|Year : 2013 | Volume
| Issue : 2 | Page : 104-107
Perioperative management of a parturient for cesarean section with confirmed H1N1 influenza
Nitin Shanker1, Sanjeev Aneja1, MV Jayalalitha1, Avdhesh Bansal2
1 Department of Anaesthesia and Critical Care, Indraprastha Apollo Hospital, Sarita Vihar, New Delhi, India
2 Department of Respiratory Medicine and Critical Care, Indraprastha Apollo Hospital, Sarita Vihar, New Delhi, India
|Date of Web Publication||19-Dec-2013|
Department of Anaesthesia and Critical Care, Indraprastha Apollo Hospital, Sarita Vihar, New Delhi - 110 001
Source of Support: None, Conflict of Interest: None
Since the last few years a new strain of influenza virus H1N1 has infected people of all age groups and has caused significant morbidity and mortality. Pregnant females are at special risk especially during the second and third trimester. We present the anesthetic management of a case of cesarean section of a parturient at 32 weeks with confirmed H1N1 who had developed acute respiratory distress syndrome and discuss the various issues concerning the perioperative management.
Keywords: Anesthesia, cesarean section, H1N1, pregnancy
|How to cite this article:|
Shanker N, Aneja S, Jayalalitha M V, Bansal A. Perioperative management of a parturient for cesarean section with confirmed H1N1 influenza. J Obstet Anaesth Crit Care 2013;3:104-7
|How to cite this URL:|
Shanker N, Aneja S, Jayalalitha M V, Bansal A. Perioperative management of a parturient for cesarean section with confirmed H1N1 influenza. J Obstet Anaesth Crit Care [serial online] 2013 [cited 2020 Sep 19];3:104-7. Available from: http://www.joacc.com/text.asp?2013/3/2/104/123309
| Introduction|| |
The H1N1 influenza pandemic that engulfed the whole world in the year 2009 and brought together different organizations in regards the diagnosis and management of this disease. Since the beginning of the pandemic of influenza A (H1N1) in India, more than 46,000 laboratory-confirmed cases, including 2,728 deaths, were reported till December 2010.  In August 2010, World Health Organization (WHO) announced the post-pandemic phase.  During this phase, the pandemic virus is expected to continue to circulate as a seasonal virus. Cases and outbreaks due to the virus would continue to occur and the high-risk groups would continue to be affected disproportionately by severe diseases.  H1N1 viral pneumonitis is caused by a novel variant of influenza A (H1N1) which is similar to seasonal influenza but contains segments of genes from pig, bird, and human influenza. At special risk are pregnant females, especially during the third trimester of pregnancy, children below 2 years of age, and people with chronic lung disease including asthma. 
| Case Report|| |
A 31-year-old pregnant female with 32 weeks of gestation was referred to our institution with acute breathlessness and hypoxia requiring noninvasive ventilation. Her past history was unremarkable except for a history of two abortions.
She was initially managed in a primary hospital for a week where she had presented with complaints of fever and dry cough which showed no signs of improvement with regular antibiotics. Her clinical condition worsened with increasing dyspnea. A possibility of H1N1 infection was considered as in the recent years there has been increased awareness among physicians of the growing endemicity of this disease. This was later confirmed by polymerase chain reaction. Subsequently, she was started on Oseltamivir phosphate (Tamiflu) 75 mg PO BD and was then transferred to our center for ventilator assistance.
On examination in the emergency room, patient was tachypneic with a respiratory rate of 36 breaths per min, with a heart rate of 130 per min, and Blood pressure of 100/70 mmHg. The patient was transferred on a biphasic positive airway pressure (BIPAP) support of 16 inspiratory positive airway pressure (IPAP) and 10 expiratory positive airway pressure (EPAP) with a high FiO 2 on which her SpO 2 was around 95%. The patient was on auscultation found to have bilateral crepts with decreased air entry in the right infraclavicular area. In view of the patient's medical condition and increasing breathlessness, she was shifted to the intensive care unit (ICU) in an isolation room in a leftward tilt position, keeping in mind the infectious etiology of the disease where she continued to be on BIPAP. In the ICU, all the staff took the necessary precautions as recommended for dealing with H1NI infected patients as recommended by the WHO. A blood gas performed on the patient showed a pH of 7.43 with partial pressure of oxygen 86.5 mmHg (for complete Arterial blood gas (ABG) [Table 1] and her X-ray chest was suggestive of Acute respiratory distress syndrome (ARDS) [Figure 1]. Her abdomen examination revealed a gravid uterus corresponding to 32 weeks of gestation. Fetal heart sounds were not well appreciated on auscultation, but were later confirmed on ultrasound. An interdisciplinary meeting was held, and it was decided to perform an emergency Cesarean section because of the respiratory instability of the patient. An informed consent was obtained from the patient's husband and he was counseled in regards the poor outcome of the new born and a high possibility of postoperative ventilation of the mother.
|Figure 1: Post intubation X-ray chest of the patient with features suggestive of acute respiratory distress syndrome (ARDS)|
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A preanaesthetic check-up was carried out and anti-aspiration prophylaxis with 30 ml of freshly prepared Sodium citrate was given. She was planned for a cesarean section under General Anesthesia. In view of her increasing dyspnea, a rapid sequence induction followed by tracheal intubation was performed in ICU itself. Her preinduction vitals were a heart rate of 120 per min with a blood pressure of 134/75 mmHg and a saturation of 93%. A left radial arterial line was secured post induction.
Thereafter, the patient was transferred to the operation theatre with a left lateral tilt with assisted ventilation. While shifting we encountered high airway pressure on ventilation and difficulty maintaining her saturation. We gave low tidal volume breaths with a rate of approximately 25-30 breaths per min. Injection Propofol boluses and Atracurium were administered while shifting the patient.
In the operation theatre, all the healthcare professionals wore personal protection as recommended by the Centers for disease Control and Prevention (CDC) and World Health Organization (WHO) guidelines. Patient was connected to ventilator and anesthesia was maintained with oxygen with a 100% FiO 2 and sevoflurane to achieve a minimum alveolar concentration (MAC) of 0.5-0.7. We faced initial difficulty in ventilating as her peak airway pressure exceeded above 40 mmHg. Therefore, we preferred to manually ventilate her with the aim of keeping her saturation around 90% with a permissible hypercapnia of end tidal carbon dioxide not exceeding 50 mmHg. After the delivery of the baby, there was a marginal improvement in ventilation though her peak airway pressures still continued to be high. Birth weight of the baby at birth was 2.2 kg with an APGAR score of 8 and 9 at 1 and 5 min, respectively. The patient was connected to the ventilator on Volume-controlled ventilation (VCV) mode with tidal volume of 325 ml, rate of 30 breaths/min with high Post end-expiratory pressure (PEEP) of 18 cm H 2 O, and inspiratory:expiratory (IE) ratio of 1:1.5. Peak airway pressures still bordered around 40 cm H 2 O and saturation was being maintained at 91% with almost 100% FiiO 2 . Rest of the intraoperative period was uneventful with patient being able to maintain her hemodynamics. The approximate blood loss during surgery was 500 ml and she maintained adequate urine output.
Following surgery, the mother was transferred back to the ICU and was kept sedated with Fentanlyl infusion 30-50 mg/h and paralyzed with Atracurium infusion 30 mg/h while on ventilator. In view of her high peak airway pressures and poor oxygenation on a 100% FiO 2 [Table 1] a trial of prone ventilation for a period of 12 h was also given in the first postoperative day. Ventilation mode was volume controlled with tidal volume of 350 ml, respiratory rate of 30 per min, PEEP of 16 cm H 2 O, and I:E ratio of 1:1.5. From the 3 rd postoperative day she was provided enteral nutrition via nasogastric tube. On the 6 th postoperative day the patient was tracheostomized. Over the next few days, there was gradual improvement in her general condition and we were finally able to take her off ventilator after 13 days following which she was transferred to high dependency unit and finally discharged along with the baby on the 18 th postoperative day in satisfactory condition.
The baby was transferred to neonatal ICU following delivery with a high suspicion for H1N1 which we later discovered was negative following polymerase chain reaction (PCR) report. An echocardiography was also performed which revealed Coarctation of Aorta and a large patent ductus aortus with bidirectional flow. The child was operated upon the 2 nd day of life for repair of the Coarctation of Aorta and Patent Ductus Arteriosus (PDA) ligation was done.
| Discussion|| |
Influenza A virus are classified according to structure of its two surface antigens: Hemagluttinin and neuraminidase.  The route of transmission of H1N1 is essentially human to human involving exposure to infected large particle respiratory droplets or contaminated surfaces.
The usual presentation of symptoms occurs within a week of exposure and patients are generally infectious for about 8 days after the onset of infection. Hospitalized patients typically present with fever (95%), cough (88%), shortness of breath (60%), fatigue (43%), runny nose (38%), sore throat (31%), headache (34%), and myalgia (36%).  Pregnant women, because of their altered immunity and physiological adaptations, are at higher risk of developing pulmonary complications, especially in the second and third trimesters. 
Experience from the first wave of pandemic (H1N1) 2009 suggests that a large number of infected people become critically ill and require admission in an ICU. These patients rapidly develop severe progressive respiratory failure which is often associated with failure of other organs. Primary viral pneumonia is the most common finding in these severe cases and a frequent cause of death. Secondary bacterial infections have been found in approximately 30% of fatal cases. Respiratory failure and refractory shock have been the most common causes of death in this group.  Increased mortality was seen in patients with acute respiratory distress syndrome following H1N1 influenza as compared to all other causes of ARDS in Indian settings.  Therefore the key to management lies in early diagnosis, isolation of such patients, and aggressive antimicrobial therapy along with all supportive measures based on the individual requirements of the patient.
In view of the contagious nature of this disease, proper handling of such patients is very important by healthcare workers in hospital settings. As droplets can spread over 1 m, patients should be nursed at least 1 m apart. Those with confirmed H1N1 should be cohorted together in an isolation unit for at least 7 days from onset of symptoms.  Meticulous handwashing remains a cornerstone for infection control. Personal protective equipment along with N95 masks should be worn when in contact with such patients. ,, In operating rooms negative pressure should be used to avoid cross contamination. It is prudent to use inline bacterial viral filters with filtration efficiency over 99.99% for both bacteria and viruses (high-efficiency particulate air (HEPA) filters). For suctioning intubated patients, closed system suction catheter should be used so as to avoid disconnecting from ventilator. 
Keeping the above mentioned preventive features in mind endotracheal intubation was performed and the patient was then transferred to an isolated operation room for cesarean section. During transportation to the operation room high airway pressures were encountered despite having administered muscle relaxant. In the operation room, patient was connected to the ventilator and settings were based on ARDS protocol guidelines, i.e., low tidal volume with high respiratory rate and a high PEEP.  In the immediate postoperative period, because of the refractory hypoxemia [Table 1] prone ventilation was initiated. While positioning in prone, all the pressure areas were adequately padded and abdominal compression was avoided. Recruitment maneuver combined with mechanical ventilation was continued as per the ARDS protocol network for a period of 12 h following which the patient was turned to supine position. 
As for the treatment guidelines, in such patients the most appropriate antiviral and antipyretic medications include Oseltamivir and Acetaminophen. Oseltamivir (Food and Drug Administration-approved use in pregnancy category C) is the drug of choice for pregnant women with confirmed, probable, or suspected cases of H1N1 and/or who have had close contact with someone with a confirmed, probable, or suspected case of the disease.  Oseltamivir therapy should begin no later than 48 h after the onset of symptoms in pregnant patients to reduce the risk of serious complications such as pneumonia and respiratory failure. Treatment should not be withheld while awaiting diagnostic testing. The recommended duration of treatment is 5 days. However, some experts have promoted longer durations and doubling of dosages in patients with severe infections.  Also of note, new mothers should be considered as high risk and treated as such until 2 weeks postpartum. Acetaminophen is an important adjunct to antiviral therapy for novel influenza A (H1N1) during pregnancy because hyperthermia has been associated with fetal damage during pregnancy, including neural tube defects during the first trimester.  Hyperthermia during the third trimester is a risk factor for preterm delivery and neonatal seizures, cerebral palsy, and neonatal death. 
In conclusion, management of H1N1 parturient as described is best carried out in a tertiary center with intensive care facilities. A multidisciplinary involvement is essential.
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