Anesthetic challenges while performing emergency laparotomy in a patient having COVID-19 infection.

An elderly hypertensive lady presented with fever, respiratory symptoms, and mild abdominal discomfort and was diagnosed to have COVID-19 pneumonia. Respiratory symptoms improved with steroids, awake proning, high flow nasal cannula oxygen therapy and antibiotics. After 4 days, she developed non-occlusive superior mesenteric artery thrombosis, which initially responded to anticoagulants but was complicated on tenth day by intestinal obstruction necessitating emergency surgery. Challenges encountered perioperatively were multi systemic involvement, pneumonia, ventilation- perfusion mismatch, sepsis along with technical difficulties like fogging of goggles, stuck expiratory valve on anesthesia machine, inaudibility through stethoscope and discomfort due to personal protective equipment. Perioperative focus should be on infection prevention, maintenance of hemodynamics, and optimization of oxygenation with preoperative high flow nasal cannula oxygen therapy. Ultrasound lung helps in correct placement of endotracheal tube. We recommend daily machine check, taping of N95 mask to face and ambient operation theatre temperatures of 20-22°C to reduce technical problems.

Introduction

COVID-19 infection changes the perioperative scenario for emergency laparotomy for intestinal obstruction, though basic principles of general anesthetic management with rapid sequence induction (RSI) remain the same [Table 1].

Table 1

Differences in perioperative management in emergency laparotomy in non-COVID patients versus those with COVID infection

	NONCOVID	COVID
Operation theatre (OT)	Isolated OT/integrated modular OT complex.Positive pressure to the surrounding areas.A minimumairchange rate (ACH) of 15-20per hourcentral AC acceptable.Common HEPA filter.No need for separate donning/doffing area.Frequently used for elective/semi-emergency/emergency surgeries.Close to surgical ward.Fumigation is preferred as mode of sterilization.All equipment/drugs/stand by drug or equipment kept in OT.	Isolated, dedicated COVID OT.Ideally- Negative pressure OT with ACH 12/hourIf positive pressure OT, ACH >25/hour to decrease virus load.[12]] HEPA filter/ultraviolet filter in HVAC duct isolated from rest of hospital.Separate donning/doffing area needed.[[23]Only for semi-emergency or life-threatening emergency surgeries. OT close to COVID wards, ICU.[2]Surface wiping with 0.1% hypochlorite/70% alcohol.[3]Only essential equipment/drugs needed for safe perioperative anesthetic care kept in OT.[2]
Risk to healthcare workers	Low risk of aerosol/fomite borne transmission.Universal precautions with scrub gown, surgical mask, gloves.	High risk of aerosol/fomite borne transmission.[2]Universal precautions with PPE, N-95 Mask, scrub gown, mask, gloves, face shield, Goggles.[123]
Patient-related risk factors	Multisystemic involvement less likely.Polypharmacy may/may not be present.	Possibility of multisystemic involvement likely in COVID-19.[4,5]Polypharmacy usually present with antiviral, antibiotics, steroids, therapeutic anticoagulation.[5]
Risk of desaturation during RSI	Low	High in presence of ARDS.[5]
Ventilation	Low V/Q mismatch.	High V/Q mismatch.[5]
Mortality	Low	High in COVID patients with surgical complications after infection.[6]

We describe perioperative anesthetic management in COVID-19 illness complicated by intestinal obstruction attributed to superior mesenteric artery thrombosis, though the causality with SARS-CoV-2 infection cannot be confirmed.

Case History

A 61-year-old female (BMI-28.3 Kg/m2) with mild hypertension presented with fever, dyspnea, tachypnea, and mild abdominal discomfort to our Institute. With a non-tender soft abdomen with normal ultrasound examination, peripheral oxygen saturation was 70% on air with bilateral peripheral and basal infiltrates on chest X-ray. Treatment was started with awake proning with high flow nasal cannula oxygen therapy (FiO2 0.4 at 30 L/min), antacids, steroids (methylprednisolone 60 mg OD intravenous), and antibiotics (piperacillin tazobactam 4.5 gm 8 hourly) with improvement in SpO2 to 94%. Paired nasopharyngeal and oropharyngeal Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) sample came positive for COVID-19. After initial improvement, she developed diffuse abdominal pain and distension on fourth day. CT scan showed non-occlusive mesenteric artery thrombosis. Therapeutic dose of unfractionated heparin, ecosprin, and clopidogrel was started. Abdominal pain and distension subsided with normal bowel movement. However, P/F ratio worsened gradually with need of FiO2 of 0.6 at 40 L/min on High flow Nasal Cannula Oxygen(HFNC). On tenth day, she developed acute pain abdomen with feculent vomiting. Abdominal X-ray, ultrasound and clinical findings were suggestive of small bowel obstruction. Immediate emergency laparotomy was planned under general anesthesia.

An isolated peripheral positive pressure operation theater (OT) with 25 air changes/hour and Ultraviolet radiation-based disinfection was used as COVID OT. Preoperative check on anesthesia machine revealed a stuck expiratory valve leading to urgent changing of workstation. Infection control practices were followed as per guidelines with use of plastic sheets, two heat and moisture exchange filters (HMEF) and fluid-resistant personal protective equipment (PPE).[7] Vision was hampered due to fogging and audibility through stethoscope was difficult with PPE. Border of N95 mask was taped to face circumferentially to ensure no fogging in goggles with ambient temperature at 20-22°C. Ultrasound machine was kept to confirm bilateral pleural sliding. RSI was planned with preparedness for difficult airway.

Patient was American Society of Anesthesiologists Physical status IV with anxiety, pain, hypotension (BP-85/45 mmHg of 2 hours duration), cytokine storm (CRP 282 mg/dl, LDH 371 Units/L), sepsis (Total leukocyte count 1800/mm3, Lactate-8 mmol/), coagulopathy (INR 2.8), and difficult airway (Mallampati classification grade 4, short neck). Coagulopathy was corrected with intravenous VitaminK10 mg, 6 units of FFP, and withholding heparin. After invasive arterial and central jugular catheterization, after fluid resuscitation with CVP of 4-6 cmH2O and IVC diameter 16 mm, norepinephrine infusion (0.05 mcg/kg/min) was started.

With standard monitoring, antibiotic therapy was escalated to metronidazole, meropenem, and teicoplanin. Dexamethasone 8 mg iv was given. After anxiolysis with iv midazolam 2 mg and preoxygenation, only two anesthetists (for intubation, drug administration and help in airway difficulty) and one technician (correct cricoid pressure application) remained in OT during intubation. After RSI with fentanyl 150μg, ketamine 80 mg, and succinylcholine 100 mg, trachea was quickly intubated under direct laryngoscopic vision by most experienced anaesthetist after apnea with a clamp applied on endotracheal tube. Clamp was removed after cuff inflation, attachment of breathing circuit. Ventilation was confirmed by EtCO2 and bilateral chest rise. Auscultation was practically not possible in PPE. Endotracheal tube placement was confirmed by presence of bilateral pleural sliding on lung ultrasound. Anesthetic depth was maintained with isoflurane, fentanyl, vecuronium.

Due to moderate Acute Respiratory Distress Syndrome ARDS with saturation of 88-90%, lung protective pressure control ventilation was started with Inspiratory pressure 22, PEEP 6, target tidal volume 6 ml/kg, FiO2 0.6, frequency 18/min with P/F ratio of 160. Intraoperatively, two units Packed Red Blood Cells (PRBCs) and crystalloids were given judiciously with central venous pressure 12-14 cmH2O and PPV <10. After handling of the bowel, there was a rise in norepinephrine till 0.2 μg/kg/min and vasopressin infusion (0.8-2.4 units/hour) was added to maintain Mean Arterial Pressure (MAP) 65-70 mmHg.

Intraoperative findings were gangrenous distal ileum 60 cm in length proximal to ileocecal junction with inflamed and thickened mesentery. Pulsation was not felt in mesenteric vessel supplying the gangrenous segment. Resection of gangrenous ileus segment and loop ileostomy was done. Vasopressor requirement decreased to norepinephrine 0.05μg/kg/min

Postoperatively patient was electively ventilated in Intensive Care Unit (ICU) in view of moderate ARDS. During disconnection, Endotracheal Tube (ETT) was clamped, with ventilator on standby mode, breathing circuit was attached beyond HMEF to the portable ventilator. High touch surfaces, airway equipment in OT were cleaned with 0.1% sodium hypochlorite for at least 1 min. No Health Care Worker (HCW) was infected with COVID-19.

Postoperatively, P/F ratio improved (220) for 12 h with decrease in vasopressor requirement. However, 24 h after surgery, patient had progressive vasoplegia, lactate >4 mmol/L, and succumbed on third postoperative day to Gram-negative septic shock and subsequent multiorgan dysfunction.

Discussion

COVID-19 may be complicated with intestinal obstruction though very scant literature exists on perioperative care in confirmed infection.[4] We report our experience of perioperative anesthetic care of an elderly hypertensive lady with COVID-19 who developed intestinal obstruction necessitating emergency laparotomy after initial presentation with pneumonia.

COVID-19 has multisystemic involvement with pneumonia, myocarditis, gut ischemia, kidney injury, liver damage, shock, and imbalance in coagulation homeostasis.[5] Our patient had moderate ARDS with bilateral peripheral and basal infiltrates. In our patient, HFNC was observed to improve oxygenation. HFNC therapy provides heated and humidified gases at high flow rates which is more comfortable to patient than BiPAP or high flow through face mask to improve ventilation perfusion mismatch, provide for higher demands in dyspneic hypoxemic patient, and it may reduce need for intubation in COVID-19.[8] Antibiotics were escalated in anticipation of gram negative endotoxemia on gut handling.

In a recent prospective observational study, patients with COVID-19 who develop acute abdominal pathologies during their hospital stay were observed to have a higher mortality (33% vs 14.3%), ARDS (50% vs 28.5%), and postoperative invasive ventilation (100% vs 28.5%) than those who were admitted to hospital for an acute surgical condition with a concomitant diagnosis of COVID-19.[6] Our patient developed SMA thrombosis 4 days after admission and intestinal obstruction by tenth day. Digestive symptoms may also indicate viral replication within gastrointestinal tract causing more severe disease.[9] Septic shock further complicated postoperative course leading to mortality.

Gao et al. highlighted the use of negative pressure OT for exploratory laparotomy for acute abdomen in four patients with suspicion of COVID-19 infection, later ruled out by negative RT-PCR.[1] Due to resource limitation, we used a positive pressure with 25 air changes/hour with disinfection by ultraviolet radiation.

During perioperative management, main technical issues were fogging of goggles and inaudibility of breath sounds due to PPE. We found better visibility once N95 mask was secured firmly with tape on face to prevent leakage of expiratory gases into the goggles. Lung ultrasonography helps confirm correct tube placement by presence of bilateral pleural sliding. To avoid stuck expiratory valve in anesthesia machine, we recommend anesthesia machine in COVID OT functions for 1-2 h daily even if no emergency surgery is done. Good air conditioning with ambient temperature 20-22°C prevented perspiration to fog the goggles from inside and ensures that valves in workstation do not get stuck due to heat and humidity.

To avoid aerosol formation, we advocate adequate anesthetic depth, muscle relaxation, use of HME filters, tube clamps with minimal circuit disconnections, or use of cautery.[23]

Declaration of patient consent

The authors certify that appropriate patient consent was obtained.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.