five groups, each with particular treatment:3 Group 1 is defined as asymptomatic patients, Group 2 includes those who had symptoms without pneumonia, Group 3 is those who had pneumonia and Groups 4 and 5 are at high risk of developing more severe illnesses, which warrant ICU admission. The treatment provided comprises general care and special treatment. General care for most patients comprises early feeding, analgesia, sedation, thromboembolism prophylaxis, head up elevation, stress ulcer prophylaxis and glycaemic control, summarised by the mnemonic FAST HUG.4

Until now, no special medication has been approved to treat COVID-19. However, each unit has its own distinct way of treating the patients. Among the drugs that have been prescribed are the anti-malarial drug chloroquine, the anti-rheumatoid arthritis drug hydroxychloroquine, and antivirals, such as lopinavir-ritonavir, ribavirin and interferon.3 These drugs act by reducing the inflammatory process. In Malaysia, these medications can only be prescribed by infectious disease physicians.3 This facility is only available in the selected hospitals that are responsible for treating COVID-19 patients.3 All these drugs are still being researched in terms of efficacy and side effects.

Infectious disease physicians will manage the cases alongside intensivists in the ICU. Anaesthesiologists and intensivists will provide their expertise particularly in ventilation strategies and haemodynamic monitoring. Patients who require high supplemental oxygen therapy require intensive lung compliance monitoring. Barotrauma of the lung due to inappropriate ventilation settings is among the risks of low-compliance lungs. In patients with low lung compliance, low tidal volume ventilator strategies such as an acute respiratory distress syndrome protocol are an optional algorithm to follow. Therefore, clinicians need to identify the severity of the lung pathology based on clinical presentation, biomarkers, chest radiography and computed tomography scan findings.

Oxygen can be administered invasively or non-invasively. The invasive technique delivers oxygen via an endotracheal tube, and the non-invasive technique delivers oxygen via nasal prongs, a simple face mask, a venturi mask, a high flow with or without a non-rebreather mask or non-invasive bilateral positive airway pressure and a high-flow nasal cannula. The invasive technique is preferred since it will reduce the rate of aerosolisation. The aerosolisation risk is higher with the continuous positive airway pressure/bilevel positive airway pressure non-invasive ventilation mode.5 Therefore, most patients in our centre will be intubated as soon as it is indicated (Figure 2).

COVID-19 can potentially cause impairment of vital organ functions, such as the lungs, heart, and kidneys, by activating the patients’ own immune system. Theoretically, COVID-19 induces an inflammatory process by binding to angiotensin converting enzyme-2 receptors, which are abundantly located in lungs.6 This inflammation causes severe acute respiratory tract infection (RTI). This will result in a ventilation-perfusion mismatch leading to the need for supplemental oxygen therapy.

High supplemental oxygen therapy can only be supplied in the ICU, which has the facility in accordance with predetermined standards. Respiratory failure is the most important sign of COVID-19 disease and the main indication for ICU admission. However, other criteria for admission to the ICU are subject to the general conditions of admission, such as for other diseases.4

Clinicians must thoroughly screen all admissions to the ICU. Many admissions to the ICU prior to COVID-19 were due to pneumonia. The presentations of COVID-19 and pneumonia are almost similar; both may present with the symptoms of severe acute respiratory illness (SARI). According to the World Health Organization, SARI encompasses every respiratory tract infection that makes the patient ill enough to require hospital admission, and it usually involves the lower respiratory tract. SARI includes the following types of pneumonia: community-acquired, hospital-acquired, aspiration, opportunistic, viral, influenza and COVID-19 pneumonia. Pneumonia diagnosed after 48 hours of hospital stay is hospital-acquired pneumonia. Therefore, it is prudent for emergency physicians, family physicians, anaesthesiologists, and intensivists to screen all patients for PUI and SARI. Patients need to be tested and treated as COVID-19 patients until proven otherwise. While waiting for the test results, all the healthcare workers who manage this group of patients should follow all the recommended precautionary measures, such as wearing full personal protective equipment (PPE), maintaining social distancing and limiting exposure unless in an emergency.

In the ICU, COVID-19 patients need to be separated in a special room called a negative pressure isolation room7 because of the uncertainty of the mode of the virus transmission. At the time of writing, the COVID-19 mode of transmission is via droplets, although airborne transmission is suspected. Therefore, healthcare workers need to wear full PPE while handling patients, especially if their work involves aerosol-generating procedures, such as intubation, suctioning, nebulising, bronchoscopy and extubation. If power air purifying respirators (PAPRs) are available, healthcare workers are recommended to wear these devices to reduce the risk of infection (Figure 3). However, not all hospitals are equipped with negative pressure isolation rooms and PAPR. Most hospitals only have standard isolation rooms without the negative pressure system, but these are an acceptable alternative.

Negative pressure isolation rooms are classified into a few types depending on their function and indication. A higher-level negative pressure room should consist of an isolated area for donning and doffing of PPE. The rooms must also have an anteroom,7 an ante suite and a separate pathway into and out of the room. This is very important to avoid mixing the clean area (donning) and the dirty area (doffing). The negative pressure inside the rooms is important to prevent highly infectious diseases with airborne transmission, such as tuberculosis, measles and chicken pox.7 An air flow rate of 6 to 12 air changes per hour is a prerequisite installation in the room with a high-efficiency particulate air filter, which must be able to filter > 99.97% of particles > 0.3 μm size.7

Intubated patients receive one-to-one monitoring and are closely observed by staff nurses in an isolation room or an isolation room with negative pressure system, depending on each hospital’s available facilities (Figures 4a and 4b). Each patient will be monitored continuously by an automatic machine that continuously displays the haemodynamic parameters, as for non-COVID-19 disease patients (Figure 1). In the ICU, all patients will be seen by one intensivist, two to three anaesthesiologists and two physicians three times daily. Each day, there will be an anaesthesiologist on call doing a physical examination, interpreting the blood results and ordering a daily radiological investigation. Routine blood investigations include a full blood count, a liver function test, a renal profile, C-reactive protein, ferritin, D-Dimer, procalcitonin, arterial blood gases and blood culture.3 The investigation frequency depends on the indication. Patients with a higher Sequential Organ Failure Assessment score, older age and D-dimer greater than 1 μg/mL on admission are at risk of a poor prognosis.8

Most patients will recover if they do not have a risk factor for severe illness. Among the commonest comorbidities identified among COVID-19 patients are diabetes, hypertension and heart disease.8 Intensive treatment will be provided for those patients who have signs of cytokine storms. Early signs, such as fever, tachycardia, low lymphocyte and increased C-reactive protein, must be monitored and identified.3 The effects of a cytokine storm can cause organ dysfunction in the lung, heart, kidneys and brain.

Patients who develop respiratory failure will be intubated to ensure that oxygen is delivered to the patient. However, they need to be intubated according to the guidelines and algorithms for management of acute hypoxaemic respiratory failure due to COVID-19.9 This is to avoid unnecessary intubation. If there are no contraindications, some patients will be put in a prone position to improve oxygenation before or after intubation.9–10 If their lung compliance is low, they will need to follow low ventilation strategies with acceptable oxygenation.9–10 Patients who develop acute kidney injury and are indicated for renal replacement therapy (RRT) will receive RRT.10 If hemodynamically unstable, they will receive continuous RRT. Patients who develop sepsis will be started on empirical antibiotic therapy according to national and ICU antibiotic guidelines, guided by sepsis biomarkers such as procalcitonin.9 The mean length of ICU stay is usually 8 days for all cases.8 Patients will undergo the weaning process once the primary pathology is resolved. The patient will be extubated after fulfilling the criteria for extubation. The doctors and staff nurse involved must wear full PPE or PAPR if available (Figure 3).

Patients will be transferred to the dedicated general wards once they fulfil the discharge criteria, which are still the same as for any other patient admitted to the ICU. These wards should consist of an isolation bed with a negative pressure system. The COVID-19 test will be repeated until negative prior to allowing discharge home. This is very important to avoid transmission to other patients and healthcare workers. Therefore, patients are also not allowed to accept other visitors besides their nearest next of kin. The median duration of viral shedding is 20 days and the longest duration is up to 37 days.8 Therefore, the duration of patients’ ward stay differs from one patient to another. In the ward, patients will be managed by infectious disease physicians assisted by dedicated medical officers and staff nurses. Once discharged, patients will be monitored and followed up by district health officers to ensure they are completely well.

Conclusion

COVID-19 patients need to be admitted to an ICU, which has the required advanced ventilation, RRT, haemodynamic, isolation rooms and monitoring facilities. Healthcare workers in the ICU have been trained for COVID-19. This high level of care is required for better management and weaning of patients.

References

  1. World Health Organization. Coronavirus disease (COVID-19) Situation Report 109 [cited 2020 May 6]. Available from: https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200508covid-19-sitrep-109.pdf?sfvrsn=68f2c632_6.
  1. World Health Organization.Coronavirus disease (COVID-19) Situation Report 6. [cited 2020 May 6]. Available from: https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200126-sitrep-6-2019--ncov.pdf?sfvrsn=beaeee0c_4.
  1. Ministry of Health, Malaysia.Guidelines COVID-19 management in Malaysia no. 5/2020. 5th ed. [cited 2020 May 6]. Available from: http://covid-19.moh.gov.my/garis-panduan/garis-panduan-kkm
  1. Malaysia ICU protocol managements 2019. [cited 2020 May 6]. Available from: http://www.msic.org.my/
  1. Wax RS, Christian MD. Practical recommendations for critical care and anaesthesiology teams caring for novel coronavirus (2019-nCoV) patients. Can J Anesth/J Can Anesth. 2020;(67):1–9.
  1. Bourgonje AR, Abdulle AE, Timens W, Hillebrands JL, Navis GJ, Gordijn SJ, Bolling MC, Dijkstra G, Voors AA, Osterhaus AD, van der Voort PH. Angiotensin‐converting enzyme‐2 (ACE2), SARS‐CoV‐2 and pathophysiology of coronavirus disease 2019 (COVID‐19). J Pathol. 2020 May 17.
  1. Siegel JD, Rhinehart E, Jackson M, Chiarello L, Health Care Infection Control Practices Advisory Committee. 2007 guideline for isolation precautions: preventing transmission of infectious agents in health care settings. Am. J. Infect.Control. 2007;35(10): S65.
  1. Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020; (395):1054-1062.
  1. European Society of Intensive Care Medicine. COVID-19. Algorhytm for the management of patients with acute hypoxaemic respiratory failure secondary to Coronavirus Disease 19. [cited 2020 May 6]. Available from:https://www.esicm.org/resources/coronavirus-public-health emergency/#GUIDELINES
  1. Alhazzani W, Møller MH, Arabi YM, Loeb M, Gong MN, Fan E, et al. Surviving Sepsis Campaign: guidelines on the management of critically ill adults with coronavirus disease 2019 (COVID-19). Intensive Care Med. 2020;(46)854–887.
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